JP2007232637A - Method and instrument for measuring film thickness of paint film on cylindrical base - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a load applied onto a base due to measurement, and to make an individual measured value very accurate, when measuring a thickness of a paint film or a coating film applied onto the cylindrical base. <P>SOLUTION: This method calculates a distance between a reference point and a circumference, based on changes due to rotation of the cylindrical base in distances of three or more of points settled on the circumference of a cross-sectional circle with respect to the reference point, set within the cross-sectional circle on a cylindrical base outer face orthogonal to an axis of the cylindrical base outer face, using a measuring means capable of measuring a displacement of the cylindrical base outer face, and specifies a shape of the cross-sectional circle of the cylindrical base outer face, the circular center thereof, the circularity thereof and an outer diameter value thereof. The method calculates also distances between one or more of points, different from the three points, on the same cross-section as the above cross-sectional circle and on an outer surface of the paint film or the coating film, and the reference point, using a measuring means capable of measuring a displacement of a paint or coating film outer face, and measures the thickness of the paint or coating film, based on the shape of the cylindrical base outer face. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for measuring the thickness of a coating film or coating on a cylindrical body having a coating film or coating provided on a cylindrical substrate. In particular, it is a technique that contributes to the measurement of the thickness of a thin film coated or coated with high accuracy.

  Conventionally, an electrophotographic photosensitive drum in an image forming apparatus such as an electrophotographic copying machine, a laser beam printer, a facsimile machine, or a printing machine uses a cylindrical member whose shape dimension is finished with a predetermined accuracy, and a photosensitive film on the surface thereof. It is manufactured by applying. However, the film thickness of the photosensitive film may be uneven depending on the location, or the film thickness of the reference photosensitive film itself may be excessively thick or thin with respect to a predetermined desired film thickness. In that case, a defect occurs in the image of the image forming apparatus. Therefore, in order to obtain an image forming apparatus with high accuracy, it is required that the film thickness of the photosensitive film is correct and flat.

  Even in the process of manufacturing such an electrophotographic photosensitive drum, a high-accuracy measuring function for the purpose of guaranteeing the coating accuracy is required. The base material used for the electrophotographic photosensitive drum is generally made of a metal typified by an aluminum alloy or the like. As a method for measuring the film thickness of the coating film formed on the substrate, the distance to the substrate surface which is a metal in a state where a displacement measuring element using eddy current is in contact with the coating film surface of the portion to be measured A method of measuring the thickness of the coating film by measuring the thickness is used. At this time, the material of the coating film to be measured is generally mostly composed of resin. However, in terms of the function as a photoreceptor, a material containing a small amount of metal is also used. In this regard, in the displacement measuring method using the eddy current, the influence of the metal contained in the coating film is unavoidable for the measurement. However, if this effect is extremely small and the content ratio as a material for forming a metal coating film is constant, the thickness of the coating film is measured to guarantee the function as an electrophotographic photosensitive member. There is no problem as a means to do.

  However, the film thickness measurement method using the general eddy current requires the following. That is, in order to make the detection distance of the eddy current equal to the thickness of the coating film to be measured, that is, the distance from the outer surface of the metal body that is the substrate to the outer surface of the coating film, It is to abut on the outer surface of and position. At this time, it is almost inevitable that the trace remains on the surface of the coating film due to the contact. Therefore, in general, in such measurement, it is impossible to measure the product itself, and it is necessary to perform measurement using a sample work for film thickness measurement prepared in advance. In addition, it is inevitable that the coating film deforms due to the contact pressure essential for contact. Furthermore, in the measurement in a state where the strength of the coating film is very low, it may be difficult to accurately measure the thickness of the coating film, no matter how much the contact pressure is suppressed.

  In such a case, when the electrophotographic photosensitive drum is a cylindrical body, both ends thereof are accurately gripped by some chucking or other means so that the cylindrical body can rotate around a fixed point. And a displacement measuring means (for example, a laser displacement meter) capable of measuring the distance to the outer surface of the object in a non-contact manner on the same cross section where the coating film to be measured exists, It fixes toward the said fixed rotation center in the same cross-sectional circle. And it is possible to measure the film thickness of the coating film by rotating the cylindrical body by the included angle of the two measuring means and calculating the difference between the two distances when the same point is measured. .

However, in recent years, due to the demand for higher accuracy of the electrophotographic photosensitive drum, it is necessary to measure the film thickness of more or all products with high accuracy. Further, since higher production capacity is required in the manufacturing process, it must be said that it is difficult to use a both-end gripping method in which the cylinder is rotated with high accuracy as described above.

  In view of these problems, the present invention reduces the load in measuring the thickness of a coating film or coating on a cylindrical body having a coating film or coating provided on a cylindrical substrate, and makes each measurement value extremely accurate. The main purpose is that.

  That is, the present invention is a method for specifying the shape of a cross-sectional circle on the outer surface of a cylindrical substrate and measuring the thickness of a coating film or a film provided on the cylindrical substrate, the outer surface of the cylindrical substrate The rotation axis of the cylindrical substrate that is the cylinder to be measured is set within the cross-sectional circle of the outer surface of the cylindrical substrate perpendicular to the axis of the outer surface of the cylindrical substrate using a measuring means capable of measuring the displacement of the cylindrical substrate. And the reference point and the circumference based on the change of the distance of three or more points defined on the circumference of the cross-sectional circle with respect to the reference point, which is a point where the cross-sectional circle intersects with the rotation of the cylindrical substrate The distance from the upper point is calculated to specify the shape of the cross-sectional circle of the outer surface of the cylindrical substrate, and using the measuring means capable of measuring the displacement of the coating film or the outer surface of the coating, the three or more On the same cross-section as the cross-sectional circle and on the outer surface of the coating film or coating, apart from the point A cylindrical substrate characterized in that a distance between one or more points and the reference point is calculated, and the thickness of the coating film or coating film is measured based on the shape of a cross-sectional circle on the outer surface of the cylindrical substrate. A method for measuring the thickness of the coating film or the coating film provided on the cylindrical substrate is specified.

  Most of the conventional measuring methods either make the probe contact with the surface of the coating film in order to obtain higher measurement accuracy, or pursue the accuracy of mechanical limitation at the center of the cylinder as the measurement reference position. The load is required. In the method provided by the present invention, there is no mechanical limitation on the assumption that the center of the cylinder is a virtual center that is moved by rotation, that is, a floating center. Then, the position of the floating center is tracked and theoretically captured and limited based on the transition of numerical values obtained sequentially from the probe according to the measurement, and the shape of the substrate and the outer surface shape of the coating film are obtained based on this. This is the main feature. Therefore, according to this method, since it is not necessary to accurately limit the center of the cylinder, such a load can be reduced. In addition, it is possible to measure the thickness of the coating film or coating film of a cylindrical body having a coating film or coating film provided on the cylindrical substrate with high accuracy and extremely simply.

  In addition, in the method provided by the present invention, the method of rotating the cylindrical body having the coating film or coating provided thereon for measuring the thickness of the coating film or coating is not limited. Therefore, it is possible to perform measurement with both ends open or with a component such as a flange attached. Even if a measuring mechanism using this measuring method is mounted in the production line, problems such as interference with the conveying means are unlikely to occur, and very simple and highly accurate measurement is possible.

The following explanation is an example of the method used in the present invention, and the same effect can be obtained with other forms. 3A, FIG. 3B, and FIG. 4A to FIG. 5A used for the following description, S1 is arranged at the apex in the vertical direction for convenience of description.
An example of an apparatus used for measuring the thickness of the coating film on the surface of the cylindrical substrate according to this embodiment is shown in FIG. First, the cylindrical substrate 1 having the coating film 7 on the surface is placed on two rollers (cylindrical receiving jig) 6, which are rotatable cylindrical receiving jigs, in contact with the outer surface of the coating film 7. The measuring device is mounted on a mounting base 2 and a supporting base 3 which are provided so as to be able to reciprocate in parallel with the rotational axis of the cylindrical body 1 by means of the guide rail 4 and the ball screw 5. It is located on the same cross section. The measuring device is directed to the measurement reference point O ₀ , which is a point where the rotation axis of the cylindrical substrate 1 and a cross section perpendicular to the rotation axis intersect. And four sensors (sensors for detecting displacement; the same applies hereinafter) S1, S2, which are arranged in a fan shape with a predetermined angle θ between each other around the measurement reference point O ₀ and fixed to the mounting base 2. S3 and S4. The rotation centers of the four sensors S1, S2, S3, S4 and the two rollers 6 are all fixed to the same machine, and their positions do not always change.

O ₀ is a measurement reference position where the detection axes of the four sensors almost intersect with each other and do not always move according to the machine reference. At the same time, it is also the virtual center or the start of the floating center O _n moves as the cylindrical substrate 1 is not a perfect circle is rotated by contacting the outer surface of the coating film 7 on the roller 6 in accordance with the measurement. (Hereinafter referred to as On _{= 0.} n is a number required to calculate the circumferential shape of the cross-sectional circle. For example, the circumferential shape of the cross-sectional circle is calculated by obtaining the above distances evenly at intervals of θ °. the, in the flowchart shown in the n = 360 ° / θ °. FIG. 1, for convenience of notation, Show on the O'.) the position of the _{O n} is _{O n} is the measured cross-section of the cylindrical substrate 1 As long as the circle does not coincide with the true center of the circle and the outer surface of the coating film 7 does not have a perfect circle shape, the cross-sectional circle to be measured of the cylindrical substrate 1 moves sequentially as it rotates with the measurement. This is regarded as a virtual center, that is, a floating center that may be moved by rotation. However, the distance between each point on the measured cross-section yen O _n and the cylindrical substrate 1 does not always change. That is, as shown in FIG. 8, when the cylinder is rotated at a predetermined angle (θ °) with the starting point of the floating center as a reference point, the floating center moves from the starting point. When the rotation is further rotated, the floating center is further moved and sequentially rotated. Finally, the floating center takes a locus of the floating center as shown in the figure by rotation of the 360 ° cylinder. Therefore, the measurement method of the present invention does not mechanically limit the measurement reference position. The position of this floating center is tracked every time the measuring cylinder rotates every step based on the change in the numerical value obtained from the probe sequentially according to the measurement, and is theoretically captured. Calculate the distance to a point on the circumference.
In addition, as used in this specification, “rotation axis”, “axis”, and “point” intersecting with them refer to a straight line having no thickness or an area having no area as used mathematically, for example. is not. As shown in FIG. 2, since the cylinder to be measured rotates with respect to its outer peripheral surface, it is rotated unless at least the cylinder to be measured is a true cylinder or the outer peripheral surface abutting on the roller 6 is not a perfect circle. Axes and points have a certain range. Below, the numerical value which shows the range is demonstrated. The range of the rotation axis preferably satisfies the following when a circle having a radius of ΔL is shown as a range centering on the least square center of the cross-sectional circle to be measured. Formula and DerutaL' met <d2 · ^{10 -3,} more preferably satisfies the following formula and ΔL'<d2 · ^{10 -4,}
Most preferably, the following formula and ΔL ′ <d2 · 10 ⁻⁵ are satisfied.

  For example, the most preferable range of the rotation axis is ΔL ′ <0.0005 mm and ΔL <0.274 mm when d2 = 50.00 mm and T = 0.05 mm, and the calculated rotation axis range is φ0.548 mm.

  Moreover, as the reality of ΔL, the sensor positioning with such accuracy is far from the level of modern machining technology (the general limit in this industry is ΔL≈0.002 mm when d2 = 50 mm). It's also possible without any problems.

In measuring the film thickness of the coating film 7, a method for measuring the shape of a circle of a cross section perpendicular to the axis of the cylindrical substrate 1 provided with the same will be described. Here, the rotation angle θ ° per measurement of the cylindrical substrate 1 was set to 30 °. Thus the measurement point on the circumference is 12 points as _{1 0-12 0} shown in Figure 4 (a). And in this measurement method, once calculated the distance between the floating center of the origin O _{0 (O} n = ₀₎ and each point 1 _{0-12 0} on the circumference of the measured cross section circle of the cylindrical substrate 1, a cylindrical The shape of the cross-sectional circle to be measured of the substrate 1 is specified. Similarly, the outer peripheral circular shape of the coating film 7 is captured, and the film thickness is finally obtained.
Next, the method for measuring the film thickness will be described sequentially. FIG. 1 is a flowchart relating to the film thickness measuring method described below, and the step of calculating the film thickness is performed according to the flowchart.

As a first step, as shown in FIG. 3A, a reference cylinder 8 whose outer diameter value is known and whose cross section is a perfect circle is used, and the circle center of the cross section of the reference cylinder 8 is used as the measurement standard. As the point O ₀ , the distance from the sensors S 1, S 2, S 3 and S 4 to O ₀ is limited. At this time, first, the reference cylinder 8 is placed on the two rollers 6, and the distance from the sensor S1 to the outer surface of the reference cylinder 8 is measured to obtain ΔS1. Since the outer diameter value of the reference cylinder 8 is known, if the radius value, that is, the distance from the circle center O ₀ to the outer surface of the reference cylinder 8 is d2, the distance LS1 from the sensor S1 to O ₀ is Is obtained by the formula.

  L1S = ΔS1 + d2

  Similarly, LS2 and LS3 as shown in FIG. 4B are obtained for the sensors S2 and S3.

At this time, when any of the detection axes of the sensors S1, S2, and S3 does not pass the measurement reference position O ₀ and the three detection axes do not intersect at one point, the measurement reference position O with respect to the detection axis. Deviation of the ₀ position causes an error in the values of LS1, LS2, and LS3. However, the error is extremely small, and this will be described using LS1 as an example with reference to FIG. Let ΔL be the minimum distance between the measurement reference position O ₀ , which is the center of the cross-sectional circle of the reference cylinder 8, and the detection axis of the sensor S 1, that is, the positioning error distance of the sensor S 1 in the direction orthogonal to the detection axis. The distance between the point where the axis parallel to the detection axis and passing through the measurement reference position O ₀ intersects the circumference and the measurement reference position O ₀ , that is, the radial distance of the cross section of the reference cylinder 8 is d2. At that time, the error ΔL ′ given to LS1 is obtained by the following equation.

As a result, ΔL ′ becomes very small. As an example, the positional deviation error assumed when the sensor S1 is positioned within the range of the current relatively easy machining method, that is, ΔL is given. At most, it is about ± 3.0 μm, and when the outer diameter of the reference cylinder 8 is 100 mm at this time, ΔL ′ is about 9.0 × 10 ⁻⁵ μm from Equation 1. Considering that this value is generally 0.1 μm in measurement reproducibility of a sensor that is generally regarded as highly accurate, it can be said that the influence on the measurement result is extremely small.

  In addition, the error caused by the positioning process of the probe should be referred to as the angle error in addition to the positioning error. With respect to this, once separated from the positioning error, the ΔL derived only from the angle error with respect to the detection axis of the sensor S1 is given by the following equation.

  ΔL = ΔS1 · tanθ

For example, the angle error assumed when processing and positioning using a touch sensor with a resolution of about 1 μm is generally about ± 14 seconds (3.9 × 10 ⁻³ ). When the distance ΔS1 between the sensor S1 and the outer surface of the reference cylinder 8 is about 1.0 mm, ΔL is 0.068 μm. At this time, when the outer diameter of the reference cylinder 8 is 100 mm, ΔL ′ is about 4.6 × 10 ⁻⁸ μm from Equation 1, and it can be said that the error is extremely small.

Therefore, in the measurement system in the range described so far, the sensor S1 performs measurement using the circle center as the measurement reference position O ₀ even if its detection axis does not pass through the circle center of the cross-sectional circle of the reference cylinder 8. I can do it. From the above, LS2 and LS3 can be handled in the same manner. Stated further added, the moving distance of the floating center O _n is an intended to be calculated only by the numerical of the LS1, LS2, LS3, not affected by the distance of the [Delta] L.

Followed by placing the cylindrical substrate 1 on the two rollers 6, the distance from the sensor S1 to the outer surface of the cylindrical substrate 1 were measured, and S1 _0. Since this time LS1 is known, LS1 after subtracting S1 ₀ calculates the _{1 0,} similarly, measuring 12 ₀ and 11 _0, is calculated.

As a second step, the cylindrical substrate 1 is rotated 30 ° in the right direction. Then measuring points ₁ 0 on the circumference of the cylindrical substrate 1 in the first stage, 12 ₀ and 11 _0, as shown in FIG. 4 (b), it moves each _{1 1,} 12 1, 11 _1. The sensors S1, S2 and S3 can measure the distances between the points 2 ₁ , 1 ₁ and 12 ₁ on the circumference of the cylindrical substrate ₁ and the measurement reference point O ₀ . At this time, assuming that the floating center O _{n = 0} is, and the outer peripheral shape of the coating film 7 does not coincide with the true center of the measured cross section circle of the cylindrical substrate 1 is not a perfect circle, O _n is O Move to _{n = 1} . At this point, the floating center O _{n = 0} and the distance between the point 2 ₁ on the circumference of the cylindrical substrate 1 is unknown. Next, using the sensors S1, S2 and S3, distances L2 ₁ , L1 ₁ and L12 ₁ between the points 2 ₁ , 1 ₁ and 12 ₁ on the circumference of the cylindrical substrate ₁ and the measurement reference point O ₀ are measured. To do.

Here, determine the position of the current position O _{n = 1} floating center O _n from the change in the distance by the rotation. L1 _0, since L12 ₀ is known, the moving distance .DELTA.L1 ₁ from _{O n = 0} to _{O n = 1} on the detection axis of the sensor S2 and S3, ΔL12 ₁ is obtained.

ΔL1 ₁ = L1 ₁ −L1 ₀ (1)
ΔL12 ₁ = L12 ₁ −L12 ₀ (2)

Thereafter, using these two distances, a moving distance ΔL2 ₁ of the floating center On _{= 1} on the detection axis of the sensor S1 is obtained. Then, by taking the difference between L2 ₁ and [Delta] L2 _1, the distance between the floating center _{O n = 0} and the point _{2 0} on the circumference is obtained. That is, the .DELTA.L1 ₁ as shown in FIG. 5 (b) is a, float sensing axis of the detection axis and the floating center O _{n = 1} of the shortest distance or sensor S1 of the sensor S1 in place represented by orthogonal coordinates to y-axis _Let b be the movement distance in the x-axis component of the center On _{= 1} . And if a and b are expressed using r and r ′ shown in FIG.
r ′ · sin θ ₁ + r = a (3)
r ′ + r · sin θ ₁ = b (4)
r ′ = (b−a · sin θ ₁ ) / (cos ² θ ₁ ) (5)
r = a−sin θ ₁ · [(b−a · sin θ ₁ ) / (cos ² θ ₁ )] (6)
Furthermore, from FIG. 5B, since ΔL2 ₁ = r · cos θ ₁ ,
_{ΔL2 1 = a · cosθ 1 -tanθ} 1 (b-a · sinθ 1) ··· (7)
Here, from FIG.
ΔL12 ₁ −b · sin (θ ₁ + θ ₂ ) = ΔL2 ₁ · cos (θ ₁ + θ ₂ ) (8)
ΔL2 ₁ = [ΔL12 ₁ −b · sin (θ ₁ + θ ₂ )] / [cos (θ ₁ + θ ₂ )] (9)
_{a · cosθ 1 -tanθ 1 · (} b-a · sinθ 1)
= [ΔL12 ₁ −b · sin (θ ₁ + θ ₂ )] / [cos (θ ₁ + θ ₂ )] (10)
b = [a (cos θ ₁ + sin θ ₁ · tan θ ₁ ) · cos (θ ₁ + θ ₂ ) −ΔL12 ₁ ] / [tan θ ₁ · cos (θ ₁ + θ ₂ ) −sin (θ ₁ + θ ₂ )] ( 11)
Therefore, ΔL2 ₁ can be obtained from the arguments included in the following two expressions, that is, the included angle of the sensor and the measured value. From Equation (7)
_{ΔL2 1 = ΔL1 1 · cosθ 1} -tanθ 1 (b-ΔL1 1 · sinθ 1) ··· (12)
b = [ΔL1 ₁ · (cos θ ₁ + sin θ ₁ · tan θ ₁ ) · cos (θ ₁ + θ ₂ ) −ΔL12 ₁ ] / [tan θ ₁ · cos (θ ₁ + θ ₂ ) −sin (θ ₁ + θ ₂ )]・ (13)
From [Delta] L2 ₁ determined using the above (12) _(13), as _L2 0 = L2 ₁ -ΔL2 1, to obtain the L2 _0.

As a third step, the cylindrical substrate 1 is further rotated 30 ° to the right. Then, the measurement points 2 ₁ , 1 ₁ , 12 ₁ on the circumference of the cylindrical substrate 1 in the second stage move to 2 ₂ , 1 ₂ , 12 ₂ , respectively. The sensors S1, S2, S3 is enabled each measure the distance between the point ₃ 2, _{2 2} and _{1 2} and the measurement reference point _{O 0} on the circumference of the cylindrical substrate 1. Further, the floating center On _{= 1} moves further to On _{= 2} . Then, by using the sensor S1 to S3, respectively measure the distance between points ₃ 2, _{2 2} and _{1 2} and _{O 0} on the circumference of the cylindrical substrate 1. Using these measured values, the moving distance from On _{= 0 of} floating center On _{= 2} is calculated in the same manner as described above. Further, using the calculation result, a moving distance (ΔL3 ₂ ) from On _{= 0 of On = 2} on the measurement axis (y-axis) of the sensor S1 is obtained. Determining the distance between the floating center O _{n = 0} and the point 3 ₀ on the circumference of the cylindrical substrate 1 therefrom. Thereafter, likewise the cylindrical substrate 1 is rotated by 30 °, the floating center _{O n = 0} and the point ₄ 0 on the circumference of the cylindrical substrate _1, 5 _{0, 6} 0, 7 _0, 8 0, _{9 0,} and 10 ₀ distance between each _{L4 0, L5 0, L6 0} , L7 0, L8 0, obtains the L9 ₀ and L10 _0. At this time, if L11 ₀ and L12 ₀ are also calculated using the same method, a measurement result with higher accuracy can be obtained.

Finally, when seeking a thickness of the coating film 7, the floating center O _n obtained until now, determining the moving distance on the detection axis of the sensor S4. Here, the floating center On _{= 1} will be used. As shown in FIG. 6, the detection axis of the sensor S <b> 1 is shown so as to overlap the Y axis of the orthogonal coordinate system. In that case, the detection axis of the sensor S4 is included angle theta _t is 90 ° + θ ₁ of an X-axis, when the .DELTA.L1 ₁ the distance an included angle theta _{f, O 0} and _{O n} the floating center _{O 1,} the moving distance [Delta] L _t on the detection axis of the sensor S4 in the floating center O _n is obtained by the following equation.

ΔL _t = ΔL1 ₁ · cos (θ _t −θ _f ) (14)

Then, the film thickness of the coating film 7 is calculated by obtaining the outer peripheral shape of the coating film 7 in the same manner as described above using this ΔL _t and subtracting the dimension shape of the measured cross section of the cylindrical substrate 1 that has already been apparent. I can do it.

Here, since the floating center O _n as previously described in that moving the position according to the cylindrical body 1 is rotated, not be expected always to always be present on the sensor detection axis, the detection deviation of the position of the floating center O _n with respect to the axis produces a measurement error. However, the error is as follows. First the minimum distance between the floating center O _n until the sensing axis [Delta] L, L ₁ the distance between the circumference and the measurement reference position O ₀ of the cylindrical substrate 1 on detection _axis, parallel and floating center O _n the sensing axis Let L ₂ be the distance between the point at which the passing axis intersects the circumference of the cylindrical substrate 1 and the measurement reference position O ₀ . At that time, the error ΔL ′ given to the detection distance is obtained by the following equation.

As a result, ΔL ′ becomes very small. As an example, if the roundness average radius of a 50mm has a circle of about 100μm measured, the moving distance of the floating center _{O n} is assumed to occur about 50 [mu] m, DerutaL' is about 0.025μm Become. This number, 5 × ^{10 -5%} with respect to the measurement value as an error, it is 0.05% with respect to the moving distance of the floating center _{O n.} Considering that the measurement reproducibility of a sensor that is generally regarded as highly accurate is approximately 0.1 μm, it can be said that the influence on the measurement result is extremely small.

In addition, the error due to the rotation angle, which is expected to occur when the cylindrical substrate 1 is rotated according to the measurement, will be described next. The rotation error angle is θ °, the distance between the circumference of the cylindrical substrate 1 on the detection axis and the measurement reference position O ₀ is L ₁ , and the axis that intersects the detection axis and the rotation error angle at the measurement reference position O _0. The upper distance from the measurement reference position O ₀ to the circumference of the cylindrical substrate 1 is L ₂ . The error ΔL ′ given to the detection distance is given by the following equation.

As a result, ΔL ′ becomes very small. As an example, ΔL ′ when the average radius of the measurement target circle is 50 mm and the rotation error is 0.1 ° is about 0.076 μm. This numerical value is 1.5 × 10 ⁻⁴ % with respect to the measured value as an error. In addition to the measurement reproducibility of the above-mentioned general sensor, this error is a measurement result when considering that the stop accuracy of a general and inexpensive rotation mechanism can be expected to be approximately 0.04 °. It can be said that the effects on the

  In the measuring method described above, since the function is less affected by the outer diameter, inner diameter, and length of the cross-section cylinder to be measured of the cylindrical substrate 1, for example, the outer diameter is very thin, about φ5 mm. It can be used for anything from one to several meters. Furthermore, because the cross-sectional cylinder to be measured of the cylindrical substrate 1 is very thin with respect to its length and weight, is soft as a material, or is very thin, it is affected by gravity during measurement. This may cause elastic deformation such as bending and affect measurement results. In that case, it is effective to perform the measurement by bringing the rotation axis of the cross-sectional cylinder to be measured of the cylindrical substrate 1 close to parallel to the direction of gravity or other external action.

  Further, when rotating the cross-section cylinder of the cylindrical substrate 1 in measuring the circumferential shape of the cross section perpendicular to each rotation axis, measurement by a sensor can be performed without stopping the rotation at each measurement position. It is effective in shortening the time.

Furthermore, by using a plurality of mounting bases for fixing the sensor and measuring the circumferential shape of a cross section perpendicular to a plurality of rotation axes at the same time, measurement with a smaller number of rotations, particularly only one rotation, is possible. It is also very effective to do.
The sensor capable of measuring the displacement is composed of two sensors A and B arranged with the angle θ interposed therebetween, and four sensors of two sensors A ′ and B ′ arranged with the angle θ interposed therebetween. . And, the coating film provided on the cylindrical substrate or a sensor capable of measuring the displacement of the coating is arranged with any one of the four sensors and an angle that is a positive integer multiple of θ, It is possible to perform measurement with a larger number of data and higher measurement accuracy. At this time, it is more preferable that the included angle between A and A ′ or B and B ′ is a positive integer multiple of θ.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these Examples.

  A cylindrical substrate made of A3003 aluminum alloy, which had been subjected to a general cutting process in advance as a cylindrical substrate and had a processing set outer diameter of φ84.0 mm, an inner diameter of φ78.0 mm, and a length of 360.0 mm, was prepared. Next, 9 parts by mass of an amine compound represented by the following formula 1,

1 part by mass of an amine compound represented by the following formula 2,

10 parts by mass of a binder resin prepared by copolymerizing both polyarylate resins represented by the following formulas 3 and 4 at a ratio of 7 to 3, respectively.

Was dissolved in monochlorobenzene to prepare a coating solution. And this coating liquid was apply | coated to the said aluminum alloy cylindrical base | substrate by the dip coating method.

  This was used as a cylindrical substrate sample to be measured. At the same time, as a reference cylinder, the roundness at a position of 80 mm from one end of the cylinder in the direction of the rotation axis is 0.20 μm, the average outer diameter value is 84.000 mm, and the measured cylindrical substrate except that the coating film is not provided The same aluminum alloy cylinder was prepared. In measuring the shape of the reference cylinder, a roundness measuring device (trade name: Round Test RA-H5000AH; manufactured by Mitutoyo Corporation) was used.

As shown in FIG. 7, three eddy current sensors S0, S45, S90 and a regular reflection type laser sensor T were mounted on the reference cylinder as follows. A cylinder in which the measurement axes of the sensors substantially intersect at a predetermined point in a circle in a cross section perpendicular to the axis of the cylinder, and are arranged in a fan shape with the angle of 45 ° between each point. Located on the cylindrical receiving jig of the body measuring instrument. The four sensors were arranged at a position of 80 mm in the rotation axis direction from one end of the cross-sectional circle to be measured of the cylindrical substrate. The eddy current sensor used was an eddy current sensor manufactured by KAMAN, and the regular reflection type laser sensor used was a CCD laser displacement sensor LK010 manufactured by Keyence Corporation. The detection values of each sensor at this time were ΔS0 = 448 μm, ΔS45 = 273 μm, ΔS90 = 296 μm, and ΔT = 321 μm. At this time, the distance from each sensor to the measurement reference position O ₀ was LS0 = 42.448 mm, LS45 = 42.273 mm, LS90 = 42.296 mm, and LT = 42.321 mm.

Next, the reference cylinder on the receiving jig was replaced with the cylindrical substrate to be measured, and the measurement was performed a total of 8 times by rotating 45 ° per measurement with a rotary drive transmission. And a detection value obtained, the subtracted from LS0, LS45, LS90 and LT for each sensor, to determine the distance from each measurement point to the measurement reference position _{O 0.} This is shown in Table 1 for sensors S0, S45, and S90, and in Table 3 for sensor T. In addition, all the dimensional units in Tables 1 to 3 are shown as mm.

  Thereafter, in the table frame used in the examples, the measurement at the S0 position is set to 0 ° at the start of measurement, and the measurement position on the circumferential surface reaches S0 according to the rotation of the cross-section cylinder of the cylindrical substrate. Add 45 ° sequentially to give.

  In obtaining the movement distance of the floating center, the movement distances on the detection axes of the sensors S45 and S90 are calculated using the equations (1) and (2). At this time, the movement distance on each axis is the difference between the measured value of S45 and the measured value of S0 before 45 ° rotation on the detection axis of S45, and the measured value of S90 and before 45 ° rotation on the detection axis of S90. Are calculated as differences from the measured values of S45. The above is shown in Table 1.

Next, Δx at the orthogonal coordinate position was obtained using the equation (13), and then Δy was calculated using the equation (12). Here Δx and Δy are the moving distance of the floating center O _n where indicated by orthogonal coordinates. Then, by subtracting this Δy from the measured values of S0, it was determined the distance to the true value, i.e. the measured cross-section cylindrical surface relative to the floating center O _n cylindrical substrate of S0 position. The above is shown in Table 2.

Finally Upon obtaining the film thickness of the coating was determined floating center O _n obtained so far, the movement distance on the detection axis of the sensor T as ΔLt using the equation (14). Here, included angle theta _t between the detection axis of the sensor T and the X axis is given as 135 °. Using this ΔL _t , the true value of T is obtained in the same manner as described above, and the difference from the already obtained true value of S0 is obtained to obtain the film thickness value. From the positional relationship between T and S0, in this embodiment, S0 is subtracted using a numerical value obtained by delaying the phase by 45 ° with respect to the rotation direction from T, that is, a true value after one rotation. The above is shown in Table 3.

  The present invention facilitates the measurement of the film thickness of a coating film or a film on a cylindrical substrate, and the present invention is expected to be used as a technique that contributes to the formation of a highly accurate coating film.

Measurement flowchart Measuring machine schematic (A) The figure which shows the position of a reference | standard cylinder and a sensor, (b) The figure which shows the positioning error of a sensor (A) Measurement position explanatory diagram, (b) Explanatory diagram regarding movement of floating center (A) Explanatory diagram regarding calculation of floating center position (1), (b) Explanatory diagram regarding calculation of floating center position (2) Floating center O _n, the movement distance on the detection axis of the sensor S4 The figure which shows the sensor position of Example 1. Diagram showing the locus of the floating center

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical base | substrate 2 Sensor mounting stand 3 Support stand 4 Guide rail 5 Ball screw 6 Cylindrical receiving jig 7 Coating film 8 Standard cylinder S1 Sensor S1
S2 sensor S2
S3 sensor S3
S4 sensor S4
S0, S45, S90 Eddy current type sensor T Regular reflection type laser displacement measurement sensor

Claims (5)

The shape of the cross-sectional circle, the center of the circle, the roundness, and the outer diameter value of the outer surface of the cylindrical substrate are specified, and the thickness of the coating film or coating film provided on the cylindrical substrate and the outer surface of the coating film or coating film Is a method of measuring by specifying the shape of the cross-sectional circle, the center of the circle, the roundness, the outer diameter value,
The cross-sectional circle with respect to a reference point set in the cross-sectional circle of the cylindrical substrate outer surface orthogonal to the axis of the cylindrical substrate outer surface using a measuring means capable of measuring the displacement of the cylindrical substrate outer surface And calculating the distance between the reference point and the point on the circumference based on the change of the distance between three or more points determined on the circumference of the cylinder by the rotation of the cylindrical base. Identify the cross-sectional circle shape, center of circle, roundness, outer diameter value of the surface,
And, using a measuring means capable of measuring the displacement of the outer surface of the coating film or coating, on the same cross section as the sectional circle and on the outer surface of the coating film or coating, apart from the three or more points. Calculating the distance between one or more points and the reference point, and measuring the thickness of the coating film or film based on the shape of the cross-sectional circle of the outer surface of the cylindrical substrate,
The shape of the cross-sectional circle, the center of the circle, the roundness, and the outer diameter value of the outer surface of the cylindrical substrate are specified, and the thickness of the coating film or coating film provided on the cylindrical substrate and the outer surface of the coating film or coating film Of measuring cross-sectional circle shape, circle center, roundness, and outer diameter value. The cylindrical base body according to claim 1 is placed on a rotating cylindrical receiving jig, and a sensor (sensor for detecting displacement) is mounted on a mounting base that is reciprocally movable in parallel with a substantially rotational axis of the cylindrical body. The same applies hereinafter) is mounted on the same cross section perpendicular to the rotation axis of the cylindrical body,
The sensor is directed to a measurement reference point (O ₀ ), which is a point where the substantially rotational axis and the cross section intersect, and is arranged in a fan shape at an angle θ around O ₀ and fixed to a mounting base 3 A sensor S (S1, S2,... Sm) for measuring the displacement of the outer surface of the cylindrical substrate of m or more, and a sensor T for measuring the displacement of the outer surface of the coating film or coating,
N from the sensors S measured by the m sensors S to the center point of the cylindrical substrate (the number required to calculate the circumferential shape of the cross-sectional circle, and the distance is evenly spaced by θ °) To calculate the circumferential shape of the cross-sectional circle, n = 360 ° / θ °) distance data LS (LS1 ₁ , LS1 ₂ ... LSm _n ) and the sensor T to the cylindrical base body From the n pieces of distance data LT (LT ₁ , LT ₂ ... LT _n ) to the center point, the cross-sectional circular shape, the circle center, the roundness, the outer diameter value of the cylindrical substrate, and the cylindrical substrate The measuring method according to claim ₁ , wherein a thickness ΔLT (LT ₁ , LT ₂ ... LT _n ) of a coating film or a film provided on the surface is obtained.   The cylindrical substrate is made of a material capable of measuring displacement using eddy current, and the coating film or coating provided on the cylindrical substrate is made of a material that cannot measure displacement using the eddy current. The measuring method according to claim 1 or 2, characterized by the above.   The displacement measuring means capable of measuring the displacement of the outer surface of the cylindrical substrate has two sensors A and B arranged with an angle θ interposed therebetween, and two of A ′ and B ′ arranged with an angle θ interposed therebetween. Displacement measuring means comprising four sensors of the four sensors and capable of measuring the displacement of the coating film or coating provided on the cylindrical substrate is a positive integer multiple of the four sensors and θ. The measurement method according to claim 1, wherein the measurement method is arranged with an angle of ≦ 5. The shape of the cross-sectional circle, the center of the circle, the roundness, and the outer diameter value of the outer surface of the cylindrical substrate are specified, and the thickness of the coating film or coating film provided on the cylindrical substrate and the outer surface of the coating film or coating film A device for measuring the shape of the cross-sectional circle, the center of the circle, the roundness, the outer diameter value,
Holding means for holding the cylindrical substrate;
Measuring means capable of measuring displacement of the outer surface of the cylindrical substrate;
Measuring means capable of measuring the displacement of the coating film or the outer surface of the film, and a supporting means for supporting the measuring means,
The measuring means capable of measuring the displacement of the outer surface of the cylindrical substrate is a circle of the sectional circle with respect to a reference point set in a sectional circle of the outer surface of the cylindrical substrate orthogonal to the axis of the outer surface of the cylindrical substrate. A distance between the reference point and a point on the circumference is calculated based on a change in the distance between three or more points determined on the circumference due to the rotation of the cylindrical base, and the outer surface of the cylindrical base is calculated. Identify the shape of the cross-sectional circle,
The measuring means capable of measuring the displacement of the coating film or the outer surface of the coating is one or more on the same cross section as the sectional circle and on the outer surface of the coating film or the coating, apart from the three or more points. Calculating the distance between the point and the reference point, and measuring the thickness of the coating film or film based on the shape of the cross-sectional circle of the cylindrical substrate outer surface,
The shape of the cross-sectional circle, the center of the circle, the roundness, and the outer diameter value of the outer surface of the cylindrical substrate are specified, and the thickness of the coating film or coating film provided on the cylindrical substrate and the outer surface of the coating film or coating film For measuring the cross-sectional circle shape, circle center, roundness, and outer diameter value.