JP2002014051A - Method and equipment for inspecting defect of porous ceramic member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for inspecting the defect of a porous ceramic member inexpensively and safely with high accuracy and productivity. SOLUTION: In the method for inspecting a defect existing in a porous ceramic member, the porous ceramic member has a large number of through holes in the longitudinal direction. The porous ceramic member is columnar and the through holes are filled, at one end parts thereof, with a filler in checker pattern. The through holes not filled with the filler at one end part are filled, at the other end parts, thereof, with the filler. Light is radiated from one end of the porous ceramic member so as to be in parallel with the through hole thereof and the light leaking to the other end of the porous ceramic member is detected, thus inspecting the defect of the porous ceramic member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a defect in a porous ceramic member for detecting a defect in a porous ceramic member, and an inspection apparatus used for the defect inspection of the porous ceramic member.

[0002]

2. Description of the Related Art Recently, it has become a problem that particulates contained in exhaust gas discharged from internal combustion engines such as vehicles such as buses and trucks and construction machines cause harm to the environment and human bodies. Various ceramic filters have been proposed which purify the exhaust gas by collecting the particulates in the exhaust gas by passing the exhaust gas through a porous ceramic.

[0003] In the ceramic filter, a plurality of porous ceramic members 30 as shown in FIG. As shown in FIG. 4, the porous ceramic member 30 has a large number of through holes 31 arranged in a longitudinal direction, and a partition wall 33 separating the through holes 31 functions as a filter.

[0004] That is, as shown in FIG. 4 (b), the through hole 31 formed in the porous ceramic member 30 is plugged with a filler 32 at one of the exhaust gas inlet and outlet ends. The exhaust gas flowing into one through hole 31 is
After passing through the partition 33 which always separates the through-hole 31, it flows out from the other through-holes 31. When exhaust gas passes through this partition 33, the particulates
The part is trapped and the exhaust gas is purified. At this time, if a defect is present in the porous ceramic member 30, the particulates pass through the defect, and a ceramic filter using such a porous ceramic member cannot sufficiently purify exhaust gas.

[0005] Therefore, it is necessary to carry out an inspection for confirming whether or not such a defect exists in the ceramic filter. However, if such an inspection is performed after the ceramic filter is manufactured, there is a lot of waste in terms of time and cost. Therefore, in the stage of the porous ceramic member 30 before the ceramic filter is manufactured, the porous ceramic member 30 is not used. An inspection is performed to determine whether a defect exists. Conventionally, as a method of confirming the presence or absence of such a defect, a method of irradiating the porous ceramic member 30 with X-rays and confirming the presence or absence of the defect based on the transmittance of the X-ray has been used.

[0006] However, such a method using X-rays is costly, resulting in an increase in manufacturing costs. In addition, since X-rays are harmful to the human body, the work is dangerous.

Further, as shown in FIG. 5, by irradiating X-rays from a direction perpendicular to the axial direction of the porous ceramic member 30, the presence or absence of a defect in the porous ceramic member 30 is determined from the transmittance of the X-rays. It can be confirmed that the filler 3
As for the defect existing in the vicinity of No. 2, the thickness through which the X-rays are transmitted becomes thick, so that it was difficult to accurately confirm the existence of the defect. Further, even when X-rays are irradiated from the axial direction of the porous ceramic member 30, it is difficult to accurately confirm the presence of defects near the filler similarly.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to solve these problems, and a porous ceramic member capable of detecting a defect of a porous ceramic member at low cost, safely, and accurately. It is an object of the present invention to provide a defect inspection method for a member and an inspection device used for the method for inspecting a porous ceramic member.

[0009]

According to the present invention, there is provided a method for inspecting a defect of a porous ceramic member, the method comprising detecting a defect present in the porous ceramic member. A large number of through holes are juxtaposed in the direction, one end of the through hole is filled with a filler in a checkered pattern, and the other end is a through hole in which the one end is not filled with the filler. Is a columnar porous ceramic member filled with a filler, and the detection of the defect of the porous ceramic member is performed so that one end of the porous ceramic member is parallel to the through hole of the porous ceramic member. The method is characterized by irradiating light and detecting light leaking to the other end of the porous ceramic member.

Further, the defect inspection apparatus for a porous ceramic member according to the present invention is a defect inspection apparatus for detecting a defect existing in the porous ceramic member, wherein the porous ceramic member has a large number in its longitudinal direction. Through holes are provided side by side, one end of the through hole is filled with a filler in a checkered pattern, and the other end is filled with a filler in a through hole where the one end is not filled with a filler. A column-shaped porous ceramic member that is filled, wherein the defect inspection device is configured to irradiate light from one end of the porous ceramic member so as to be parallel to a through hole of the porous ceramic member;
Light detection means for detecting light leaking to the other end of the porous ceramic member, the porous ceramic member,
After moving the porous ceramic member between the light irradiating means and the light detecting means, such that a straight line connecting the light irradiating means and the light detecting means and the through hole are parallel to each other, A moving means configured to sequentially move the porous ceramic member so that light is irradiated from one end of the porous ceramic member to all through holes including the through hole sealed with the filler. It is characterized by having.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a method and an apparatus for inspecting defects of a porous ceramic member according to the present invention will be described with reference to the drawings.

[0012] The defect inspection method for a porous ceramic member according to the present invention is a defect inspection method for detecting a defect present in a porous ceramic member, wherein the porous ceramic member has a large number of through holes in a longitudinal direction thereof. Are arranged side by side, one end of the through hole is filled with a filler in a checkered pattern, and the other end is filled with a filler in a through hole in which the one end is not filled with a filler. Is a columnar porous ceramic member, and the detection of the defect of the porous ceramic member is performed by irradiating light from one end of the porous ceramic member so as to be parallel to a through hole of the porous ceramic member,
The detection is performed by detecting light leaking to the other end of the porous ceramic member.

First, a porous ceramic member to be inspected in the present invention will be described with reference to FIGS. 1 (a) and 1 (b). FIG. 1A is a perspective view showing one embodiment of the porous ceramic member, and FIG.
FIG. 3A is a sectional view taken along line AA of FIG.

The porous ceramic member is shown in FIG.
As shown in the figure, a large number of through holes 11 are arranged in the longitudinal direction, one end of the through hole 11 is filled with a filler 12 in a checkered pattern, and the other end is filled with one end. Lumber 12
Is a columnar shape in which the filler 12 is filled in the through holes 11 not filled with the filler.

The inside of the porous ceramic member is shown in FIG.
The partition 13 is formed as shown in FIG. Therefore, the gas flowing into one through hole 11 must be
After passing through the partition 13 separating the partition wall 13, it flows out from the other through-hole 11. If there is a substance such as powder in the gas that cannot pass through the partition 13, the substance that cannot pass through the partition 13 is When the gas passes through the partition 13, the gas is trapped at the partition 13. FIG. 1 (a)
Although the porous ceramic member 10 shown in (1) has a square pillar shape, the shape of the porous ceramic member to be subjected to the defect inspection is not limited to the square pillar shape, and may be a triangular pillar or a pentagonal pillar shape. It may be cylindrical.

The porous ceramic member 10 is prepared by, for example, preparing a mixed composition of a ceramic powder, a binder, and a dispersion medium, and then molding the mixed composition using an extruder.
After the filler is filled in a checkered pattern in the through-holes of the obtained molded body, drying, degreasing and firing are performed.
The ceramic powder is not particularly limited, for example,
Non-oxide ceramic powders such as silicon carbide, silicon nitride, aluminum nitride, boron nitride, titanium nitride, and titanium carbide; and oxide ceramic powders such as alumina, cordierite, mullite, silica, zirconia, and titania. be able to. Among these, powders of silicon carbide, silicon nitride, aluminum nitride, and the like having excellent heat resistance are preferable.

The particle size of these ceramic powders is not particularly limited, but it is preferable that the shrinkage is small in the subsequent firing step, for example, 100 parts by weight of a powder having an average particle size of about 0.3 to 50 μm. What combined with 5 to 65 weight part of powder which has an average particle diameter of about 0.1-1.0 micrometer is preferable.

The binder is not particularly limited.
For example, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyethylene glycol, phenol resin, epoxy resin and the like can be mentioned. Usually, the amount of the binder is preferably about 1 to 10 parts by weight based on 100 parts by weight of the ceramic powder.

The dispersion medium is not particularly restricted but includes, for example, organic solvents such as benzene; alcohols such as methanol, and water. The dispersion medium is mixed in an appropriate amount so that the viscosity of the mixed composition falls within a certain range. The ceramic powder, the binder, the dispersion medium, and the like are mixed by an attritor or the like, then sufficiently kneaded by a kneader or the like, and then put into an extrusion molding apparatus.

Next, a method for inspecting a porous ceramic member for defects according to the present invention will be described with reference to FIG. The defect inspection method of the porous ceramic member of the present invention,
After irradiating light from one end of the through hole 11 in a direction parallel to the through hole 11, the presence or absence of the defect 14 is detected by detecting the presence or absence of light leaking to the other end of the through hole 11. It is.

That is, the filler 12 or the filler 12 and the partition 1
3 and the like, when the defect 14 exists,
The light emitted from one end of the
The light reaches the other end of the through hole 11 (optical path α). Therefore, the defect 14 can be detected by detecting the presence or absence of the reaching light.

On the other hand, the filler 12 or the filler 12 and the partition 1
If no defect 14 exists between the through hole 1 and
The light emitted from one end of the first hole 1 cannot pass through the filler 12, so that no light is detected at the other end of the through hole 11 (optical path β). Therefore, it can be seen that no defect 14 exists in the porous ceramic member 10 in which no light is detected at the other end of the through hole 11. By performing the above-described defect inspection method, it is possible to inspect whether or not the defect 14 exists in the porous ceramic member 10.

The type of light to be irradiated is not particularly limited, but is preferably visible light. This light may be white light or monochromatic light. This is because the presence or absence of light leakage can be visually observed,
This is because such light does not pass through the porous ceramic member 10 or the filler 12.

As described above, according to the defect inspection method of the present invention, the presence or absence of a defect is determined based on whether or not the light emitted from one end of the through hole leaks to the other end of the through hole. Therefore, as compared with the method of determining the presence or absence of a defect by X-ray irradiation, the presence or absence of a defect can be determined cheaply, safely, and accurately, and a 100% inspection can be performed unlike a destructive inspection.

Next, a defect inspection apparatus for a porous ceramic member according to the present invention will be described with reference to FIG. The defect inspection device for a porous ceramic member according to the present invention is a defect inspection device for detecting a defect existing in the porous ceramic member, and the porous ceramic member has a large number of through holes arranged in a longitudinal direction thereof. And one end of the through hole is
The checkerboard pattern is filled with filler, and the other end is
A pillar-shaped porous ceramic member in which the filler is filled in the through hole in which the one end is not filled with the filler,
The defect inspection device is a light irradiation unit that irradiates light from one end of the porous ceramic member so as to be parallel to a through hole of the porous ceramic member, and leaks to the other end of the porous ceramic member. Light detecting means for detecting incoming light; and the porous ceramic member, wherein the light irradiating means and the light detecting means are arranged such that a straight line connecting the light irradiating means and the light detecting means is parallel to the through hole. After moving the porous ceramic member between the means, so that light is irradiated from one end of the porous ceramic member to all through holes including the through hole plugged with the filler, Moving means configured to sequentially move the porous ceramic member.

FIG. 2A is a plan view schematically showing a part of the defect inspection apparatus for a porous ceramic member according to the present invention, and FIG. 2B shows the direction in which the porous ceramic member moves. FIG. The defect of the porous ceramic member to be inspected by the defect inspection apparatus for a porous ceramic member according to the present invention is the same as that described in the defect inspection method for a porous ceramic member according to the present invention.

As shown in FIG. 2A, a defect inspection apparatus 20 for a porous ceramic member according to the present invention comprises a light irradiation means 21 for irradiating light, a light detection means 22 for detecting light, and Although not shown, a moving means for moving the porous ceramic member 10 to a predetermined position is provided.

Here, the porous ceramic member 10 is
This is the same as the porous ceramic member 10 described in the above-described method for inspecting the porous ceramic member for defects.

The light irradiating means 21 is not particularly limited as long as it can irradiate light in parallel with the through-hole of the porous ceramic member 10. For example, an irradiating device using a light bulb or the like, a search light, Any means such as a light emitting diode and a laser can be used. Further, it is preferable that the irradiated light is a visible light. The reason is the same as that described in the method for inspecting defects of a porous ceramic member.

As the light detecting means 22, any means can be used as long as it can detect light, but it is preferable to use a CCD camera. C
By connecting the CD camera and the display device with wiring,
This is because light leakage can be easily confirmed visually, and whether the porous ceramic member 10 is at a predetermined position can be confirmed. Also, CC
When light enters the D camera, the current escapes. Therefore, by detecting this current and inputting it to a computer or the like, it is possible to automatically determine whether or not light has leaked.

The light irradiation means 21 and the light detection means 2
2 is fixed on the same line. This is because the light detection unit 22 detects whether or not the light irradiated from the light irradiation unit 21 in parallel to the through hole of the porous ceramic member 10 has leaked.

The moving means is not particularly limited. For example, the porous ceramic member 10 can be supported and moved by a robot arm or the like. Further, the moving means includes a through hole sealed by a filler after moving one through hole of the porous ceramic member 10 on a straight line formed by the light irradiation means 21 and the light detection means 22. All the through holes of the porous ceramic member 10 are configured to sequentially move. Here, in FIG. 2 (b), the moving direction 23 of the porous ceramic member 10 is indicated by a bent arrow, but the moving direction of the porous ceramic member in the porous ceramic member defect inspection apparatus of the present invention is as follows. The present invention is not limited to this, and examples thereof include a direction obtained by rotating the moving direction 23 in FIG. 2B by 90 ° and a moving direction such as a spiral.

Next, a defect inspection method using the defect inspection apparatus for a porous ceramic member according to the present invention will be described.
First, a porous ceramic member filled with a filler and fired is manufactured. Next, the porous ceramic member is supported and fixed by a robot arm or the like, and then moved on a straight line formed by the light irradiation means and the light detection means.

At this time, the porous ceramic member is moved so that the light irradiated by the light irradiation means is irradiated in parallel to one through hole of the porous ceramic member.
Further, the one through hole is preferably any one of the four through holes formed at the four corners of the porous ceramic member. This is because the moving direction when moving the porous ceramic member can be simplified.

After moving the porous ceramic member to a predetermined position, a laser or the like is irradiated from a light irradiation means in parallel with the through-hole of the porous ceramic member. Then, light detecting means such as a CCD camera detects the presence or absence of leaking light.
Here, if light leakage is not confirmed, the same inspection is performed by moving the porous ceramic member so that the next through hole is on a straight line formed by the light irradiation means and the light detection means.
The same inspection is sequentially performed on all the through-holes including the through-hole sealed with the filler, thereby inspecting the porous ceramic member for defects.

When light leakage is detected by a light detecting means such as a CCD camera, the robot arm or the like repels the porous ceramic member as a defective product from the production line at that time. After inspecting all of the through holes, the porous ceramic member may be set to repel, but in this case, it is set to repel at the time when light leakage is confirmed due to much waste of time. Is preferred.

Such a series of inspection steps are performed while being automatically controlled by control means such as a computer. That is, the control unit such as the computer is connected to each unit such as a light irradiation unit, a light detection unit, and a movement unit, and the movement of the porous ceramic member, the irradiation of light, the confirmation of light leakage,
Each control such as popping out of the porous ceramic member is automatically performed. Further, by connecting display means such as a display directly to the light detection means or via the control means, each inspection process can be visually confirmed.

By controlling the defect inspection apparatus for a porous ceramic member of the present invention by a control means such as a computer, the defect inspection of the porous ceramic member can be performed quickly and accurately, and the display and the like can be controlled. Inspection status can be checked visually one by one by providing the display means.

As described above, the defect inspection apparatus for a porous ceramic member according to the present invention uses the porous ceramic member according to whether or not the light irradiated from one end of the through hole leaks to the other end of the through hole. In order to determine the presence or absence of a defect, compared to a method of determining a defect by X-ray irradiation, it is cheaper, safer, and
The presence or absence of a defect can be accurately determined. Also, unlike the destructive inspection, a 100% inspection can be performed. Also,
When the leaked light is detected, it can be immediately determined to be a defect, so that the productivity is high.

[0040]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 An organic binder, water, etc. were added to a silicon carbide powder and kneaded, followed by extrusion molding to produce a honeycomb-shaped molded body, followed by drying, degreasing, and firing. 1
A porous ceramic member having an average pore diameter of 5 to 20 μm, 31 cells per cm ² , and a partition wall thickness of 0.3 mm was prepared as shown in FIG.

Next, the obtained porous ceramic member is inspected for defects using the porous ceramic member defect inspection apparatus 20 shown in FIG. It was separated into a porous ceramic member.

Next, the vicinity of the filler of each porous ceramic member was cut in a direction perpendicular to the axial direction of the porous ceramic member, and the presence or absence of defects was visually checked.

As a result, in the porous ceramic member in which a defect was detected by the porous ceramic member defect inspection apparatus 20 of the present invention, a defect was confirmed between the filler and the partition wall, while no defect was detected. No defects were found in the porous ceramic member.

[0045]

The method for inspecting defects of a porous ceramic member according to the present invention is as described above. Therefore, the defect of the porous ceramic member can be detected at low cost, safely and accurately, and the production can be performed. It is highly likely.

The defect inspection apparatus for a porous ceramic member according to the present invention is as described above. Therefore, by using this inspection apparatus, it is possible to provide a low-cost, safe, and accurate apparatus.
In addition, defects of the porous ceramic member can be detected with high productivity.

[Brief description of the drawings]

FIG. 1A is a perspective view schematically showing an example of a porous ceramic member to be inspected according to the present invention,
(B) is a sectional view taken along line AA of (a).

FIG. 2 (a) is a partial plan view schematically showing a part of one embodiment of a porous ceramic member defect inspection apparatus of the present invention, and FIG. 2 (b) is a porous ceramic of the present invention. It is the front view which showed an example of the moving direction of the porous ceramic member of the member defect inspection apparatus.

FIG. 3 is a perspective view schematically showing a ceramic filter.

FIG. 4A is a perspective view schematically showing a porous ceramic member constituting a ceramic filter, and FIG.
FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 5 is a cross-sectional view schematically showing one embodiment of a conventional defect detection by X-ray irradiation.

[Explanation of symbols]

 10, 30 Porous ceramic member 11, 31 Through hole 12, 32 Filler 13, 33 Partition wall 14 Defect 20 Defect inspection device for porous ceramic member 21 Light irradiation means 22 Light detection means 40 Ceramic filter

Claims (2)

[Claims] 1. A defect inspection method for detecting a defect present in a porous ceramic member, wherein the porous ceramic member has a plurality of through holes arranged in a longitudinal direction thereof, and one end of the through hole. Is a pillar-shaped porous ceramic member in which a checkerboard pattern is filled with a filler, and the other end is filled with a filler in a through hole in which the one end is not filled with the filler, The detection of the defect of the porous ceramic member is performed by irradiating light from one end of the porous ceramic member so as to be parallel to a through hole of the porous ceramic member and leaking to the other end of the porous ceramic member. A defect inspection method for a porous ceramic member, which is performed by detecting incoming light. 2. A defect inspection apparatus for detecting a defect existing in a porous ceramic member, wherein the porous ceramic member has a large number of through holes arranged in a longitudinal direction thereof, and one end of the through hole. Is a pillar-shaped porous ceramic member in which a checkerboard pattern is filled with a filler, and the other end is filled with a filler in a through hole in which the one end is not filled with the filler, The defect inspection apparatus, light irradiation means for irradiating light from one end of the porous ceramic member so as to be parallel to the through hole of the porous ceramic member,
Light detection means for detecting light leaking to the other end of the porous ceramic member, and the porous ceramic member,
After moving the porous ceramic member between the light irradiating means and the light detecting means, so that a straight line connecting the light irradiating means and the light detecting means and the through hole are parallel to each other, A moving means configured to sequentially move the porous ceramic member so that light is applied to all through holes including a through hole sealed with the filler from one end of the porous ceramic member; A defect inspection apparatus for a porous ceramic member, comprising: