JP2009085673A - Defect inspection method and defect inspection device of sealed honeycomb structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defect inspection method and a defect inspection device of a sealed honeycomb structure, capable of specifying the position of a cell having a defect and of readily grasping the defect size. <P>SOLUTION: In this method for inspecting a penetration defect of a sealed honeycomb structure 1 equipped with a honeycomb structure 2, wherein a plurality of cells 9 communicated between two end faces are partitioned and formed by a porous bulkhead 7, and a sealing part 11 disposed so as to seal either of two opening ends of each cell 9, particles 51 for quantification having a prescribed particle size range are introduced into the cell 9 from either end face; the number and the particle size of the particles 51 for quantification passing a penetration defect 17 and discharged from the end face on the opposite side are measured relative to each cell having the defect through which the particles are discharged; and the defect size is quantified from the measured number and particle size of the particles 51 for quantification. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for detecting a defect in a plugged honeycomb structure used for a filter for filtering particulate matter such as a diesel particulate filter (DPF).

  Since exhaust gas discharged from internal combustion engines such as diesel engines contains a large amount of particulates (particulate matter) mainly composed of carbon that cause environmental pollution, these exhaust systems In general, a filter for collecting (filtering) particulates is mounted.

  Normally, a filter used for such a purpose has a honeycomb structure in which a plurality of cells 9 communicating between two end faces are defined by porous partition walls 7 as shown in FIGS. 6 and 7. The one end surface side and the other end surface side of the honeycomb structure 2 have a complementary checkered pattern so as to plug the body 2 and one of the two open ends of each cell 9. A plugged honeycomb structure 1 including a plugged portion 11 disposed on the plug is used.

  The exhaust gas flows into the inside from one end face 3 of the filter made of such a plugged honeycomb structure 1 and flows out from the other end face 5 after the particulates contained in the gas are removed. Specifically, first, the exhaust gas flows into a cell 9b whose end is not sealed at one end face 3 of this filter and whose end is sealed at the other end face 5, and the porous partition wall 7 is passed through. Then, the cell moves to a cell 9a whose end is sealed at one end surface 3 and whose end is not sealed at the other end surface 5, and is discharged from this cell 9a. At this time, the partition walls 7 become filtration layers, and particulates in the gas are captured by the partition walls 7 and deposited on the partition walls 7.

  By the way, in such a plugged honeycomb structure, in the manufacturing process, a penetrating defect such as a pinhole or a crack penetrating the partition wall is likely to occur, and when there is a penetrating defect larger than the particulate, a part of the particulate Will pass through the defect without being captured and will be discharged to the outside. Therefore, it is extremely important to grasp the presence or absence of through defects in the plugged honeycomb structure and the size thereof.

  Conventionally, as a method for inspecting such defects, fine particles are introduced into the cell from one end face of the plugged honeycomb structure, and laser light is irradiated to the fine particles that pass through the through defects and are discharged from the opposite end face. An inspection method for detecting defects by visualizing fine particles is known (for example, see Patent Document 1).

However, with this inspection method, although it is possible to identify the position of a cell having a defect (a cell having a through defect in a partition wall that divides the cell), it is difficult to grasp the size of the defect. .
JP 2002-357562 A

  The present invention has been made in view of such conventional circumstances, and the object of the present invention is to identify the position of a defective cell and to easily grasp the size of the defect. An object of the present invention is to provide a defect inspection method and a defect inspection apparatus for a plugged honeycomb structure.

  In order to achieve the above object, according to the present invention, the following defect inspection method and defect inspection apparatus for a plugged honeycomb structure are provided.

[1] A honeycomb structure in which a plurality of cells communicating between two end faces are partitioned by a porous partition wall, and either one of two open ends of each cell is plugged. A method for inspecting a penetration defect of a plugged honeycomb structure provided with a plugging portion disposed in the cell, wherein the quantification particles having a predetermined particle size range from any one end face The number of particles for quantification and the particle size discharged from the opposite end surface after passing through the penetration defect were measured for each cell having a defect discharging the particle, and measured. A defect inspection method (first inspection method) for a plugged honeycomb structure in which the size of the defect is quantified based on the number and particle diameter of the quantification particles.

[2] A honeycomb structure in which a plurality of cells communicating between two end faces are partitioned by a porous partition wall, and either one of two open ends of each cell is plugged. A method for inspecting a through-hole defect of a plugged honeycomb structure provided with a plugged portion disposed in the laser, introduces laser visualization particles into a cell from one of the end faces, and passes through the through-hole defect Then, the laser visualization particles discharged from the opposite end face are visualized by irradiating with laser light, and the position of the cell having the defect is specified, and then the quantification having a predetermined particle size range from either one end face The quantification particles are introduced into the cell, and the number and the particle size of the quantification particles discharged from the opposite end face through the penetrating defect are measured for each cell having the defect discharging the particle. The number of quantification particles measured and Defect inspection method of the plugged honeycomb structure to quantify the size of the defect from the particle size (second inspection method).

[3] A honeycomb structure in which a plurality of cells communicating between two end faces are partitioned by a porous partition wall, and either one of two open ends of each cell is plugged. Quantifying particle generating means for inspecting a penetration defect of a plugged honeycomb structure provided with a plugging portion disposed on the generating unit and generating quantifying particles having a predetermined particle size range Quantifying particle introducing means for introducing the quantifying particles generated by the quantifying particle generating means into a cell from any end face of the honeycomb structure, and passing through a penetration defect A defect of a plugged honeycomb structure provided with a measuring means for measuring the number and particle size of the quantifying particles discharged from the end surface on the opposite side to the end surface on which the quantifying particles are introduced Inspection device (first inspection device).

[4] A honeycomb structure in which a plurality of cells communicating between two end faces are partitioned by a porous partition wall, and either one of two open ends of each cell is plugged. A device for inspecting a penetration defect of a plugged honeycomb structure provided with a plugging portion disposed in a laser visualization particle generating means for generating laser visualization particles, and generation of the laser visualization particles Laser visualization particle introduction means for introducing the laser visualization particles generated by the means into the cell from any end face of the honeycomb structure, and introducing the laser visualization particles through a penetration defect Laser light generating means for generating laser light for visualizing the laser visualization particles discharged from the end face opposite to the end face on the opposite side, and quantification having a predetermined particle size range Quantifying particle generating means for generating particles, and for quantification for introducing the quantifying particles generated by the quantifying particle generating means into a cell from any end face of the honeycomb structure Particle introduction means, and measurement means for measuring the number and particle size of the quantification particles discharged from the end face opposite to the end face on which the quantification particles are introduced after passing through a penetration defect; A defect inspection apparatus for a plugged honeycomb structure (second inspection apparatus).

[5] The defect inspection apparatus for a plugged honeycomb structure according to [3] or [4], wherein an ultrasonic atomizer is used as the quantification particle generating unit.

[6] The eye according to [3] or [4], wherein the measurement unit includes an illumination for visualizing the quantification particles and a camera for photographing the visualized quantification particles. Defect inspection device for sealed honeycomb structure.

[7] The defect inspection apparatus for a plugged honeycomb structure according to [3] or [4], wherein a particle counter is used as the measurement unit.

  ADVANTAGE OF THE INVENTION According to this invention, while specifying the position of the cell with a defect of a plugged honeycomb structure, the magnitude | size of a defect can be quantified and can be grasped | ascertained easily.

  Hereinafter, typical embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and those skilled in the art can depart from the scope of the present invention. It should be understood that design changes, improvements, and the like can be made as appropriate based on general knowledge of the above.

  FIG. 1 is a schematic explanatory view showing an example of an embodiment of the first inspection method of the present invention. The first inspection method of the present invention can be easily implemented by using the first inspection apparatus of the present invention. The first inspection apparatus of the present invention comprises a quantifying particle generating means for generating quantifying particles having a predetermined particle size range, and the quantifying particles generated by the quantifying particle generating means. Quantifying particle introduction means for introducing into the cell from any end face of the honeycomb structure, and discharging from an end face opposite to the end face on the side through which the quantifying particles have been introduced after passing through a penetration defect Measuring means for measuring the number and particle size of the quantifying particles.

  In the embodiment of FIG. 1, an ultrasonic atomizer 20 is used as the quantification particle generating means, and the ultrasonic atomizer 20 and one end face of the plugged honeycomb structure 1 are communicated with the quantification particle introducing means. A hood 21 is used. Further, a laser light source 22 for visualizing the quantification particles and a camera 23 for photographing the visualized quantification particles are used as the measurement means. It is preferable to seal between the hood 21 and the plugged honeycomb structure 1 with a sealing material 19 in order to maintain airtightness.

  In the present embodiment, first, a honeycomb structure 2 in which a plurality of cells 9 communicating between two end surfaces are partitioned by a subject of the present invention, that is, a porous partition wall 7, and two cells 9 are provided. A plugged honeycomb structure 1 including a plugged portion 11 disposed so as to plug any one of the two open ends is disposed such that two end surfaces are in the vertical direction. Then, liquid particles having a predetermined particle size range (for example, 10 to 30 μm) generated by the ultrasonic atomizer 20 are guided to the upper end face of the plugged honeycomb structure 1 through the hood 21 as quantification particles 51. Then, the quantification particles 51 are introduced into the cell 9 opened at the end face.

  When the plugged honeycomb structure 1 has the penetration defect 17, a part of the quantification particles 51 passes through the penetration defect 17 and is discharged from the lower end face. The number and particle size of the quantification particles 51 thus discharged are measured for each defective cell that has discharged the particles. The measurement for each cell is performed by, for example, attaching a masking material 25 having a hole only in a portion corresponding to the opening of the cell 9 to be measured to the lower end face as shown in the figure. The quantification particle 51 is discharged only from the opening of the laser beam, and the quantification particle 51 is discharged by irradiating the laser light along the end surface from the laser light source 22 disposed in the vicinity of the lower end surface. Is visualized and the image is taken by a camera 23 arranged at a position facing the laser light source 22. The number and particle size of the quantification particles 51 discharged from the image thus taken are measured.

  In general, the larger the penetrating defect, the larger the number of quantification particles discharged, and the more quantification particles having a larger particle size are discharged. Therefore, between the number of quantification particles having a particle size in a predetermined range discharged through the through defects of the plugged honeycomb structure and the size of the through defects that passed through, an experimental example to be described later There is a correlation as shown in If such a correlation is examined in advance and graphed, the size of the penetrating defect is quantified from the number and particle diameter of the quantification particles measured as described above based on the correlation. Can be By quantifying the size of the through defect in this way, it is possible not only to specify the position of the cell having the defect but also to easily grasp the size of the defect.

  In the embodiment of FIG. 1, the plugged honeycomb structure is arranged so that the two end faces thereof are in the vertical direction so that the flow of the quantification particles is smooth, and the quantification is performed from the top to the bottom. Chemical particles are allowed to flow. This is because the direction of the flow of the quantification particles is the direction of gravity, so that even quantification particles with a relatively large particle size flow smoothly due to natural fall, but the arrangement of the plugged honeycomb structure The direction and the direction in which the quantification particles flow are not limited to this.

  FIG. 2 is a schematic explanatory view showing an example of an embodiment of the second inspection method of the present invention. The second inspection method of the present invention can be easily implemented by using the second inspection apparatus of the present invention. The second inspection apparatus according to the present invention includes a laser visualization particle generating means for generating laser visualization particles, and the laser visualization particles generated by the laser visualization particle generation means in any of the honeycomb structures. A laser visualization particle introducing means for introducing the laser visualization particle into the cell from the end surface of the laser, and the laser visualization particle discharged from the end surface opposite to the end surface on the side through which the laser visualization particle is introduced after passing through the penetration defect. Laser light generation means for generating laser light for visualization, quantification particle generation means for generating quantification particles having a predetermined particle size range, and the quantification particle generation means generated by the quantification particle generation means Quantification particle introduction means for introducing quantification particles into the cell from any end face of the honeycomb structure, and through the through defects, the quantification particles And a measuring means for measuring the number and particle size of the quantification for particles discharged from the end face opposite the end face on the side where the introduction of the child.

  In the embodiment of FIG. 2, the ultrasonic humidifier 30 is used as the laser visualization particle generating means, and the ultrasonic humidifier 30 and the one end face of the plugged honeycomb structure 1 are used as the laser visualization particle introducing means. A communicating hood 31 is used, and a laser light source 32 is used as laser light generating means. Further, an ultrasonic atomizer 20 is used as the quantification particle generating means, and a hood 21 communicating between the ultrasonic atomizer 20 and one end face of the plugged honeycomb structure 1 is used as the quantification particle introducing means. A particle counter 24 is used as the measuring means. The space between the hoods 21 and 31 and the plugged honeycomb structure 1 is preferably sealed with a sealing material 19 in order to maintain airtightness.

  In the present embodiment, first, the plugged honeycomb structure 1 which is the subject of the present invention is arranged so that the two end faces thereof are in the vertical direction. Then, liquid particles having a predetermined particle size range (for example, 5 to 10 μm) generated by the ultrasonic humidifier 30 are used as laser visualization particles 52, and the lower end surface of the plugged honeycomb structure 1 through the hood 31. Then, the laser visualization particles are introduced into the cell 9 that is open at the end face. In this case, since the laser visualization particles 52 need to flow from the bottom to the top against gravity, a certain pressure is applied to the fluid containing the laser visualization particles, or suction is performed from the upper end surface with a suction nozzle or the like. It is preferable to do.

  When the through-hole defect 17 is present in the plugged honeycomb structure 1, the laser visualization particles 52 pass through the through-hole 17 and are discharged from the upper end surface. The laser visualization particles 52 thus discharged are visualized by irradiating laser light along the end surface from a laser light source 32 disposed in the vicinity of the upper end surface. The laser visualizing particle 52 is discharged from a cell having a defect (a cell having a penetrating defect in a partition partitioning the cell), so that the position of the cell having the defect is specified by visualizing the particle. it can. Although it is possible to identify the position of a cell having a defect with the naked eye, the laser visualization particles 52 are discharged by the camera 40 disposed above the plugged honeycomb structure 1 as shown in FIG. It is preferable to take a picture of the situation and specify the position of a cell having a defect from the obtained image.

  Next, liquid particles having a predetermined particle size range (for example, 10 to 30 μm) generated by the ultrasonic atomizer 20 are used as the quantification particles 51 and led to the upper end face of the plugged honeycomb structure 1 through the hood 21. Then, the quantification particles 51 are introduced into the cell 9 opened at the end face.

  When the plugged honeycomb structure 1 has the penetrating defect 17, a part of the quantification particles 51 passes through the penetrating defect and is discharged from the lower end face. The number and particle size of the quantification particles 51 thus discharged are measured for each defective cell that has discharged the particles. In the measurement for each cell, for example, as shown in the figure, the opening of the cell 9 to be measured and the particle counter 24 are communicated with each other by a cylindrical communication member 26, and then discharged from the opening of the cell 9. Only the quantification particles are sent to the particle counter 24, and the number and particle size of the quantification particles 51 discharged by the particle counter 24 are measured.

  As described above, there is a correlation between the number of quantification particles having a particle size in a predetermined range discharged through the through defects of the plugged honeycomb structure and the size of the through defects that have passed. Therefore, if such correlation is examined in advance and graphed, the size of the penetrating defect is quantified from the measured number and particle size of the quantification particles based on the correlation. be able to. By quantifying the size of the through defect in this way, it is possible not only to specify the position of the cell having the defect but also to easily grasp the size of the defect.

  In the embodiment of FIG. 2, the plugged honeycomb structure is arranged so that the two end faces thereof are in the vertical direction, the laser visualization particles flow from the bottom to the top, and the quantification particles from the top. It is made to flow down. This is because laser visualization particles are used only to locate defective cells, so there is no need to use particles with a wide particle size range, and they can be easily applied by slight pressure or suction. In contrast, particles with a relatively small particle size that can be increased can be used, while particles for quantification use particles with a certain wide particle size range in order to accurately quantify the size of defects. Since it is necessary to use, the direction in which the quantification particles flow is the gravity direction, so that the quantification particles having a relatively large particle diameter flow smoothly due to natural fall. However, in the present invention, the arrangement direction of the plugged honeycomb structure and the flowing direction of the laser visualization particles and the quantification particles are not limited thereto.

  FIG. 3 is a schematic explanatory view showing another example of the embodiment of the second inspection method of the present invention. The present embodiment and the embodiment of FIG. 2 differ in the method for measuring the number and particle diameter of the quantification particles passing through the penetration defect and discharged from the lower end face for each cell. That is, in the present embodiment, the masking material 25 in which the hole is formed only in the portion corresponding to the opening of the cell 9 to be measured is attached to the lower end surface, for example, only from the opening of the cell 9. By irradiating the laser light along the end surface from the laser light source 22 disposed in the vicinity of the lower end surface, the discharged quantifying particle 51 is visualized in a state where the quantifying particle 51 is discharged. The image is taken by a camera 23 arranged at a position facing the laser light source 22. The number and particle size of the quantification particles 51 discharged from the image thus taken are measured. The present embodiment is the same as the embodiment of FIG. 2 except for this measurement method.

  FIG. 4 is a schematic explanatory view showing still another example of the embodiment of the second inspection method of the present invention. In this embodiment, the same particle chamber 33 is used for the laser visualization particle introduction means and the quantification particle introduction means of the second inspection apparatus of the present invention. In the particle chamber 33, the laser visualization particles 52 generated by the ultrasonic humidifier 30 and the quantification particles 51 generated by the ultrasonic atomizer 20 flow into the inside, and the plugged honeycomb structure. An opening 34 that communicates with one end surface of the body 1 is provided, and the particles can be introduced into the cell 9 through the opening 34.

  In the present embodiment, first, the plugged honeycomb structure 1 which is the subject of the present invention is fitted so that the two end faces are in the vertical direction and the lower end is fitted into the opening 34 of the particle chamber 33. Arrange to do. It is preferable to seal between the particle chamber 33 and the plugged honeycomb structure 1 with a sealing material 19 in order to maintain airtightness. Then, liquid particles having a predetermined particle size range (for example, 5 to 10 μm) generated by the ultrasonic humidifier 30 are flown into the particle chamber 33 as laser visualization particles 52, and then the inside of the particle chamber 33 is filled. The laser visualization particles 52 are introduced into the cells 9 opened on the lower end surface of the plugged honeycomb structure 1 by pressurization or suction from the upper end surface with a suction nozzle or the like.

  When the through-hole defect 17 is present in the plugged honeycomb structure 1, the laser visualization particles 52 pass through the through-hole 17 and are discharged from the upper end surface. The laser visualization particles 52 thus discharged are visualized by irradiating laser light along the end surface from a laser light source 32 disposed in the vicinity of the upper end surface. The laser visualizing particle 52 is discharged from a cell having a defect (a cell having a penetrating defect in a partition partitioning the cell), so that the position of the cell having the defect is specified by visualizing the particle. it can. Although it is possible to identify the position of the cell having a defect with the naked eye, as shown in the figure, the state in which the laser visualization particles 52 are discharged by the camera 40 disposed above the plugged honeycomb structure is shown. It is preferable that the position of a cell having a defect is specified from the obtained image.

  Next, liquid particles having a predetermined particle size range (for example, 10 to 30 μm) generated by the ultrasonic atomizer 20 are allowed to flow into the particle chamber 33 as quantification particles 51, and then the inside of the particle chamber 33 is added. The quantification particles 51 are introduced into the cells 9 that are open on the lower end surface of the plugged honeycomb structure 1 by, for example, pressing or suctioning from the upper end surface with a suction nozzle or the like.

  When the plugged honeycomb structure 1 has the penetration defect 17, a part of the quantification particles 51 passes through the penetration defect 17 and is discharged from the upper end face. The number and particle size of the quantification particles 51 thus discharged are measured for each defective cell that has discharged the particles. The measurement for each cell is, for example, discharged from the opening of the cell 9 by communicating the opening of the cell 9 to be measured and the particle counter 24 with a cylindrical communication member 26 as shown in FIG. Only the quantification particles 51 to be sent are sent to the particle counter 24, and the number and particle diameter of the quantification particles 51 discharged by the particle counter 24 are measured.

  As described above, there is a correlation between the number of quantification particles having a particle size in a predetermined range discharged through the through defects of the plugged honeycomb structure and the size of the through defects that have passed. Therefore, if such correlation is examined in advance and graphed, the size of the penetrating defect is quantified from the measured number and particle size of the quantification particles based on the correlation. be able to. By quantifying the size of the through defect in this way, it is possible not only to specify the position of the cell having the defect but also to easily grasp the size of the defect.

  In the embodiment of FIG. 4, the particle chamber is arranged on the lower side of the plugged honeycomb structure, and the laser visualization particles and the quantification particles both flow from the bottom to the top. The particle chamber may be arranged on the upper side of the plugged honeycomb structure so that the laser visualization particles and the quantification particles flow from top to bottom. In this case, since the direction in which the quantification particles flow matches the direction of gravity, even quantification particles having a relatively large particle diameter can flow smoothly due to natural fall.

  FIG. 5 is a schematic explanatory view showing still another example of the embodiment of the second inspection method of the present invention. The present embodiment and the embodiment of FIG. 4 differ in the method of measuring the number and particle size of the quantification particles that pass through the penetration defect and are discharged from the upper end surface for each cell. That is, in this embodiment, the masking material 25 in which a hole is formed only in a portion corresponding to the opening of the cell 9 to be measured is attached to the upper end surface, and the quantity is determined only from the opening of the cell 9. The quantification particles 51 are discharged, and the quantification particles 51 discharged are visualized by irradiating laser light from the laser light source 22 disposed in the vicinity of the upper end surface along the end surfaces. Is photographed with a camera 23 arranged at a position facing the laser light source. The number and particle size of the quantification particles 51 discharged from the image thus taken are measured. The present embodiment is the same as the embodiment of FIG. 4 except for this measurement method.

  In the present invention, it is preferable that the particle size range of the laser visualization particles is about 5 to 10 μm in consideration of the ease of passing through defects. As the laser visualization particle generating means for generating laser visualization particles, in addition to the ultrasonic humidifier used in the above embodiment, for example, a device that generates fine particles (smoke) by burning such as an incense stick is used. You can also.

  On the other hand, in order to accurately quantify the size of defects, it is necessary to use particles having a certain wide particle size range, and the particle size range should be about 10 to 30 μm. Is preferred. The ultrasonic atomizer used in the above-described embodiment is suitable for the particle generation means for quantification, but is particularly limited as long as particles having a wide particle size range as described above can be generated. It is not a thing.

  The laser visualization particle introduction means and the quantification particle introduction means include a gap between the laser visualization particle generation means and the quantification particle generation means and one end face of the plugged honeycomb structure as in the above embodiment. A communicating hood or particle chamber can be suitably used. If particles cannot be introduced into the cell by natural fall, such as when the direction of introduction of laser visualization particles or quantification particles is from top to bottom, laser visualization particle introduction means or quantification The chemicalizing particle introducing means may be provided with a pressurizing device or a suction device.

  The measurement means is a combination of the particle counter used in the embodiment, illumination for visualizing the quantification particles (for example, a laser light source), and a camera for photographing the visualized quantification particles. However, there is no particular limitation as long as the number and size of particles can be measured with a certain degree of accuracy. As a measuring means combining a laser light source and a camera, for example, an image analysis type particle size measuring system (trade name: VisiSizer) manufactured by Nippon Laser Co., Ltd. can be preferably used.

  In addition, when using illumination and lasers, such as a laser light source, as a measurement means, if it is possible to measure discharged | emitted quantification particle | grains for every cell with a defect, it shows in FIG.1, FIG.3, FIG.5. As in the embodiment, it is not always necessary to arrange the illumination and the camera on a straight line parallel to the end face of the plugged honeycomb structure. For example, the position where the camera faces the end face of the plugged honeycomb structure You may arrange in.

  In the following, an experiment is conducted on the correlation between the number of particles for quantification having a particle size in a predetermined range discharged through the through defects of the plugged honeycomb structure and the size of the through defects that have passed. This will be explained with an example.

(Experimental example)
Plugged honeycomb structure made of cordierite (diameter: 9 inches (229 mm), length: 11 inches (279 mm), partition wall thickness: 12 mil (304 μm), porosity: 52%, cell density: 300 cells / Square inch (46.5 cells / cm ² ), cell shape: square, plugging pattern: plugged portions are formed at one end of each cell so that both end faces have a complementary checkerboard pattern) 6 (sample Nos. 1 to 6) were prepared. A cell opened at one end face of each of the plugged honeycomb structures as a laser visualization particle having a particle size range of 5 to 10 μm generated by an ultrasonic humidifier. The position of the cell with the defect was specified by visualizing the laser visualization particles introduced into the interior and discharged from the opposite end face by irradiating laser light from a laser light source disposed in the vicinity of the end face.

  Next, from one end face of each plugged honeycomb structure, a liquid particle having a particle size range of 10 to 30 μm generated by an ultrasonic atomizer is used as a quantifying particle, and a cell is opened at the end face. Quantification that is introduced into the opposite end surface of the defective cell identified as described above on the opposite end surface and the particle counter with a cylindrical communication member and discharged from the opening of the cell. Only the particles for use are sent to the particle counter (particle counter flow rate: 30 L / min), and the number of particles for quantification (number per particle counter flow rate of 10 L) and particles discharged from the cell by the particle counter The diameter is measured, and the result of measurement is the number of particles having a particle size of 10 μm or more and less than 20 μm, and the particle size is 20 μm And Table 1 is divided into a number of upper 30μm or smaller particles.

  In addition, for each plugged honeycomb structure, by introducing a fiberscope into the defective cell whose position is specified as described above, the actual position of the penetrating defect (quantification particles are discharged). The distance from the end face on the surface side), the type of defect, and the size of the defect are shown in the table, and the graph shows the relationship between the number of particles for quantification measured as described above and the actual size of the defect. This is shown in FIG.

  In this experimental example, a correlation was recognized between the number of quantification particles having a particle diameter of 10 μm or more and less than 20 μm, which was measured by a particle counter after passing through a penetration defect, and the measured quantification. The number of crystallization particles and the size of defects are approximately proportional. Thus, there is a correlation between the number of quantification particles having a particle size in a predetermined range discharged through the through defects of the plugged honeycomb structure and the size of the through defects that passed through, If the relationship between the two is grasped by graphing in advance, the size of the defect is measured by measuring the number and particle size of the quantification particles discharged from the defective cell as in the inspection method of the present invention. It becomes possible to quantify the thickness.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used as a method and apparatus for detecting defects in a plugged honeycomb structure used for a filter or the like for filtering particulate matter such as DPF.

It is a schematic explanatory drawing which shows an example of embodiment of the 1st test | inspection method of this invention. It is a schematic explanatory drawing which shows an example of embodiment of the 2nd test | inspection method of this invention. It is a schematic explanatory drawing which shows another example of embodiment of the 2nd test | inspection method of this invention. It is a schematic explanatory drawing which shows another example of embodiment of the 2nd test | inspection method of this invention. It is a schematic explanatory drawing which shows another example of embodiment of the 2nd test | inspection method of this invention. It is the schematic plan view seen from the end surface side which shows the basic structure of a plugged honeycomb structure. It is a schematic sectional drawing which shows the basic structure of a plugged honeycomb structure. It is a graph which shows the relationship between the number of the particle | grains for quantification measured in the experiment example, and the magnitude | size of an actual defect.

Explanation of symbols

1: plugged honeycomb structure, 2: honeycomb structure, 3: end face, 5: end face, 7: partition wall, 9: cell, 11: plugged portion, 17: penetration defect, 19: sealing material, 20: Ultrasonic atomizer, 21: Hood, 22: Laser light source, 23: Camera, 24: Particle counter, 25: Masking material, 26: Communication member, 30: Ultrasonic humidifier, 31: Hood, 32: Laser light source, 33: Particle chamber, 34: opening, 40: camera, 51: particles for quantification, 52: particles for laser visualization.

Claims (7)

A honeycomb structure in which a plurality of cells communicating between two end faces are partitioned by a porous partition wall, and either one of two open ends of each cell is plugged. A method for inspecting a penetration defect of a plugged honeycomb structure provided with a plugged portion,
Quantification particles having a predetermined particle size range from any one end face are introduced into the cell, and the number and the particle diameter of the quantification particles discharged from the opposite end face after passing through a through defect. For each cell having a defect discharging the particles, and quantifying the size of the defect from the measured number and particle size of the quantification particles, a defect inspection method for a plugged honeycomb structure . A honeycomb structure in which a plurality of cells communicating between two end faces are partitioned by a porous partition wall, and either one of two open ends of each cell is plugged. A method for inspecting a penetration defect of a plugged honeycomb structure provided with a plugged portion,
Particles for laser visualization are introduced into the cell from one of the end faces, and the particles for laser visualization that pass through the penetrating defect and are discharged from the end face on the opposite side are visualized by laser light irradiation. After the position is specified, the quantification particles having a predetermined particle size range are introduced from one of the end faces into the cell, pass through the penetration defect, and discharged from the opposite end face. Plugged honeycomb structure for measuring the number and particle size of each of the cells having defects discharging the particles, and quantifying the size of the defect from the measured number and particle size of the quantification particles Body defect inspection method. A honeycomb structure in which a plurality of cells communicating between two end faces are partitioned by a porous partition wall, and either one of two open ends of each cell is plugged. A device for inspecting a penetration defect of a plugged honeycomb structure provided with a plugged portion,
Quantification particle generating means for generating quantification particles having a predetermined particle size range;
Quantification particle introduction means for introducing the quantification particles generated by the quantification particle generation means into a cell from any end face of the honeycomb structure;
Plugging device provided with a measuring means for measuring the number and particle size of the quantification particles discharged from the end surface on the opposite side to the end surface on which the quantification particles are introduced through a penetration defect Defect inspection device for honeycomb structure. A honeycomb structure in which a plurality of cells communicating between two end faces are partitioned by a porous partition wall, and either one of two open ends of each cell is plugged. A device for inspecting a penetration defect of a plugged honeycomb structure provided with a plugged portion,
Laser visualization particle generating means for generating laser visualization particles;
Laser visualization particle introduction means for introducing the laser visualization particles generated by the laser visualization particle generation means into a cell from any end face of the honeycomb structure;
Laser light generating means for generating laser light for visualizing the laser visualization particles discharged from the end surface on the opposite side to the end surface on the side through which the laser visualization particles are introduced through a penetration defect;
Quantification particle generating means for generating quantification particles having a predetermined particle size range;
Quantification particle introduction means for introducing the quantification particles generated by the quantification particle generation means into a cell from any end face of the honeycomb structure;
A plug provided with a measuring means for measuring the number and particle diameter of the quantification particles discharged from the end surface on the opposite side to the end surface on which the quantification particles are introduced through a penetration defect Defect inspection system for fixed honeycomb structure.   The defect inspection apparatus for a plugged honeycomb structure according to claim 3 or 4, wherein an ultrasonic atomizer is used as the quantification particle generating means.   The plugged honeycomb structure according to claim 3 or 4, wherein illumination for visualizing the quantification particles and a camera for photographing the visualized quantification particles are used for the measurement means. Defect inspection equipment.   The defect inspection apparatus for a plugged honeycomb structure according to claim 3 or 4, wherein a particle counter is used as the measuring means.

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