JP2013173243A - Inspection method for honeycomb structure, method for manufacturing honeycomb structure, honeycomb structure, design method of sealing mask, and inspection program for honeycomb structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection method and an inspection program for a honeycomb structure by which deviation in cell position of the honeycomb structure can be detected with higher accuracy, and to provide a method for manufacturing the honeycomb structure using the inspection method, a design method of a sealing mask, and the honeycomb structure manufactured by the manufacturing method.SOLUTION: Cell actual positions P at end faces 71a, 71b of a cell 70a of a honeycomb structure 70 are detected in advance (S104a), a mold cell 20a of a mold 20 for extrusion-molding the honeycomb structure 70 is used a cell reference point p and the cell actual positions P are compared with the cell reference point p-position (S104b). Deviation in the actual cell positions of the honeycomb structure 70 subjected to the extrusion molding by the mold 20 is evaluated using the mold 20 for extrusion-molding the honeycomb structure 70 as the reference, and as a result, the deviation in the cell positions of the honeycomb structure 70 can be detected with higher accuracy compared to a method of simply measuring dimensions of respective parts of the honeycomb structure 70 subjected to the extrusion molding.

Description

  The present invention relates to a honeycomb structure inspection method, a honeycomb structure manufacturing method, a honeycomb structure, and a honeycomb structure inspection program.

  Conventionally, honeycomb filter structures are widely known for DPF (Diesel particulate filter) and the like. In this honeycomb filter structure, a honeycomb structure in which a large number of through holes are arranged substantially in parallel and a plurality of through holes are arranged in a cell shape when viewed from the end face is manufactured by extrusion molding using a predetermined mold. After the extruded honeycomb structure is dried and cut to a predetermined length, one end side of a part of the cell structure consisting of many through holes is sealed with a sealing material, and the other end side of the remaining cells Seal with a sealing material.

  When only the desired through-holes on the end face of the honeycomb structure are sealed with the sealing material, a sealing mask made of metal or the like provided with openings at positions corresponding to the through-holes to be sealed is used. The following Patent Documents 1 and 2 describe a method of sealing a honeycomb structure using a sealing mask.

JP-A-2004-290766 JP 2008-132749 A

  By the way, in the manufacture of the honeycomb structure as described above, it is important to align the opening of the sealing mask and the through hole of the honeycomb structure. The sealing mask is designed, for example, by converting the shrinkage rate in the drying process performed after the extrusion molding process based on the design drawing of the mold used for the extrusion molding of the honeycomb structure. However, even if the positioning of the opening of the sealing mask and the through hole of the honeycomb structure is performed in this manner, the position of the through hole of the manufactured honeycomb structure is displaced from the ideal position. This is a problem for improving production efficiency and yield. In particular, when the honeycomb structure has a large diameter, the problem of cell wobbling particularly in the outer peripheral portion becomes a problem.

  The present invention has been made in view of the above problems, and has a honeycomb structure inspection method, a honeycomb structure inspection program, and an inspection method capable of detecting a displacement of a cell position of the honeycomb structure with higher accuracy. It is an object of the present invention to provide a method for manufacturing a used honeycomb structure, a sealing mask design method using this inspection method, and a honeycomb structure manufactured by this manufacturing method.

  The present invention relates to an actual position detecting step of detecting an actual position on an end face of a through hole of a honeycomb structure in which a plurality of through holes are arranged substantially in parallel and a plurality of through holes are arranged when viewed from the end face, and a honeycomb structure A method for inspecting a honeycomb structure including a position comparison step of comparing the actual position detected in the actual position detection step with the reference position, with a portion corresponding to the through hole in the mold for extrusion molding as a reference position.

  According to this configuration, the position corresponding to the through hole in the mold for detecting the actual position on the end face of the through hole of the honeycomb structure in the position detecting step and extruding the honeycomb structure in the position comparing step Is used as a reference position, and the actual position detected in the actual position detection step is compared with the reference position. In other words, on the basis of the mold for extruding the honeycomb structure, in order to evaluate the deviation of the actual cell position of the honeycomb structure extruded by the mold, each part of the honeycomb structure simply extruded It is possible to detect the displacement of the cell position of the honeycomb structure with higher accuracy than the method of measuring the dimensions of the honeycomb structure.

  In this case, in the actual position detection step, each actual position of the plurality of through holes is detected, and in the position comparison step, a position corresponding to each of the plurality of through holes in the mold is used as a reference position for each through hole. It is preferable to compare each actual position detected in the process with each reference position, derive each displacement between each actual position and each reference position, and derive a maximum displacement among each displacement.

  According to this configuration, in the actual position detection step, each of the actual positions of the plurality of through holes is detected, and in the position comparison step, a portion corresponding to each of the plurality of through holes in the mold is used as a reference position of each of the through holes. Each actual position detected in the actual position detection step is compared with each reference position, each displacement between each actual position and each reference position is derived, and the maximum displacement among each displacement is derived. Thereby, the shift of the cell position with respect to the mold can be quantitatively evaluated with a simple numerical value. For this reason, the deviation of the cell position with respect to the mold is reflected in the conditions such as the upstream extrusion process and the drying process, the downstream sealing process, etc. (feedback) to improve the manufacturing accuracy and yield of the honeycomb structure. Is possible.

  In this case, in the position comparison step, it is preferable to derive a correction amount that minimizes the maximum displacement when the entire reference position is corrected with respect to the entire actual position.

  According to this configuration, in the position comparison step, when the entire reference position is corrected with respect to the entire actual position, a correction amount that minimizes the maximum displacement is derived. Thereby, the displacement of the cell position with respect to the mold can be quantitatively evaluated with more specific numerical values. Further, it becomes easier to reflect the deviation of the cell position with respect to the mold in conditions such as the upstream extrusion process and the drying process and the downstream sealing process.

  In this case, in the position comparison step, in the Cartesian coordinate system with the coordinate axis orthogonal to the predetermined origin, the total correction amount of the reference position with respect to the entire actual position is calculated as the amount of movement in the direction parallel to the coordinate axis and the rotation angle around the origin. It is preferable to derive as at least one of the reduction ratio centered on the origin.

  According to this configuration, in the position comparison step, in the orthogonal coordinate system with the coordinate axes orthogonal to the predetermined origin, the total correction amount of the reference position with respect to the entire actual position is changed to the amount of movement in the direction parallel to the coordinate axis, around the origin It is derived as at least one of the rotation angle and the reduction ratio centered on the origin. Thereby, the displacement of the cell position with respect to the mold can be quantitatively evaluated with more specific numerical values. Further, it becomes easier to reflect the deviation of the cell position with respect to the mold in conditions such as the upstream extrusion process and the drying process and the downstream sealing process.

  Further, the present invention provides an extrusion process for extruding a honeycomb structure by a mold, a drying process for drying the honeycomb structure extruded by the extrusion process, and a honeycomb structure dried by the drying process. Inspection process for inspecting by the honeycomb structure inspection method of the present invention, and a plurality of through holes of the honeycomb structure inspected by the inspection process are covered with a sealing mask, and the sealing mask is interposed through the sealing mask And a sealing step of sealing a part of the through hole by supplying a sealing material to the through hole that is not covered with.

  According to this configuration, the inspection for inspecting the honeycomb structure by the inspection method of the present invention is performed after the extrusion process for extruding the honeycomb structure with a mold and the drying process for drying the extruded honeycomb structure. Then, a sealing step of sealing the through-holes of the honeycomb structure using a sealing mask is performed. For this reason, it is possible to improve the manufacturing accuracy and yield of the honeycomb structure by reflecting the displacement of the cell position with respect to the mold in the conditions such as the upstream extrusion process and the drying process and the downstream sealing process. Become.

  In this case, in the sealing step, it is preferable to select a honeycomb structure that does not perform the sealing step according to the inspection result in the inspection step.

  According to this configuration, in the sealing step, the honeycomb structures not subjected to the sealing step are selected according to the inspection result in the inspection step. As a result, for example, a honeycomb structure having a large cell position misalignment that cannot be sealed can be omitted, and generation of defective products can be prevented.

  In the drying process, it is preferable to change the drying conditions for drying the honeycomb structure according to the inspection result in the inspection process.

  According to this configuration, in the drying process, the drying conditions for drying the honeycomb structure are changed according to the inspection result in the inspection process. Thereby, for example, it is possible to change the drying conditions so as to suppress the variation in shrinkage rate in the drying process detected in the inspection process, and to improve the manufacturing accuracy and yield of the honeycomb structure.

  In the extrusion molding process, it is preferable to change the extrusion molding conditions for extruding the honeycomb structure according to the inspection result in the inspection process.

  According to this configuration, in the extrusion process, the extrusion conditions for extruding the honeycomb structure are changed according to the inspection result in the inspection process. Accordingly, for example, the extrusion molding conditions can be changed so as to suppress the deviation of the cell position detected in the inspection process, and the manufacturing accuracy and yield of the honeycomb structure can be improved.

  In the sealing step, it is preferable to select a sealing mask according to the inspection result in the inspection step.

  According to this configuration, in the sealing step, the sealing mask is selected according to the inspection result in the inspection step. Thereby, it is possible to select a sealing mask that matches the actually manufactured honeycomb structure.

  Further, the present invention is a honeycomb structure manufactured by the method for manufacturing a honeycomb structure of the present invention.

  According to this configuration, since the inspection process according to the inspection method of the present invention can be performed and the honeycomb structure manufactured with high accuracy and high yield can be obtained, the cost can be further reduced.

  In the present invention, a part of the plurality of through holes of the honeycomb structure is covered with a sealing mask, and a sealing material is supplied to the through holes not covered with the sealing mask through the sealing mask. This is a sealing mask design method in which a sealing mask for sealing a part of the sealing mask is designed according to the inspection result of the honeycomb structure inspection method of the present invention.

  According to this configuration, since the sealing mask is manufactured according to the inspection result of the inspection method of the present invention, it is possible to design the sealing mask having properties such as an optimal shrinkage rate.

  Further, the present invention provides an actual position detecting step for detecting an actual position on an end face of a through hole of a honeycomb structure in which a plurality of through holes are arranged substantially in parallel and a plurality of through holes are arranged when viewed from the end face; A honeycomb that causes an electronic computer to execute a position comparison step that compares the actual position detected in the actual position detection step with the reference position, with the portion corresponding to the through hole in the mold for extruding the structure as the reference position This is a structure inspection program.

  In this case, in the actual position detecting step, the electronic computer is made to detect each of the actual positions of the plurality of through holes, and in the position comparing step, the computer is made to select a portion corresponding to each of the plurality of through holes in the mold. As the reference position, each actual position detected in the actual position detection process is compared with each reference position, and the computer is caused to derive the displacement between each actual position and each reference position, and the maximum displacement among the displacements. Is preferably derived.

  In this case, in the position comparison step, it is preferable that the computer calculates a correction amount that minimizes the maximum displacement when the entire reference position is corrected with respect to the entire actual position.

  In this case, in the position comparison process, in the orthogonal coordinate system with the coordinate axes orthogonal to the predetermined origin, the total correction amount of the reference position with respect to the entire actual position is changed to the amount of movement in the direction parallel to the coordinate axis, the origin It is preferable to derive it as at least one of the rotation angle around and the reduction ratio centered on the origin.

  According to the honeycomb structure inspection method and the honeycomb structure inspection program of the present invention, the displacement of the cell position of the honeycomb structure can be detected with higher accuracy. In addition, according to the method for manufacturing a honeycomb structure of the present invention, it is possible to improve the manufacturing accuracy and yield of the honeycomb structure. Further, the honeycomb structure of the present invention can be made cheaper. Moreover, according to the sealing mask design method of the present invention, it is possible to design a sealing mask having properties such as an optimal shrinkage rate.

(A) is a perspective view of a honeycomb structure, (b) is the elements on larger scale of (a). It is a schematic sectional drawing which shows an example of the extrusion molding apparatus with which the metal mold | die which concerns on embodiment was mounted | worn. (A) is a figure which shows an example of the metal mold | die used for extrusion molding of the honeycomb structure which concerns on embodiment, (b) is the elements on larger scale of (a). It is a perspective view which shows the honeycomb structure with which the mask for sealing was mounted | worn with the end surface. (A) is a figure which shows the mask for sealing with which one end surface of a honeycomb structure is mounted | worn, (b) is the elements on larger scale of (a). (A) is a figure which shows the mask for sealing with which the other end surface of a honeycomb structure is mounted | worn, (b) is the elements on larger scale of (a). It is a figure which shows the apparatus for sealing concerning this embodiment. (A) is a figure which shows one end surface of the honeycomb structure sealed through the mask for sealing of Fig.5 (a), (b) is the elements on larger scale of (a). (A) is a figure which shows one end surface of the honeycomb structure sealed through the mask for sealing of Fig.6 (a), (b) is the elements on larger scale of (a). It is a figure which shows the state with the cell which each cell shifted | deviated from the reference position. (A) is a figure which shows one end surface of the honeycomb structure sealed through the mask for sealing of Fig.6 (a), (b) is the elements on larger scale of (a), Comprising: An example in which sealing was successful is shown, and an area F shows an example in which sealing has failed due to cell twisting. It is a flowchart which shows the process of the manufacturing method of the honeycomb structure of this embodiment. It is a flowchart which shows the detail of the test | inspection process of the honeycomb structure of this embodiment. It is a figure which shows the process of detecting the actual position of each cell based on the end surface image of the honeycomb structure extruded. It is a figure which shows what coordinated the real position of each cell of FIG. 14 on a rectangular coordinate. It is a figure which shows the process of determining the reference position of each cell based on the design drawing of the metal mold | die used for extrusion molding. FIG. 17 is a diagram illustrating a process of comparing the reference position determined in FIG. 16 and the actual position in FIG. 15 on orthogonal coordinates. It is a figure which shows the process which translates the whole reference position of FIG. 17 along an X-axis and a Y-axis, and rotates it around an origin. It is a figure which shows the process which shrinks | contracts the whole reference position of FIG. 17 centering on the origin. FIG. 20 is a diagram illustrating a state where the maximum deviation between the reference position and the actual position is minimized by repeating the processes of FIGS. 18 and 19. It is a figure which shows the state which displayed each deviation of the reference | standard position and real position of FIG. 20 with the vector. It is a figure which shows the state which displayed each shift | offset | difference of the reference | standard position and real position of FIG. 20 with a vector and a numerical value.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. First, prior to the description of the inspection method, inspection program, and manufacturing method according to the present invention, the honeycomb structure will be described.

(Honeycomb structure)
As shown in FIG. 1A, the honeycomb structure 1 is a cylindrical body in which a large number of through-holes (cells) 70a are arranged substantially in parallel. The cross-sectional shape of the through hole 70a is a regular hexagon as shown in FIG. The plurality of cells formed by the through holes 70a are arranged in the honeycomb structure 70 so that the central axes of the through holes 70a are located at the apexes of the equilateral triangle when viewed from the end faces 71a and 71b. The size and number of the through holes 70a can be arbitrarily set. Although the size of the honeycomb structure 70 can be arbitrarily set, as will be described later, in the present embodiment, the honeycomb structure 70 after the extrusion molding process and the drying process can be inspected with high accuracy. For example, the large honeycomb structure 70 having a diameter of the end faces 71a and 71b of 6 inches (15.24 cm), 10.5 inches (26.67 cm), or 12.5 inches (31.75 cm) or more is highly accurate and high. It becomes possible to manufacture with a yield.

  The material of the honeycomb structure 70 is not particularly limited, but a ceramic material is preferable from the viewpoint of high temperature resistance. Examples thereof include alumina, silica, mullite, cordierite, glass, oxides such as aluminum titanate, silicon carbide, silicon nitride, and metal. The aluminum titanate can further contain magnesium and / or silicon. Such a honeycomb structure 70 is usually porous.

  Further, the honeycomb structure 70 may be a green molded body (unfired molded body) that becomes a ceramic material as described above by being fired later. A green molded object contains the inorganic compound source powder which is a ceramic raw material, organic binders, such as methylcellulose, and the additive added as needed.

  For example, in the case of a green molded body of aluminum titanate, the inorganic compound source powder includes an aluminum source powder such as α-alumina powder, and a titanium source powder such as anatase-type or rutile-type titania powder. Furthermore, magnesium source powders such as magnesia powder and magnesia spinel powder and / or silicon source powders such as silicon oxide powder and glass frit can be included.

  Examples of the organic binder include celluloses such as methylcellulose, carboxymethylcellulose, hydroxyalkylmethylcellulose, and sodium carboxymethylcellulose; alcohols such as polyvinyl alcohol; and lignin sulfonate.

  Examples of the additive include a pore-forming agent, a lubricant and a plasticizer, a dispersant, and a solvent.

  Examples of the pore-forming agent include carbon materials such as graphite; resins such as polyethylene, polypropylene, and polymethyl methacrylate; plant materials such as starch, nut shells, walnut shells, and corn; ice; and dry ice.

  Examples of the lubricant and the plasticizer include alcohols such as glycerin; higher fatty acids such as caprylic acid, lauric acid, palmitic acid, arachidic acid, oleic acid and stearic acid; and stearic acid metal salts such as Al stearate.

  Examples of the dispersant include inorganic acids such as nitric acid, hydrochloric acid and sulfuric acid; organic acids such as oxalic acid, citric acid, acetic acid, malic acid and lactic acid; alcohols such as methanol, ethanol and propanol; ammonium polycarboxylate, poly Surfactants such as oxyalkylene alkyl ethers are listed.

  As the solvent, for example, alcohols such as methanol, ethanol, butanol and propanol; glycols such as propylene glycol, polypropylene glycol and ethylene glycol; and water can be used.

(Extrusion molding equipment and mold)
Next, an extrusion molding apparatus and a mold for manufacturing the above-described honeycomb structure 70 by extrusion molding will be described. The extrusion molding apparatus 10 shown in FIG. 2 is equipped with a mold 20 and is for manufacturing a honeycomb structure 70 from a powdery or pasty raw material composition.

  The extrusion molding apparatus 10 includes a screw 2A provided at the upper stage in the housing 1 and a screw 2B provided at the lower stage. The screws 2A and 2B are for kneading the raw material composition supplied from the inlet 1a and transferring it downstream through the flow path 1b. A vacuum chamber 3 is provided between the screws 2A and 2B, and the raw material composition can be degassed by reducing the pressure in the vacuum chamber 3. The raw material composition in the vacuum chamber 3 is introduced into the lower screw 2B by a roller 3a.

  The extrusion molding apparatus 10 includes a rectifying plate 5 provided on the downstream side of the screw 2B, a mold 20 from which a molded body 70A made of a raw material composition is extruded, a resistance tube 9 that communicates the flow path 1b and the mold 20 with each other. Is further provided. The resistance tube 9 has a tapered inner flow path, and the flow path cross-sectional area gradually decreases from the upstream side toward the downstream side. A support base 15 for supporting the molded body 70A is installed next to the extrusion molding apparatus 10 so that the molded body 70A extruded from the mold 20 is not deformed. Prior to the introduction of the raw material composition into the mold 20, the rectifying plate 5 is intended to make the flow velocity distribution uniform.

  As shown in the enlarged view of FIG. 3B, the mold 20 shown in FIG. 3A includes a mold groove 20b corresponding to the through hole 70a of the honeycomb structure 70 to be extruded, and a mold groove 20b. A plurality of regular hexagonal mold cells 20a are provided. From the mold groove 20, the raw material composition introduced from the current plate 5 side is extruded as a molded body 70A in which a plurality of regular hexagonal through holes 70a are arranged. Examples of the material of the mold 70 include carbon steel; special steel containing nickel, chromium, tungsten and the like.

(Extrusion of honeycomb structure)
Next, a method for manufacturing the honeycomb structure 70 using the extrusion molding apparatus 10 will be described. First, the mold 20 is mounted on the extrusion molding apparatus 10. When the preparation of the extrusion apparatus 10 is completed, the raw material composition is introduced into the flow path 1b from the inlet 1a. By operating the screws 2A, 2B and the roller 3a, the raw material composition is kneaded and transferred downstream. The kneaded material is passed through the opening 5 a of the rectifying plate 5 to make the flow velocity distribution uniform, and then introduced into the mold 20 through the resistance tube 9. The linear velocity of the raw material composition on the downstream side of the mold 20 is preferably about 10 to 150 cm / min, for example.

  The raw material composition having a uniform flow velocity distribution is extruded from the mold 20 and the compact 70 </ b> A is collected on the support base 15. After drying the formed body 70A, the honeycomb structure 70 described above is obtained by precision cutting to a predetermined length.

(Sealing mask and cell sealing)
Next, the sealing mask of the honeycomb structure 70 extruded as described above and the sealing of the cell 70a using the sealing mask will be described. As shown in FIG. 4, the sealing of the cells 70a of the honeycomb structure 70 is performed by mounting a sealing mask 170a on the end surface 71a. A sealing mask 170a shown in FIG. 5 (a) is used to seal cells 70a by predetermined through holes 70a on the end surface 71a side of the honeycomb structure 70 shown in FIG. As shown in the enlarged view of FIG. 5B, the sealing mask 170a is used for sealing such that only the portions of the through holes 70a that are not adjacent to each other among the through holes 70a on the end surface 71a side of the honeycomb structure 70 are opened. A mask opening 171 is provided. On the other hand, a sealing mask 170b shown in FIG. 6 (a) is used for sealing cells 70a by predetermined through holes 70a on the end face 71b side of the honeycomb structure 70 shown in FIG. As shown in the enlarged view of FIG. 6 (b), the sealing mask 170b is a part of the through holes 70a on the end surface 71b side of the honeycomb structure 70 other than the non-adjacent through holes 70a that are not open on the end surface 71a side. A sealing mask opening 171 is provided so that only the through hole 70a is opened.

  As materials for the sealing masks 170a and 170b, metals and resins can be used. As described later, in the present embodiment, the honeycomb structure 70 after the extrusion molding process and the drying process is inspected with high accuracy. Therefore, it can be made of stainless steel having excellent durability.

  Sealing of each through-hole 70a of the honeycomb structure 70 can be performed by a sealing device 200 as shown in FIG. The sealing device 200 includes a sealing device main body 210 and a support tool 80. The support 80 applies a load for pressing the honeycomb structure 70 having the end face 71a on which the sealing mask 170a is attached to the sealing device body 210. The sealing device main body 210 allows the through hole 70a by injecting the sealing material 130 into the through hole 70a through the sealing mask opening 171 of the sealing mask 170a. When the sealing on the end surface 71a side is completed, the sealing mask 170b is similarly mounted on the end surface 71b side, and the sealing on the end surface 71b side is similarly performed.

  The sealing material 130 is not particularly limited as long as it can close the end portion of the through hole 70a of the honeycomb structure 70, but is preferably liquid. For example, examples of the sealing material 130 include a slurry containing a ceramic material or a ceramic raw material, a binder, a lubricant, a pore forming agent, and a solvent.

  Examples of the ceramic material include the constituent material of the above-described honeycomb structure and the raw material thereof. The usage-amount of ceramic material can be 50-85 weight part with respect to 100 weight part of slurry, for example.

  Examples of the binder include celluloses such as methylcellulose, carboxymethylcellulose, hydroxyalkylmethylcellulose, and sodium carboxymethylcellulose; alcohols such as polyvinyl alcohol; and organic binders such as lignin sulfonate. The usage-amount of a binder can be 0-30 weight part with respect to 100 weight part of slurries, for example.

  Examples of the lubricant include alcohols such as glycerin; higher fatty acids such as caprylic acid, lauric acid, palmitic acid, arachidic acid, oleic acid and stearic acid; and stearic acid metal salts such as aluminum stearate. The usage-amount of a lubrication agent can be 0.5-20 weight part with respect to 100 weight part of slurries, for example.

  Examples of the pore-forming agent include carbon materials such as graphite; resins such as polyethylene, polypropylene, and polymethyl methacrylate; plant materials such as starch, nut shells, walnut shells, and corn; ice; and dry ice. The amount of pore-forming agent used can be, for example, 0 to 20 parts by weight with respect to 100 parts by weight of the slurry.

  As the solvent, for example, alcohols such as methanol, ethanol, butanol and propanol; glycols such as propylene glycol, polypropylene glycol and ethylene glycol; and water can be used. Of these, water is preferable, and ion-exchanged water is more preferably used from the viewpoint of few impurities. The usage-amount of a solvent can be 10-40 weight part with respect to 100 weight part of slurries, for example.

  As a result of such sealing, as shown in FIG. 8, only the through holes 70a that are not adjacent to each other are sealed on the end surface 71a side of the honeycomb structure 70. On the other hand, as shown in FIG. 9, on the end surface 71b side of the honeycomb structure 70, the through holes 70a other than the non-adjacent through holes 70a that are not sealed on the end surface 71a side are sealed.

  There is no problem if the positions of the through holes 70 of the honeycomb structure 70 after the extrusion molding and drying described above coincide with the positions of the sealing mask openings 171 of the sealing masks 170a and 170b. However, as shown in FIG. 10, there may be a cell wobbling in which the position of the through hole 70 a deviates from the ideal position 70 s depending on the conditions of extrusion molding and drying. In this case, as shown in FIG. 11 (b), which is an enlarged view of FIGS. 11 (a) and 11 (b), normal sealing is not performed as in the region S, and unintentional abnormal sealing is performed as in the region F. May be. Therefore, in the present embodiment, as described below, the inspection process is performed on the honeycomb structure 70 after the extrusion molding process and the drying process, and the result is fed back to each process.

(Manufacture of honeycomb structure and evaluation of cell twist)
Hereinafter, a method for manufacturing a honeycomb structure according to the present embodiment and a method for evaluating cell warpage will be described. As shown in FIG. 12, in this embodiment, as described above, the extrusion molding step (S101), the drying step (S102), and the precision cutting step (S103) are sequentially performed. After the precision cutting step, in this embodiment, a cell twist evaluation step described below is performed (S104).

  Hereinafter, the cell twist evaluation process of this embodiment will be described. The series of processes in the cell-by-cell evaluation process described below is automatically performed when the inspection program for the honeycomb structure of the present embodiment installed in the electronic computer causes the electronic computer to execute each process. Done. The following cell twist evaluation process may be performed on all the honeycomb structures 70 after the precision cutting process, or may be performed on a part of the honeycomb structures 70 after the precision cutting process.

  As shown in FIG. 13, the inspection program causes the electronic computer to execute a process to coordinate each cell based on the images of the end faces 71a and 71b of the honeycomb structure 70 (S104a). Assuming that image data of the end face 71a of the honeycomb structure 70 after the precision cutting process as shown in FIG. 14 is given, the inspection program reads the center of gravity of the cell 70a located at the center of the end face 71a into the electronic computer, The center of gravity of the cell 70a located at the center is defined as the origin of coordinates shown in FIG.

  The inspection program causes the computer to define a straight line passing through the origin and passing through the center of gravity of the other cell 70a as the Y axis. The inspection program causes the computer to define a straight line passing through the origin and perpendicular to the Y axis as the X axis. The inspection program instructs the computer to set the center of gravity of the first to ninth cells 70a on the X-axis and Y-axis cells 70a from the origin cell 70a to the outer periphery of the end face 71a as the cell actual position P of the cell 70a. Let it be coordinated. In the example of FIGS. 13 and 14, the inspection program instructs the electronic computer 70a on a straight line having angles of 30 °, 60 °, 120 °, 150 °, 210 °, 240 °, 300 ° and 330 ° from the X axis. Also, the center of gravity of the first to ninth cells 70a from the origin cell 70a toward the outer periphery of the end face 71a is coordinated as the cell actual position P of the cell 70a. In addition, the inspection program sends the computer a cell on a straight line on the X axis, on the Y axis, and at angles of 30 °, 60 °, 120 °, 150 °, 210 °, 240 °, 300 ° and 330 ° from the X axis. The center of gravity of the cell 71a located at the outermost periphery of the end surface 71a is defined as the cell actual position P.

  The inspection program causes the computer to compare the reference point based on the design drawing of the mold 20 in the extrusion process (S101) and the coordinated cell actual position P (S104b). As shown in FIG. 16, assuming that the data of the mold design drawing 20D of the mold 20 is given, the inspection program instructs the electronic computer to design the mold in the same manner as the cell actual position P described above is defined. The center of gravity of the mold cell 20a in the drawing 20D is defined as the cell reference point p. As a result, as shown in FIG. 17, on the orthogonal coordinates, each cell actual position P is located closer to the origin than each corresponding cell reference point p due to shrinkage due to the drying step (S102). .

  Note that the method of defining the cell actual position P and the cell reference point p can be changed according to individual situations. Arrangement, number, interval and the like of the cell actual position P and the cell reference point p can be arbitrarily set. In addition, the arrangement of the cell actual position P and the cell reference point p is not necessarily limited to the average arrangement on the end surface 71a. Depending on the situation, the cell actual position P and the cell reference point p may be placed in a specific range of the end surface 71a. Localization may be defined.

  As shown in FIG. 18, the inspection program causes the electronic computer to execute a process of moving a predetermined angle around the origin with respect to the whole cell position reference point p to reduce the deviation from each cell actual position P ( S104c). The inspection program causes the electronic computer to execute a process of moving a predetermined distance along the X axis with respect to the whole cell position reference point p to reduce the deviation from each cell actual position P (S104d). The inspection program causes the electronic computer to execute a process of moving a predetermined distance along the Y axis with respect to the entire cell position reference point p to reduce the deviation from each cell actual position P (S104e). As shown in FIG. 19, the inspection program executes a process of reducing the deviation from each cell actual position P by multiplying the whole cell position reference point p by a predetermined contraction rate with respect to the origin, as shown in FIG. (S104f).

  As shown in FIG. 20, the inspection program repeatedly executes the processes of S104c to S104f until the maximum amount of deviations of the cell position reference points p with respect to the cell actual positions P is minimized. (S104g). The inspection program tells the electronic computer the shrinkage rate α (%), angle β (°), maximum deviation when the maximum amount of deviations of each cell position reference point p with respect to each cell actual position P is minimized. The values of γ (mm), X coordinate δ (mm) and Y coordinate ε (mm) are calculated.

  As shown in FIG. 21, the inspection program causes the electronic computer to display the deviation between each cell actual position P and each cell reference position p as a vector. As shown in FIG. 22, the inspection program causes the electronic computer to display the deviation between each cell actual position P and each cell reference position p also as a numerical value. The above processing can be similarly performed on the end surface 71b.

  Returning to FIG. 12, the inspection result obtained in the cell twist evaluation step (S104) as described above is fed back to each step. The variation in the shrinkage rate α obtained in the cell-by-cell evaluation process is fed back to the drying process (S105). The maximum deviation γ, the angle β, the X coordinate δ, the Y coordinate ε, the displacement vector, and the like obtained in the cell-by-cell evaluation process are fed back to the extrusion process (S106). The honeycomb structure 70 that cannot be sealed in the downstream sealing step (S110) is removed based on the shrinkage rate α and the maximum deviation γ obtained in the cell-by-cell evaluation step (S107). The optimal sealing mask 170 is selected from the sealing masks 170 designed with a plurality of types of contraction rates based on the contraction rate α obtained in the cell-by-cell evaluation process (S108). In particular, by calculating the shrinkage rate α of the honeycomb structure 70 manufactured under the new conditions in steps S101 to S103 and having an unknown shrinkage rate in the cell-by-cell evaluation step, the sealing mask 170 having the optimum shrinkage rate is obtained. Designed (S109). Note that the feedback of the inspection results obtained in the cell-by-cell evaluation process to each process may reflect data as shown in FIG. 22 in each process manually or by using a program similar to the above-described inspection program. You may make a computer perform the process which reflects a test result in each process.

  The honeycomb structure 70 selected by the inspection result in the cell twist evaluation process is sealed (S107), and the sealing of the cell 70a is performed by the sealing mask 170 reflecting the inspection result in the cell twist evaluation process (S110).

  According to the present embodiment, the cell actual position P on the end faces 71a and 71b of the cell 70a of the honeycomb structure 70 is detected (S104a), and the mold in the mold 20 for extruding the honeycomb structure 70 is detected. Using the cell 20a as the cell reference point p, the cell actual position P and the cell reference point p position are compared (S104b). In other words, on the basis of the mold 20 for extruding the honeycomb structure 70 as a reference, in order to evaluate the displacement of the actual cell position of the honeycomb structure 70 extruded by the mold 20, the simply extruded honeycomb As compared with a method of measuring the dimensions of each part of the structure 70, the displacement of the cell position of the honeycomb structure 70 can be detected with higher accuracy.

  Further, in the present embodiment, each of the cell actual positions P of the plurality of cells 70a is detected (S104a), and each of the plurality of mold cells 20 in the mold 20 is defined as the cell reference point p, and each of the cell actual positions P and the cell reference. Each point p is compared with each other, and the maximum displacement among the displacements between the cell actual position P and the cell reference point p is derived (S104b). Thereby, the shift | offset | difference of the cell position with respect to the metal mold | die 20 can be quantitatively evaluated with a simple numerical value. For this reason, the deviation of the cell position with respect to the mold 20 is reflected in the conditions of the upstream extrusion step (S101) and the drying step (S102), the downstream sealing step (S110), etc., and the manufacture of the honeycomb structure 70 Accuracy and yield can be improved.

  Further, in the present embodiment, when the entire cell reference point p is corrected with respect to the entire cell actual position P, a correction amount that minimizes the maximum displacement is derived (S104g). Thereby, the shift of the cell position with respect to the mold 20 can be quantitatively evaluated with more specific numerical values. In addition, it becomes easier to reflect the displacement of the cell position with respect to the mold 20 in conditions such as the upstream extrusion process (S101) and the drying process (S102) and the downstream sealing process (S110).

  Further, in the present embodiment, in the orthogonal coordinate system with the coordinate axes orthogonal to the predetermined origin, the total correction amount of the reference position with respect to the entire actual position is changed to the movement amount (S104d, S104e) in the direction parallel to the coordinate axis, It is derived as the rotation angle around (S104c) and the reduction ratio (S104f) centered on the origin. Thereby, the shift of the cell position with respect to the mold 20 can be quantitatively evaluated with more specific numerical values. In addition, it becomes easier to reflect the displacement of the cell position with respect to the mold 20 in conditions such as the upstream extrusion process (S101) and the drying process (S102) and the downstream sealing process (S110).

  Further, in the present embodiment, after the extrusion process (S101) for extruding the honeycomb structure 70 with the mold 20, and the drying process (S102) for drying the extruded honeycomb structure 70, the above-described present embodiment. A cell twist evaluation step for inspecting the honeycomb structure 70 by the inspection method is performed (S104), and then a sealing step (S110) for sealing the cells 70a of the honeycomb structure 70 using the sealing mask 170 is performed. For this reason, the deviation of the cell position with respect to the mold 70 is reflected in the conditions of the upstream extrusion process (S101) and the drying process (S102), the downstream sealing process (S110), and the like, so that the honeycomb structure 70 is manufactured. Accuracy and yield can be improved.

  In the present embodiment, in the sealing step, the honeycomb structures that are not subjected to the sealing step are selected according to the inspection results such as the shrinkage rate α and the maximum deviation γ in the cell twist evaluation step (S107). As a result, for example, the honeycomb structure 70 that has a large cell position shift and cannot be sealed can be omitted, and generation of defective products can be prevented.

  In the present embodiment, in the drying process, the drying conditions for drying the honeycomb structure are changed according to the inspection result such as the shrinkage rate α in the cell twist evaluation process (S105). Thus, for example, the drying conditions can be changed so as to suppress variation in the shrinkage rate α in the drying process detected in the cell evaluation process, and the manufacturing accuracy and yield of the honeycomb structure 70 can be improved.

  In the present embodiment, in the extrusion molding process, the extrusion molding conditions for extrusion molding the honeycomb structure 70 are changed according to the inspection results such as the maximum deviation γ and the vector in the cell evaluation process. Thus, for example, the extrusion molding conditions can be changed so as to suppress the deviation of the cell position detected in the cell twist evaluation step, and the manufacturing accuracy and yield of the honeycomb structure 70 can be improved.

  In the present embodiment, in the sealing step, an optimum one is selected from a plurality of sealing masks 170 having different shrinkage rates in accordance with the inspection result in the cell twist evaluation step. Thereby, it is possible to select the sealing mask 170 that matches the actually manufactured honeycomb structure 70.

  Moreover, in this embodiment, since the cell twist evaluation process by the inspection method of the present embodiment can be performed and the honeycomb structure 70 manufactured with high accuracy and high yield can be obtained, the cost can be further reduced.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation aspect is possible. For example, in the above-described embodiment, the description has focused on the honeycomb structure 70 in which regular hexagonal cells 70a are arranged. However, the present invention can also be applied to a honeycomb structure in which square cells 70a are squarely arranged, for example.

DESCRIPTION OF SYMBOLS 10 ... Extrusion molding apparatus, 20 ... Mold, 20a ... Mold cell, 20b ... Mold groove, 70 ... Honeycomb structure, 70a ... Through-hole (cell), 70s ... Ideal position, 71a, 71b ... End face, 80 ... Support tool, 130: sealing material, 170a, 170b: sealing mask, 171: sealing mask opening, 200: sealing device, 210: sealing device main body.

Claims (15)

An actual position detecting step of detecting an actual position at the end face of the through-hole of the honeycomb structure in which a plurality of through-holes are arranged substantially in parallel and the plurality of through-holes are arranged when viewed from the end face;
A position comparison step of comparing the actual position detected in the actual position detection step with the reference position, with a portion corresponding to the through hole in the mold for extruding the honeycomb structure as a reference position,
For inspecting a honeycomb structure. In the actual position detecting step, each of the actual positions of the plurality of through holes is detected,
In the position comparison step,
With each site corresponding to each of the plurality of through holes in the mold as the reference position of each of the through holes, each of the actual positions detected in the actual position detecting step is compared with each of the reference positions
The method for inspecting a honeycomb structure according to claim 1, wherein each displacement of the actual position and each of the reference positions is derived, and a maximum displacement among the displacements is derived.   The honeycomb structure according to claim 2, wherein the position comparison step derives a correction amount that minimizes the maximum displacement when the entire reference position is corrected with respect to the entire actual position. Inspection method.   In the position comparison step, in an orthogonal coordinate system with coordinate axes orthogonal to a predetermined origin, the total correction amount of the reference position with respect to the entire actual position is calculated as a movement amount in a direction parallel to the coordinate axis, The method for inspecting a honeycomb structure according to claim 3, wherein the method is derived as at least one of a rotation angle and a reduction ratio centered on the origin. An extrusion process for extruding the honeycomb structure with the mold; and
A drying step of drying the honeycomb structure extruded by the extrusion molding step;
An inspection step of inspecting the honeycomb structure dried in the drying step by the honeycomb structure inspection method according to any one of claims 1 to 4,
A part of the plurality of through-holes of the honeycomb structure inspected by the inspection step is covered with a sealing mask, and the sealing material is sealed to the through-holes not covered with the sealing mask through the sealing mask. A sealing step of sealing a part of the through hole by supplying
The manufacturing method of the honeycomb structure containing this.   The method for manufacturing a honeycomb structure according to claim 5, wherein, in the sealing step, the honeycomb structure not subjected to the sealing step is selected according to the inspection result in the inspection step.   The method for manufacturing a honeycomb structure according to claim 5 or 6, wherein in the drying step, a drying condition for drying the honeycomb structure is changed according to an inspection result in the inspection step.   The method for manufacturing a honeycomb structure according to any one of claims 5 to 7, wherein, in the extrusion process, an extrusion condition for extruding the honeycomb structure is changed according to an inspection result in the inspection process. .   The method for manufacturing a honeycomb structure according to any one of claims 5 to 8, wherein, in the sealing step, the sealing mask is selected according to an inspection result in the inspection step.   A honeycomb structure manufactured by the method for manufacturing a honeycomb structure according to any one of claims 5 to 9.   A part of the plurality of through-holes of the honeycomb structure is covered with a sealing mask, and a sealing material is supplied to the through-holes not covered with the sealing mask via the sealing mask. A sealing mask design method, wherein the sealing mask for sealing a part of the sealing mask is designed according to an inspection result of the honeycomb structure inspection method according to any one of claims 1 to 4. An actual position detecting step of detecting an actual position at the end face of the through-hole of the honeycomb structure in which a plurality of through-holes are arranged substantially in parallel and the plurality of through-holes are arranged when viewed from the end face;
A position comparison step of comparing the actual position detected in the actual position detection step with the reference position, with a portion corresponding to the through hole in the mold for extruding the honeycomb structure as a reference position,
Inspection program for honeycomb structure that allows an electronic computer to execute. In the actual position detecting step, the electronic computer is caused to detect each of the actual positions of the plurality of through holes,
In the position comparison step,
Each of the actual position detected in the actual position detection step and each of the reference positions is set in the electronic computer, with the portions corresponding to the plurality of through holes in the mold as the reference positions of the through holes. Compare
The inspection program for a honeycomb structure according to claim 12, wherein the electronic computer is caused to derive each displacement of each of the actual position and each of the reference positions, and to derive a maximum displacement among the displacements.   14. The position comparison step causes the electronic computer to derive a correction amount that minimizes the maximum displacement when the entire reference position is corrected with respect to the entire actual position. Inspection program for honeycomb structures.   In the position comparison step, the correction amount of the entire reference position relative to the whole of the actual position is moved in a direction parallel to the coordinate axis in the orthogonal coordinate system with the coordinate axes orthogonal to a predetermined origin. The inspection program for a honeycomb structure according to claim 14, wherein the inspection program is derived as at least one of a rotation angle around the origin and a reduction ratio centered on the origin.

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