JPS6014629B2 - Uniform paint coating method on color steel plate manufacturing line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating method in a coating process of a color steel plate production line.

In recent years, colored steel sheets have been used for various purposes, and are being manufactured in large quantities.

In addition, there is a growing demand for high-quality products, and for this purpose, the paint applied to steel plates must be applied with a uniform thickness. Conventionally, rotary gauge method, comb gauge method, lens gauge method, etc. are known as methods for measuring the thickness of paint films on color steel plates, etc., but all of these measurement methods require a gauge. However, there are disadvantages such as low accuracy, human error, fragmentary detection, and inability to perform online control.

The present invention uses an optical detector using a laser beam,
The present invention provides a method for automatically and continuously detecting paint film thickness in units of high precision and controlling the paint film thickness at a constant level by feeding back the measured values.

The following will explain the embodiments shown in the drawings. FIG. 1 is a schematic diagram showing a part of a color steel plate manufacturing line where paint is applied to the surface of a steel plate, where 1 is a steel plate fed in the direction of the arrow, and 2 is a paint tank.

Reference numerals 3 and 3' denote coating rolls, which are constructed in a vertically stacked manner.

The upper roll 3 is in contact with the lower roll 3' with an appropriate rolling force, and is also lightly pressed against the surface of the steel plate, and is suspended so as to be rotatable and adjustable in rolling. The lower roll 3' is rotatably mounted in the paint tank 2 with its lower part immersed in the paint. Reference numeral 4 denotes a paint film, which shows a state in which the paint in the paint tank 2 is transferred from the lower roll 3' to the upper roll 3, and is further applied to the surface of the steel plate.

5 is a film thickness detection device, 9 is a signal processing device, and 10 is a hydraulic or other operating device for adjusting the amount of reduction of the upper roll 3.

Now, the film thickness detection device 5 is composed of a laser transmitter 6 provided obliquely on the surface of the upper roll 3, a reception sensor 7, and an Atsumitsu lens 8, and its principle is explained in FIGS. The detection method will be explained.

As shown in FIG. 2, the laser beam emitted from the transmitter 6 is bent and reflected by the roll surface or the pus surface.

In other words, the bending point is different when there is no paint on the roll surface (solid line A) and when there is paint on the roll surface (broken line B).
Therefore, if you memorize the value of the solid line A when there is no paint, and read the value of the broken line B using the receiving sensor 7 when there is paint left, you can always detect the difference x. be. It is expressed as film thickness L≠voice ma. 8 is the ray entrance and reflection angle.

Next, a specific detection method will be explained with reference to FIG.

First, the upper roll 3 is divided into appropriate sections and a reference point (for example, 0 position) is determined, and then the upper roll 3 is rotated idly without the initial membrane, and the receiving sensor 7 sequentially reads the reflected light at each section point from the reference point. This value is stored in the signal processing device 9. Next, the reflected light beams at each division point of the upper roll 3 are read sequentially from the reference point in the state with the film present, and this value is sent to the signal processing device 9, and the reflected light beams at each division point of the roll in the state without the film stored in the memory are read. The paint film thickness at each division point is detected by comparison with the value corresponding to . Since the roll rotates and coats the steel plate continuously, it is reset by the reference point passing signal every time the upper roll 3 rotates once, and the paint film thickness at each division point is continuously measured from the reference point. can be detected. As described above, the film thickness on the upper roll surface can be detected continuously and with high accuracy. Therefore, by comparing the reference film thickness value to be coated, which is input in advance to the signal processing device 9, with the paint film thickness value detected on the upper roll, it is possible to check whether the coating is being applied as planned. It can be confirmed. If there is a difference value in the comparison of the film thicknesses, the difference is outputted as an operation signal for the lowering force adjustment operation device 1 for the lower roll 3' of the upper roll 3. As a result, the pushing force of the upper roll 3 is adjusted, and the coating thickness can be controlled to a desired value. As described above, the present invention uses an optical film thickness detection device using a laser beam to detect the film thickness with high precision, and controls the coating film thickness by feeding back the detected value. It has the great effect of being able to consistently and uniformly paint the steel plate surface.

In the above description, the film thickness of the upper roll of the coating roll was detected, but the coating thickness on the steel plate surface may also be detected.

Moreover, although the amount of pressure applied to the upper roll is adjusted in order to control the coating film thickness, adjustment can also be made by adjusting the steel plate feeding speed or the like.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a coating section for carrying out the method of the present invention, FIG. 2 is a diagram explaining the principle of an optical film thickness detector, and FIG. 3 is a diagram explaining the film thickness detection method. 1... Steel plate, 3, 3'... Paint roll, 4... Paint film, 5... Film thickness detector, 9.
...Signal processing bag demon, 10... Actuation device. Leopard 1 Illustration Section 2 BI Number Illustration

Claims (1)

[Claims] 1. A film thickness detector consisting of a laser beam transmitter and a receiving sensor detects the paint film thickness on the surface of the paint roller or steel plate, and this detected value is sent to the signal processing device.
A method for uniformly coating paint in a color steel plate production line, characterized in that the thickness of the coating film is made uniform by comparing the thickness with a standard thickness and adjusting and controlling the reduction amount of the coating roll or the feed speed of the steel plate according to the difference value.