JP2964801B2 - 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 measures a wet coating film thickness from dynamic roughness information of an undried coating surface immediately after a paint is applied, and estimates a dry coating film thickness from the wet coating film thickness. The present invention relates to a coating film thickness measuring device.

[0002]

2. Description of the Related Art There are various types of conventional film thickness measuring devices of this type, such as a contact type using a needle gauge and a non-contact type using an electromagnetic or eddy current type. FIG. 19 is an explanatory view showing a non-contact type coating film thickness measuring apparatus utilizing the non-magnetic polarity of a paint, among such conventional coating film thickness measuring apparatuses. In this conventional coating film thickness measuring apparatus, 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. The contactless film thickness sensor 82
The body 81 to be coated is provided by a transmitting / receiving coil provided in the inside.
And a non-contact film thickness sensor 82 to generate a magnetic field. Then, as shown in FIG. 6B, when the wet paint 83 is applied on the surface of the object 81, the object 81 after the application is applied.
The magnetic field between the sensor and the non-contact film thickness sensor 82 is attenuated by the electromagnetic resistance due to the coating film 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.

[0004] Among the non-contact types, the non-contact type coating film thickness measuring device as shown in FIG. 19 determines the distance between the object to be coated and the non-contact film thickness sensor to a predetermined close distance before coating. Although it is necessary to set to, the problem that it is not possible to measure the thickness of the coating after coating the object to be coated, or that the measurement itself is required twice immediately after coating,
Further, there is a problem that the measurement accuracy is poor.

Further, the coating film thickness measuring device measures the coating film thickness in order to control the coating quality, and the coating quality is controlled by the coating film thickness in a dry state where the coating is dried. However, since the conventional coating thickness measuring device measures the coating thickness in the dry state after drying, the coating in the dry state must be performed several hours or more equivalent to the drying time after applying the coating. There is a problem that the film thickness cannot be obtained and information on the coating film thickness cannot be fed back promptly. Even if the measurement of the dry film thickness after drying reveals that the film thickness is not optimal, the coating performed within a few hours before drying is performed is not optimal. In some cases, there is a problem that painting needs to be performed again.

[0006] The present invention has been made in view of the above,
It is an object of the present invention to provide a coating film thickness measuring device capable of measuring a coating film thickness in a wet state immediately after coating and estimating a dry coating film thickness from the wet coating film thickness.

Another object of the present invention is to measure the coating thickness and sharpness of a wet coated surface immediately after coating, and determine the dry coating surface based on the coating thickness and sharpness of the wet coated surface. An object of the present invention is to provide a coating film thickness measuring device which can estimate a coating film thickness and sharpness, and can estimate a coating characteristic and an optimum coating film thickness from both information.

[0008]

In order to achieve the above object, a coating film thickness measuring apparatus according to the present invention comprises: an image pickup means for picking up an image of the roughness of an undried painted surface immediately after a paint is applied; Input means for inputting coating conditions including information; and wet coating film thickness calculating means for calculating a wet coating film thickness using a smoothing theory of surface roughness from the coating conditions and surface roughness information imaged by the imaging means. And a dry paint film thickness calculating means for calculating a dry paint film thickness based on the wet paint film thickness calculated by the wet paint film thickness calculating means and the applied paint solid content ratio information of the above-mentioned coating conditions. And

Further, the coating film thickness measuring apparatus of the present invention comprises an image pickup means for picking up an image of the roughness of an undried coated surface immediately after coating with a paint, and an image processing means for image processing image information from the image pickup means. An input unit for inputting a coating condition, a wet sharpness calculating unit for calculating the sharpness of a wet coated surface based on the image information processed by the image processing unit and the coating condition, and the wet coated surface. Dry sharpness estimating means for estimating the sharpness of the dry painted surface from the sharpness of the
Wet coating film thickness calculating means for calculating the wet coating film thickness using the smoothing theory of the surface roughness from the coating conditions and the surface roughness surface imaged by the imaging means, and calculated by the wet coating film thickness calculating means A dry coating film thickness calculating means for calculating a dry coating film thickness based on the wet coating film thickness and the coating composition solid content ratio information of the above-mentioned coating conditions, and the sharpness of the wet coated surface and the dry coated surface and the wet coating A paintability judging means for judging paintability based on the film thickness and the dry paint film thickness, calculating an optimum paint film thickness, and calculating a deviation of the dry paint film thickness with respect to the optimal paint film thickness; A control means for controlling the coating conditions based on a deviation of the dry coating film thickness from the film thickness.

[0010]

According to the coating thickness measuring apparatus of the present invention, the wet coating film thickness is calculated from the surface roughness information obtained by imaging the roughness of the undried coating surface immediately after coating and the coating condition using the smoothing theory of the surface roughness. Then, the dry coating film thickness is calculated based on the wet coating film thickness and the coating solid content ratio information of the coating conditions.

Further, the coating thickness measuring apparatus of the present invention calculates the sharpness of a wet coated surface based on image information obtained by imaging the roughness of the undried coated surface immediately after coating and the coating conditions, and calculates the wet coating. Estimating the sharpness of the dry painted surface from the sharpness of the surface, calculating the wet coating film thickness using the smoothing theory of the surface roughness from the coating conditions and the imaged surface roughness information, this wet coated film Calculates the dry coating thickness based on the coating composition solid content information of the thickness and coating conditions, and evaluates the sharpness of the wet painted surface and the dry painted surface, and the paintability based on the wet painted film thickness and the dry painted film thickness. By making a judgment, the optimum coating thickness is calculated, the deviation of the dry coating film thickness from the optimum coating thickness is calculated, and the coating conditions are controlled based on this deviation.

[0012]

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 coating film thickness measuring apparatus according to a first embodiment of the present invention. The wet film thickness measuring apparatus according to the first embodiment shown in FIG. 1 is provided so as to face the object 1 to be coated, and images the surface of the object 1 to be coated to obtain a rough surface. It has an imaging unit 2 that obtains information. In the present embodiment, the image pickup unit 2 is of an explosion-proof type as a measure against static electricity, and the work 1 is coated with an overcoat paint.

The information on the roughness of the surface of the workpiece 1 picked up by the image pickup unit 2 is supplied to an image processing unit 3. The image processing unit 3 includes various image processing programs, an image analysis sequence program, a waveform analysis program, and the like. The image processing unit 3 performs image processing on the surface roughness information supplied from the imaging unit 2, and performs frequency analysis (FFT) of power spectrum and long wave. Is performed, and the surface roughness information is supplied to the power spectrum integral value calculation unit 21 as power spectrum data.

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 wet film thickness calculating section 22. The wet film thickness calculator 22 performs wet coating using a smoothing theoretical formula using the power spectrum P based on the coating conditions input from the input device 8 in addition to the power spectrum integrated value P _i and the long wavelength λ. The thickness h is calculated.

The wet film thickness h calculated by the wet film thickness calculator 22 is supplied to a dry film thickness calculator 23. In addition to the wet coating thickness h, the input coating device 8 supplies the coating solid content ratio information of the coating conditions, that is, the coating NV information (non-boller information) to the dry coating thickness calculating unit 23. .

The NV information includes a paint NV and a paint NV.
The paint NV is calculated by placing a fixed amount of paint on an aluminum foil whose weight has been measured in advance, and measuring the weight before and after drying (aluminum weight method). The coating NV is basically measured using the same aluminum gravimetric method as the coating NV.
On coating line flowing a sample carrying the aluminum foil, it is calculated by measuring the weight before and after drying of painted aluminum foil immediately after coating _{t (t = t 1, t} 2, t 3).

When supplied with the wet film thickness h and the NV information, the dry film thickness calculating section 23 estimates the dry film thickness h 'based on the information. The wet coating thickness h and the dry coating thickness h ′ are displayed on the display 10 and printed by the plotter 11.

The calculation of the wet coating thickness h 'and the dry coating thickness h' based on the NV information in the dry coating thickness calculating section 23 is performed by the following equation.

H ′ = h × (NV value) Next, the derivation of the theoretical equation for smoothing using the power spectrum P will be described.

[0021] First, when describing the smoothing characteristics of the power spectrum P, the surface roughness R _a and the power spectrum integral value P _i, has a following relationship.

P _i = P _o + k × R _a ^1/2 (1) R _a = {(P _i −P _o ) / k} ² (2) 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) (3) By substituting equation (2) into equation (3),

１ (P _i −P _o ) / k｝ ² = ｛(P _io −P _oo ) / k｝ ² exp (−t / τ) (4) where P _io is P _i the initial value of, P _oo is the initial value of P _o.

[0024] _{Therefore, P = P o · exp (} -t / 2τ) ... (5) _{However, P = P i -P o,} τ = 3ηλ 4 / 16π 4 γh 3
It is.

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

[0026]

(Equation 2) Here, τ ′ _i = 3ηiλ ⁴ / 16π ⁴ γ.

Next, the operation of the embodiment of FIG. 1 will be described.

When the surface of the coating film of the object 1 is imaged by the imaging unit 2 and the surface roughness information after the application of the paint is measured, this information is input to the image processing unit 3 where it is subjected to image processing and frequency analysis ( The power spectrum data is supplied to the power spectrum integral value calculation unit 21 as FFT) processing and power spectrum data for each 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 supplied to the wet film thickness calculator 22. The coating conditions are input from the input device 8 to the wet film thickness calculating section 22. The wet coating film is calculated from the information, the power spectrum integrated value P _i and the long wavelength λ from the power spectrum integrated value calculating section 21 as described above. The thickness h is calculated.

The wet coating thickness h is supplied to the dry coating thickness calculating section 23, and the dry coating thickness calculating section 23 calculates the NV based on the NV information from the input device 8 and the wet coating thickness h as described above. Estimate the dry coating thickness h '. The estimated dry film thickness h ′ and the wet film thickness h are displayed on the display 10 and printed by the plotter 11.

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

The coating film thickness measuring device shown in FIG. 2 is different from the coating film thickness measuring device for estimating the dry coating film thickness from the wet coating film thickness in the embodiment shown in FIG. A dry sharpness computing unit 61, a paintability determining unit 63, and a painting condition control system 65 are added, whereby the sharpness of the dry painted surface is estimated from the sharpness of the wet painted surface, and these sharpness and The paintability was determined from the dry paint film thickness and the optimum paint film thickness was calculated, and the deviation of the dry paint film thickness from the optimal paint film thickness was calculated, and the deviation was fed back as the paint condition. The difference is that the same components as those shown in FIG. 1 are denoted by the same reference numerals.

In the embodiment shown in FIG. 2, the image-processed surface roughness information from the image pickup unit 2 is stored in the wet sharpness calculating unit 41.
And supplied to the power spectrum integral value calculation unit 21.

The wet sharpness computing unit 41 determines the sharpness, ie, smoothness, of the wet painted surface based on the image processing data from the image processing unit 3 and the painting conditions including the paint color and the like supplied from the input device 8. , And the sharpness including the glossiness and glossiness are calculated, and the sharpness is supplied to the dry sharpness calculating unit 61. The dry clarity computing unit 61 estimates the clarity of the dry painted surface, which is the final coating quality, based on the clarity of the wet painted surface supplied from the wet clarity computing unit 41, and The sharpness of the surface and the sharpness of the wet painted surface are supplied to the paintability determining unit 63.

Here, the comparison of the sharpness of the wet painted surface and the sharpness of the dry painted surface will be described.

The smoothness of the sharpness will be described.
As shown in FIG. 3, the numerical value of the smoothness of the wet painted surface is low immediately after application, but gradually increases with time according to the smoothing theory. This tendency basically continues even after drying. Therefore, the smoothness of the target value of the wet coated surface is reduced to the value of the dry coating surface, the smoothness of the wet coated surface and H _w, when the smoothness of the dry coating surface and H _d, shown in the following equation Become like

H _d = K ₁ · H _w (7) Here, K ₁ is a wet smoothing coefficient and is a value larger than ₁ (K ₁ > 1). The target value of the smoothness of the wet painted surface is as follows.

H _w ≧ 0.5 (8) Next, the durability will be described. As shown in FIG. 4, the wet-keeping property of the wet-painted surface increases immediately after application, but after drying, on the other hand, the wet-keeping property decreases due to rough skin during baking. Therefore, the target value of the meat has properties of wet coated surface is higher than the value of the dry coating surface, the meat has properties of wet coated surface and N _w, when the meat has properties of dry paint surface and N _d, the following equation It becomes as shown in.

N _d = K ₂ · N _w (9) Here, K ₂ is a coefficient of wet stickiness and is a value smaller than 1 (K ₂ <1). The target value of the durability of the wet painted surface is as follows.

N _w ≧ 1.0 (10) The gloss, that is, the gloss, will be described. As shown in FIG. 5, the glossiness of the wet-painted surface is numerically greater immediately after application, as in the case of the fleshyness, but after drying, the glossiness is reduced due to rough skin due to baking. T _w for glossiness of wet painted surface
Assuming that the glossiness of the dry painted surface is _Td , the following expression is obtained.

Td = K3 · Tw (11) Here, K3 is a wet glossiness coefficient, and is a value smaller than 1 (K3 < 1). The target value of the glossiness of the wet painted surface is as follows.

T _w ≧ 0.6 (12) On the other hand, the power spectrum integral value calculation section 21 calculates a power spectrum integral value P _i corresponding to roughness and a long wavelength λ from the power spectrum data from the image processing section 3. Then, it is supplied to the wet film thickness calculator 22. Wet film thickness calculator 2
2 is based on the coating conditions input from the input device 8 in addition to the power spectrum integral value P _i and the long wavelength λ,
The wet coating thickness h is calculated by using a smoothing theoretical formula using the power spectrum P. This wet coating thickness h
Is supplied to the dry film thickness calculating section 23, and the input device 8 provides information on the coating composition solid content ratio of the coating conditions, that is, the coating N
The dry film thickness h ′ is estimated based on the V information (non-bora information), and the dry film thickness h ′ and the wet film thickness h are supplied to the paintability determining unit 63.

The paintability judging section 63 is provided with the clarity of the dry painted surface supplied from the dry clarity computing section 61 and the clarity of the wet painted surface and the dry paint supplied from the dry film thickness computing section 23. Based on the film thickness h 'and the wet film thickness h, the paintability (quality) of the painted surface is determined, the optimum film thickness is calculated, and the deviation of the dry film thickness h' from the optimum film thickness is calculated. calculate. The coating thickness deviation information is supplied to the coating condition control system 65, and the coating thickness deviation, the dry coating thickness, the wet coating thickness, the clarity of the dry coating surface, and the clarity of the wet coating surface are provided. Is output to the display 10 and the plotter 11 to be displayed and printed, respectively.

The coating condition control system 65 controls, for example, coating conditions based on the coating thickness deviation information supplied from the coating quality judging section 63, and thereby performs feedback control so as to obtain the optimum coating thickness and coatability. I do.

It should be noted that the wet coating quality is determined with respect to the target values of the above-mentioned equations (8), (10) and (12) for the smoothness of the sharpness, the stickiness and the gloss. The coating quality is determined based on a clear image value or quality. In addition, the calculation of the optimum coating film thickness value is performed in the actual production line as shown in FIGS.
Correlation between wetness and dryness of each image sharpness as shown in FIG. 5 and measurement of the film thickness at that time ensure the target value of the image sharpness and determine the thinnest possible film thickness. The optimum coating thickness is h _o . In the examples of FIGS. 3 to 5, the target optimum coating thickness h _o is about 40 to 45 μm. Therefore,
When the coating thickness of the coated surface that has cleared the target sharpness is h, the coating thickness deviation becomes as follows.

Δh = h−h _o (13) Then, the coating thickness deviation h _o is determined by the coating condition control system 6.
5 will be fed back.

In each of the embodiments described above, the method using the smoothing theory using the power spectrum to calculate the wet coating film thickness is described. However, the method for calculating the wet coating film thickness is as follows. Not limited to this method, various methods such as a method using a peak-to-peak value of the roughness of the painted surface, a method using the degree of roughness of the painted surface, a method using a smoothing initial value, and the like are used. Next, each of these methods will be described.

FIG. 6 is a block diagram showing the configuration of a third embodiment of the present invention. In this embodiment, the wet coating film thickness is measured using the peak-to-peak value of the roughness of the coating surface. It is.

The configuration of the wet coating thickness measuring apparatus shown in FIG. 6 will be described. In FIG. 6, an object 1 to be coated is coated.
Is provided with a non-contact light interference type surface roughness meter 4 which constitutes a roughness measuring means facing the surface. In this embodiment, the top coat is also applied to the object 1 to be coated.

As shown in FIG. 7, the surface roughness meter 4 allows the light generated from the light source 13 to pass through the pinhole and the 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 workpiece 1 from the surface roughness meter 4 is supplied to an image processing device 5 constituting a controller 9, where the image 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.

Here, the film thickness calculation processing device 7 is configured to calculate the wet coating film thickness. By adding the processing function of the calculation unit 23 shown in FIG. 1 or FIG. The dry coating film can be estimated. Then, it is needless to say that this embodiment can be applied to the first and second embodiments shown in FIG. 1 or FIG.

Next, the operation of the embodiment shown in FIG. 6 will be described with reference to the flowchart shown in FIG.

In FIG. 8, 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).

The acquisition of the surface roughness information is performed repeatedly 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 the 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 of the surface of the object 1 to be coated by the coating film roughness smoothness processing device 6 in step 180 and the film thickness calculation processing device in step 200 7 will be described with reference to FIG. 9 and subsequent figures.

The coating surface in the wet state immediately after the coating is applied to the surface of the object 1 has a large roughness,
This surface state can be represented by surface irregularities a and a wavelength λ as shown in FIGS. 9A and 9B.

The surface irregularities in the wet state immediately after the application shown in FIG. 9A are smoothed over time as described above, and the dynamic characteristics of this surface smoothing are as shown in FIG. 9A. 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.

[0060]

D / dt = (− h ³ γ) / (3η) × (2π / λ) ⁴ a (14) a = a _o · exp −t / τ (15) τ = 3ηλ ⁴ / ( 16π ⁴ × γh ³ ) (16) Actually, the viscosity of the coating film after application of the paint is shown as an example as shown in FIG. 10 under the condition that the atomizing air pressure, the solvent, the viscosity before application, and the temperature are constant. Is done. In FIG. 10, the horizontal axis represents the elapsed time after application of the paint, and the vertical axis represents the coating film viscosity η.
η0 and η1 represent the viscosity value before application and the initial viscosity value immediately after coating, respectively.

Accordingly, as shown in FIG. 10, since the viscosity immediately after application of the paint changes with time, the above formulas (14) to (14) are used.
For the viscosity η of (16), it is necessary to use a correction value such as the following equation.

Η = η ₁ + Kt (17) 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. 11, the peak-to-peak values of the unevenness of the coating surface at times t ₁ and t ₂ immediately after application of the coating material are a ₁ and a ₂ , respectively.
, And the case where the wavelength of the unevenness is lambda _12, expressed by the following equation. Note that λ ₁ = λ ₂ = λ ₁₂ .

[0064]

Equation 4] _{a 1 = a 0 exp (-t} 1 / τ 1) ... (18) τ 1 = {3 × η (t 1) × λ 12 4} / (16π 4 × γ × h 3) ... ( _{19) a 2 = a 0 exp} (-t 2 / τ 2) ... (20) τ 2 = {3 × η (t 2) × λ 12 4} / (16π 4 × γ × h 3) ... (21) When the coating thickness h is calculated from the above equations (18) to (21),
Dividing equation (18) by equation (20) gives:

[0065]

A ₁ / a ₂ = exp (−t ₁ / τ ₁ + t ₂ / τ ₂ ) (22) ₁ na ₁ / a ₂ = (− t ₁ / τ ₁ + t ₂ / τ ₂ ) (23) Then, the paint film thickness h is obtained from the equations (19), (21) and (23) as follows.

[0066]

[6] _{h = {(1na 1 / a} 2) / (- t 1 / τ 1 '+ t 2 / τ' 2)} 1/3 ... (24) τ 1 '= (3η 1 × λ 12 4) ^{/ (16π 4 γ) ... (} 25) τ 2 '= (3η 2 × λ 12 4) / from ^{(16π 4 γ) ... (26} ) these equations (24) - (26), immediately after the paint application time t ₁ and t ₂ , the roughness of the painted surface a ₁ and a ₂ and the wavelength λ ₁₂ Is measured, the coating film thickness h can be calculated.

Similarly, the equation (14) is changed to da / dt = (a ₂
−a ₁ ) / (t ₂ −t ₁ ), and by adding equation (17),
It is also possible to calculate the coating film thickness h.

[0068]

(Equation 7) It is necessary to select either equation (24) or equation (27) depending on the measurement system.

FIG. 12 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.
μ, which is a value almost close to the actually measured value.

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

In the fourth embodiment shown in FIG. 13, the wet coating thickness measuring device is the same as the coating roughness smoothness calculation processing device 6 constituting the controller 9 in the third embodiment shown in FIG.
Is different from the first embodiment in 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 fourth 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 third 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 as the roughness degree and wavelength, the average roughness degree R _a and mean wavelength lambda _a,
Or root mean square R _q and root mean square wavelength λ
_You are using _q .

Here, similarly to the third embodiment shown in FIG. 6 described above, the film thickness calculating device 7 is configured to calculate the wet coating film thickness. By adding the processing function of the calculation unit 23 shown in FIG. 2, a dry coating film can be estimated. Then, it is needless to say that this embodiment can be applied to the first and second embodiments shown in FIG. 1 or FIG.

Next, with reference to the flowchart shown in FIG. 14, the operation of the embodiment shown in FIG. 13.

FIG. 14 is a flowchart showing the operation of the fourth embodiment.
Is different from the flowchart of the third embodiment in 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. Only.

In the wet film thickness measuring apparatus of the fourth embodiment shown in FIGS. 13 and 14, 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. 14) 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 (28) to (33) corresponding to the above equation (24) (step) 200).

[0077] That is, the above-described formula (24) is 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.

[0078]

H = {(1nR _a1 / R _a2 ) / (− t ₁ / τ ₁ '+ t ₂ / τ ₂ ')} ^1/3 (28) τ ₁ '= (3η ₁ × λ _a ) / ^{(16π 4 γ) ... (29} ) τ 2 '= (3η 2 × λ a) / (16π 4 γ) ... (30) h = {(1nR q1 / R q2) / (- t 1 / τ 1' + t ₂ / τ ₂ ′)｝ ^1/3 (31) τ ₁ ′ = (3η ₁ × λ _q ) / (16π ⁴ γ) (32) τ ₂ ′ = (3η ₂ × λ _q ) / (16π ⁴ γ) ... (33) FIG. 15 is a graph showing the smooth Kado characteristics of the surface roughness of the surface roughness of the vertical axis with respect to the elapsed time after paint application indicated on the horizontal axis R _a, R _q Is shown. From the same figure, after application 6
It can be seen that the smoothed dynamic characteristics at 0 to 100 seconds are almost the same as the theoretical values and the measured values with respect to the roughness (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.

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

The fifth embodiment shown in FIG. 16 is for measuring the thickness of the wet coating film. The fifth embodiment shown in FIG. 13 is different from the fourth embodiment shown in FIG. 7 except that a smoothing initial value estimating device 18 is provided between the control device 7 and the paint condition information from the input device 8 is input to the smoothing initial value estimating device 18. And the function is the same. The wet coating thickness measuring apparatus of the fifth 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.

Here, similarly to the third embodiment shown in FIG. 6 described above, the film thickness calculation processing device 7 is configured to calculate the wet coating film thickness. By adding the processing function of the calculation unit 23 shown in FIG. 2, a dry coating film can be estimated. Then, it is needless to say that this embodiment can be applied to the first and second embodiments shown in FIG. 1 or FIG.

FIG. 17 is a flowchart showing the operation of the fifth embodiment.
In the flowchart of the fourth embodiment shown in FIG. 4, 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 wet coating film thickness measuring apparatus of the fifth embodiment shown in FIGS. 16 and 17, the surface roughness calculating processor 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.

[0085] irregularities peak-to-peak value a _o immediately after coating the above-described (18) equation, the following equation.

A _o = a ₁ exp (t ₁ / τ ₁ ) (34) Note that τ ₁ and η ₁ (t ₁ ) in this equation are those shown in the aforementioned equations (17) and (19), respectively. Is the same as

[0087] 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 (34) (where, as a cancer properties constant).

Further, for example, when the coating film thickness h = 60 μm and the wavelength λ = 6 mm, the peak-to-concave 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 the coating shown in FIG.

Λ ⁴ / h ³ = K _o (constant) (35) 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 mentioned above (34), (19), (17), can be determined in advance before using equation (35). 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 calculating device 7, and the coating film thickness h is calculated (step 200).

The calculation of the coating thickness h will be described.

[0092] 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 (24) to (26).
Thus, the following equation can be obtained.

[0093]

H = {(1na ₀ / a ₁ ) / (− 0 / τ ₀ + t ₁ / τ ₁ ') ^1/3 = {(1na _o / a ₁ ) / (t ₁ / τ ₁ ')} ^1/3 (36) τ ₁ ′ = (3η ₁ × λ ⁴ ) / (16π ⁴ γ) (25) η ₁ = η ₀ + Kt ₁ (17) The above (36), (25), ( 17) From the formula, the coating thickness h
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 fifth embodiment, 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.

[0095]

H = {(1nR _a0 / R _a1 ) / (t ₁ / τ ₁ ′)} ^1/3 (37) τ ₁ ′ = (3η ₁ × λ _a ⁴ ) / (16π ⁴ γ) (38) h = {(1nR q0 / R q1) / (t 1 / τ 1 ')} 1/3 ... (39) τ 1' = (3η 1 × λ q 4) / (16π 4 γ) ... ( 40)

[0096]

As described above, according to the present invention,
The wet coating thickness is calculated from the surface roughness information obtained by imaging the roughness of the wet coating surface immediately after coating and the coating conditions using the smoothing theory of surface roughness, and the wet coating thickness and coating conditions are applied. The dry paint film thickness is calculated based on the paint solid content ratio information, so the paint film thickness of the dry paint surface can be quickly estimated from the wet paint surface immediately after painting, and the dry paint film thickness is applied. Feedback to conditions can be quickly performed, and the stability of coating quality can be improved.

Further, according to the present invention, the sharpness of the wet painted surface is calculated based on image information obtained by imaging the roughness of the undried painted surface immediately after the painting and the painting conditions, and the sharpness of the wet painted surface is calculated. Estimate the sharpness of the dry coated surface from the properties, calculate the wet coating thickness using the smoothing theory of the surface roughness from the coating conditions and the imaged surface roughness information, this wet coating film thickness and coating conditions The dry paint film thickness is calculated based on the paint solid content ratio information, and the paintability is determined based on the sharpness of the wet paint surface and the dry paint surface and the wet paint film thickness and the dry paint film thickness. The optimum film thickness is calculated, the deviation of the dry coating film thickness from the optimum coating film thickness is calculated, and the coating conditions are controlled based on this deviation. Quick film thickness It is possible to quickly give feedback to the coating conditions of the dry film thickness, improve the stability of coating quality, and also prevent excessive quality, that is, waste of paint, Economy can also be achieved.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a configuration of a coating film thickness measuring apparatus according to a second embodiment of the present invention.

FIG. 3 is a graph showing a comparison between wet smoothness and dry smoothness.

FIG. 4 is a graph showing a comparison between wet meat holding property and dry meat holding property.

FIG. 5 is a graph showing a comparison between wet glossiness and dry glossiness.

FIG. 6 is a block diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 7 is a view showing a configuration of a surface roughness meter used in the wet coating film thickness measuring device of FIG.

FIG. 8 is a flowchart showing the operation of the wet coating film thickness measuring device of FIG.

FIG. 9 is a diagram showing an uneven state of a coating surface in a wet state immediately after coating.

FIG. 10 is a graph showing the relationship between coating film viscosity and setting time.

FIG. 11 is a graph showing a dynamic characteristic of smoothing a wet film thickness.

FIG. 12 is a graph comparing measured values of a top coating with theoretical values.

FIG. 13 is a block diagram showing a configuration of a wet coating film thickness measuring apparatus according to a fourth 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 is a graph showing a smoothing dynamic characteristic of a surface roughness.

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

FIG. 17 is a flowchart showing the operation of the wet coating film thickness measuring device of FIG.

FIG. 18 shows a comparison between a theoretical value of a smoothing dynamic characteristic and a measured value.
It is a graph shown by -p) value.

FIG. 19 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 8 input device 21 power spectrum integral value calculation unit 22 wet film thickness calculation unit 23 dry film thickness calculation unit 41 wet sharpness calculation unit 61 dry sharpness calculation unit 63 painting Sex determination section 65 Painting condition control system

Claims (2)

(57) [Claims] 1. An imaging means for imaging the roughness of an undried painted surface immediately after a paint is applied, an input means for inputting a coating condition including component information of the paint, and an imaging by the coating condition and the imaging means. Wet coating film thickness calculating means for calculating the wet coating film thickness using the smoothing theory of the surface roughness from the obtained surface roughness information, and the wet coating film thickness calculated by the wet coating film thickness calculating means and the coating conditions A dry coating film thickness calculating device for calculating a dry coating film thickness based on information on a coating solid content ratio. 2. An image pickup means for picking up an image of the roughness of an undried coating surface immediately after coating with a paint, an image processing means for image processing image information from the image pickup means, and an input means for inputting coating conditions. Wet sharpness calculating means for calculating the sharpness of the wet-painted surface based on the image information image-processed by the image processing means and the coating condition, and sharpness of the dry-painted surface based on the sharpness of the wet-painted surface. Dry sharpness estimating means for estimating image quality, and wet coating film thickness calculation for calculating a wet coating film thickness using a smoothing theory of surface roughness from the coating conditions and surface roughness information imaged by the imaging means. A dry coating film thickness calculating means for calculating a dry coating film thickness based on the wet coating film thickness calculated by the wet coating film thickness calculating means and the applied paint solid content ratio information of the coating conditions; Judging the paintability based on the sharpness of the wet painted surface and the dry painted surface and the wet painted film thickness and the dry painted film thickness, and calculating the optimal film thickness,
The paintability determining means for calculating a deviation of the dry coating film thickness with respect to the optimum coating film thickness, and a control means for controlling the coating conditions based on the deviation of the dry coating film thickness with respect to the optimum coating film thickness. Characteristic coating film thickness measuring device.