JPH06142582A - Coating-monitoring device - Google Patents

Abstract

PURPOSE:To accurately detect any improper coating by a method wherein a distance sensor is disposed at a predetermined distance from a coating material feed nozzle, a distance between the sensor and the coating material at the end of the nozzle is measured and, from variations in the distance thus obtained, a discontinued feed of the coating material is detected. CONSTITUTION:Silicone 3 is forced out of a nozzle 4 for application to the surface of work 2. At this time, the surface of the silicone 3 at the end of the nozzle is irradiated with laser from the head of a sensor 5 to detect the reflected light by the sensor 5. The result of detection is input into a control unit 6 and an average value of the measured data is obtained separately from long time widths and short time widths. Both the average values are compared and, if the difference therebetween exceeds a predetermined value, the feed of the silicone 3 is judged to be discontinued, and then the operation of a nozzle driving circuit 7 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating state monitoring apparatus for coating a work with a coating material.

[0002]

2. Description of the Related Art A device for detecting the application state of a viscous material applied to the surface of a work is known. An example of such a device is disclosed in, for example, Japanese Patent Laid-Open No. 64-63806. In the disclosed device, the coating failure is detected by detecting coating breakage by image processing of the coating state on the work surface.

[0003]

However, the technique disclosed in the above publication is disadvantageous in terms of time because it detects whether or not there is a coating failure after the coating operation of the viscous material is completed. In some cases, even if a defect occurs in the initial stage, the coating operation may be continued as it is and the defect may be subsequently determined, so that there is a problem that the coating operation is wasted.

The present invention is configured in view of the above circumstances, and provides a viscous material application monitoring device capable of efficiently and reliably detecting a defective application of viscous material applied to a work. To aim.

[0005]

In order to achieve the above-mentioned object of the present invention, a coating monitoring apparatus according to the present invention is a supply nozzle which is located facing a surface to be coated of a work and which supplies a coating material to the surface to be coated. A distance sensor arranged with a certain distance from the nozzle to measure the distance from the nozzle tip to the coating material supplied, and the sensor measured by the distance sensor and the coating material at the nozzle tip. And a detection means for detecting a supply cut of the coating material based on a change in the distance.

In a preferred mode, the detection means has a storage means for storing the data from the sensor, and the average value of the measurement data in the first period having a predetermined time width stored in the storage means and the mean value. The average value of the measurement data during the second period having a time width shorter than that of the first period is calculated and compared, and when the difference exceeds a predetermined value, it is determined that the supply of the coating material is out of supply. .

In this case, when the difference between the measured value of the distance to the viscous material at the nozzle tip and the average value of the measured values in the first period is a predetermined value or more, a value obtained by adding the predetermined value to the average value. Is stored as average value calculation data corresponding to the measured value. If the measured value deviates significantly from the average value in the first period, it is highly possible that the tip of the nozzle is out of coating material. If the coating material is cut, the sensor cannot measure the distance, or it will measure the distance to an object other than the coating material. In this case, in order to proceed the subsequent processing, a predetermined value is set for the time being and adopted as the measured value data.

In a preferred embodiment, the sensor is a reflection type sensor using a laser. Furthermore, the present invention is preferably used for an automatic liquid packing application device used for bonding between parts of a transmissive unit.

[0009]

According to the present invention, a sensor is provided for detecting the supply state of the coating material from the tip of the nozzle of the coating device,
This sensor is installed at a position spaced from the nozzle so that the relative position to the nozzle does not change. This sensor measures the distance to the coating material supplied from the tip of the nozzle. Typically, this sensor measures the distance between the coating material and the sensor by irradiating the coating material at the tip of the nozzle with a laser beam and detecting the reflected light. When the coating material is continuously supplied from the nozzle, the distance between the coating material and the sensor is short. When the coating material is interrupted, the reflected light from the sensor passes through the tip of the nozzle, so the reflected light cannot be detected or the measurement distance becomes significantly large. The supply of the coating material is cut off when the coating material containing bubbles reaches the nozzle. In the case where the supply of the coating material is interrupted due to the bubbles, the supply of the coating material is restored again when the bubbles pass, so that the supply of the coating material is interrupted for a moment and then the normal supply state is restored. However, if the supply of the coating material is cut off, coating failure on the work will be caused. In the present invention, the discontinuity of the coating material from the nozzle is detected by measuring the distance between the tip of the nozzle and the sensor.

The relative distance between the nozzle and the sensor does not change regardless of the movement of the nozzle.
However, when moving while performing the coating operation, the nozzle vibrates subtly and the distance between the nozzle and the sensor fluctuates slightly. In order to distinguish this minute fluctuation from the coating material shortage from the nozzle, in a preferred embodiment of the present invention, measurement is performed in a first period having a relatively long time width and a second period having a relatively short time width, respectively. The average value of the values is calculated, the average values are compared with each other, and when the difference exceeds a predetermined value, it is determined that the supply of the coating material is cut off.

The monitoring device of the present invention can be suitably used when monitoring the supply state of the liquid packing applied to the mating surface of the transmission of an automobile.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Referring to FIG. 1, an example of a coating monitoring device according to one embodiment of the present invention is schematically shown. The coating monitoring device 1 of this example can be applied to any device that supplies a coating material from a nozzle in principle. As shown in FIG. 1, the monitoring device 1 of the present example is provided so as to face the surface to be coated of the workpiece 2 and has a nozzle 4 for supplying the coating material 3 to the surface. The application material is silicon 3 in this example, and the work 2 constitutes a liquid packing applied to the joint surface of the transmission case. The silicon of this example is an opaque material and has a certain viscosity.

Next to the nozzle 4, a head 5 of a distance sensor for measuring the distance from the nozzle 4 to the surface of the silicon supplied from the nozzle 4 is arranged at regular intervals. In the configuration of this example, the laser beam is emitted from the sensor head 5 toward the base end portion of the silicon discharge portion supplied from the nozzle 4. This irradiation angle is the work 2 in this example.
Irradiation is performed from above by 30 ° with respect to a plane parallel to the surface. This sensor head 5 has silicon 3
A light receiving element (not shown) for receiving the reflected light from is provided, and the reflected light is detected. By detecting the reflected light from the silicon 3, the distance between the sensor head 5 and the surface of the silicon 3 at the tip of the nozzle is detected. In this case, the data input from the sensor head 5 is processed by the control unit 6 to detect the above distance. The control unit 6 calculates the distance between the sensor 5 and the nozzle 4,
As a result, when it is determined that the supply of silicon 3 from the nozzle 4 is cut off, a signal is output to the nozzle driving device 7 to stop the operation.

Further, an alarm may be issued at the same time as the stop, or the nozzle may be returned to the position where the supply is stopped and the coating operation may be performed again. Referring to FIG. 2, an outline of the configuration of the control unit 6 is shown in the form of a block diagram. The signal from the sensor is first input to the A / D conversion circuit 8 in the control unit 6 and converted into a digital signal. The signal from the A / D conversion circuit 8 is input to the data correction circuit 9. In this example, the signal from the sensor 5 is input to the A / D conversion circuit 8 every 0.001 seconds. The data correction circuit 9 is adapted to make a correction when the data from the sensor 5 is not suitable for the subsequent processing. For example, when the discharge of the silicon 3 from the nozzle 4 is interrupted, the laser from the sensor 5 passes through the tip of the nozzle 4 and hits something other than the silicon 3 to be reflected. In such a case, the reflected light cannot be detected by the sensor 5, or even if it can be detected, the value becomes extremely large, and the subsequent data processing cannot be performed properly.

Therefore, in this case, the data correction circuit 9
Gives an appropriate value as measured value data. The output from the data correction circuit 9 is input to and stored in the memory 10. The control unit 6 includes a long section average calculation circuit 11 for obtaining an average value of measured value data in a relatively long time width (0.2 seconds in this example) and an average in a relatively short time width (0.02 seconds). And a short-term average calculation circuit 12 for obtaining a value.

The control unit 6 is provided with a judgment circuit 13 for judging that the supply of silicon 3 from the nozzle 4 has been cut off.
Is a long interval average calculation circuit 11 and a short interval average calculation circuit 12
Are compared with each other, and when the difference exceeds a predetermined value, it is determined that the silicon 3 is out of supply. The output signal from the long-term average calculation circuit 11 is also input to the data correction circuit 9. In the data correction circuit 9, when the above measurement impossible state or the measured value is abnormally large from the average value of the measured value data from the long interval average calculation circuit 11, the measured value is a value obtained by adding a predetermined value to this average value. I am trying to give it as data.

The reason why special measurement value data is calculated and given in the case of abnormality such as when measurement is impossible is as follows. A general reflective laser sensor is
This is because if a reflected light cannot be detected, a certain specific value is output, but if this value is adopted as the measured value, it may interfere with the subsequent processing. In the apparatus having the above configuration, the silicon 3 forming the liquid packing is extruded from the nozzle 4 toward the surface of the work 2. At this time, the sensor head 5 irradiates a laser onto the surface of the base end portion of the silicon 3 ejected in a rod shape from the nozzle 4. Then, the reflected light is detected by the sensor 5. This reflected light is A / A every 0.001 seconds as described above.
It is taken into the D conversion circuit 8. The data correction circuit 9 is A /
The memory 1 by processing the digitized signal from the D conversion circuit 8
Store in 0. The memory 10 stores 0.2 seconds worth, that is, 200 pieces of data, and is sequentially updated every time new data is loaded.

When the taken measurement value is 1.19 mm or more longer than the long-range average value of the distance,
The data correction circuit 9 adds a predetermined value to the long section average value to obtain measured value data. In addition, the short section average value and the long section average value are calculated each time a new measurement value is input. Then, the determination circuit 13 determines that the supply of silicon has been cut off when the difference between the short section average value and the long section average value is 0.64 mm or more.

In this case, the control unit 6
Generally stops the subsequent coating operation. Further, the movement of the nozzle may be stopped. As a result, it is possible to judge the quality during the coating operation.

[0020]

As described above, according to the present invention, the quality of the coating state of the coating material can be judged without waiting for the completion of the work with a simple structure, which is efficient. In addition, it is possible to reduce useless application work as much as possible.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a coating monitoring apparatus according to an embodiment of the present invention,

FIG. 2 is a block diagram of a control unit used in the monitoring device of FIG.

[Explanation of symbols]

 1 Coating monitoring device 2 Work 3 Silicon 4 Nozzle 5 Sensor head 6 Control unit 7 Nozzle drive circuit 8 A / D conversion circuit 9 Data correction circuit 10 Memory 11 Long interval average calculation circuit 12 Short interval average calculation circuit 13 Judgment circuit.

Claims (5)

[Claims] 1. A supply nozzle located opposite to a surface to be coated of a work for supplying a coating material to the surface to be coated, and a coating nozzle which is arranged with a certain distance from the nozzle and is supplied from a tip portion of the nozzle. A coating monitoring apparatus including a distance sensor that measures a distance to a material, and a detection unit that detects a supply cut of the coating material based on a variation in the distance between the sensor measured by the distance sensor and the coating material at the tip of the nozzle. . 2. The measuring means according to claim 1, wherein the detecting means has a storage means for storing the data from the sensor, and the average of the measurement data during the first period having a predetermined time width stored in the storage means. Value and the average value of the measurement data in the second period having a time width shorter than the first period are calculated and compared, and when the difference exceeds a predetermined value, it is determined that the supply of the coating material is out of supply. apparatus. 3. The average value when the difference between the measured value of the distance to the viscous material at the nozzle tip and the average value of the measured values in the first period is equal to or more than a predetermined value. A coating monitoring device that stores a value obtained by adding as a mean value calculation data corresponding to the measured value. 4. The coating monitoring apparatus according to claim 1, wherein the sensor is a reflection type sensor using a laser. 5. A coating monitoring device according to claim 1, which is used in a liquid packing automatic coating device.