JPH0777494A - Inspection method and inspection device for filter element - Google Patents

Abstract

PURPOSE:To provide the inspecting method and inspecting device for a filter element capable of correctly and quickly inspecting the filter element. CONSTITUTION:A light source 2 arranged on one face side of an element 4 illuminates one side face of the element 4, a photo-sensor 11 arranged on the other face side receives the light to generate the output voltage Va corresponding to the transmitted light quantity, and a display corresponding to the transmitted light quantity is made by a signal processing system 12, 13, 14. The presence or absence of a defect of the element 4 is inspected based on the change of the transmitted light quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for inspecting a filter element used in a dust collector for filtering dust contained in gases such as gases discharged from various plants. It is a thing.

[0002]

2. Description of the Related Art In recent years, various ceramic filters as disclosed in Japanese Patent Laid-Open No. 2-31811 have been proposed, but these are equipped with a filter element.
The filter element is an important factor that determines the filtration performance, and if cracks, thin walls, or holes are generated in it,
Not only does the filtration performance deteriorate, but it also causes trouble in the next process and pollution. Therefore, quality inspection of the filter element must be reliable.

Conventionally, this quality inspection is a visual inspection, an inspection in which an oil mist is applied at a desired pressure from the inside to the outside or from the outside to the inside of the filter element to visually inspect the ejection state, or a pressure loss is caused by permeating gas. The inspection method to see the change of is adopted.

[0004]

The above-mentioned visual inspection is the simplest, but it tends to be overlooked by an operator and lacks reliability. In the inspection for visually inspecting the ejection state of the oil mist, the oil mist contaminates the filter element and the surroundings. In addition, in the inspection due to the change in the pressure loss, the equipment such as the pressure inspection device and the exhaust is required, and the measurement takes time. The present invention has been made to solve the above problems all at once, and an object of the present invention is to provide a method for inspecting a filter element capable of inspecting a filter element accurately and quickly, and an inspection apparatus for executing the inspection method. It is in.

[0005]

The above object according to the present invention is achieved by the following constitution. (1) Inspecting the filter element based on the amount of transmitted light from one surface side to the other surface side of a filter element that filters dust and the like contained in the gas by transmitting gas. How to inspect the filter element. (2) A filter element that filters dust and the like contained in the gas by transmitting the gas, a light source that irradiates light to one side surface of the filter element, and receives light that has passed through the filter element A filter element inspection device comprising: an optical sensor that obtains an output voltage corresponding to the received light amount; and a signal processing system that displays the light transmission amount of the filter element corresponding to the output voltage.

[0006]

According to the method of inspecting a filter element of the present invention, when a crack or a thin portion is formed in the filter element, the amount of transmitted light increases, so that the increase or decrease in the amount of transmitted light causes defects in the filter element. It is possible to accurately and swiftly determine whether or not it is detected. According to the filter element inspection device of the present invention, one side surface of the filter element is illuminated by the light source provided on one side surface of the filter element, and received by the optical sensor provided on the other side surface to correspond to the transmitted light amount. Generate the output voltage. Since the signal processing system makes an indication corresponding to the amount of transmitted light based on the output voltage, it is possible to detect cracks and thin portions that are undesirably formed on the filter element by this indication, and to inspect the filter element accurately and quickly. It can be performed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment of the present invention will be described below with reference to FIGS.
An example will be described. FIG. 1 is a schematic configuration diagram showing an example of a filter element inspection method and an inspection apparatus according to the present invention, and FIG. 2 is an explanatory diagram showing an inspection mode. First, the structure of the inspection device 1 will be described. The light source 2 is composed of various lamps and emits a predetermined amount of light.
If the amount of light from the light source 2 changes, an accurate inspection cannot be performed, so the light source 2 is turned on by the stabilized power source 3. The element 4 corresponds to the filter element in the present invention, and the overall shape is formed into a cylindrical body, and the openings at both ends are light-tightly shielded by the closing plates 5a and 5b. The outer periphery of the element 4 is also light-tight so that only the light emitted from the light source 2 illuminates one side surface of the element 4, that is, the outer surface in this embodiment, during the inspection. Element 4
Is configured to move upward or downward while being rotated by drive means (not shown). Therefore, in the present embodiment, only one light source 2 is provided, but by rotating the element 4 and moving it up and down, for example, the entire outer periphery can be sequentially irradiated in a spiral shape.

At the center of the element 4, there is provided a cylindrical body 6 which blocks unnecessary incident light and serves as an appropriate optical path, and a reflection mirror 7 is provided at the tip of the cylindrical body 6 so as to face the light source 2. There is. The light source 2 and the reflection mirror 7 are adapted to hold a fixed position regardless of the rotation and the elevation of the element 4. Therefore, when the light emitted from the light source 2 passes through the element 4, it always reaches the reflection mirror 7, and when there is no transmitted light, no light reaches the reflection mirror 7. On the other hand, an optical sensor 11 is provided at one end of the cylindrical body 6. The optical sensor 11 is a photoelectric conversion element and generates an output voltage Va corresponding to the amount of received light. 12 is a linear amplifier, which is an optical sensor 11
The output voltage Vb is adjusted to obtain an output voltage Vb of 0 V when the incident light is 0, and 1 V (the setting is optional) when the incident light is maximum.

Reference numeral 13 is a rectifying circuit or a smoothing circuit,
Stabilizes the output voltage Vb. The display 14 is basically a digital voltmeter, but is configured to display the output voltage Vb by dividing it into, for example, 1000. Therefore, for example, when 0 V is displayed, the light transmission of the element 4 is 0, and when it becomes full scale, it indicates that the light emitted from the light source 2 is detected by the optical sensor 11 without being attenuated.

Note that it is necessary for an operator to constantly monitor the amount of light transmitted only by digitally displaying it. Therefore, in the present embodiment, the output voltage Vc stabilized by the comparison circuit 15
Is compared with a preset reference voltage Vref to obtain Vre
When the relation of f <Vc is satisfied, that is, when the light transmission amount becomes equal to or more than a predetermined light amount, the control voltage Vd is generated to issue an alarm, or the rotation or vertical movement of the element 4 is stopped. ing. The reference voltage Vref serves as a reference for determining whether the quality is good or bad, and the voltage level thereof may be set in advance by an experiment.

Next, a method of inspecting the element 4 will be described. First, the element 4 is moved up and down to match the upper end or the lower end with the light transmission position, and then rotated by 360 °. At this time, if there is no crack or thin portion in the element 4,
The amount of light transmission is the standard amount of light. This standard amount of light is the amount of light that has passed through an extremely minute gap or the amount of light that has reached the reflection mirror 7 due to diffraction, and the output voltage Va of the optical sensor 11 becomes a minute voltage level of 0 V or higher due to this standard amount of light, and 14 also displays a numerical value corresponding to the voltage level.
However, the voltage level of the voltage Vc generated by the standard light amount is a minute voltage equal to or lower than the reference voltage Vref, and can be clearly distinguished from the numerical value displayed when a crack or the like described later is detected. If the element 4 has a crack A as shown in FIG. 2, for example, the light emitted from the light source 2 passes through the element 4, passes through the element 4, is reflected by the reflection mirror 7, and enters the optical sensor 11. Therefore, the output voltage Va of the optical sensor 11 reaches the maximum value and the display 1
4 is displayed, it is possible to determine that the product has a crack A and is defective.

Further, according to the structure of this embodiment, the relation of Vref <Vc is satisfied as shown in the lower part of FIG.
The control output Vd is obtained from the comparison circuit 14. This control output Vd generates an alarm and stops the driving of the element 4. Therefore, when the worker is away from his / her seat for another work, for example, the seat is prepared for the preparation work for inspecting the other element 4. Never miss a defective product, even if it is far away. When the display 4 is visually inspected and it is determined that the subsequent inspection is unnecessary, the element 4 is replaced,
A mark can be added to the defective portion, that is, the position of the crack A. Alternatively, if there is another purpose, such as collecting data for quality control, continue the inspection. Continuation of inspection is
This is performed by driving the reset means provided separately.

Next, the case where the thin portion B is generated in the element 4 will be described. Since the amount of transmitted light increases corresponding to the thickness, the amount of light received by the optical sensor 11 also increases, and the voltage of the output voltage Vc increases. The level changes according to the thickness as shown in the lower part of FIG. Such a change in voltage level is digitally displayed on the display 14, and Vref
When <Vc is reached, an alarm is issued in the same manner as above and the driving of the element 4 is stopped. At this time, since the display on the display 14 does not show a higher numerical value than the position of the crack A, the operator can distinguish the difference from the crack A, and if the operator wants to know the range of the thin portion B, the resetting means can be used. To drive element 4 and display 1
From the numerical value of 4, the rough shape of the thin portion B can be known. Also, since it is stopped at the same time when the thin portion B is detected,
It is possible to easily attach a mark to the thin portion B, so that later examination for quality control can be easily performed.

Next, a second embodiment of the present invention will be described with reference to FIG. The main difference between the present embodiment and the first embodiment is that the optical sensor 11 is provided at the installation position of the reflection mirror 7, and therefore the same reference numerals are used for members that perform the same operations as described above. The description is omitted. That is, the optical sensor 11 is provided at the position corresponding to the optical axis of the light emitted from the light source 2 at the tip of the cylindrical body 6. In this case, the cylindrical body 6 is not used for transmitting light, but an electric wire is laid for supplying the output voltage of the optical sensor 11 to the linear amplifier 12.

The inspection of the element 4 is performed in the same manner as in the first embodiment, and when the crack A is formed in the element 4 or the thin portion B is further formed, the amount of light received by the optical sensor 11 increases. However, the voltage level of the output voltage Va becomes high. The circuit operation of the linear amplifier 12 and thereafter is also performed in the same manner as described above, and the display 14 digitally displays an alarm by the control voltage and the driving of the element 4 is stopped.

Next, the shape of light transmitted through the element 4 and the driving of the element 4 will be described with reference to the first and second embodiments. When the element 4 is rotated and moved in the vertical direction at the same time, the locus S of light becomes spiral.
Then, when the trajectory S of light is shown on the expanded element 4, it is inclined as shown in FIG. If a position where light is not irradiated appears between the loci S, a position where light is not irradiated will be omitted from the inspection. Therefore, it is necessary to perform light irradiation on the entire outer surface of the element 4. Therefore, element 4
When spirally rotating, the diameter R of light is increased and the outer edge portions are overlapped with each other as shown in FIG. Further, as shown in FIG. 4, if the configuration is such that two sets of detecting means of the light source 2 and the optical sensor 11 are provided at 180 ° intervals and the spiral pitch of the optical path S is increased, the inspection speed can be increased. it can. When one set of detecting means is provided and the diameter of light is not increased, the filter 4 is rotated 360 °, the filter 4 is moved up and down by the diameter of light, and then 360
° There is a method to rotate.

The processing of the output voltage Va shows the simplest method, and the output voltage Va may be A / D converted and digitally processed. When digital processing is performed, a clock signal, a gate circuit, and the like may be used, and the width of the crack A and the like may be indicated by numerical values. Furthermore, an image sensor such as a CCD can be used as the optical sensor 11. In this case, the shape of the crack A and the thin portion B can be imaged, and the entire shape and shade of the crack A are clearly shown. Therefore, the data is not only data for mere quality judgment but also data suitable for quality control.

In each of the above embodiments, the light source 2 is replaced by the element 4
The reflection mirror 7 and the optical sensor 11 are provided on the outside of the above, but the configuration is not limited to this and may be reversed. Further, the light source 2 and the optical sensor 11 may be arranged continuously in the longitudinal direction of the element 4. In this case, element 4
The inspection can be performed by rotating the gyro once. Furthermore,
The element 4 may be fixed and the light source 2 and the optical sensor 11 may be moved. The light source 2 may be of any type, for example, an incandescent lamp, a fluorescent lamp, an LE.
D, a semiconductor laser, or a gas laser can be used.
Further, sunlight or indoor illumination light can be used as it is as inspection light. In each of the above-described embodiments, an example in which the crack A and the thin portion B are inspected has been described.
If> Vc is detected, it is possible to detect an abnormal thick portion. Furthermore, by providing a level difference between the upper limit (VrefH) and the lower limit (VrefL) of the reference voltage Vref, the crack A and the thin portion B and the thick portion can be inspected together. With either configuration, the inspection can be performed accurately and quickly without contacting the element 4. Further, there is an advantage that the work site can be inspected in a comfortable working environment without being soiled. Although the above-mentioned embodiment is directed to a gas filter element, the present invention is also applicable to a liquid filter element and has the same effect.

[0019]

As described above, the method and apparatus for inspecting a filter element according to the present invention irradiate one side surface of the filter element with a light source disposed on one side surface of the filter element, and the other side. The optical sensor arranged on the side receives light to generate an output voltage corresponding to the amount of transmitted light, and the signal processing system is configured to display corresponding to the amount of transmitted light. It is possible to detect the formed cracks, thin portions, and thick portions, so that the filter element can be inspected accurately and promptly.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a filter element inspection device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an aspect of inspection.

FIG. 3 is a schematic configuration diagram of a filter element inspection device according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a relationship between movement of a filter element and light irradiation.

FIG. 5 is an explanatory diagram showing a form of light irradiation.

[Explanation of symbols]

 1 Filter Element Inspection Device 2 Light Source 3 Stabilized Power Supply 4 Element 5a, 5b Closure Plate 6 Cylindrical Body 11 Optical Sensor 12 Linear Amplifier 13 Rectifier Circuit 14 Display 15 Comparison Circuit Va-Vc Voltage A Crack B Thin Section

Claims (2)

[Claims] 1. A method of inspecting a filter element for filtering dust and the like contained in the gas by allowing gas to pass therethrough, based on the amount of light transmitted from one surface side to the other surface side. Inspection method for characteristic filter elements. 2. A filter element for filtering dust and the like contained in the gas by allowing the gas to pass therethrough,
A light source that irradiates light to one side surface of the filter element, an optical sensor that receives light transmitted through the filter element to obtain an output voltage corresponding to the amount of received light, and a light sensor of the filter element that corresponds to the output voltage. And a signal processing system for displaying the amount of light transmission.