JPS5880506A - Coat thickness meter - Google Patents

Abstract

PURPOSE:To continuously measure coat thickness when coating and to control coat thickness easily and exactly, by computing it from irradiation of high frequency waves and measurement of reflected waves. CONSTITUTION:A coat thickness meter consisting of an oscillator 4, receiver 6, computer 7, converter 8, display device 9, etc. is attached to a coater 1. It computes the thickness wet coat 5 through emitted high frequency waves and received reflected waves, converts it in accordance with an angle of the coater 1, the kind of coating material, components of its volatile metter, etc., and displays its dry coat thickness on the device 9, thus permitting easy and exact control of coat thickness to be executed by this method of coating and simultaneous measuring coat thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a coating film thickness measuring device that facilitates the management of coating film thickness by measuring the wet coating film when painting large structures such as the outer panels of ships. Regarding.

Conventionally, large structures such as ships have been painted using a coating machine (1) consisting of an airless spray gun or air spray gun (hereinafter referred to as spray gun), as shown in Figure 1. A coating film (3) is formed on the surface of the dust receiving body (2).

By the way, one of the management methods for achieving the intended purpose of rust prevention, which is the original purpose of coating, is 11 coating film thickness management.

However, conventionally, this coating thickness management has been done by measuring the coating thickness after the coating has dried using a measuring device that uses electromagnets, permanent magnets, ultrasonic waves, etc. Painting is being done again. Furthermore, in this case, it is impossible to cover all the measurement points, and therefore, the current situation is that the inspection is carried out at one point every several square meters. Therefore, in this case, it cannot be said that the coating film thickness is completely controlled; 1. Furthermore, the more severe the coating thickness control, the more labor and time are required for this coating film thickness inspection and repainting.

This invention was made with the above points in mind,
The coating machine itself is equipped with a device or tool that measures coating film thickness using high frequency waves such as ultrasonic waves or laser beams, and the coating thickness can be controlled by sequentially measuring coating thickness while painting. This invention can be used to eliminate the work of coating film thickness measurement and repainting, which conventionally required a lot of labor and time. This will be explained in detail with reference to the drawings.

As shown in Figure 2, a coating machine (1
), a high frequency transmitter (4) that projects high frequency waves such as ultrasonic waves or laser beams, and a wet coating film (5) on the surface of the object to be coated (2) formed by the coating machine (1) and a high-frequency receiver (6) that receives the high-frequency reflected wave from the surface of the object to be painted (2); and a computer that calculates the film thickness of the wet coating film (5) from the high-frequency projected wave and the reflected wave. (7), a converter (8) that converts the thickness of the dry coating film from the thickness of the wet coating film (5), and an indicator (9) that displays the thickness of the dry coating film are integrated. It has a function that allows input of the specific gravity of the paint used, the specific gravity of the volatile content, the ratio of volatile content in the paint, etc., and is housed in an explosion-proof case that does not ignite the volatile content in the paint. It has a built-in microcomputer to make it compact and lightweight.

By the way, the coating thickness measured during painting is a wet coating thickness, which is different from a dry coating thickness.

However, since there is a relationship between the dry coating thickness and the wet coating thickness, the dry coating thickness can also be determined by measuring the wet coating thickness.

Dry coating thickness Dd = W (λ-1□□) = ADw (x-E) Here, A is the specific gravity of the paint, and W is the amount of coating (g/ff11)
, B is the specific gravity of volatile matter, S is the proportion of volatile matter in the paint (g)
It is.

Next, the dry paint film thickness can be displayed numerically, or, for example, if 100 houses are painted with a dry paint film thickness, the dry paint film thickness is 100.11 times (at the time when the paint is applied) an audible alarm is displayed on the display device. or give a visual alarm. In this case, a film thickness setting switch is required.

In addition, as a method for measuring the wet coating film thickness, it is necessary to be able to measure the wet coating film thickness without directly touching the coating film due to the functionality of this device. 2) Irradiate the surface and calculate the coating thickness from the reflected wave.

On the other hand, in order to improve the adhesion of paint to the object to be painted (21), as shown in FIG.
~45p In terms of coating thickness management and rust prevention, it is desirable to maintain the film thickness A from the convex portion to the coating surface at a predetermined value.

Therefore, when measuring the wet coating thickness, a function is provided to automatically eliminate high-frequency reflected waves from the recesses as noise, as shown in FIG.

In addition, when painting, the spray gun is not always directed at right angles to the surface of the object to be painted (2), so even if the spray gun is tilted diagonally toward the surface of the object to be painted (2), the true Make it possible to measure the coating thickness. This is because the surface of the paint film is almost smooth, so the tilt of the spray gun is calculated based on the waves reflected from the paint film surface, and the true wet paint film thickness is derived.

Furthermore, when a spray gun paints, it applies the first frost over a certain area, and as shown in Figure 5, the paint pattern requires some overlap between the passes of the spray gun and the bath. The cross-sectional shape of the coating film is thought to be as shown in FIG. 5(a).

Therefore, it is considered safe to measure the coating film thickness at approximately the center of the initial frost range of the coating.

Next, conventional paint film management is total paint film thickness management, and as shown in FIG. 6, the total paint film thickness B is measured after the final coating is performed. This is because the coating film thickness measuring instruments commonly used in the past cannot measure the film thickness between the surface of the object to be coated (steel) and the surface of the dried coating film. That is, it is not above the previously applied coating (51 or (5)").

Incidentally, in recent years, from the viewpoint of energy conservation, strict control of coating film thickness has been required for coating the outer panels of ships. Then, it is necessary to apply anti-corrosion paint and anti-fouling paint, each with a different performance, to the hull outer panels, especially the bottom and boot top, and measure the coating film for each paint. I was managing the paint film.

First, when applying anti-corrosion paint, the object to be painted (stay)
Measure the film thickness from the surface of the rust preventive coating to the surface of the rust preventive coating. Next, when antifouling paint is applied, the body to be coated/covered (stay)
Measure the total film thickness from the surface to the surface of the antifouling coating. Then, the coating thickness of the antifouling paint is calculated by subtracting the former coating thickness from the latter coating thickness. However, measuring the coating film thickness twice in this way requires a great deal of effort and time.

However, in this invention, since irradiated waves and reflected waves having high frequencies are used, coating films (5) and (5) in FIG.
The film thicknesses C and D can also be measured during coating, respectively. Furthermore, since the measurement is performed during painting, a predetermined film thickness can be easily ensured. Therefore, even when coating paints with different properties overlappingly, the thickness of each coating can be easily controlled.

Next, the principle of film thickness measurement using high frequency will be explained.

If a continuous wave whose frequency is modulated is used as the irradiated wave S, as shown by the solid line in Fig. 7fa), the reflected wave T shown by the broken line
is obtained, and the frequency difference as shown in the figure is obtained,
The distance corresponding to time P in the figure is the distance between the transmitter (4), the receiver (6), and the subject.

As shown in Fig. 8, the irradiated waves emitted from the transmitter (4) are diffusely reflected by the anchor pattern or the coating surface. Only the reflected waves incident on the waveform are used, and the rest are eliminated as noise.

When the coating film is formed on the object to be painted, the ninth
As shown in Figure (a), the irradiated wave S produces a reflected wave T' from the surface of the coating film and a reflected wave T'' from the surface of the object to be painted, and as shown in Figure (b). Such a frequency difference is obtained, and the length corresponding to the time P' in the figure is obtained as the coating film thickness.

Next, processing of reflected waves from the anchor pattern and the irregularities on the surface of the coating film will be explained.

As shown in Fig. 1O (a), when the irradiation wave is incident on the anchor pattern, the irradiation wave S causes a reflected wave T from the top of the anchor pattern, as shown in Fig. 1(b).
I is obtained, and the reflected waves T2°T3 . ...
is obtained, and the reflected wave Tn from the bottom of the anchor pattern is
is obtained. Then, the average value of the reflected waves T1 and Tn is defined as the reflected wave from the anchor pattern. Furthermore, for reflected waves from unevenness on the surface of the coating film, the average of the unevenness is taken as the reflected wave.

Next, as shown in FIG. 11, correction will be explained when the object to be coated (2) is inclined with respect to the measurement instruments of the transmitter (4) and receiver (6).

Since high frequency waves such as ultrasound or laser beams have very good directionality, the distance d between the top 0 and bottom (T) of the measuring instrument does not change up to a certain distance.

Now, the object to be coated (2) is two-dimensional with respect to the measuring instrument.
A'-B' θ = -□ Here, A' is the distance from the top of the measuring instrument (B) to the objects to be painted, B' is the distance from the bottom of the measuring instrument to the objects to be painted, The frequencies emitted from the top 0 and the bottom (to) are different from the frequencies for coating film measurement. Also, by making the frequencies from the upper part 0 and the lower part different from each other, even if the reflected wave from the leap enters the upper part,
Since the frequencies are different, they are erased as noise.

Next, as shown in FIG. 12, if the object to be painted (2) is three-dimensionally inclined with respect to the measuring instrument, the transmitter,
As shown in Fig. 13, the structure of the receiver is as shown in Fig. 13.A measuring instrument (main unit) consisting of a transmitter for measuring coating film thickness and a receiver is provided in the center, and a measuring instrument (main unit) is provided around it for measuring the inclination of the object to be coated (2). Three measuring instruments (X) and (Y
), (Z) with different frequencies, 8
By measuring the points, the three-dimensional inclination can be calculated, and once the inclination is determined, a that takes the inclination into account can be determined from a' in FIG. 12.

Next, FIG. 14 is a flowchart of coating film thickness measurement.

As described above, according to the coating film thickness measuring device of the present invention, coating film thickness can be easily managed by measuring a wet coating film.

[Brief explanation of the drawing]

Fig. 1 is a side view of a conventional coating device, Fig. 2 and the following drawings show an embodiment of the coating film thickness measuring device of the present invention, Fig. 2 is a side view of the measuring device, and Fig. 3 is an object to be coated. 4 is an explanatory diagram of reflected waves, and FIG. 5(a) is a cross-sectional view of the anchor pattern.
(b) The figure shows the path of the spray gun, a side view, a front view,
Figure 6 is a side view of multi-layer coating, Figures 7 (a) and (b).
) Figure 8 is a frequency diagram showing the principle of film thickness measurement.9 Frequency difference diagram.
The figure is an explanatory diagram of diffuse reflection, and Figures 9(a) and 9(b) are frequency diagrams of coating film thickness measurement. Frequency difference diagram, Figures 10 (a) and 10 (b) are side views showing the processing of reflected waves from unevenness. 1 frequency diagram, Figures 11 and 12 are two-dimensional and 8 An explanatory diagram of correction for dimensional inclination, Figure 13 is the same as Figure 12 (1)
...painting machine, (2) ... object to be painted, (4) ... transmitter, (5) ... wet coating film, (6) ... receiver, (7
)...Arithmetic machine, (8)...Conversion machine. Agent Patent Attorney Ryuta Fujita □ Figure 3 Figure 4 Figure 5 a) (b) Figure 6 Figure 7 Figure 9 Figure 10 CG) (b) Figure 14

Claims (1)

[Claims] ■ A coating machine consisting of a spray gun, a high-frequency oscillator that irradiates high frequency waves to the wet coating film formed on the surface of the object to be coated formed by the coating machine, and the surface of the object to be coated and the surface of the wet coating film. a high-frequency receiver that receives high-frequency reflected waves from the
The present invention is characterized by comprising a calculator that calculates the thickness of the wet coating film from the high-frequency irradiation wave and the reflected wave, and a converter that converts the thickness of the dry coating film from the thickness of the wet coating film. Paint film thickness measuring device.