JPH0385404A - Inspecting apparatus of coating agent in form of thin film - Google Patents

Abstract

PURPOSE:To enable easy and sure inspection of the coating state of a coating agent applied to a workpiece of low light transmittivity by a construction wherein a compara tor element compares a transmitted light quantity change rate determined by an arithmetic element with a reference value and outputs a control signal in accordance with the degree thereof. CONSTITUTION:A light projected from a projector 12 and transmitted through a work piece W or the like enters a photodetector 13. The photodetector 13 outputs a detection signal in accordance with the quantity of the incident light and an amplifier 33 amplifies this detection signal with an appropriate amplification factor. A hold element 34 holds an output signal of the amplifier 33 as to the workpiece W before it is coated with a coating material BP. Moreover, an arithmetic element 35 determines, as a transmitted light quantity change rate, a value of the ratio between an output signal of the amplifier 33 as to the workpiece W after it is coated with the coating agent BP and the signal held by the hold element 34. A comparator element 36 compares the transmitted light quantity change rate determined by the arithmetic element 35 with a reference value Bt and outputs a control signal in accordance with the degree thereof. In this way, the coating state of the coating agent BP applied on the work piece W of low light transmittivity can be inspected easily and surely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for inspecting the coating state of a thin film of coating agent applied to a material to be coated.

[Conventional technology]

In the automobile assembly process, window glass such as the windshield and rear glass is assembled into the window frame of the car body after a sealant is applied to the entire periphery of the window glass, but before the sealant is applied, a black primer is applied.
Efforts are being made to improve the reliability of adhesion.

The present applicant has developed a device for inspecting the state of application of black brusher applied to window glass, which is disclosed in Japanese Unexamined Patent Publication No. 61-2
The device described in Japanese Patent No. 42666 was previously proposed. This conventional inspection device places a light emitter and a light receiver across the window glass, amplifies the detection signal output from the light receiver according to the amount of light transmitted through the window glass, and then uses that output signal as a reference. It is configured to output a control signal depending on the magnitude of the comparison with the bell.

[Problem to be solved by the invention]

However, when so-called ceramic glass, in which the peripheral part of the glass is treated with black ceramic, is used as window glass, the light transmittance is extremely low (for example, 0.1 % or less).

In other words, since both the coating material, Black Brimer, and the peripheral portion of the ceramic glass, which is the coating surface, are black and have low light transmittance, the detection signal output from the light receiver is extremely small, and the difference between them is small.

Therefore, with conventional inspection equipment, it is necessary to use components with particularly high stability and precision in order to detect these differences.In addition, the variation in light transmittance of ceramic glass has a direct impact, resulting in increased costs. There are also drawbacks in terms of ease of adjustment, and it is not easy to reliably inspect the coating state.

In view of the above-mentioned problems, the present invention has been devised to provide an inspection method that can easily and reliably inspect the coating state of a coating material applied to a material with low light transmittance, such as black primer applied to ceramic glass. The purpose is to provide equipment.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides an inspection device for a thin film coating agent applied to a material to be coated, which includes a light projector and a light receiver disposed with the material to be coated sandwiched therebetween, and the light receiver. an amplifier for amplifying a detection signal from the amplifier, a holding means for holding an output signal of the amplifier for the material to be coated before the coating agent is applied, and the amplifier for the material to be coated after the coating agent is applied. calculating means for calculating a rate of change in amount of transmitted light, which is a value of the ratio between the output signal of the output signal and the signal held by the holding means; and a comparison means for outputting a control signal.

[For production]

The light emitted from the projector and transmitted through the material to be coated enters the light receiver.

The light receiver outputs a detection signal according to the amount of incident light.

The amplifier amplifies the detection signal from the photoreceiver with an appropriate amplification factor.

The holding means holds the output signal of the amplifier for the material to be coated before the coating agent is applied.

The calculating means determines the ratio of the output signal of the amplifier to the signal held by the holding means for the material to be coated after the coating agent has been applied as the rate of change in amount of transmitted light.

The comparison means compares the rate of change in the amount of transmitted light determined by the calculation means with a reference value, and outputs a control signal depending on the magnitude thereof.

〔Example〕

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

FIG. 1 is a block diagram showing the configuration of an inspection apparatus 1 according to the present invention.

The inspection device 1 is configured to inspect the quality of the coating state of the black brimer BP (thin film coating agent) applied to the workpiece W, which is the material to be coated, and output a control signal S6 according to the inspection result. There is.

The workpiece W is an automobile window glass made of ceramic glass whose periphery is treated with black ceramic. The light transmittance of the portion subjected to the black ceramic treatment is extremely low, for example, about 0.1%. The workpiece W is transported, for example, by a conveyor (not shown) and positioned at a coating/inspection station, where the amount of transmitted light is detected before coating, and then the black brimer BP is applied, and immediately after the coating, the amount of transmitted light is detected. Inspections are performed by detecting the amount of light and calculating the rate of change in the amount of transmitted light.

In FIG. 1, the inspection device l includes a detection sensor 11, an oscillator 21, a light emission control section 22, a filter 31, a demodulator 32
, amplifier 33, hold section 34, calculation section 35, comparison section 3
6, an output control section 37, and an operation panel section on which a power supply section (not shown), a voltmeter, operation switches, indicator lights, etc. are mounted.

The detection sensor 11 includes a light emitter 12 and a light receiver 13 that are integrally held by a manipulator of a robot (not shown).
It consists of. The projector 12 is a light emitting diode that emits near-infrared rays.

The oscillator 21 outputs a pulse signal with a frequency of several KHz.

The light emission control unit 22 is modulated by a pulse signal from the oscillator 21, and supplies power (pulse output) to the projector 12 to cause it to emit light.

Of the detection signal Sl from the light receiver 13, the filter 31
This is a bandpass filter that allows only the frequency components from the projector 12 to pass.

The demodulator 32 operates in synchronization with the output signal of the oscillator 21, and demodulates the output from the filter 31 into a DC voltage signal according to its amplitude.

Amplifier 33 amplifies the output from demodulator 32. The adjuster 61 provided in the amplifier 33 can adjust the zero point, and the adjuster 62 can adjust the amplification factor. Note that, in reality, amplifiers are also provided at other appropriate locations, such as before the filter 31 or inside the light receiver 13.

The hold unit 34 converts the signal S2 output from the amplifier 33 into
Hold signal S output from the control device that controls the whole
Hold at timing ll.

The hold signal Sll is generated at a timing when the detection sensor 11 is detecting the amount of light transmitted through the work W before the black brider BP is applied to the work W. Therefore, the signal S3 output from the hold section 34 is
The signal S2 of the amplifier 33 for the workpiece W before the application of the black primer BP is held.

The calculation unit 35 receives the signal S3 output from the hold unit 34,
The value of the ratio with the signal S2 output from the amplifier 33 (S2/S3
) is calculated and output as a signal S4. In other words, the signal S3 output from the hold section 34 is the workpiece W before coating.
By determining the value of this ratio, the rate of change in amount of transmitted light RE indicating how many times the amount of transmitted light has changed (decreased) by applying the black primer BP can be determined.

The comparison unit 36 compares the rate of change in transmitted light amount Rt determined by the calculation unit 35 with the reference value Bt set by the setting unit 38, and outputs a signal S5 depending on the magnitude thereof.

The output control section 37 receives the signal S5 output from the comparison section 36.
A control signal S6 is output based on. The control signal S6 is
For example, this is a defect signal that is turned on when the coating state of the brimer BP applied to the workpiece W is "poor". Note that the control signal S6 is controlled not to be output at a time when the detection sensor 11 is not detecting the workpiece W.

The coating device 1 is connected to a control device that manages or controls the entire coating/inspection stage tongue through a large number of signal lines.
In addition to the above-mentioned signal Sll, various signals are exchanged.

Next, the inspection operation of the coating device fl will be explained.

When the workpiece W is positioned at a predetermined position, the detection sensor 11 first detects the amount of light transmitted through the workpiece W, and at that timing, a signal Sll is output from the control device that controls the whole, and the output of the amplifier 33 at that time is The signal S2 is held by the hold section 34.

Next, a black primer BP is applied to the workpiece W.

Thereafter, the detection sensor 11 detects the amount of transmitted light after coating, and from the signal S2 of the amplifier 33 and the signal S3 of the hold section 34 at that time, the calculation section 35 calculates the rate of change in the amount of transmitted light R.
t is calculated. Note that at this time, the detection sensor 11 is moved along the coating trajectory of the workpiece W coated with the black primer BP. In the meantime, receiver 1
3 outputs a detection signal S1 corresponding to the amount of transmitted light after application of the black primer BP, the signal S2 outputted by the amplifier 33 changes accordingly, and the signal S4 (change rate of transmitted light amount Rt) also changes.

The rate of change in the amount of transmitted light Rt and the reference value Bt are compared by the comparing section 36, and a signal S5 is outputted depending on the magnitude thereof.

The value of the reference value Bt is determined by testing an appropriate number of sample products, but for example, if the rate of change in amount of transmitted light Rt is 1/2
The coating condition is determined to be "good" if the value is about 1150 or less.

The output control unit 37 outputs a control signal S6 when the coating state is "poor".

When the control signal S6 is output, for example, an alarm is issued and the coating device is stopped, and predetermined recovery processing such as checking the workpiece W and coating device and removing defective workpieces is performed.

According to the above-mentioned embodiment, since the quality of the coating condition is determined based on whether the rate of change in transmitted light amount Rt before and after coating reaches the reference value Bt, the workpiece W with low light transmittance such as ceramic glass Inspection can be easily and reliably performed even if the workpiece W has a wide range of light transmittance.

In the embodiments described above, the light projector 12 is a light emitting diode, a semiconductor laser, or a light bulb, and the light receiver 4 is a photodiode, a phototransistor, or a C
It is possible to adopt OD, etc., respectively.

In the above embodiment, the configuration of the inspection device 1 and the configuration of each part thereof can be various configurations other than those described above. For example, although an example has been described in which the configuration of each part is realized by a hardware circuit, it is also easy to configure it by software using an appropriately programmed microcomputer or the like. Furthermore, the control signal S6 output from the inspection device 1 can be used for various controls.

〔Effect of the invention〕

According to the present invention, it is possible to easily and reliably inspect the application state of a coating agent applied to a material to be coated with low light transmittance, such as black primer applied to ceramic glass.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an inspection device according to the present invention. l... Inspection device, 12... Emitter, 13... Light receiver, 33... Amplifier, 34... Hold section (holding means), 35... Arithmetic section (arithmetic means), 36...・・・
Comparison section (comparison means), Rt...transmitted light amount change rate, Bt
...Reference value, Sl...Detection signal, S5...Signal (
control signal), S6... control signal, W... workpiece (material to be coated), BP... black primer (coating agent).

Claims (1)

[Claims] (1) An inspection device for a thin film coating agent applied to a material to be coated, comprising: a light projector and a light receiver arranged to sandwich the material to be coated; and an amplifier for amplifying a detection signal from the light receiver. , a hold means for holding the output signal of the amplifier for the material to be coated before the coating agent is applied; and an output signal of the amplifier for the material to be coated after the coating agent is applied and held by the holding means. a calculation means for calculating a rate of change in the amount of transmitted light, which is a value of the ratio between the calculated signal and the calculated signal; and a comparison means for comparing the rate of change in the amount of transmitted light obtained by the calculation means with a reference value and outputting a control signal depending on the magnitude thereof. An inspection device for a thin film coating agent, comprising: