JP2964800B2 - Wet film thickness measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet coating film thickness measuring apparatus for measuring a coating film thickness from dynamic roughness information of an undried coating surface immediately after coating of a coating material.

[0002]

2. Description of the Related Art Conventional wet film thickness measuring devices of this type include various types such as a contact type using a needle gauge and a non-contact type using an electromagnetic or eddy current type. . FIG. 20 is an explanatory view showing a non-contact wet film thickness measuring device utilizing the non-magnetic polarity of the paint, among such conventional wet film thickness measuring devices. In this conventional wet coating film thickness measuring device, as shown in FIG. 1A, a non-contact film thickness sensor 82 is previously positioned at a close distance _ho in opposition to a coating surface of an object 81 made of a steel plate. Thereafter, the object to be coated 81 and the non-contact film thickness sensor 82 are controlled by a transmitting / receiving coil provided in the non-contact film thickness sensor 82.
To generate a magnetic field. Then, as shown in FIG. 3B, when the wet paint 83 is applied on the surface of the object 81, the object 81 and the non-contact film thickness sensor 82 are applied.
Is attenuated by the electromagnetic resistance due to the coating thickness and is sensed by the receiving coil. Therefore, the coating film thickness can be measured by detecting a change in magnetic flux inversely proportional to the film thickness.

[0003]

Among the above-mentioned wet film thickness measuring devices, those of a contact type such as a needle gauge type have a problem that the quality of the coating is affected by flaws on the coating surface.

Among the non-contact types, the non-contact type wet film thickness measuring apparatus as shown in FIG. 20 sets a distance between the object to be coated and the non-contact thickness sensor to a predetermined distance before coating. Although it is necessary to set the distance, after coating the object to be coated, there is a problem that the thickness of the coating cannot be measured, or a problem that the measurement itself is required twice before and after the coating, and further, There is a problem that the measurement accuracy is poor.

[0005] The present invention has been made in view of the above,
The object is to provide a wet coating film thickness measuring device capable of accurately measuring a coating film thickness in a non-contact manner from a dynamic smoothing characteristic of the roughness of a coating surface immediately after application of a coating material. It is in.

[0006]

In order to achieve the above object, a wet coating thickness measuring apparatus of the present invention comprises a roughness measuring means for measuring the roughness of an undried coating surface immediately after coating a paint, A time change amount calculating means for calculating a time change amount of the surface roughness information measured by a roughness measuring means, an input means for inputting the component information of the paint, and the component information of the paint and the surface roughness information. The gist of the invention is to have a coating film thickness calculating means for calculating the coating film thickness based on the time change amount.

Further, the wet film thickness measuring apparatus of the present invention comprises a roughness measuring means for measuring the roughness of an undried coated surface immediately after coating with a paint, and the surface roughness measured by the roughness measuring means. Calculating means for calculating the peak-to-peak value and the wavelength of the surface unevenness from the information, time change calculating means for calculating the time-change amount of the peak-to-peak value of the surface unevenness, and inputting the component information of the paint; An input means and a paint film thickness calculating means for calculating a paint film thickness based on the component information of the paint, the time variation of the peak-to-peak value of the surface unevenness and the wavelength of the surface unevenness. .

Further, the wet film thickness measuring apparatus of the present invention comprises a roughness measuring means for measuring the roughness of an undried coated surface immediately after the coating of the paint, and the surface roughness measured by the roughness measuring means. Calculating means for calculating a surface roughness and a wavelength from information; time change calculating means for calculating a time change of the surface roughness; input means for inputting component information of the paint; and the paint And a coating film thickness calculating means for calculating a coating film thickness based on the component information, the time variation of the surface roughness and the wavelength of the surface roughness.

Further, the apparatus for measuring the thickness of a wet coating film according to the present invention further comprises a roughness measuring means for measuring the roughness of the undried coated surface immediately after the coating of the paint, and the surface roughness measured by the roughness measuring means. Computing means for calculating the surface roughness and wavelength or the peak-to-peak value and wavelength of the surface irregularities from input information, input means for inputting the component information and coating conditions of the paint, and component information and coating of the paint Estimating means for estimating a smoothing initial value based on a condition, the surface roughness and the wavelength or the peak-to-peak value of the surface roughness, and a peak-to-peak value of the surface roughness and the wavelength or the surface roughness. It is a gist of the present invention to have a coating film thickness calculating means for calculating a coating film thickness based on a peak value, a wavelength, and the smoothing initial value.

An apparatus for measuring the thickness of a wet coating film according to the present invention comprises: an imaging means for imaging the roughness of an undried coated surface immediately after coating with a paint; and power spectrum analysis of surface roughness information imaged by the imaging means. Power spectrum analyzing means for outputting as power spectrum data; calculating means for calculating a power spectrum integrated value and a wavelength corresponding to surface roughness from the power spectrum data from the power spectrum analyzing means; and component information and coating conditions of the paint. Input means for inputting, using a smoothing theoretical formula using a power spectrum analysis value, a coating film thickness calculating means for calculating a coating film thickness from the power spectrum integrated value, wavelength, the paint component information and coating conditions. It is the gist to have.

[0011]

The wet coating thickness measuring apparatus of the present invention measures the roughness of the undried coating surface immediately after coating, calculates the time variation of the surface roughness information, and obtains the component information and the surface roughness information of the paint. Is calculated based on the amount of change in time.

Further, the wet coating thickness measuring apparatus of the present invention measures the roughness of an undried coating surface immediately after coating, and calculates the peak-to-peak value and wavelength of surface irregularities from the surface roughness information, The time change amount of the peak-to-peak value of the surface unevenness is calculated, and the coating film thickness is calculated based on the component information of the paint, the time change amount of the peak-to-peak value of the surface unevenness, and the wavelength of the surface unevenness.

Further, the apparatus for measuring the thickness of a wet coating film of the present invention measures the roughness of an undried coating surface immediately after coating, calculates the surface roughness and wavelength from the surface roughness information, and calculates the surface roughness. The amount of time change of the roughness is calculated, and the coating film thickness is calculated based on the component information of the paint, the amount of time change of the surface roughness, and the wavelength of the surface roughness.

Further, in the wet coating thickness measuring apparatus of the present invention, the roughness of the undried coating surface immediately after coating is measured, and the surface roughness and the wavelength or the peak of the surface unevenness are measured from the surface roughness information. Calculate the peak value and wavelength, and estimate the smoothing initial value based on the paint component information and the coating conditions, the surface roughness and the wavelength or the peak-to-peak value and wavelength of the surface irregularities, and calculate the surface roughness and The coating film thickness is calculated based on the wavelength or the peak-to-peak value of the surface irregularities and the wavelength, and the smoothing initial value.

In the wet coating thickness measuring apparatus of the present invention, the surface roughness information obtained by imaging the roughness of the undried coating surface immediately after coating is subjected to power spectrum analysis, and the power spectrum integration corresponding to the surface roughness is obtained from the power spectrum data. The value and the wavelength are calculated, and the coating film thickness is calculated from the integrated value of the power spectrum, the wavelength, the coating composition information, and the coating condition, using a smoothing theoretical formula using the power spectrum analysis value.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a wet coating film thickness measuring apparatus according to a first embodiment of the present invention.
The wet film thickness measuring device shown in FIG. 1 measures the coating film thickness by focusing on the flattening phenomenon of the undried state, that is, the wet state of the coating surface immediately after the paint is applied. Specifically, as shown in FIG. 2 (a), the coating surface in a wet state immediately after coating is in an uneven state, and an initial eddy flow exists. The unevenness in such a state is flattened with time by the leveling force as shown in FIG. 3B, and finally becomes a flattened state as shown in FIG. The wet film thickness measuring device pays attention to such a flattening phenomenon, and accurately calculates the coating film thickness after the wet coating surface is dried by measuring the unevenness of the coating surface in a non-contact manner. And can be calculated by measurement only after application of the paint.

The configuration of the wet coating thickness measuring apparatus shown in FIG. 1 will be described. In FIG. 1, an object to be coated 1
Is provided with a non-contact light interference type surface roughness meter 4 which constitutes a roughness measuring means facing the surface. In the present embodiment, a top coat is applied to the object 1 to be coated.

As shown in FIG. 3, the surface roughness meter 4 allows light generated from the light source 13 to pass through a pinhole and an opening,
The objective lens 1 is reflected downward by the half mirror and is reflected downward.
5, the reference surface 16, the beam splitter, 1
Hits the surface and is reflected upwards, the beam splitter,
After passing through the reference surface 16 and the objective lens 15, the light passes through the half mirror upward, passes through the filter, and is received by the CCD sensor 12, whereby the surface roughness information of the work 1 is obtained. I have.

The surface roughness information of the object to be coated 1 from the surface roughness meter 4 is supplied to an image processing device 5 constituting a controller 9, where it is subjected to coordinate conversion and coordinate conversion. It is supplied to the smoothness arithmetic processing unit 6.

The coating roughness smoothness arithmetic processing unit 6 calculates surface roughness smoothness information from the surface roughness image information supplied from the image processing unit 5, that is, peak-to-peak (p-
p) The value a and the wavelength λ of the unevenness are calculated and supplied to the film thickness calculation processing device 7. In addition, the film thickness calculation processing device 7 receives from the input device 8 component information of the paint including the content of volatile components and the like, whereby the film thickness calculation processing device 7 performs the wet coating film thickness measurement method described later. Based on the calculated coating film thickness, the calculated coating film thickness is output to the display 10 and the plotter 11. The image processing device 5, the coating roughness smoothness calculation processing device 6, and the film thickness calculation processing device 7 constitute a controller 9.

Next, the operation of the embodiment shown in FIG. 1 will be described with reference to the flowchart shown in FIG.

In FIG. 4, first, at time t ₁ immediately after the paint is applied by the surface roughness meter 4,
Is irradiated with light, and the reflected light is received to obtain surface roughness information of the object 1 to be coated.
In step, light is generated from the light source 13 (step 110).
It was dispersed by the spectroscopic unit (step 120), irradiating the coated surface of the object to be coated 1 (step 130), and photometry by the photometric unit reflected light from the painted surface (step 140), thereby the image at time t ₁ Information, that is, information on the surface roughness of the work 1 is obtained (step 150), and this image information is stored in a memory (step 160).

FIG. 5A is a view showing an example of optical interference fringe data indicating the surface roughness of the work 1 measured by the surface roughness meter 4. FIG. 5B shows an analysis example of three-dimensional surface roughness.

The acquisition of the surface roughness information is repeated at the time t ₂ (= t ₁ + Δt) after the time Δt, following the time t ₁ , whereby the object to be coated at the times t ₁ and t ₂ is obtained. The surface roughness information of the object 1 is measured and stored in a memory as image information. This image information is stored in the image processing device 5
Is supplied to the image processing device 5, and the image processing device 5 performs coordinate conversion and coordinate conversion (step 170).

Next, the surface roughness information of the object to be coated 1, which is the image information converted and coordinated by the image processing device 5, is supplied to a coating film roughness smoothness arithmetic processing device 6, where it is coated. From the surface roughness information of the coating ₁ , the time t ₁ , t ₂
Is calculated (step 180). The calculated peak-to-peak value a and the wavelength λ of the surface irregularities at the times t ₁ and t ₂ are calculated together with the coating conditions such as the components of the paint input from the input device 8 (step 190), and the film thickness is calculated. The input coating thickness h is calculated by the processing device 7 (step 200), and the calculated coating thickness h is displayed on the display 10 and printed by the plotter 11 (step 210).

Next, the processing for calculating the peak-to-peak value a and the wavelength λ of the unevenness on the surface of the object 1 to be coated by the coating film roughness smoothness processing unit 6 in step 180 and the film thickness calculation processing unit in step 200 7 will be described with reference to FIG. 6 and subsequent figures.

As described with reference to FIG. 2, the coating surface in the wet state immediately after the coating is applied to the surface of the workpiece 1 has a large roughness, and the surface state is as shown in FIG.
As shown in (b), it can be represented by surface irregularities a and wavelength λ.

The surface irregularities in the wet state immediately after coating shown in FIG. 6A are smoothed over time as described above, and the dynamic characteristics of this surface smoothing are as shown in FIG. 6A. the average value of the coating thickness in the wet state h, and viscosity of the coating eta, the surface tension of the coating film gamma, irregularities initial value of the surface When a _o a, generally represented by the following formula.

[0030]

[Number 1] ^{da / dt = (- h 3} γ) / (3η) × (2π / λ) 4 a ... (1) a = a o · exp -t / τ ... (2) τ = 3ηλ 4 / ( 16π ⁴ × γh ³ ) (3) Actually, the coating film viscosity after coating is shown as an example as shown in FIG. 7 under the conditions where the atomizing air pressure, solvent, viscosity before coating, temperature, etc. are constant. Is done. In FIG. 7, the horizontal axis represents the elapsed time after the paint application, the ordinate indicates the coating viscosity eta, eta ₀
And η ₁ indicate the viscosity value before application and the initial viscosity value immediately after coating, respectively.

Accordingly, as shown in FIG. 7, since the viscosity immediately after the application of the paint changes with time, the above equations (1) to (3)
It is necessary to use a correction value such as the following equation for the viscosity η.

Η = η ₁ + Kt (4) Note that η ₁ > η ₀ and K is a coefficient much smaller than 1.0 (K << 1.0).

As shown in the dynamic characteristic of smoothing the wet film thickness in FIG. 8, the peak-to-peak values of the unevenness of the coating surface at times t ₁ and t ₂ immediately after application of the paint are a ₁ and a ₂ , respectively. Is λ12, the following equation is obtained. The wavelength lambda ₁ at time t _1, t _{2, λ 2} is, λ ₁ = λ ₂
= And having a lambda ₁₂ and the relationship.

[0034]

[Number 2] _{a 1 = a 0 exp (-t} 1 / τ 1) ... (5) τ 1 = {3 × η (t 1) × λ 12 4} / (16π 4 × γ × h 3) ... ( _{6) a 2 = a 0 exp} (-t 2 / τ 2) ... (7) τ 2 = {3 × η (t 2) × λ 12 4} / (16π 4 × γ × h 3) ... (8) When the coating thickness h is obtained from the above equations (5) to (8), (5)
Dividing the equation by equation (7) gives:

[0035]

A ₁ / a ₂ = exp (−t ₁ / τ ₁ + t ₂ / τ ₂ ) (9) ₁ na ₁ / a ₂ = (− t ₁ / τ ₁ + t ₂ / τ ₂ ) (10) Then, the coating film thickness h is obtained from the equations (6), (8) and (10) as follows.

[0036]

Equation 4] _{h = {(1na 1 / a} 2) / (- t 1 / τ 1 '+ t 2 / τ 2')} 1/3 ... (11) τ 1 '= (3η 1 × λ 12 4) ^{/ (16π 4 γ) ... (} 12) τ 2 '= (3η 2 × λ 12 4) / (16π 4 γ) ... (13) from these equations (11) - (13), immediately after the paint application time t by measuring the _1, roughness of the painted surface at t ₂ a _1, a ₂ and the wavelength lambda _0, it is possible to calculate the paint film thickness h.

Similarly, the expression (1) is changed to da / dt = (a ₂ −
a ₁ ) / (t ₂ −t ₁ ), and it is also possible to calculate the coating film thickness h by adding the expression (4).

[0038]

(Equation 5) It is necessary to select either equation (11) or equation (14) depending on the measurement system.

FIG. 9 is a graph comparing measured values of the top coating with theoretical values. The smoothing dynamic characteristics at 60 to 100 seconds after the application are very close to the theoretical values and the measured values, and the film thickness value is also about 38 to 40 μm according to the equation (11).
, Which is almost the same as the measured value.

Next, a second embodiment of the present invention will be described with reference to FIG.

The wet coating thickness measuring apparatus according to the second embodiment shown in FIG. 10 is different from the first embodiment shown in FIG. However, the only difference is that a surface roughness calculation processing device 17 is used, and the other configurations and operations are the same. The wet film thickness measuring apparatus of the second embodiment uses a surface roughness arithmetic processing unit 17 instead of the peak-to-peak value a and the wavelength λ of the surface unevenness in the first embodiment. By calculating the surface roughness and the surface roughness wavelength, and by using the surface roughness and the wavelength, it is possible to calculate the average coating film thickness in a relatively short measurement time and to select a specific unevenness. Is unnecessary. The surface roughness and the wavelength are the average roughness _Ra and the average wavelength λ.
_a , or the root mean square R _q and the root mean square wavelength λ _q are used.

FIG. 11 is a flowchart showing the operation of the second embodiment.
Is that the step 182 calculates the surface roughness and the surface roughness wavelength instead of calculating the peak-to-peak value and the wavelength in step 180 in the flowchart of the first embodiment shown in FIG. Only.

In the wet film thickness measuring apparatus of the second embodiment shown in FIGS. 10 and 11, the surface roughness arithmetic processing unit 17 calculates the time t ₁ and the time t ₁ from the surface roughness image information supplied from the image processing unit 5. Surface roughness and wavelength at t ₂ , ie, average roughness _Ra and its average wavelength λ _a
Or (Step 182 in FIG. 11) the root mean square calculating the R _q and root mean square lambda _q, and supplies the thickness arithmetic processing unit 7.

The film thickness arithmetic processing unit 7 calculates the surface roughness and wavelength, that is, the average roughness _Ra and its average wavelength λ.
_a or root mean square R _q and root mean square λ _q
Is supplied, the paint film thickness h is calculated from the information and the paint conditions supplied from the input device 8 according to the following equations (15) to (20) corresponding to the above equation (11) (step). 200).

[0045] That is, the above-described (11) the surface roughness level and the wavelength, i.e. to mean roughness degree R _a and its mean wavelength lambda _a and the root mean square R _q and the root mean square wavelength lambda _q However, the following holds.

[0046]

H = {(1nR _a1 / R _a2 ) / (− t ₁ / τ ₁ '+ t ₂ / τ ₂ ')} ^1/3 (15) τ ₁ '= (3η ₁ × λ _a ) / ^{(16π 4 γ) ... (16} ) τ 2 '= (3η 2 × λ a) / (16π 4 γ) ... (17) h = {(1nR q1 / R q2) / (- t 1 / τ 1' + t ₂ / τ ₂ ′)｝ ^1/3 (18) τ ₁ ′ = (3η ₁ × λ _q ) / (16π ⁴ γ) (19) τ ₂ ′ = (3η ₂ × λ _q ) / (16π ⁴ γ) (20) FIG. 12 is a graph showing the smoothing dynamic characteristic of the surface roughness, and the vertical axis represents the surface roughness R _a , R _{q with} respect to the elapsed time after application of the paint shown on the horizontal axis. Is shown. From the same figure, after application 6
It can be seen that the theoretical values and the measured values of the smoothing dynamic characteristics at 0 to 100 seconds substantially match the roughness values (R _a , R _q ) as in the case shown in FIG. Further, the coating thickness value h also h _a = 40 [mu] m, substantially coincides with the h _q = 39 .mu.m.

In the second embodiment, the optical interference fringe data indicating the surface roughness of the object 1 shown in FIG. 5A is measured by the surface roughness meter 4 as shown in FIG. average roughness degree Ra and the root mean square Rq in this case are those indicated by the following equation, the average roughness degree Ra = 0.861Myuemu, root mean square Rq = 0.959Myuemu, wavelength lambda = 4.6 m m It is.

[0048]

(Equation 7) Next, a third embodiment of the present invention will be described with reference to FIG.

The wet coating film thickness measuring apparatus according to the third embodiment shown in FIG. 13 is different from the second embodiment shown in FIG. The only difference is that a smoothing initial value estimating device 18 is provided in between, and that the paint condition information from the input device 8 is input to the smoothing initial value estimating device 18. Is the same. The wet coating film thickness measuring apparatus of the third embodiment estimates and calculates the smoothing initial value by the smoothing initial value estimating device 18 so that only one short time after t seconds after the application of the paint is obtained. It is possible to calculate the coating film thickness h only by measuring the roughness information, thereby improving the adaptability to the line of the present wet film thickness measuring apparatus.

FIG. 11 is a flowchart showing the operation of the third embodiment.
In the flow chart of the second embodiment shown in FIG. ₁ , instead of calculating the surface roughness and the wavelength twice at times t ₁ and t ₂ in step 182, one surface roughness only in time t ₁ is used in step 184. The only difference is that the calculation of the degree and the wavelength is performed, and subsequently, a step 186 is added, and the smoothing initial value is estimated in this step.

In the apparatus for measuring the thickness of a wet coating film according to the second embodiment shown in FIGS. 13 and 14, the processing unit 17 calculates the surface roughness _Ra and the wavelength λ at time t ₁ .
measured _a (step 184), and supplies the surface roughness of R _a and wavelength lambda _a smoothing initial value estimation device 18.
Smoothing the initial value estimation device 18, in addition to the surface roughness of R _a and wavelength lambda _a, estimates a smoothing initial value a _o from the coating conditions including the coating components and the like input from the input device 8 (step 186).

The estimation of the smoothing initial value a _o will be described.

[0053] irregularities peak-to-peak value a _o immediately after coating the above-mentioned (5) is as follows.

A _o = a ₁ exp (t ₁ / τ ₁ ) (21) Note that τ ₁ and η ₁ (t ₁ ) in this equation are those shown in the above-described equations (4) and (6), respectively. Is the same as

[0055] irregularities peak-to-peak value a _o immediately after coating from the measured data of the coated surface smooth Kado characteristics (t = 0) is determined from the above equation (21) (where, as a cancer properties constant).

Further, for example, when the coating film thickness h = 60 μm and the wavelength λ = 6 mm, the uneven peak-to-peak value a _o = 8.
5 to 8.7 μm (t = t _{1 to} t ₃ ), and the coating film thickness h
= 40 [mu] m, when the wavelength lambda = 4.3 mm, uneven peak-to-peak value _{a o = 8.4~8.6μm (t = t} 1 ~
It can be seen that the initial value is substantially constant with respect to the coating film thickness h and the wavelength λ, such as t ₃ ). That is,
It can be said that there is a relationship shown in the following equation. This relationship is shown in FIG.
This is also evident from the comparison between the measured values and the theoretical values of the smoothed dynamic characteristics shown in the graph of peak-to-peak (pp) values of the surface roughness of the coating film with respect to the time immediately after coating shown in FIG.

Λ ⁴ / h ³ = K _o (constant) (22) Therefore, if the paint component is known in advance, the unevenness peak-to-peak value a and the wavelength λ at a certain time t are measured to obtain the unevenness. The initial value a _o of the peak-to-peak value can be obtained in advance by using the above-described equations (21), (6), (4), and (22). In addition, it may have been previously measured the initial value a _o.

When the smoothing initial value a _o is calculated as described above, the smoothing initial value is supplied to the film thickness calculation processing device 7, and the coating film thickness h is calculated (step 200).

The calculation of the coating thickness h will be described.

[0060] coating components in the calculation of the above-described smoothed initial value is known, also if coating conditions (cancer properties) is constant, uneven peak-to-peak value a _o immediately after coating can be estimated as described above Therefore, the coating film thickness h is calculated as t ₁ = 0, t ₂ = t _{1 in the} above-described equations (11) to (13).
Thus, the following equation can be obtained.

[0061]

H = {(1na ₀ / a ₁ ) / (− 0 / τ ₀ + t ₁ / τ ₁ ′)} ^1/3 = {(1na _o / a ₁ ) / (t ₁ / τ ₁ ′) ｝ ^1/3 (23) τ ₁ ′ = (3η ₁ × λ ⁴ ) / (16π ⁴ γ) (12) η ₁ = η ₀ + Kt ₁ (4) The above (23), (12), (4) coating thickness h from the equation can be calculated by measuring the time t _1, the wavelength lambda, uneven peak at time t ₁ to peak value a _1.

In the third embodiment described above, the case where the surface peak-to-peak value is used has been described. Instead, the surface roughness and its wavelength, that is, the average roughness _Ra and the average wavelength λ are used. _a , or the root-mean-square _Rq and the root-mean-square wavelength λq are _satisfied as shown in the following equation.

[0063]

H = {(1nR _a0 / R _a1 ) / (t ₁ / τ ₁ ′)} ^1/3 (24) τ ₁ ′ = (3η ₁ × λ _a ⁴ ) / (16π ⁴ γ) (25) h = {(1nR q0 / R q1) / (t 1 / τ 1 ')} 1/3 ... (26) τ 1' = (3η 1 × λ q 4) / (16π 4 γ) ... ( 27)

The wet film thickness measuring apparatus according to the fourth embodiment shown in FIG. 16 is provided to face the object 1 to be coated, and images the surface of the object 1 to be coated. An imaging unit 2 for obtaining surface roughness information is provided. In the present embodiment, the work 1 is coated with a top coat.

As shown in detail in FIG. 17, the image pickup section 2 comprises a light source 31, a light / dark pattern plate 32, a reflecting mirror 33, a lens 34, and a CCD camera 35. The surface roughness information of the object 1 is stored in the image processing unit 3
Supplied to

The image processing section 3 is composed of various image processing programs, an image analysis sequence program, a waveform analysis program, a film thickness calculation program, etc., performs image processing on the surface roughness information supplied from the image pickup section 2 and performs power spectrum analysis. And the waveform analysis of the long wave is performed, and the surface roughness information is supplied to the power spectrum integral value calculation unit 21 as the power spectrum data P.

The power spectrum integrated value calculating section 21 calculates a power spectrum integrated value P _i corresponding to roughness and a long wavelength λ from the power spectrum data from the image processing section 3 and supplies them to the film thickness calculating section 22. The film thickness calculating unit 22 calculates a coating film using a smoothing theoretical formula using a power spectrum P described later based on the coating conditions input from the input device 8 in addition to the power spectrum integral value i and the long wavelength λ. Calculate the thickness h. Then, the calculated coating film thickness h
Is displayed on the display 10 and printed by the plotter 11.

Next, the derivation of the theoretical equation for smoothing using the power spectrum P will be described.

[0069] First, explaining the smoothing characteristics of the power spectrum P, a surface roughness R _a and the power spectrum integral value P _i, is in the relationship as shown in FIG. 18, has the following relationship.

P _i = P _o + k × R _a ^1/2 (28) _Ra = {(P _i −P _o ) / k} ² (29) In the derivation of the smoothing theoretical formula based on the power spectrum analysis value, First, as a wet coating smoothing theoretical formula (approximate formula),
The surface roughness _Ra is represented by the following equation.

R _a = R _ao · exp (−t / τ) (30) By substituting equation (29) into equation (30),

１０ (P _i −P _o ) / k｝ ² = ｛(P _io −P _oo ) / k｝ ² exp (−t / τ) (31) where P _io is P _i Is the initial value of _Po and _Po is _Po
Is the initial value of.

[0072] _{Therefore, P = P o · exp (} -t / 2τ) ... (32) However, P = P _i -P _o, is ^{τ = 3ηλ 4 / 16π 4 γh} .

From the above, the coating film thickness h based on the power spectrum analysis value is as follows.

[0074]

[Equation 11] Here, τ ′ _i = 3ηiλ ⁴ / 16π ⁴ γ.

Next, the operation of the fourth embodiment shown in FIG. 16 will be described.

The surface of the coating film of the object 1 is imaged by the imaging unit 2 and the surface roughness information at times t ₁ and t ₂ after the application of the paint is measured. This information is input to the image processing unit 3. The image is processed, and is supplied to the power spectrum integral value calculation unit 21 as power spectrum data for each frequency analysis (FFT) process and spatial frequency. The power spectrum integral value calculation unit 21 uses the power spectrum data from the image processing unit 3 to separate the waveform of the power spectrum and calculate the long-wave power spectrum integral value P _i and the long wavelength λ. The information is used as the film thickness calculating unit 22.
Supplied to The coating condition is input to the film thickness calculating unit 22 from the input device 8, and as described above, the coating film thickness h is obtained from the information, the power spectrum integrated value P _i and the long wavelength λ from the power spectrum integrated value calculating unit 21. Is calculated,
It is displayed on the display 10 and printed by the plotter 11.

[0077] Figure 19, the horizontal axis represents time, the vertical axis of the power spectrum integral value P _i, wet smooth Kado characteristics comparing the measured values with smoothed theoretical value using the equation (32) ( 7 is a graph showing a power spectrum value. For the measurement, an image immediately after application was photographed by the imaging unit 2 and power spectrum analysis was performed. From FIG. 19, it can be seen that the measured value has a smoothing characteristic almost coincident with the theoretical value.

Table 1 shows that the film thickness is 60 μm, 54 μm
The results obtained by measuring the film thickness h for the sample No. using the estimation formula of the above-described formula (33) are shown. Several μm from the table
It can be seen that measurement is possible with an accuracy of.

[0079]

[Table 1]

[0080]

As described above, according to the present invention,
Calculate the peak-to-peak value and wavelength of surface irregularities or the surface roughness and wavelength from the roughness information of the undried painted surface immediately after painting, paint composition information, peak-to-peak value or roughness of surface irregularities Calculate the coating film thickness based on the time change amount and the wavelength of the surface unevenness or surface roughness,
Or calculate the surface roughness and the peak-to-peak value and wavelength of surface roughness and wavelength or surface irregularities from surface roughness information,
Estimate the smoothing initial value based on the paint composition information and the coating conditions, surface roughness and wavelength or the peak-to-peak value and wavelength of the surface unevenness, and estimate the surface roughness and wavelength or the peak-to-peak value of the surface unevenness. Since the coating thickness is calculated based on the wavelength and the smoothing initial value, the wet coating thickness immediately after coating can be accurately measured without contact.

According to the present invention, power spectrum analysis is performed on surface roughness information, a power spectrum integrated value and a wavelength corresponding to the surface roughness are calculated from the power spectrum data, and smoothing is performed using the power spectrum analysis value. Using the theoretical formula, the paint film thickness is calculated from the power spectrum integrated value, wavelength, paint component information, and paint conditions.
In addition to being able to accurately and accurately measure the thickness of the undried coating film immediately after coating without contact, the cost of equipment including imaging means has been reduced, the separation distance from the coating surface has been increased, and the risk of contact has been reduced. The imaging means can be simplified and reduced in weight, the vibration resistance can be improved, and the like, and it is most suitable for application to, for example, a coating line of an automobile.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a wet coating film thickness measuring apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a flattening phenomenon of an uneven state of a coating surface in a wet state immediately after coating.

FIG. 3 is a diagram showing a configuration of a surface roughness meter used in the wet coating film thickness measuring device of FIG.

FIG. 4 is a flowchart showing the operation of the wet coating film thickness measuring device of FIG. 1;

5 is a diagram showing an example of optical interference fringe data indicating the surface roughness of an object to be coated measured by a surface roughness meter in the wet coating film thickness measuring device of FIG.

FIG. 6 is a diagram showing an uneven state of a coating surface in a wet state immediately after coating.

FIG. 7 is a graph showing the relationship between coating film viscosity and setting time.

FIG. 8 is a graph showing a dynamic characteristic of smoothing a wet film thickness.

FIG. 9 is a graph comparing measured values of a top coating with theoretical values.

FIG. 10 is a block diagram showing a configuration of a wet coating film thickness measuring apparatus according to a second embodiment of the present invention.

11 is a flowchart showing the operation of the wet coating film thickness measuring device of FIG.

FIG. 12 is a graph showing a smoothing dynamic characteristic of surface roughness.

FIG. 13 is a block diagram showing a configuration of a wet coating film thickness measuring apparatus according to a third embodiment of the present invention.

FIG. 14 is a flowchart showing the operation of the wet coating film thickness measuring device of FIG.

FIG. 15 shows a comparison between the theoretical value of the smoothing dynamic characteristic and the measured value.
It is a graph shown by -p) value.

FIG. 16 is a block diagram showing a configuration of a wet coating film thickness measuring apparatus according to a fourth embodiment of the present invention.

17 is a diagram showing a configuration of an imaging unit used in the wet coating film thickness measuring device of FIG.

FIG. 18 shows the surface roughness _Ra and the integrated value of the power spectrum P _i.
6 is a graph showing the relationship of.

19 the horizontal axis represents time, the vertical axis of the power spectrum integral value P _i, is a graph showing the wet smoothing Kado characteristics comparing the measured values with smoothed theory (power spectrum values).

FIG. 20 is an explanatory view showing a conventional coating film thickness measuring device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 object to be coated 2 imaging unit 3 image processing unit 4 surface roughness meter 5 image processing device 6 coating roughness smoothness calculation processing device 7 film thickness calculation processing device 8 input device 9, 19, 29 controller 10 display 11 plotter 17 Surface Roughness Calculation Processing Device 18 Smoothing Initial Value Estimation Device 21 Power Spectrum Integrated Value Calculation Unit 22 Film Thickness Calculation Unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) G01B 11/00-11/30 102 G01B 21/00-21/32 B05C 7/00-21/00

Claims (5)

(57) [Claims] 1. A roughness measuring means for measuring the roughness of an undried coated surface immediately after coating with a paint, and a time variation for calculating a time variation of the surface roughness information measured by the roughness measuring means. Calculating means, input means for inputting the component information of the paint, and paint film thickness calculating means for calculating a paint film thickness based on a time change amount of the component information of the paint and the surface roughness information. Characteristic wet film thickness measuring device. 2. A roughness measuring means for measuring the roughness of an undried coated surface immediately after coating with a paint, and a peak-to-peak value of surface irregularities based on the surface roughness information measured by the roughness measuring means. Arithmetic means for calculating the wavelength, time change amount calculating means for calculating the time change amount of the peak-to-peak value of the surface irregularities, input means for inputting the component information of the paint, component information of the paint, A wet film thickness measuring device, comprising: a paint film thickness calculating means for calculating a paint film thickness based on a time variation of a peak-to-peak value of the surface unevenness and a wavelength of the surface unevenness. 3. A roughness measuring means for measuring the roughness of an undried coated surface immediately after coating with a paint, and calculating a surface roughness and a wavelength from the surface roughness information measured by the roughness measuring means. Calculating means for calculating the time change amount of the surface roughness, input means for inputting the component information of the paint, component information of the paint, and time of the surface roughness. A coating film thickness calculating device for calculating a coating film thickness based on the amount of change and the wavelength of the surface roughness. 4. A roughness measuring means for measuring the roughness of an undried coated surface immediately after coating with a paint, and a surface roughness and a wavelength or a surface based on the surface roughness information measured by the roughness measuring means. Calculating means for calculating the peak-to-peak value and wavelength of the irregularities, input means for inputting the coating composition information and coating conditions, and the coating composition information and coating conditions, the surface roughness and wavelength or the surface Estimating means for estimating the smoothing initial value based on the peak-to-peak value and wavelength of the unevenness, and the peak-to-peak value and wavelength of the surface roughness and wavelength or the surface unevenness, and the smoothing initial value. A coating film thickness calculating device for calculating a coating film thickness based on the coating film thickness. 5. An image pickup means for picking up an image of the roughness of an undried coating surface immediately after coating with a paint, and a power spectrum analysis for outputting power spectrum data by analyzing the surface roughness information picked up by the image pickup means. Means, calculating means for calculating a power spectrum integrated value and a wavelength corresponding to surface roughness from power spectrum data from the power spectrum analyzing means, input means for inputting component information and coating conditions of the paint, and power spectrum analysis. A coating film thickness calculating means for calculating a coating film thickness from the power spectrum integrated value, the wavelength, the coating material component information and the coating conditions by using a smoothing theoretical formula using a value. Thickness measuring device.