JPH0811210B2 - Primer coating state inspection method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for inspecting a coating state of a primer coated on a coating surface of a material to be coated. It is used to inspect the applied state of the primer applied to adhere to the window frame).

[Prior Art and Problems Thereof] In an automobile assembling process, a window glass such as a windshield or a rear glass is attached to a window frame of a vehicle body after a sealing material is applied to its peripheral portion. At that time, the surface of the window glass and the window frame before applying the sealing material are coated with a black primer or the like to increase the reliability of the adhesion. Manipulators are used for automation.

However, in general, the fluidity and surface condition of the primer change significantly depending on the temperature change and the presence or absence of contact with air, etc., and the coating condition also changes due to changes in the discharge amount of the primer and changes in the coating speed. Therefore, it is relatively difficult to carry out quantitative control in the coating process and to coat in a uniform state. Therefore, for example, defects such as scale due to insufficient primer film thickness and scraping due to insufficient primer may occur, which is a cause of defective adhesion.

Therefore, before applying the sealing material, it is necessary to inspect whether or not the primer is normally applied. As an inspection method for this purpose, the applicant of the present invention has disclosed in JP-A-61-242666.
The method of issue was proposed first. In this conventional inspection method, a light projector and a light receiver are arranged with a window glass interposed therebetween, and an increase in the amount of light received by the light receiver is detected to detect a primer application failure.

However, in this conventional inspection method, the material to be applied with the primer cannot be inspected unless it is a light-transmissive material such as a window glass, and it is applied to a body-coated steel sheet such as a window frame. It was not possible to detect poor primer application.

[Technical means for solving problems]

In view of the above problems, the present invention aims to easily and surely inspect the coating state of a primer applied to a material to be coated, regardless of whether or not the material to be coated is light transmissive, and a technique therefor. Means for detecting the temperature of each of the coating portion immediately after the primer is coated on the coating surface of the coating material and the non-coating portion of the coating material to which the primer is not coated by an infrared sensor, It is a method for inspecting the coating state of the primer, in which the coating state of the primer is detected by comparing the temperatures of.

[Work]

Immediately after the primer is applied, the temperature of the application part to which the primer is applied decreases due to the volatilization of the volatile solvent contained in the primer. The infrared sensor detects the temperature of this application part and the temperature of the non-application part where the primer is not applied. The temperatures of these two are compared, and it is detected whether or not the temperature change of the coating portion or the temperature difference between the coating portion and the non-coating portion is normal, and the coating state of the primer is inspected.

〔Example〕

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

FIG. 1 is a block diagram showing an example of the configuration of an inspection apparatus for carrying out the method of the present invention.

In the figure, reference numeral 1 denotes a material to be coated such as a window glass of an automobile. The material to be coated 1 is conveyed by, for example, a conveyor (not shown) and positioned at a coating / inspecting station. In this state, a coating nozzle (not shown) is moved by a manipulator along a predetermined locus, and the primer 2 is coated along the peripheral edge of the coating material 1.

The pyroelectric infrared sensors 3 and 4 are held by the above-mentioned manipulator (not shown) with a certain distance toward the surface 1a of the material to be coated 1, and immediately after the primer 2 is applied. One pyroelectric infrared sensor 3 is moved along the coating locus. Therefore, one pyroelectric infrared sensor 3 detects the temperature of the coating portion A immediately after the primer 2 is applied on the surface 1a, and the other pyroelectric infrared sensor 4 detects the temperature of the primer on the surface 1a. The temperature of the non-application part B which is not applied will be detected.

The outputs of the pyroelectric infrared sensors 3 and 4 are respectively amplifiers.
It is amplified by 5, 6 and is calibrated so that its output voltage corresponds to each temperature, and is input to the operational amplifier 7. In the operational amplifier 7, the output of the amplifier 6 corresponding to the temperature of the non-application section B is used to determine the amplifier 5 corresponding to the application section A.
The output of is subtracted and the differential voltage S2 is output. Operational amplifier 7
The difference voltage S2 from is compared with the reference voltage S3 preset in the setting unit 9 by the comparator 8, and the difference voltage S2 is compared with the reference voltage S2.
When it is smaller than S3, the control signal S1 is output.

The surface temperature of the coating section A is lowered by several tens of degrees due to the volatilization of the volatile solvent contained in the primer 2, which is detected by the pyroelectric infrared sensors 3 and 4 and the detection circuit. When the primer 2 is not applied sufficiently, the temperature difference between the applied portion A and the non-applied portion B becomes smaller than the reference value, and the control signal S1 is output. Predetermined abnormality alarms and measures are performed by the control signal S1.

As a result, a coating defect such as a scale or scraping of the primer is detected, and the coating state is inspected.

FIG. 2 shows an embodiment in which the application state of the primer 12 applied to the surface 11a of the material 11 to be coated on the window frame of an automobile is inspected by one pyroelectric infrared sensor 13.

In the figure, 14 is a mirror, and this mirror 14 is
Infrared rays from the coating portion A coated with the primer 12 and the non-coating portion B not coated with the primer 12 (side surface portion of the window frame 11) are selectively incident on the pyroelectric infrared sensor 13. It is rotationally driven periodically. While the mirror 14 is driven to rotate, the mirror 14 and the pyroelectric infrared sensor 13 are
Similar to the above-described example, the manipulator (not shown) allows the primer 12 to be moved immediately after the application along the application locus.

In this case, the temperature of the coating portion A and the non-coating portion B is detected by one pyroelectric infrared sensor 13, and an error due to a difference in sensitivity of the pyroelectric infrared sensor is reduced.

In the above embodiment, the pyroelectric infrared sensor 3,4,13
A shutter may be provided in front of the pyroelectric infrared sensor in order to prevent the infrared rays from being saturated, and the infrared rays are temporarily prevented from entering by the rotation of the mirror 14 in FIG. Good.

In the above-mentioned embodiment, instead of the operational amplifier 7, the outputs of the amplifiers 5 and 6 are converted into digital signals, which are sampled at an appropriate period, and the obtained data may be analyzed by a microcomputer or the like. Good.

In the above-described embodiment, in order to promote the volatilization of the solvent of the primers 2 and 12 and increase the temperature difference from the non-application part B, the application part A is blown with air, or the application part A and the non-application part B are applied. May be heated by a heater. In this case, the infrared rays from the heater should not be directly incident on the pyroelectric infrared sensor.

Although the pyroelectric infrared sensor is used as the infrared sensor in the above-described embodiments, other infrared sensors such as a thermopile, a thermistor, and a semiconductor sensor may be used.

The present invention can be used for inspecting the coating state of paints, adhesives, etc. containing volatile organic solvents.

〔The invention's effect〕

According to the present invention, it is possible to easily and surely inspect the coating state of the primer applied to the material to be coated, regardless of whether or not the material to be coated is light transmissive. Since the temperature of the coating part and non-coating part is detected by non-contact,
It is possible to inspect even when the coating portion is complicatedly curved, and it is possible to inspect the coating state of the primer applied to a complicated shape such as the body of an automobile.

In addition, the temperature drop due to the volatilization of the solvent of the applied primer is effectively used, and the application state can be inspected in the same step as the step of applying the primer.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an inspection apparatus for carrying out the inspection method of the present invention, and FIG. 2 is a diagram showing another example of temperature detection by an infrared sensor. 1,11 …… Material to be coated, 1a, 11a …… Surface (coated surface), 2,12…
… Primer, 3,4,13 …… Pyroelectric infrared sensor (infrared sensor), 7… Operational amplifier, 8… Comparator, A…
… Applied part, B …… non-applied part, S3 …… reference voltage.

Claims (1)

[Claims] 1. An infrared sensor detects the temperature of each of an application portion immediately after a primer has been applied to the application surface of a material to be coated and a non-application portion of the material to be coated which is not coated with a primer. A method for inspecting the coating state of a primer, wherein the coating state of the primer is detected by comparing the temperatures of both.