WO2019151428A1 - Inspection system and inspection device of hollow columnar structure aggregate - Google Patents

Abstract

A device according to the present invention that applies light to one end surface of a subject in which a plurality of columnar hollow sections are arranged in parallel and inspects the condition of the hollow sections in accordance with light received by a sensor disposed on the other end surface is configured so as to perform an accurate inspection of a hollow columnar structure aggregate by providing guidance to appropriately determine the configuration and arrangement of a lighting device in relation to the subject. The lighting device is provided with a light-emitting unit that has light-emitting sections for emitting diffused light and non-light-emitting sections alternately arrayed on one end surface of the subject. When the widths of the light-emitting sections and the non-light-emitting sections in the array direction are c₁ and c₂, respectively, the length of the hollow sections of the subject is h, the width of the hollow sections in the array direction is w, and the distance from the other end surface to the light emitting unit is d, the arrangement position of the light-emitting unit and/or the structure of the light-emitting unit is designed so as to satisfy the relationship c₂ < w × d/h.

Description

Inspection apparatus and inspection system for hollow columnar structure aggregate

The present invention relates to an inspection apparatus and an inspection system for a hollow columnar structure assembly in which a plurality of columnar hollow portions are arranged in parallel. For example, by utilizing a chemical reaction with a fluid or filtering particulate matter. The present invention relates to a technique for inspecting a hollow columnar structure aggregate used in automobile catalysts and filters for cleaning fluids.

For example, automobile catalysts and filters are configured as a hollow columnar structure aggregate in which a large number of very thin hollow portions are arranged in parallel. If there is a defect in the hollow part of such a hollow columnar structure aggregate, the desired performance cannot be exhibited, so it is important to correctly inspect the presence or absence of the defect.

Therefore, as a device for inspecting defects such as clogging by condensing and imaging light that has passed through the hollow portion on the other end surface side while irradiating light to one end surface of the hollow columnar structure aggregate, Patent Literature 1 has been proposed (the contents of this document are incorporated into this application by reference). In this document, an illumination device that irradiates uniform diffused light is disposed on one end surface (hereinafter referred to as an incident end) of a hollow columnar structure assembly, and the other end surface (hereinafter referred to as an output end) is disposed on the other end surface. Disposing a line sensor array including a lens array is disclosed. In addition, it is described that the arrangement position of the line sensor array is set to a position where the lens array is spaced from the emission end of the hollow columnar structure aggregate by a distance equal to or greater than the focal length.

When using an illumination device that emits parallel light, if the hollow columnar structure aggregate is tilted and the extension axis of the hollow portion does not coincide with the optical axis of the parallel light, the parallel light incident from the incident end is used. It is preferable to use an illuminating device that irradiates diffused light as in the same document, because erroneous determination may occur due to light striking a partition wall that defines a hollow portion. In addition, setting the lens array at a position more than the focal length with respect to the emission end of the hollow columnar structure aggregate can ensure the necessary resolution in the sensor array, and the interval when inspecting the hollow columnar structure aggregate. Even if there is a fluctuation of the above, and even if there is an inclination of the hollow columnar structure aggregate, it is preferable because observation is possible.

Japanese Patent Laying-Open No. 2015-163857

The present invention provides an accurate inspection of a hollow columnar structure aggregate by providing a guideline for appropriately determining the configuration and arrangement of the illumination device in relation to the hollow columnar structure aggregate as a subject. With the goal.

Therefore, the present invention is an inspection apparatus for a hollow columnar structure assembly in which a plurality of columnar hollow portions, in which the emitted light becomes light that spreads slightly when the light is emitted, are arranged in parallel,
An illumination device having a light emitting unit that irradiates diffused light to one end surface of the hollow columnar structure aggregate in which one end of the plurality of hollow portions is located;
A line sensor array that is arranged so as to be able to receive light from the other end surface of the hollow columnar structure aggregate where the other ends of the plurality of hollow portions are located, and detects the amount of light received from the plurality of hollow portions. When,
With
In the light emitting unit, first portions having relatively high light intensity and second portions having relatively low light intensity are alternately arranged,
The widths of the first part and the second part in the arrangement direction are c ₁ and c ₂ , the length of the hollow part is h, the width of the hollow part in the arrangement direction is w, and the light emission from the other end surface When the distance to the unit is d,
c ₂ <w × d / h
It is characterized by satisfying the relationship.

Further, the present invention is an inspection system for a hollow columnar structure assembly provided with the above inspection device,
Conveying means for supporting and transporting the hollow columnar structure aggregate to the inspection device,
The transport means is disposed at an interval in the transport direction with respect to the upstream transport unit so that light passes from the upstream transport unit disposed on the upstream side in the transport direction and the other end surface. Having a downstream conveying section,
The lighting device and the line sensor array are arranged up and down across the conveying means,
The upstream side transport unit and the downstream side transport unit have a form of an endless belt conveyor and a regulating member that regulates the surface of the belt supporting the hollow columnar structure aggregate to a flat state.
It is characterized by that.

According to the present invention, since the configuration and arrangement of the illumination device are appropriately determined in relation to the hollow columnar structure aggregate that is the subject, the hollow columnar structure aggregate is accurately inspected.

It is a fracture perspective view showing typically an example of the hollow columnar structure aggregate which can become the inspection object of the present invention. It is a fracture | rupture perspective view which shows typically the other example of the hollow columnar structure aggregate | assembly which can become the test object of this invention. (A) And (b) is a schematic diagram for demonstrating the basic composition and inspection principle of the inspection apparatus of the hollow columnar structure aggregate | assembly which concerns on one Embodiment of this invention, (a) is a hollow columnar structure aggregate | assembly. (B) has shown the state with the inclination of a hollow columnar structure aggregate. It is typical sectional drawing for demonstrating an example of the defect which may arise in the hollow columnar structure aggregate | assembly F of a closure type | mold structure, and its detection aspect. It is explanatory drawing for demonstrating the structure of an illuminating device, and the conditions of arrangement | positioning. (A) And (b) is explanatory drawing for demonstrating the basic condition of a structure and arrangement | positioning of the illuminating device of embodiment. (A)-(c) is explanatory drawing for demonstrating the development conditions of a structure and arrangement | positioning of the illuminating device of embodiment. (A) is an inspection in a state where the gap between the light emitting end of the hollow columnar structure having an open structure and the sensor device is uniform, and (b) is a state where the hollow columnar structure is removed from the horizontal plane with respect to the horizontal plane. It is a schematic diagram for demonstrating the test | inspection in the state inclined. (A) is an inspection in a state where the gap between the light emitting end of the hollow columnar structure having a closed structure and the sensor device is uniform, and (b) is a state in which the hollow columnar structure is removed from the horizontal plane with respect to the horizontal plane. It is a schematic diagram for demonstrating the test | inspection in the state inclined. (A) And (b) is for demonstrating the light reception amount detection waveform by a detection element array in the case of setting a gap with respect to the hollow columnar structure of an open type structure, and the hollow columnar structure of a block type structure, respectively. It is a schematic diagram. It is a typical side view which shows schematic structure of one Embodiment of the test | inspection system comprised by applying the test | inspection apparatus shown in FIG. It is a block diagram which shows the structural example of the control system of the inspection system shown in FIG. It is a flowchart which shows an example of the test | inspection processing procedure by the control system of FIG. It is a typical side view which shows schematic structure of other embodiment of the test | inspection system comprised by applying the test | inspection apparatus shown in FIG. It is a typical side view which shows schematic structure of other embodiment of the test | inspection system comprised by applying the test | inspection apparatus shown in FIG.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1. Inspection Object and Basic Configuration FIGS. 1 and 2 show two examples of a hollow columnar structure assembly (hereinafter also referred to as a subject) that can be an object of an inspection apparatus and an inspection system according to the embodiments described below. The subject C shown in FIG. 1 has a large number of hollow columnar structures extending in a straight tube shape through two opposing ends, that is, the light incident end C1 of the subject C and the light emitting end C2 opposed thereto. 2 have a plurality of hollow portions H that are open at both ends and partitioned by a partition wall P (hereinafter also referred to as an open type structure). Further, the subject F shown in FIG. 2 has a hollow portion H1 having one end opened at the light incident end F1 and closed at the other end on the light exit end F2, and one end on the incident end F1 side. It has a configuration in which the hollow portions H2 that are closed and open at the other end on the side of the emission end F2 are arranged in a staggered manner (hereinafter also referred to as a closed-type structure).

It should be noted that the specimens shown in these drawings are only for illustrating the basic configuration, and the shape and dimensions of the specimen itself, the number of hollow portions, the cross-sectional shape, the cross-sectional dimensions, and the axial length , It is not intended to limit the thickness of the partition walls. However, a subject to which the present invention can be preferably applied has a hollow portion having a cross-sectional dimension and a length such that the emitted light becomes a minutely spread light (quasi-parallel light) (for example, a hollow portion having a circular cross-section) If so, it has a length more than a significant multiple of the diameter).

The form of the specimen is a catalyst (hollow columnar structure aggregate C in FIG. 1) or a filter (hollow in FIG. 2) that cleans the fluid by utilizing a chemical reaction with the fluid or filtering particulate matter. Columnar structure aggregates F) are included, but not limited to them. That is, according to the present invention, if the subject has a plurality of open-type hollow portions H or closed-type hollow portions H1 and H2 that are arranged in parallel, the hollow columnar structures, It can be used to inspect the state (such as the presence or absence of defects). In the present specification, the term “defect” means, for example, in an open type structure, clogging of an open type hollow part caused by manufacturing factors or mixing of unnecessary substances (in addition to those that are completely blocked, Including those partially occluded or constricted), manufacturing factors of the subject itself, or unevenness of the partition wall caused by unevenness of the substance applied to the inner surface of the hollow part. Further, the “defect” in the closed structure includes a hole in the closed end, a notch of a partition between cells, and the like.

FIG. 3A is a schematic diagram for explaining a basic configuration and an inspection principle of an inspection apparatus for a subject C according to an embodiment of the present invention. The inspection apparatus according to the illustrated embodiment includes an illumination device 10 for irradiating light to an incident end C1 of a subject C, and a contact image sensor (CIS) configured to be able to receive light emitted from the output end C2. Line sensor array 20 of the form. The illumination device 10 is configured as an illumination device that irradiates the incident end of the subject C with the diffused light DL. The line sensor array 20 includes a lens array, and the lens array is set at a position that is more than the focal length with respect to the emission end C2 of the subject C, and collects the light OL that has passed through the hollow portion H.・ Inspect defects such as clogging by imaging.

2. Advantages and Problems of Use of Diffused Light Illuminating Device As the illuminating device 10, a device having an appropriate light emitting unit can be adopted as long as it can emit diffused light. However, from the viewpoints of simple configuration, easy acquisition of the necessary amount of light, and reduction of power consumption, it is not a two-dimensional or planar light emitting unit, but a one-dimensional or linear extension. It is advantageous to employ one having an existing light emitting unit. In this case, it has an effective irradiation width corresponding to the dimension of the end face of the hollow columnar structure that can be an inspection target.

Part of the diffused light DL is incident on the opening Hi (hereinafter referred to as an incident opening) Hi of the hollow portion H at the incident end C1 of the subject C. Then, the light incident in parallel or substantially parallel to the extending direction of the hollow portion H proceeds to the opening Ho (hereinafter referred to as an emission opening) Ho of the hollow portion H at C2 as it is. For this reason, even if the subject C is inclined as shown in FIG. 3B, the line sensor array 20 can perform the required detection. “Inclination” which is a problem in the inspection means a state where the axis of the hollow portion is inclined with respect to the optical axis, and is not necessarily limited to the state shown in FIG. That is, for example, even when the emission end C2 of the subject C is not perpendicular to the axis of the hollow portion H, the axis of the hollow portion is inclined with respect to the optical axis. It is effective to use light.

Moreover, as shown in FIG. 4, in the subject F having the hollow portions H1 and H2 having the closed structure, the diffused light is used even when a partition wall defect that cannot be found by just visually observing the end face occurs. Is valid. That is, the light incident from the hollow portion H1 having the open end H1i at the incident end F1 enters the adjacent hollow portion H2 having the open end H2o at the output end H2 through the defect portion, and is emitted from the open end H2o. Therefore, by detecting this, it is possible to know the presence or absence of a partition wall defect.

Patent Document 1 exemplifies an illuminating device having a linear light emitting section such as a straight tube fluorescent lamp, a transmission light type halogen lamp, and a metal halide lamp. Mercury is generally used for fluorescent lamps, and lighting equipment can be used as long as the content is within the limits of the regulation value, it is not subject to the Minamata Convention on Mercury and production and sales will continue. It is. However, its use should be avoided as much as possible from the viewpoint of eliminating environmental impact. In addition, the halogen lamp and the metal halide lamp are inferior in responsiveness until the light emission state is stabilized, and also have problems in maintenance performance such as running cost and replacement of the inspection apparatus due to large power consumption or heat generation. In addition, although not illustrated by patent document 1, use of organic EL is also considered. However, organic EL does not have sufficient illuminance to be used as a light emitting unit for examining a subject.

On the other hand, Patent Document 1 exemplifies using an LED array as a light emitting unit. As an LED array, for example, an axial lead type LED element called a shell type (hereinafter also simply referred to as an LED element), or an LED chip, particularly an LED chip using a phosphor (hereinafter simply referred to as an LED element) (Also referred to as LED chip). In this case, the light-emitting portion that is the first portion that actually emits light of one LED element or one LED chip is a substantial light source.

However, since it is practically impossible to seamlessly arrange the light-emitting portion that becomes a light source due to restrictions on the housing, substrate, or wiring of a light-emitting device such as an LED element or LED chip, in practice, the light-emitting unit A light-emitting part (light source) that actually emits light and a non-light-emitting part that is a second part that does not emit light periodically appear along the length direction. When the subject is inspected using such a light emitting unit, if there is a hollow portion where no light is incident, the line sensor array 20 does not detect the emitted light OL from the hollow portion, so that it is determined that there is a defect (open). Erroneous detection leading to a determination that there is no defect (in the case of a closed structure). In order to avoid such false detection, it is strongly desirable that light be incident on any hollow part.

Therefore, it is conceivable to arrange the light emitting unit sufficiently separated from the incident end of the subject.However, separating the light emitting unit more than necessary leads to an increase in the size of the device, or a necessary and sufficient distance due to the space of the device. It may be difficult to set. In addition, it is conceivable to insert a diffusion plate between the light emitting unit and the incident end of the subject, but there is a limit in eliminating the periodicity of the light emitting unit. Further, regardless of which configuration is employed, the illuminance at the incident end can be reduced. To compensate for this, the input power to the light emitting device must be increased to increase the light intensity of the light source. However, as the temperature of the light emitting device rises accordingly, the light emission efficiency is lowered, and the life is also affected. To avoid these, it is necessary to add a large cooling means.

3. Configuration and Arrangement Condition of Illumination Device In view of the above, in this embodiment, the arrangement and arrangement of the illumination device so that light is incident on all the hollow portions without requiring the distant arrangement of the illumination device 10 and the insertion of the diffusion plate. The following conditions (hereinafter referred to as basic conditions) are defined. Furthermore, the configuration of the illumination device and the light emitting unit and the non-light emitting unit appear alternately and periodically so as to reduce the unevenness of the incident light quantity and thus the emitted light quantity for each hollow part due to the fact that this does not coincide with the pitch of the hollow part. Define the conditions (development conditions) for placement.

FIG. 5 is a diagram schematically showing the light emitting unit 11 that is a component of the illumination apparatus 10 and the subject C in order to explain the conditions. As described above, in the light emitting unit 11, the light emitting units 12 and the non-light emitting units 14 are periodically and alternately arranged. Here, when the widths of the light emitting unit 12 and the non-light emitting unit 14 in the arrangement direction are c ₁ and c ₂ , respectively, and the value obtained by adding them is c, the value c is the light emitting unit 12 in the extending direction of the light emitting unit 12. And the period (pitch) of the non-light emitting portion 14. Further, the length (that is, the height from the exit end C2 to the entrance end C1) and the width of the hollow portion H are set to h and w, respectively, and the distance from the exit end C2 to the light source surface 16 of the light emitting unit 11 (hereinafter referred to as a counter light source). D) is referred to as the surface distance.

The light that enters from the entrance opening Hi, passes through the hollow portion H, and exits from the exit opening Ho enters the line sensor array 20. As will be described later, the line sensor array 20 is configured to include a lens array and a detection element array, and incident light is captured by the sensor element via the lens. Even if the arrangement period of the sensor elements does not coincide with the period of the exit opening Ho, the light captured by the sensor element always passes through one point in the exit opening Ho. In other words, when it is assumed that the light source surface 16 is viewed from the point of view, if the light emitting portion is in the field of view, light is always incident on the sensor element regardless of the thickness of the partition wall P.

The width of the light source surface entering the field of view from an arbitrary point in the exit aperture Ho (hereinafter referred to as field of view width) v is the same for any hollow part. As shown in FIG. 5, whether the viewpoint is at the rightmost end (ir) of the exit aperture, the center (ic), or the leftmost end (il),
v / d = w / h
From the relationship
v = w × d / h
Because it becomes.

here,
c ₂ = c−c ₁
Therefore, if the field width v from an arbitrary point in the exit aperture Ho is larger than the length of the non-outgoing region corresponding to the width c ₂ of the non-light emitting portion 14, it is within the range of the field width v. Has a light emitting region corresponding to the length of at least a part of the light emitting unit 12. Therefore,
c ₂ <v = w × d / h
The light emitting unit 11 is disposed so as to satisfy the above condition (basic condition) (that is, the distance d from the emission end C2 to the light source surface 16 of the light emitting unit 11) and / or the structure of the light emitting unit 11 ( By designing the width c _{1 of} the light emitting portion, the width c ₂ of the non-light emitting portion, and the period c), light can be incident on and emitted from all the hollow portions H facing the light emitting unit 11.

This will be described with reference to FIGS. 6 (a) and 6 (b). In these drawings, reference numerals p1 to p7 denote the light emitting units 11 at different relative positions with respect to the viewpoint vp in the emission opening Ho. FIG. 6A shows a case where the light emitting unit 12 is small enough to be regarded as a point light source (c ₁ ≈0) and the non-light emitting unit 14 is large enough to occupy most of the visual field width v (c ₂ ≈v). FIG. 6B shows the case where the width c ₁ of the light emitting portion 12 is equal to the visual field width v (c ₁ = v) and the width c ₂ of the non-light emitting portion 14 is substantially equal to the visual field width v (c ₂ ≈v ). As is apparent from these drawings, if the basic condition (c ₂ <v) is satisfied, the field width v is always obtained regardless of the size of the widths c1 and c2 and regardless of the relative position of the light emitting unit 11. It can be seen that there is a light emitting region corresponding to the length of at least a part of the light emitting unit 12 within the range.

Furthermore, unevenness in the incident light amount and thus the emitted light amount (that is, unevenness in the received light amount of the sensor element) for each hollow portion caused by the appearance of the light emitting unit 12 and the non-light emitting unit 14 in the visual field width v depending on the relative position. By reducing, accurate inspection becomes possible. The inventors have
c ₂ <v / 2 = w × d / (2 × h)
If the light emitting region corresponding to the length of at least a part of the light emitting portion 12 exists in half or more of the visual field width v, the accurate inspection can be ensured. I got the knowledge.

This will be described with reference to FIGS. 7 (a) to (c). In the case where the above development conditions are satisfied, the case where the period c is equal to or smaller than the visual field width (c ≦ v) and the case where the period c is equal to or larger than the visual field width v (c ≧ v) are further considered.

FIG. 7A illustrates the case of c ₁ ≈0 and c ₂ ≈v / 2 in the former case, and it can be seen that there are always two light emitting portions 12 in the field of view width v. FIG. 7B also illustrates the case where c ₁ ≈v / 4 and c ₂ ≈v / 2. The field width v has two light emitting units 12 at the maximum and 1 at the minimum. It can be seen that there are two light emitting portions 12. Further, FIG. 7C illustrates a case where c ₁ ≈v / 2 and c ₂ ≈v / 2 when the field width is greater than or equal to v, and the field width v always includes one light emitting unit. It can be seen that a light emitting region corresponding to a width c ₁ of 12 exists.

Therefore, from these figures, as long as the development conditions are satisfied, the maximum amount of emitted light that can be generated regardless of the size of the widths c ₁ and c ₂ and the magnitude relationship between the period c and the visual field width v. The relationship between the value Ho _max and the minimum value Ho _min is Ho _max / 2 <Ho _min
Thus, it can be seen that the amount of incident light and thus the amount of emitted light (that is, the amount of light received by the sensor element) for each hollow portion is reduced.

If it is desired to further reduce unevenness,
c ₂ <v / n = w × d / (n × h); n> 2
And it is sufficient. In this case, the minimum value Ho _{min of the} amount of emitted light is not less than (n−1) / n times the maximum value Ho _max , and uniform illumination without unevenness can be performed as the n value increases.

The hollow columnar structure aggregate C used as a catalyst or the hollow columnar structure aggregate F used as a filter generally has a hollow portion having a length h = 50 to 250 mm and a width w = 1 to 1.5 mm. The light emitting unit 11 of the illuminating device 10 is opposed to the incident end C1 or F1 with an interval (hereinafter referred to as a working distance, and the value is referred to as wd). Therefore, for example, if the working distance value wd is a specified value (about 10 mm), it is based on the length h, the width w, and the distance to the light source surface d (= h + wd) of the subject that can be examined. Then, the visual field width v is calculated, the width c ₂ of the non-light emitting portion is determined according to the basic condition or the development condition, and the light emitting unit 11 is designed and manufactured. Conversely, if the width c ₂ of the non-light emitting portion specified value, it is possible to determine the value of the pair light source surface distance d or the working distance wd based on the basic conditions or development conditions. Or further, considering the light intensity or the like of the space and the light emitting portion of the inspection apparatus, it may be set to values wd and width c ₂ while compromise other.

Note that the length of the light emitting region included in the range of the visual field width v does not necessarily mean that the light emitting unit 12 fills the length. Since the width c ₁ of the light emitting part 12 (or the width c ₂ of the non-light emitting part 14) and the period c generally do not coincide with the width and period of the hollow part H in the extending direction of the light emitting unit 11, FIG. , (C), it should be noted that two or more light emitting units 12 may be filled. Further, although the LED element can be generally regarded as a point light source, since it actually has a light emitting part of a finite length, even when a light emitting unit 11 having an array of LED elements is employed, The basic conditions and development conditions are applicable.

Furthermore, the present invention does not require a diffusion plate, but does not exclude its use. In the case where there is a restriction on the arrangement position of the light emitting unit 11 or the illumination device 10, it is also effective to insert a diffusion plate. Actually, the diffusion plate does not eliminate the periodicity of the light emitting part. The diffuser plate has a strong light emitting part which is a first part having a relatively high light intensity and a first light emitting part having a relatively low light intensity. The weak light emitting parts which are two parts appear alternately alternately. When the light intensity of the low light emitting part is 1 / f of the light intensity of the high light emitting part, the value obtained by multiplying the width of the low light emitting part by (1-1 / f) is regarded as virtual c ₂ , Development conditions can be applied.

In any case, according to this embodiment, an illuminating device in which an appropriate arrangement position and structure are determined in relation to the hollow columnar structure aggregate is realized in consideration of environmental performance and power saving. In other words, restrictions on the arrangement position and structure design of the light emitting unit 11 are eased based on the basic conditions and the development conditions. Further, even when a diffusion plate is used, it is not necessary to use a low transmittance so as to eliminate the periodicity of the light emitting part as much as possible.

4). Line Sensor Array The line sensor array 20 of this embodiment includes a lens array (for example, a rod lens array in which a plurality of rod lenses are linearly arranged over a range corresponding to the dimension of the end surface of a hollow columnar structure that can be a subject) and The configuration disclosed in Patent Document 1 can be adopted as including the detection element array. The configuration will be described. First, the illumination device 10 and the line sensor array 20 are arranged on the same plane, preferably in parallel. In the present embodiment, the CIS type line sensor array 20 is used as the line sensor array 20, and the distance between the light incident end of the lens and the light exit end of the other end surface of the subject is equal to or greater than the focal length (hereinafter referred to as a gap). The light emitted from the hollow portion is captured.

This includes the case where the light emitting end of the hollow columnar structure is observed at a position out of focus (non-imaging position). However, in this embodiment, since the light emitted from the hollow portion is quasi-parallel light and the line sensor array 20 having the short-focus lens array is adopted, the light receiving angle is large, and therefore, to some extent. Light can be received even if a gap is present, and a necessary resolution can be secured in the sensor array. This also means that observation is possible even when there is a change in the gap or the inclination of the subject during examination of the subject.

FIG. 8A shows an inspection in a state where a gap according to the provision of the present invention is set between the light emitting end of the hollow columnar structure C having an open structure and the light incident end of the lens array 22. FIG. FIG. 8B shows an inspection in a state inclined from the state of FIG. 8A, that is, a state where the gap is not uniform. In the state of FIG. 8B, the incident position shifts in the lateral direction by tilting the optical axis incident on the lens array 22 compared to the state of FIG. 8A, but the incident light is refracted in the lens. Since the light is guided to the detection element array 24, black spots corresponding to defects such as clogging are detected even if there is an inclination.

FIG. 9 (a) shows an inspection of a hollow columnar structure F with a closed structure in a state where the gap is uniform as in FIG. 8 (a), and FIG. 9 (b) shows the state shown in FIG. 8 (b). Similarly to FIG. 9, the case where the inspection is performed in a state inclined from the state of FIG. Even in the case of FIG. 9B, the incident light from the defective hollow portion H2 ′ is refracted in the lens and guided to the detection element array 24. Bright spots corresponding to defects such as unintended holes are detected.

In addition to the above, it was found that setting a gap appropriately enables a correct inspection for defects.

FIG. 10A is a schematic diagram for explaining a received light amount detection waveform by the detection element of the detection element array 24 when a gap is set for the hollow columnar structure C having an open type structure. In the figure, Ha schematically represents a hollow part having no defect, Hb represents a hollow part having a defect due to clogging, and Hc schematically represents a hollow part having a defect due to irregularities in the partition wall P. For simplification, the detection waveform of the detection element is drawn based on a simple rectangular wave.

Since the gap is set as shown in FIG. 10 (a), the detection element array 24 can capture the light coming inward from the light emitting end. The incident position and intensity of the light differ depending on the degree of clogging and the unevenness of the partition wall, and this appears as a difference in the contour of the detection waveform of the detection element, making it easy to identify the type of defect. .

FIG. 10B is a schematic diagram for explaining a received light amount detection waveform by the detection element of the sensor array 24 when a gap is set for the hollow columnar structure F having a closed structure. In FIG. 10 (b), H1a and H2a schematically show a hollow portion having no defect, H2b schematically shows a hollow portion in which a defect due to perforation occurs at the end to be closed, and the hollow portion H2b and A state in which there is a partial defect in the partition wall P ′ between the adjacent hollow portions H1b is shown.

The light that has entered the hollow portion H2b through the perforated portion reaches its open end. In addition, a part of the light incident on the adjacent hollow portion H1b enters the hollow portion H2b through the missing portion of the partition wall P ', and this also reaches the open end.

As shown in FIG. 10B, by setting a gap, a weak signal change caused by light entering through the missing portion of the partition wall P ′ and coming obliquely from the open end of the hollow portion H2b. Can be detected. Therefore, it becomes easy to detect the defect of the partition wall, which is extremely difficult to detect when there is no gap or by visual inspection.

The quality of the subject is comprehensively determined based on the number of defective hollow portions, the ratio to the total number, the distribution state of defective hollow portions, and the like. However, it is meaningful to specify the type of defect because it can contribute to improvement of the manufacturing process and the like by ascertaining the cause of occurrence through analysis of its occurrence frequency and distribution.

5). Next, an embodiment of an inspection system to which the inspection apparatus according to the above-described embodiment is applied will be described.

FIG. 11 is a schematic side view showing a schematic configuration of an inspection system according to the embodiment. The inspection system 30 according to the present embodiment includes an introduction unit 40, a preprocessing unit 50, and an inspection unit 60, and the subject A that is the hollow columnar structure aggregate C or F is conveyed in the direction of the arrow T along these. The

The introduction unit 40 is a unit that guides the manufactured subject A to the preprocessing unit 50. For example, the driving pulley 42 and the driven pulley 44 that are arranged on the upstream side and the downstream side in the transport direction are stretched over these. And a conveyor belt 46 in the form of an endless belt conveyor.

The preprocessing unit 50 is a means for removing dust and the like from the subject A prior to the examination. In particular, when the subject A is made of ceramics, a large amount of dust may be generated at the time of manufacture and may adhere to the subject A. If dust remains attached to the subject A, or drops and accumulates on the line sensor array 20 or the like at the time of inspection, the inspection accuracy is remarkably lowered and erroneous detection may occur. Therefore, in the present embodiment, the pretreatment unit 50 performs a process for efficiently and actively removing the dust.

Specifically, the pre-processing unit 50 includes one or more conveyance rollers 52 interposed between the introduction unit 40 and the inspection unit 60, a gap between the introduction unit 40 and the conveyance roller 52, and the conveyance roller 52 and the inspection unit. An air nozzle 54 that ejects air is provided so as to face the gap with the section 60 or the gap between the conveyance rollers 52. Further, a vibration exciter 56 is provided for the transport roller 52 so that vibration is transmitted to the subject A via the transport roller 52 so that dust can be easily removed from the subject A. That is, in the pre-processing unit 50, dust is eliminated by the vibration of the transport roller 52 by the vibrator 56 and the air jetted from the air nozzle 54.

In this embodiment, as shown in FIG. 11, the air nozzle 54 alternately arranges the one that injects air downward and the one that injects upward. According to this, dust is excluded from the upper surface (incident end C1 or F1) and the lower surface (exit end C2 or F2) of the subject A. Further, when the subject A is the hollow columnar structure aggregate C, the dust is removed from the hollow portion H when the dust is dropped by the downward jetting or blown up by the upward jetting. On the other hand, when the subject A is the hollow columnar structure aggregate F, the dust is wound up from the hollow portion H1 by the downward injection, the dust is separated from the hollow portion H2 by the upward injection, and falls off due to the interruption of the upward injection. , Dust is eliminated.

In addition, in FIG. 11, although the embodiment which alternately arrange | positioned what performs upward injection and what performs downward injection was illustrated, the arrangement | positioning aspect of an air nozzle and the injection direction of air are not restricted to this, Dust Can be determined as appropriate in order to effectively eliminate the above. For example, instead of or in addition to the arrangement mode of the illustrated embodiment, an air nozzle that injects obliquely upward, obliquely downward, or laterally may be provided. Further, in order to effectively eliminate dust, the air injection force and the excitation force can be appropriately determined. Further, the pretreatment unit 50 is accommodated in a chamber as indicated by a one-dot chain line, and an exhaust unit is provided in the chamber to discharge and collect the dust to the outside. It may not be reattached.

The inspection unit 60 includes a transport unit (upstream transport unit) 61 that receives and transports the subject A from the preprocessing unit 50, and a transport unit that is disposed on the downstream side in the transport direction with a predetermined interval from the transport unit 61. (Downstream transport unit) 71 as transport means. The predetermined interval is an interval through which light passes from the other end surface, and is an interval at which the subject does not tilt at the time of transition between the transport units. These conveying sections 61 and 71 generally have the same configuration, and drive pulleys 62 and 72 and driven pulleys 64 and 74, respectively, and conveying belts 66 and 76 in the form of endless belt conveyors stretched around them, respectively. And plate-like restricting members 68 and 78 for restricting the upper surfaces of the conveyor belts 66 and 76 to a flat state. The transport system of the inspection unit 60 can also be configured by a transport roller in the same manner as the preprocessing unit 50. However, as in the present embodiment, it is assumed that the transport belt is used and the back surface side of the transport surface is supported by a flat plate-shaped regulating member, so that the transport roller is highly accurate in order to prevent rattling of the subject A. It is preferable that the flatness can be maintained over a long period of time.

The illumination device 10 including the light emitting unit 11 and the line sensor array 20 including the detection element array 24 are disposed above and below the transport unit including the interval between the transport unit 61 and the transport unit 71 (described later). This arrangement relationship may be reversed as shown). By arranging the illumination device 10 on the upper side and the line sensor array 20 on the lower side in this way, the influence of the shaking and inclination of the subject A accompanying the conveyance is minimized at the emission end, and the time and space of the imaging conditions are reduced. Uniformity can be improved.

The lighting device 10 may be provided with a lighting lifting / lowering device 120 (FIG. 12) that adjusts the position so that a height (to the light source surface distance d) that satisfies the basic condition or the development condition described above is set. it can. The line sensor array 20 can also be provided with a sensor lifting device (FIG. 12) that adjusts the position so that the above-described appropriate gap is set with high accuracy. When the illuminating device 10 is arranged on the upper side as in the present embodiment, if only one type of subject having a fixed length (fixed height) is to be examined, or even if it is not a fixed length, the range of change is large. If a plurality of small types of subjects are to be examined, the arrangement of the illumination lifting device 120 is not essential. However, as described above, the arrangement of the illumination lifting / lowering device 120 is effective in consideration that subjects having various dimensions with different heights are to be examined.

In the process in which the subject A passes through the interval between the transport unit 61 and the transport unit 71, the illumination device 10 emits light to the incident end C1 or H1, and the line sensor array 20 causes the light exit end C2 or H2 side to be irradiated. A scan is performed. The lighting device 10 and the line sensor array 20 are preferably arranged so as to be parallel to each other so as to be in the same plane. Moreover, the illuminating device 10 and the line sensor array 20 can be arrange | positioned so that those longitudinal directions may correspond to the direction which cross | intersects the conveyance direction T, for example, the orthogonal direction.

The inspection unit 60 has an air nozzle 81 that removes dust by injecting air in order to further improve inspection accuracy. By disposing an air nozzle 81 in the immediate vicinity of the inspection position, that is, the position between the light emitting unit 11 and the detection element array 24 and upstream of the illumination device 10 in the transport direction, the subject A, in particular, immediately before the inspection. By injecting air into the hollow portion H of the hollow columnar structure aggregate C, the hollow portion H is brought into a cleaner state.

A configuration is provided on the side of the line sensor array 20 opposite to the air nozzle 81 to receive and exclude the falling dust. This configuration includes a transparent thin plate 91 that covers the line sensor array 20 and is inclined, and means for cleaning the thin plate 91. The cleaning means includes an air nozzle 93 that injects air onto the surface of the thin plate, and a wiper 95 that wipes the surface of the thin plate 91 by rotating about the rotation shaft 95a. At the time of inspection, the light emitted from the exit end of the subject A passes through the transparent thin plate 91 and reaches the line sensor array 20. Further, the dust falling on the thin plate 91 is quickly and effectively excluded from the detection area of the line sensor array 20 by the inclination of the thin plate 91 and the injection of air. Further, when an unnatural vertical line (conveying direction) black line or the like appears on the image acquired by the line sensor array 20, the wiper 95 is driven to completely remove dust accumulated on the thin plate 91. A cleaning process can be performed.

12 is a block diagram showing a configuration example of a control system of the inspection system shown in FIG. 11, and FIG. 13 is a flowchart showing an example of an inspection processing procedure by the control system of FIG.

The above units are controlled by the control device 100 shown in FIG. The control device 100 has, for example, a CPU 101, a ROM 103, an EEPROM 105, a RAM 107, and a VRAM 109 as basic configurations. The CPU 101 controls each unit according to a program stored in the ROM 103 and corresponding to a processing procedure as will be described later. The EEPROM 105 is used to hold required information even when the system power is off, for example, while the RAM 107 can be used as a temporary work memory in the course of data processing by the CPU 101. . Furthermore, the VRAM 109 is used to develop information based on the detection output of the line sensor array 20, for example, data obtained from the light exit end of the subject in association with scanning, in association with the position of the light exit end. Can do.

Diffuse light illuminator 10, illumination elevating device 120, line sensor array 20, sensor elevating device 130, drive pulley 42 of introduction unit 40, transport roller 52 of pretreatment unit 50, and drive pulley 62 of inspection unit The transport system 160 including 72, the air nozzles 54 and 93, and the wiper 95 are connected to the CPU 101 via the input / output device 111, and driving / stopping and the like are controlled. Although the air nozzle is connected to a compressed air source such as a compressor, the driving / stopping may be performed by starting and stopping the compressed air source, or may be performed by opening and closing a valve provided in the middle. .

The detection output of the line sensor array 20 is input via the input / output device 111, subjected to appropriate processing as necessary, and developed in the VRAM 109. A GUI 70 is further connected to the input / output device 111. The GUI 70 includes, for example, information on the subject, that is, the type of the subject (whether it is a hollow columnar structure aggregate C having an open structure or a hollow columnar structure aggregate F having a closed structure), shape, dimensions, In addition to input means such as a keyboard and a pointing device for setting the shape and dimensions of the hollow portion, information for assisting the operator in inputting the information, information transmitted from the control device 100 (according to a processing procedure described later) Display means for displaying the determined information and the light output end visualization information).

In the configuration of the control system described above, when the examination processing procedure shown in FIG. 13 is started, first, the information relating to the subject described above is fetched in step S1, and then the examination conditions are fetched in step S3. Is called. The inspection condition is, for example, whether the above-described defect type identification is desired, or whether it is desired to acquire clear data in order to know only the presence or absence of a defect. In step S5, based on the acquired information, the lighting lifting device 120 and / or the lighting device 10 and / or the line sensor array 20 are set to an appropriate height and / or an appropriate gap of the line sensor array 20 as necessary. Alternatively, the sensor lifting device 130 may be controlled.

Furthermore, when using the light emitting unit 11 in which LED elements and LED chips are wired so that an appropriate number of units can be driven as the illumination device 10, the dimensions of the end face of the subject captured in step S1 are used. It is possible to make a setting so that irradiation corresponding to is performed. At this time, since the width in the direction intersecting the subject transport direction changes in the transport process with respect to the irradiation light, the irradiation light deviated from the edge of the subject affects the detection operation of the line sensor array. May be set so that the irradiation range dynamically changes in accordance with the change.

After the above initial processing, the diffused light illuminating device 10 is turned on, and the transport system 160 and the air nozzle 54 (or the air nozzle 93 when the subject is the hollow columnar structure aggregate C) are activated (step) S7). Then, scanning of the light emitting end is performed while the subject is being transported, and in this process, data corresponding to the detection output of the detection element array 24 (noise removal as necessary, as described in FIG. 10B). The threshold setting or signal amplification processing for processing a weak detection signal change, waveform shaping or contour correction, and other processing can be performed), which are developed in the VRAM 109 (step S9). Prior to the processing in step S9, when dust adheres to the thin plate 91 based on the detection output of the detection element array 24, the transport system 160 is stopped and the wiper 95 is activated to clean the thin plate 91. The transport of the subject can be resumed after the conversion.

When the data development for one subject is completed, the following processing is performed (step S11). That is, in step S13, the state of each hollow part is analyzed and determined (the presence or absence of a defect, and if desired, the result type is determined), and further, in step S15, the defective hollow part The quality of the subject is determined on the basis of the number, the ratio to the total number, the distribution state of the defective hollow portions, and the like. In step S17, these determinations and determination results are notified to the GUI 70 and can be presented to the operator via the display means. Further, based on the data developed in the VRAM 109 corresponding to the detection output of the detection element array 24, the subject as shown in FIGS. 8 (a), 6 (b) and FIGS. 9 (a), 7 (b). It is possible to construct a two-dimensional image of the light emitting end of the light and display it on the display means, or to determine the quality of the subject based on the two-dimensional image.

In step S19, it is determined whether or not there is a subject to be subsequently transferred. If an affirmative determination is made, the process returns to step S7 and the subsequent steps are repeated. On the other hand, if a negative determination is made, diffuse light illumination is performed. Termination processing including turning off the apparatus 10 and stopping the conveyance system 160 and the air nozzle is performed. Prior to returning to step S7, when dust adheres to the thin plate 91, the same cleaning process as described above may be performed.

According to the above embodiment, the hollow columnar structure aggregate that is the subject in the process of passing between the line sensor array 20 and the diffused light illuminating device 10 arranged in the space between the transport unit 61 and the transport unit 71. Since the inspection is performed, a plurality of hollow columnar structure aggregates can be inspected continuously and at high speed while having a simple and small configuration. Moreover, since the height of the illuminating device 10 and the gap of the line sensor array 20 are set according to information and requests relating to the subject, it is possible to perform a highly accurate and appropriate examination on the hollow columnar structure aggregate. It becomes like this.

6). Others The present invention is not limited to the embodiments described above and the modifications described in various places.

For example, in the above-described embodiment, the configuration in which one set of the diffused light illumination device 10 and the line sensor array 20 is provided has been described, but two or more sets may be provided. In this case, the positions of the light emitting units 12 in the extending direction of the light emitting units 12 are complemented between the two or more lighting devices 10, and the images of corresponding pixels are detected with respect to the detection results of the two or more line sensor arrays 20. It is possible to perform an inter-operation. According to this, the detection accuracy is further improved, and the occurrence of erroneous detection can be effectively prevented.

In FIG. 11, the illumination device 10 including the light emitting unit 11 and the line sensor array including the detection element array 24 are respectively provided on the upper side and the lower side of the conveyance unit including the interval between the conveyance unit 61 and the conveyance unit 71. A configuration in which 20 is arranged is illustrated. However, as shown in parentheses for reference numerals 10 and 20 that refer to the illumination device and the line sensor array, respectively, these arrangement positions may be reversed. In the case where the line sensor array 20 is arranged on the upper side, the sensor lifting device 130 needs to be disposed in order to deal with subjects having various heights. Installation may not be necessary. These also apply to the embodiments of FIGS. 14 and 15 described below.

Further, FIG. 11 illustrates a configuration in which the illumination device 10 and the line sensor array 20 are arranged to face each other and the optical path (broken line) between the illumination device 10 and the line sensor array 20 is linear. . However, as shown in FIG. 14, the line sensor array 20 is arranged in a non-opposing state with respect to the illumination device 10, and a mirror 97 that bends the optical path between the illumination device 10 and the line sensor array 20 as indicated by a broken line is provided. You may arrange. When the mirror 97 is disposed on the lower side, the air nozzle 93 injects air to the mirror 97, and the wiper 95 performs an operation of wiping the surface of the mirror 97 as necessary.

Furthermore, in the embodiment of FIGS. 11 and 14, in the inspection unit 60, the subject is transported by the transport units 61 and 71 including the transport belts 66 and 76. However, as shown in FIG. 15, it may be transported by transport units 61 and 71 including one or more transport rollers 69 and 79, respectively.

In addition, the light used for inspection is not limited to visible light. For example, the illumination device 10 may irradiate light in the wavelength band of 830 nm to 3 μm (near infrared light), and the line sensor array 20 may have a detection element having sensitivity in the wavelength band.

Claims (11)

1. A plurality of columnar hollow portions where the emitted light becomes micro-spread light when the light is emitted, an inspection device for a hollow columnar structure aggregate arranged in parallel,
   An illumination device having a light emitting unit that irradiates diffused light to one end surface of the hollow columnar structure aggregate in which one end of the plurality of hollow portions is located;
   A line sensor array that is arranged so as to be able to receive light from the other end surface of the hollow columnar structure aggregate where the other ends of the plurality of hollow portions are located, and detects the amount of light received from the plurality of hollow portions. When,
   With
   In the light emitting unit, first portions having relatively high light intensity and second portions having relatively low light intensity are alternately arranged,
   The widths of the first part and the second part in the arrangement direction are c ₁ and c ₂ , the length of the hollow part is h, the width of the hollow part in the arrangement direction is w, and the light emission from the other end surface When the distance to the unit is d,
   c ₂ <w × d / h
   The hollow columnar structure aggregate inspection apparatus characterized by satisfying the above relationship.
2. The inspection apparatus for a hollow columnar structure aggregate according to claim 1, further satisfying a relationship of c ₂ <w × d / (2 × h).
3. 3. The inspection apparatus for a hollow columnar structure aggregate according to claim 1 or 2, wherein the second part is a non-light emitting part.
4. The light emitting unit includes a diffusion plate disposed between the one end surface, and the strong light emitting portion and the weak light emitting portion where the first portion and the second portion appear on the diffusion plate, respectively, by the diffusion plate. The inspection apparatus for a hollow columnar structure aggregate according to claim 1 or 2, wherein the inspection apparatus is a hollow columnar structure aggregate.
5. 5. The inspection apparatus for a hollow columnar structure aggregate according to any one of claims 1 to 4, wherein the light emitting unit has an array of LED elements or LED chips.
6. The line sensor array includes a lens array and a detection element array, and the lens array is disposed at a position where the light incident end is spaced from the other end surface of the hollow columnar structure aggregate by a distance equal to or greater than a focal length. The inspection apparatus for a hollow columnar structure aggregate according to any one of claims 1 to 5, wherein the inspection apparatus is provided.
7. An inspection system for a hollow columnar structure assembly comprising the inspection device according to any one of claims 1 to 6,
   Conveying means for supporting and transporting the hollow columnar structure aggregate to the inspection device,
   The transport means is disposed at an interval in the transport direction with respect to the upstream transport unit so that light passes from the upstream transport unit disposed on the upstream side in the transport direction and the other end surface. Having a downstream conveying section,
   The lighting device and the line sensor array are arranged up and down across the conveying means,
   The upstream side transport unit and the downstream side transport unit have a form of an endless belt conveyor and a regulating member that regulates the surface of the belt supporting the hollow columnar structure aggregate to a flat state.
   An inspection system for a hollow columnar structure aggregate.
8. Means for setting the position of the illumination device with respect to the hollow columnar structure aggregate and / or means for setting the position of the line sensor array with respect to the hollow columnar structure aggregate The inspection system for a hollow columnar structure aggregate according to claim 7.
9. The lighting device and the line sensor array are arranged to face each other,
   A transparent thin plate is disposed to be inclined so as to cover the illumination device or the line sensor array disposed below the conveying unit, and a means for cleaning the surface of the thin plate is disposed. The inspection system for a hollow columnar structure aggregate according to claim 7 or 8, wherein
10. The lighting device and the line sensor array are arranged in a non-opposing manner,
    A mirror that bends the optical path between the illumination device and the line sensor array is disposed below the transport unit, and a unit for cleaning the surface of the mirror is disposed. The inspection system for a hollow columnar structure aggregate according to claim 7 or 8.
11. 11. The hollow according to claim 7, further comprising a nozzle that is disposed upstream of the inspection device in the transport direction and that injects air into the hollow columnar structure aggregate. Inspection system for columnar structures.

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