JP5753526B2 - Method for manufacturing ceramic honeycomb structure - Google Patents

Description

  The present invention relates to a method for manufacturing a ceramic honeycomb structure. More specifically, the present invention relates to a method for manufacturing a ceramic honeycomb structure capable of manufacturing a ceramic honeycomb structure having excellent productivity and excellent cylindricity regardless of the outer diameter of the ceramic honeycomb structure.

  Ceramic honeycomb structures (ceramic honeycomb structures) are used as carriers for catalyst devices used for environmental measures and recovery of specific materials in various fields such as chemistry, electric power, and steel. . Ceramic honeycomb structures are also used as filters for exhaust gas purification. Such a ceramic honeycomb structure is excellent in heat resistance and corrosion resistance, and is employed in various applications as described above. A honeycomb structure is a structure having partition walls that partition and form a plurality of cells extending from one end face to the other end face that serve as a fluid flow path.

  Conventionally, a honeycomb structure having an outer diameter of less than 150 mm is manufactured by the following method. First, a clay containing a forming raw material is formed into a honeycomb shape to obtain a honeycomb formed body. The honeycomb formed body has a cylindrical shape in which a plurality of cells extending from one end face to the other end face are partitioned by partition walls. The honeycomb formed body is cut so that the length in the cell extending direction is longer than the length of the finished dimension, and the honeycomb formed body is further dried to obtain a honeycomb dried body. Next, the finished honeycomb dried body is obtained by finishing the length of the dried honeycomb body in the cell extending direction to the finished dimension. Next, the finished honeycomb dried body is fired to obtain a honeycomb structure. In addition, the honeycomb structure manufactured by such a method is inspected whether or not its outer diameter dimension satisfies a reference outer diameter dimension tolerance, and a product that passes the inspection is shipped as a product. Is done.

  On the other hand, when manufacturing a honeycomb structure having an outer diameter of 150 mm or more, a step of separately manufacturing the outer wall may be added. As a step of separately manufacturing the outer wall, for example, after firing the finished honeycomb dried body, the outer periphery of the obtained fired body is ground, and the outer wall is separately manufactured by performing outer periphery coating on the outer peripheral portion that has been ground Can be mentioned. A honeycomb structure having an outer diameter of 150 mm or more is sometimes referred to as a “large-sized honeycomb structure”.

  The above-described manufacturing method for manufacturing a honeycomb structure by drying, finishing, and firing the honeycomb formed body may be hereinafter referred to as “manufacturing method by integral forming”. In addition, a manufacturing method in which a step of separately manufacturing the outer wall is added may be referred to as a “manufacturing method using an outer peripheral coat”. Further, as a method of finishing the end face of the honeycomb structure, a method of correcting the posture of the honeycomb structure and performing the finishing process in this state is disclosed (for example, see Patent Document 1).

JP 2006-231475 A

  However, the conventional method for manufacturing a honeycomb structure has a problem that the obtained honeycomb structure has insufficient cylindricity. In particular, in the above-described manufacturing method by integral molding, the above-described decrease in cylindricity becomes significant. In recent years, the allowable range for the cylindricity of the honeycomb structure has become strict, and an improvement in the cylindricity of the honeycomb structure is required. The allowable range of cylindricity means a range that satisfies the standard value of cylindricity required for a ceramic honeycomb structure as a product.

  Further, the manufacturing method using the outer periphery coat has a problem that the manufacturing process is complicated. For example, since a large honeycomb structure has a large distortion or the like of a formed body, a manufacturing method using an outer peripheral coat is mainly used. However, from the viewpoint of reduction in manufacturing cost, etc., it has been studied to manufacture a large honeycomb structure by a manufacturing method using integral molding. However, when a large honeycomb structure is manufactured by a manufacturing method by integral molding, the decrease in the cylindricity of the honeycomb structure becomes more remarkable. For these reasons, conventionally, it has been considered extremely difficult to manufacture a large honeycomb structure by a manufacturing method using integral molding.

  The present invention has been made in view of the above-described problems. The present invention provides a method for manufacturing a ceramic honeycomb structure capable of manufacturing a ceramic honeycomb structure having excellent productivity and excellent cylindricity regardless of the outer diameter of the ceramic honeycomb structure. To do.

  According to the present invention, the following method for manufacturing a ceramic honeycomb structure is provided.

[1] A finishing step of finishing the one end face and the other end face of a cylindrical ceramic honeycomb dried body having one end face and the other end face to obtain a finished ceramic honeycomb dried body, and the finished ceramic honeycomb Firing the dried body to obtain a ceramic honeycomb structure, and the finishing position of the one end face and the other end face of the ceramic honeycomb dried body in the finishing step is the following (A) No. A method for manufacturing a ceramic honeycomb structure, which is determined by one outer peripheral shape measuring step, (B) a second outer peripheral shape measuring step, (C) a third outer peripheral shape measuring step, and (D) a minimum cylindricity calculating step.

(A) First outer peripheral shape measurement: In the end portion on the one end face side of the ceramic honeycomb dried body, the ceramic honeycomb drying is performed at a plurality of locations separated in a direction from the one end face toward the other end face. The outer peripheral shape of the outer wall surface of the body is measured.
(B) Second outer peripheral shape measurement: In the central part of the ceramic honeycomb dried body from the one end face toward the other end face, the (A) first end face in the direction from the one end face toward the other end face. The outer peripheral shape of the outer wall surface of the dried ceramic honeycomb body is measured at a plurality of locations spaced apart from each measurement location of one outer peripheral shape measurement by a certain distance.
(C) Third outer peripheral shape measurement: Distance corresponding to the finished dimension of the ceramic honeycomb dried body from each measurement location of the (A) first outer peripheral shape measurement at the end portion on the other end face side of the ceramic honeycomb dried body. The outer peripheral shape of the outer wall surface of the ceramic honeycomb dried body is measured at a plurality of spaced locations.
(D) Cylindricity calculation step: From (A) one outer peripheral shape of the outer peripheral shapes measured in the first outer peripheral shape measurement, and (B) from the measurement location of the one outer peripheral shape in the second outer peripheral shape measurement. The outer peripheral shape measured at the measurement points spaced apart by a certain distance, and the measurement at a distance corresponding to the finished dimension of the dried ceramic honeycomb body from the measurement point of the first outer peripheral shape in the (C) third outer peripheral shape measurement. The measured outer peripheral shapes are grouped so that the three outer peripheral shapes measured at the locations are one set, and the ceramics for each set are separated from the outer peripheral shapes of the groups. A cylindricity of the dried honeycomb body is calculated, and from the calculated cylindricity, a set of the outer peripheral shape having the smallest cylindricity is obtained, and a set having the smallest cylindricity is obtained. The measurement points of the (A) measurement point and said first outer circumferential shape measurement (C) a third outer circumferential shape measurement, and the finishing position.

[2] In the (A) first outer peripheral shape measuring step, (B) second outer peripheral shape measuring step, and (C) third outer peripheral shape measuring step, the one end surface is the bottom surface of the ceramic honeycomb dried body. As described above, the method for manufacturing a ceramic honeycomb structure according to [1], wherein the outer peripheral shape is measured by placing on a measurement table.

[3] The method for manufacturing a ceramic honeycomb structure according to [2], wherein spacers are arranged in at least three places between the ceramic honeycomb dried body and the measurement table.

[4] The ceramic according to [2] or [3], wherein a difference in inclination of a bottom surface of the ceramic honeycomb dried body with respect to a horizontal plane when the ceramic honeycomb dried body is placed on the measurement table is 4 mm or less. A method for manufacturing a honeycomb structure.

[5] The method for manufacturing a ceramic honeycomb structure according to any one of [1] to [4], wherein the outer peripheral shape is measured by a reflective non-contact laser displacement meter.

[6] The method for manufacturing a ceramic honeycomb structure according to any one of [1] to [5], wherein the temperature of the ceramic honeycomb dried body when measuring the outer peripheral shape is 20 to 150 ° C.

[7] The method for manufacturing a ceramic honeycomb structure according to any one of [1] to [6], wherein the dried ceramic honeycomb body has irregularities on an outer periphery.

[8] The method for manufacturing a ceramic honeycomb structure according to any one of [1] to [7], wherein an outer diameter of the ceramic honeycomb dried body is 100 mm or more.

[9] The method for manufacturing a ceramic honeycomb structure according to any one of [1] to [8], wherein the dried ceramic honeycomb body is made of a forming raw material that is fired to become cordierite.

[10] The method according to any one of [1] to [9], further including a plugging portion manufacturing step in which an end portion of a cell of the finished ceramic honeycomb dried body or the ceramic honeycomb structure is filled with a sealing material. A method for manufacturing a ceramic honeycomb structure.

  According to the method for manufacturing a ceramic honeycomb structure of the present invention, a ceramic honeycomb structure having excellent cylindricity can be manufactured regardless of the size of the outer diameter of the ceramic honeycomb structure. Moreover, since it is not necessary to perform a complicated process like the manufacturing method by the outer periphery coat mentioned above, it is excellent also in productivity.

1 is a perspective view schematically showing a process of forming a ceramic honeycomb structure in one embodiment of a method for manufacturing a ceramic honeycomb structure of the present invention. It is a perspective view which shows typically an example of the measuring method of the outer periphery shape in a finishing process. (A) It is a perspective view which shows typically an example of a 1st outer periphery shape measurement process. (B) It is a perspective view which shows typically an example of a 2nd outer periphery shape measurement process. (C) It is a perspective view which shows typically an example of a 3rd outer periphery shape measurement process. It is a perspective view which shows typically the other example of (A) 1st outer periphery shape measurement process, (B) 2nd outer periphery shape measurement process, and (C) 3rd outer periphery shape measurement process. It is a perspective view which shows typically the side surface of a ceramic honeycomb dried body. It is a side view which shows typically the state which mounted the ceramic honeycomb dried body in the 1st receiving stand and the 2nd receiving stand. FIG. 4B is a plan view of FIG. 4A viewed from one end face side of the ceramic honeycomb dried body. It is a side view which shows typically an example of the finishing process in a finishing process.

  Next, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments, and it is understood that design changes, improvements, and the like can be added as appropriate based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Should.

(1) Manufacturing method of ceramic honeycomb structure:
One embodiment of the method for manufacturing a ceramic honeycomb structure of the present invention is a method for manufacturing a ceramic honeycomb structure including a finishing step A and a firing step B as shown in FIG. FIG. 1 is a perspective view schematically showing a process of forming a ceramic honeycomb structure in one embodiment of a method for manufacturing a ceramic honeycomb structure of the present invention. The finishing step A is a step of finishing the one end surface 61 and the other end surface 62 of the cylindrical ceramic honeycomb dried body 50 having one end surface 61 and the other end surface 62 to obtain a finished ceramic honeycomb dried body 70. is there. The dried ceramic honeycomb body 50 has a cylindrical shape in which a plurality of cells 52 extending from one end face 61 to the other end face 62 are partitioned by partition walls 51. The firing step B is a step in which the finished ceramic honeycomb dried body 70 obtained in the finishing step A is fired to obtain the ceramic honeycomb structure 100. Hereinafter, the ceramic honeycomb dried body 50 may be simply referred to as “honeycomb dried body 50”. The finished ceramic honeycomb dried body 70 may be simply referred to as “finished honeycomb dried body 70”. The ceramic honeycomb structure 100 may be simply referred to as “honeycomb structure 100”.

  Here, the ceramic honeycomb dried body 50 before finishing is cylindrical, more specifically, substantially cylindrical. However, distortion and the like occur at the time of molding and after molding, and the degree of cylindricity is slightly increased. May be worse. Here, “cylindricity” means the amount of deviation from the geometric cylinder of the portion that should be a cylinder. For example, the cylindricity of a cylindrical object is such that all points on the surface of the object are between two coaxial cylinders and the distance from the cylinder in the radial direction is minimal. It can be represented by the radial spacing of two cylinders. If the cylindricity is small, it can be said that the shape is closer to the geometric cylinder.

  In the method for manufacturing the ceramic honeycomb structure of the present embodiment, the finishing positions of the one end face 61 and the other end face 62 of the ceramic honeycomb dried body 50 in the finishing step A are determined as follows. That is, the finishing position described above by the following (A) first outer peripheral shape measuring step, (B) second outer peripheral shape measuring step, (C) third outer peripheral shape measuring step, and (D) minimum cylindricity calculating step. To decide. Here, FIG. 2 is a perspective view schematically showing an example of a measuring method of the outer peripheral shape in the finishing process. FIG. 3A is a perspective view schematically showing an example of the first outer peripheral shape measurement step (A). FIG. 3B is a perspective view schematically showing an example of the (B) second outer peripheral shape measurement step. FIG. 3C is a perspective view schematically showing an example of the (C) third outer peripheral shape measurement step. FIG. 3E is a perspective view schematically showing a side surface of the dried ceramic honeycomb body.

(A) In the first outer peripheral shape measurement, at one end face 61 side end of the ceramic honeycomb dried body 50, the ceramic honeycomb dried at a plurality of locations separated in the direction from the one end face 61 toward the other end face 62. The outer peripheral shape of the outer wall 63 surface of the body 50 is measured. In Figure 3A, at four positions spaced apart in a direction toward the other end surface 62 from one end face 61, an example in the case of measuring the outer circumferential shape _{A 1, A 2, A 3} , A 4. Here, “(A) the outer peripheral shape measured in the first outer peripheral shape measurement” is referred to as “the outer peripheral shape A _x (x = 1, 2, 3,...)”. Further, “(B) the outer peripheral shape measured in the second outer peripheral shape measurement”, which will be described later, is referred to as “the outer peripheral shape B _x (x = 1, 2, 3,...)”. Also, “(C) the outer peripheral shape measured in the third outer peripheral shape measurement” is referred to as “peripheral shape C _x (x = 1, 2, 3,...)”. x corresponds to the number of measurements of the outer peripheral shape at the end on the one end face 61 side, the center, and the end on the other end face 62 side, for example, measured first at the end on the one end face 61 side. Let the outer peripheral shape be “outer peripheral shape A ₁ ”. Further, the length from the location where the outer peripheral shape A _x is measured to the location where the outer peripheral shape C _x is measured is referred to as “finished dimension m _x (x = 1, 2, 3,...)”. For example, the length from the location where the outer peripheral shape A ₁ is measured to the location where the outer peripheral shape C ₁ is measured is referred to as “finished dimension m ₁ ”.

(B) In the second outer circumferential shape measurement, at the center of a direction from one end face 61 of the ceramic honeycomb dried body 50 on the other end surface 62, to measure the peripheral shape B _x of the outer wall 63 surface of the ceramic honeycomb dried body 50 . Measurement of peripheral shape B _x at the central portion, at a plurality of locations spaced a predetermined distance from each measurement point of one of the end face 61 toward the other end face 62 (A) first peripheral shape measurement Do. That is, in FIG. 3B, (A) the outer peripheral shape B ₁ , the four outer peripheral shapes B ₁ , the first outer peripheral shape measurement at four locations that are spaced apart from each other in the direction from the one end surface 61 to the other end surface 62. the B _{2, B} 3, _{B 4} illustrates an example of a case where the measurement. That is, the measurement location of the outer peripheral shape B ₁ is located at the center of the outer peripheral shape A ₁ and the outer peripheral shape C ₁ described later. The same positional relationship is measured for the outer peripheral shapes B ₂ , B ₃ , and B ₄ .

(C) The third outer circumferential shape measurement, the end of the other end surface 62 side of the ceramic honeycomb dried body 50, to measure the peripheral shape C _x of the outer wall 63 surface of the ceramic honeycomb dried body 50. The measurement of the outer peripheral shape C _x at the end portion on the other end face 62 side is as follows: (A) The distance corresponding to the finished dimension of the ceramic honeycomb dried body (finished dimension m _x (x = 1, 2, 3,...)) Performed at a plurality of spaced locations. That is, in FIG. 3C, (A) distances corresponding to the finished dimensions of the ceramic honeycomb dried body 50 from the four measured positions of the first outer peripheral shape measurement (finished dimensions m ₁ , m ₂ , m ₃ , m ₄ ). at spaced four positions, an example in the case of measuring the outer circumference _{C 1, C 2, C 3} , C 4.

As shown in FIG. 3E, (A) first outer peripheral shape measurement, (B) second outer peripheral shape measurement, and (C) third outer peripheral shape measurement, as shown in FIG. 3E, the outer peripheral shapes A ₁ , A ₂ , A ₃ , A ₄ , outer peripheral shapes B ₁ , B ₂ , B ₃ , B ₄ and outer peripheral shapes C ₁ , C ₂ , C ₃ , C ₄ are measured. Here, the length obtained by subtracting the “finished dimensions m ₁ , m ₂ , m ₃ , m ₄ ” from the “length from one end surface 61 to the other end surface 62 of the ceramic honeycomb dried body 50” is defined as the ceramic honeycomb. When the “excess length” of the dry body 50 is used, it is preferable that (A) the first outer shape measurement and (C) the third outer shape measurement are performed in the following ranges. (A) The first outer peripheral shape measurement is preferably performed in a range corresponding to the surplus length from one end face 61 of the ceramic honeycomb dried body 50. That is, (A) “the end portion on the one end face 61 side” where the first outer peripheral shape measurement is performed is preferably in a range corresponding to the above-described surplus length from the one end face 61. In addition, (C) the third outer peripheral shape measurement is preferably performed in a range corresponding to the surplus length from the other end face 62 of the ceramic honeycomb dried body 50. That is, (C) “the end portion on the other end face 62 side” where the third outer peripheral shape measurement is performed is preferably in a range corresponding to the surplus length from the other end face 62. In addition, (B) the “center portion” where the second outer peripheral shape measurement is performed excludes the above-mentioned “end portion on the one end face 61 side” and “end portion on the other end face 62 side” described above. This is an intermediate portion in the direction from one end face 61 to the other end face. In particular, it is preferable that positions at equal intervals from the measurement location of the outer peripheral shape A _{1 and} the measurement location of the outer peripheral shape C _{1 become} the measurement locations of the outer peripheral shape B ₁ . The same applies to the measurement points of the outer peripheral shapes B ₂ , B ₃ , and B ₄ .

Next, in the (D) cylindricity calculation step, first, the outer peripheral shapes measured in (A) first outer peripheral shape measurement, (B) second outer peripheral shape measurement, and (C) third outer peripheral shape measurement are grouped. To do. This grouping is performed so that, for example, the three outer peripheral shapes of the outer peripheral shape A ₁ , the outer peripheral shape B ₁ , and the outer peripheral shape C ₁ are a set. That is, the outer peripheral shape A ₁ , the outer peripheral shape B ₁ measured at a measurement location spaced apart from the measurement location of the outer peripheral shape A ₁ , and the measurement separated from the measurement location of the outer peripheral shape A ₁ by a distance corresponding to the finished dimension. an outer peripheral shape C ₁ measured at a point is the same set. Similarly, for example, when the outer peripheral shape A ₂ is selected, the combination is performed so that the outer peripheral shape B ₂ and the outer peripheral shape C ₂ become one set.

Next, the cylindricity of the dried ceramic honeycomb body 50 is calculated for each group from the outer peripheral shape of each group. Next, from the calculated cylindricity, a set of outer peripheral shapes having the smallest cylindricity is obtained. The finishing position is defined as (A) the measurement position of the first outer periphery shape measurement and (C) the measurement position of the third outer periphery shape measurement of the set having the smallest cylindricity obtained in this way. For example, in FIG. 4A~ 4C are measurement points of the outer shape A ₄ and the outer peripheral shape C ₄ indicates an example in which the finishing position. Here, FIG. 4A is a side view schematically showing a state in which the dried ceramic honeycomb body is placed on the first cradle and the second cradle. 4B is a plan view of FIG. 4A viewed from one end face side of the ceramic honeycomb dried body. FIG. 4C is a side view schematically showing an example of the finishing process in the finishing process.

  With such a configuration, when one end face 61 and the other end face 62 of the ceramic honeycomb dried body 50 are finished to obtain the finished ceramic honeycomb dried body 70, the processing position where the cylindricity is improved is obtained. Finishing can be performed. The finishing process refers to a process of cutting excess portions 50a and 50b from the finished dimension m of one end face 61 and the other end face 62 of the dried honeycomb body 50. In the conventional manufacturing method, finishing may be performed at substantially equal distances from both end faces. However, in such a method, finishing may be performed at a location outside the processing position where the cylindricity is improved. In addition, it is difficult to produce a ceramic honeycomb structure having excellent productivity and excellent cylindricity regardless of the outer diameter of the ceramic honeycomb structure.

  The “finished dimension of the dried ceramic honeycomb body” refers to a length from one end face to the other end face required for the finished ceramic honeycomb dried body. About the length from one end face to the other end face required for the finished ceramic honeycomb dried body, from the standard length from one end face to the other end face of the ceramic honeycomb structure that is the final product, It is determined appropriately in consideration of the amount of shrinkage and the like.

  Hereinafter, the manufacturing method of the ceramic honeycomb structure of the present embodiment will be described in more detail.

(1-1) Production of dried ceramic honeycomb body:
First, a method for producing a ceramic honeycomb dried body used in the method for producing a ceramic honeycomb structure of the present embodiment will be described. The manufacturing method of the ceramic honeycomb dried body is not limited to the following manufacturing method. That is, if the length of the ceramic honeycomb dried body from one end surface to the other end surface is before being finished so as to be the finished dimension, the manufacturing method and the like are not particularly limited. Absent.

  As a method for producing the dried ceramic honeycomb body, a general extrusion molding method is used. For example, there can be mentioned an intermittent forming (ram forming) method in which a forming raw material containing a ceramic material and a forming aid is kneaded and a clay is formed by a vacuum clay kneader or the like. As another method, a continuous molding method in which the mixed powder is directly ground and molded can be exemplified. There is no restriction | limiting in particular as a ceramic material contained in a shaping | molding raw material, The ceramic material used as a shaping | molding raw material can be used in the manufacturing method of a conventionally well-known ceramic honeycomb structure. For example, examples of the ceramic material include cordierite, a cordierite-forming raw material, silicon carbide, and alumina. The cordierite forming raw material is a ceramic raw material blended so as to have a chemical composition that falls within the range of 42 to 56% by mass of silica, 30 to 45% by mass of alumina, and 12 to 16% by mass of magnesia. The cordierite forming raw material is fired to become cordierite.

  Further, the forming raw material contains water as a dispersion medium. Furthermore, the forming raw material may contain a pore former, a binder, a dispersing agent, a surfactant, and the like, if necessary. As the pore former, the binder, the dispersant, the surfactant, and the like, those used in a conventionally known method for manufacturing a ceramic honeycomb structure can be suitably used.

  Next, for example, by extrusion molding, a cylindrical honeycomb molded body is formed in which a plurality of cells extending from one end face to the other end face are partitioned by partition walls. Examples of the molding method include intermittent extrusion molding or continuous extrusion molding. In extrusion molding, a die having a desired overall shape, cell shape, partition wall thickness, cell density and the like is used.

  Next, the obtained honeycomb formed body is cut in the cell extending direction of the honeycomb formed body. When the honeycomb formed body is cut, the length in the direction from one end face to the other end face of each cut honeycomb formed body is set to be longer than the finished dimension of the honeycomb structure. A portion longer than the finished dimension of each honeycomb formed body is cut and removed in the finishing process.

  Next, the cut honeycomb formed body is dried to obtain a honeycomb dried body. The drying method is not particularly limited, and examples thereof include hot air drying, microwave drying, dielectric drying, reduced pressure drying, vacuum drying, and freeze drying. Among them, it is preferable to perform dielectric drying, microwave drying, or hot air drying alone or in combination.

(1-2) Finishing process:
Next, as shown in FIGS. 1 and 2, one end face 61 and the other end face 62 of the ceramic honeycomb dried body 50 are finished to obtain a finished ceramic honeycomb dried body 70. By this finishing step, the ceramic honeycomb dried body 50 is processed so that the length from one end face 61 to the other end face 62 becomes the finished dimension m. At this time, the ceramic honeycomb dried body 50 is subjected to (A) a first outer peripheral shape measuring step, (B) a second outer peripheral shape measuring step, (C) a third outer peripheral shape measuring step, and (D) a minimum cylindricity calculating step. The finishing position of one end face 61 and the other end face 62 is determined.

(1-2A) (A) First outer peripheral shape measurement step:
(A) In the first outer peripheral shape measurement, as shown in FIG. 3A, at the end portion on the one end face 61 side of the ceramic honeycomb dried body 50, a plurality of pieces separated in a direction from one end face 61 to the other end face 62 are separated. The outer peripheral shape A _x (x = 1, 2, 3,...) Of the surface of the outer wall 63 of the ceramic honeycomb dried body 50 is measured at the location. There is no restriction | limiting in particular about the measuring method of outer periphery shape _Ax . For example, as shown in FIG. 3A, the outer peripheral shape _Ax can be measured by a laser displacement meter 67. As the laser displacement meter 67, a reflective non-contact laser displacement meter can be suitably used. Such a laser displacement meter can more accurately measure the outer peripheral shape of the ceramic honeycomb dried body 50.

Ceramic honeycomb outer peripheral shape A _x of the drying body 50 during the measurement, first, the measurement start point P1 of the outer peripheral shape A _1, outer peripheral shape A ₁ over the entire circumference including the measurement start point P1 of the outer peripheral shape Measure. It followed the measurement of the outer peripheral shape A ₁ has been completed, from the start of the measurement point P2 of the outer circumferential shape A _2, to measure the peripheral shape A ₂ over the entire circumference including the measurement start point P2 of the outer peripheral shape. Hereinafter, successively, the outer peripheral shape A ₃ measured from the start of the measurement point P3, to measure the peripheral shape A ₄ from the start of the measurement point P4. In this way, the necessary number of outer peripheral shapes _Ax are measured. Moreover, you may perform (B) 2nd outer periphery shape measurement mentioned later and (C) 3rd outer periphery shape measurement simultaneously with (A) 1st outer periphery shape measurement. For example, as shown in FIG. 3D, the outer peripheral shape A ₁ , the outer peripheral shape B ₁ , and the outer peripheral shape C ₁ are simultaneously measured, and the outer peripheral shape A ₂ , the outer peripheral shape B ₂ , and the outer peripheral shape C ₂ are sequentially measured. May be performed. And measuring the position of the outer peripheral shape A _1, no particular limitation is imposed on the interval between the measurement positions of the outer peripheral shape A _2, for example, preferably are separated about 10 mm. Here, FIG. 3D is a perspective view schematically showing another example of (A) the first outer periphery shape measuring step, (B) the second outer periphery shape measuring step, and (C) the third outer periphery shape measuring step. .

  Although there is no restriction | limiting in particular about the temperature of a ceramic honeycomb dried body at the time of outer periphery shape measurement, It is preferable that the temperature of a ceramic honeycomb dried body is 20-150 degreeC. The temperature of the ceramic honeycomb dried body is more preferably room temperature if possible. The dried ceramic honeycomb body after drying the ceramic honeycomb formed body has a temperature of about 50 to 150 ° C., and the outer peripheral shape can be measured after the ceramic honeycomb dried body is once cooled to room temperature. However, if it cools to room temperature, thermal efficiency and work efficiency will worsen. Conversely, if the ceramic honeycomb dried body after drying the ceramic honeycomb formed body can be quickly subjected to measurement of the outer peripheral shape, the working efficiency can be further improved. In the measurement of the outer peripheral shape, temperature correction may be performed on the measurement result, or temperature correction may not be performed. When temperature correction is performed, the “standard outer diameter size” of the ceramic honeycomb molded body is measured in advance, and the thermal expansion coefficient of the ceramic material and the molding aid is measured in advance to obtain the “standard outer diameter size corresponding to the temperature”. to correct.

As shown in FIG. 3A, the measurement of the outer peripheral shape is preferably performed by placing the ceramic honeycomb dried body 50 on a measurement table 65 on which a measurement object can be placed horizontally. When such a measuring table 65 is used, the outer peripheral shape of the ceramic honeycomb dried body 50 can be easily measured. For example, when the laser displacement meter 67 is a fixed type, as shown in FIG. 3D, three laser displacement meters 67 are arranged to measure the outer peripheral shape A _x , the outer peripheral shape B _x , and the outer peripheral shape C _x simultaneously. Preferably it is done. The outer peripheral shape of the ceramic honeycomb dried body 50 can be continuously measured by rotating the measuring table 65 on which the ceramic honeycomb dried body 50 is placed once in a horizontal plane. In FIG. 3A, the dried ceramic honeycomb body 50 placed on the measuring table 65 is rotated in the rotation direction indicated by reference numeral 80 to measure the outer peripheral shape. The laser displacement meter 67 may be a movable type. Moreover, it is preferable to arrange a spacer 66 between the measurement table 65 and one end face 61 of the ceramic honeycomb dried body 50. In the ceramic honeycomb dried body 50, the flatness of the end face 61 is deteriorated due to the cutting and drying process at the time of molding, and the honeycomb dried body 50 may move by centrifugal force when the measuring table 65 rotates. In order to ensure the measurement accuracy of the outer peripheral shape, it is preferable to arrange three spacers 66.

  The number of measurements of the outer peripheral shape at the end portion on the one end face 61 side of the ceramic honeycomb dried body 50 is not particularly limited, as shown in FIG. Extrusion molding is characterized in that the same face appears no matter where it is cut, as represented by Kintaro, that is, if it is a honeycomb formed body, it has the same shape no matter where it is cut. If the honeycomb has a relatively high shape reproducibility and an outer diameter of 150 mm or less, it is possible to measure 2 to 4 locations offline, determine the cutting position for finishing, and produce at the same cutting position. . For a large honeycomb having a relatively low shape reproducibility and an outer diameter of 150 mm or more, it is also preferable to measure 2 to 4 locations in-line and determine the cutting position for each individual. That is, it is preferable to select off-line or in-line according to the shape of the honeycomb formed body and measure 2 to 4 points.

(1-2B) (B) Second outer peripheral shape measurement step:
(B) In the second outer peripheral shape measurement, as shown in FIG. 3B, the surface of the outer wall 63 surface of the ceramic honeycomb dried body 50 at the center portion in the direction from one end face 61 to the other end face 62 of the ceramic honeycomb dried body 50. Measure the outer shape. The measurement of the outer peripheral shape in the central portion is performed at a plurality of locations spaced apart from each measurement location of (A) first outer peripheral shape measurement in a direction from one end surface 61 to the other end surface 62. For example, the distance from the measurement location of the outer peripheral shape A _{1 to} the measurement location of the outer peripheral shape B ₁ and the distance from the measurement location of the outer peripheral shape A _{2 to} the measurement location of the outer peripheral shape B ₂ are the same. The shape _Bx is measured. About the measuring method of an outer periphery shape, it can carry out by the method similar to the (A) 1st outer periphery shape measuring process mentioned above.

(1-2C) (C) Third outer peripheral shape measurement step:
(C) In the third outer peripheral shape measurement, as shown in FIG. 3C, the outer peripheral shape of the surface of the outer wall 63 of the ceramic honeycomb dried body 50 is measured at the end portion on the other end face 62 side of the ceramic honeycomb dried body 50. The measurement at the end portion on the other end face 62 side is performed at a plurality of locations separated from each measurement location of (A) first outer peripheral shape measurement by a distance corresponding to the finished size of the ceramic honeycomb dried body. For example, the distance from the measurement point of the outer shape A ₁ to a measurement position of the outer peripheral shape C ₁ is such that a distance corresponding to the finished size, the measurement of the peripheral shape C _x. About the measuring method of an outer periphery shape, it can carry out by the method similar to the (A) 1st outer periphery shape measuring process mentioned above.

(1-2D) (D) Cylindricity calculation step:
(D) In the cylindricity calculation step, first, the outer peripheral shapes measured in (A) first outer peripheral shape measurement, (B) second outer peripheral shape measurement, and (C) third outer peripheral shape measurement are grouped. The grouping is performed so that, for example, the three outer peripheral shapes of the outer peripheral shape A ₁ , the outer peripheral shape B ₁ , and the outer peripheral shape C ₁ are a set.

Next, the cylindricity of the dried ceramic honeycomb body 50 is calculated for each group from the outer peripheral shape of each group. The end face 61 of the ceramic honeycomb dried body 50 is inclined, and the amount of inclination is added to the calculation result of the cylindricity. For this reason, when calculating the cylindricity, it is preferable to correct this inclination amount. In addition, (A) the first outer periphery shape measurement, (B) the second outer periphery shape measurement, and (C) the third outer periphery shape measurement are performed without placing the ceramic honeycomb dried body 50 on the measurement table 65. Therefore, relative comparison of cylindricity is also possible. That is, when obtaining the minimum cylindricity, the inclination amount need not be corrected. Examples of the cylindricity calculation method include the following methods. First, the area center of gravity is obtained for the three outer peripheral shapes that are grouped, for example, the outer peripheral shape A ₁ , the outer peripheral shape B ₁ , and the outer peripheral shape C ₁ . Then, from the center of gravity of each area, a calculated central axis of “a solid having the outer peripheral shape A ₁ , the outer peripheral shape B ₁ , and the outer peripheral shape C ₁ as a cross-sectional shape” is obtained. The calculated central axis can be obtained from each area centroid by approximation using the least square method or the like. The calculated central axis thus obtained is set as the central axis of the geometric cylinder. Therefore, the cylindricity of the “solid shape having the outer peripheral shape A ₁ , the outer peripheral shape B ₁ , and the outer peripheral shape C ₁ as a cross-sectional shape” is the amount of deviation from the geometric cylinder having the calculated central axis as an axis. Next, from the calculated cylindricity, a set of outer peripheral shapes having the smallest cylindricity is obtained. The finishing position is defined as (A) the measurement position of the first outer periphery shape measurement and (C) the measurement position of the third outer periphery shape measurement of the set having the smallest cylindricity obtained in this way.

  After determining the finishing position in this way, one end face and the other end face of the ceramic honeycomb dried body are finished at the determined finishing position. As shown in FIGS. 4A to 4C, a method of supporting the outer wall 63 of the dried ceramic honeycomb body 50 with a first receiving stand 68a and a second receiving stand 68b and performing finishing in that state can be mentioned. 4A to 4C, the ceramic honeycomb dried body 50 is supported by the first cradle 68 a and the second cradle 68 b described above and the auxiliary cradle 69. Moreover, in the example shown to FIG. 4A-FIG. 4C, the 1st receiving stand 68a and the 2nd receiving stand 68b, and the cutting tools 75a and 75b are arrange | positioned so that it may become parallel. That is, one end surface and the other end surface of the dried ceramic honeycomb body 50 cut by the cutting tools 75a and 75b are parallel to the first receiving table 68a and the second receiving table 68b. In this manner, the end surfaces of the ceramic honeycomb dried body 50 placed on the first cradle 68a and the second cradle 68b are finished by the cutting tools 75a and 75b.

  As described above, a finished ceramic honeycomb dried body having excellent cylindricity can be obtained. In the method for manufacturing the ceramic honeycomb structure of the present embodiment, the cylindricity of the finished dried ceramic honeycomb body can be improved regardless of the size of the outer diameter of the dried ceramic honeycomb body. For this reason, the method for manufacturing a ceramic honeycomb structure of the present embodiment is suitable when the outer diameter of the ceramic honeycomb dried body is 100 mm or more, and the outer diameter of the ceramic honeycomb dried body is 150 mm or more. More preferred in some cases. A ceramic honeycomb dried body having an outer diameter size of 100 mm or more is likely to be deformed at the time of molding, and the cylindricity is remarkably reduced in the finishing process in the conventional manufacturing method.

  In the method for manufacturing the ceramic honeycomb structure of the present embodiment, the shape measurement of the dried ceramic honeycomb body can be performed based on the measurement results of the outer peripheral shape described so far. That is, in the in-line measurement, it is possible to determine whether or not the outer peripheral shape of the dried ceramic honeycomb body satisfies the specified condition from the measurement result of the outer peripheral shape. For example, when the outer peripheral shape of the ceramic honeycomb dried body is within a specified numerical range, it is determined that “the specified condition is satisfied”. If the outer peripheral shape of the dried ceramic honeycomb body is outside the specified numerical range, it is determined that “the specified condition is not satisfied”. The ceramic honeycomb dried body that does not satisfy the prescribed conditions may not be finished.

  By measuring the shape of the ceramic honeycomb dried body described above, it is possible to perform a finishing process that improves the cylindricity, and to finish the ceramic honeycomb dried body whose outer peripheral shape does not satisfy the specified conditions. Can be removed before. A ceramic honeycomb dried body whose outer peripheral shape does not satisfy the prescribed conditions is judged to be defective by the final inspection. Therefore, by removing such a ceramic honeycomb dried body before finishing processing, unnecessary finishing processes and firing are performed. The process and the inspection process can be omitted.

(1-3) Firing step:
In the method for manufacturing a ceramic honeycomb structure of the present embodiment, the finished ceramic honeycomb dried body obtained in this way is fired to obtain a ceramic honeycomb structure. As a result, a ceramic honeycomb structure reflecting the good cylindricity of the finished ceramic honeycomb dried body can be obtained.

  When firing is performed, first, degreasing is performed in order to remove the molding aid and the like, and then the temperature is further raised and main firing is performed to form a ceramic honeycomb structure. There are no particular restrictions on the degreasing and firing conditions. It is preferable to perform degreasing and main firing under conditions suitable for the forming raw material of the ceramic honeycomb dried body. For example, the degreasing is preferably performed according to the type of organic substance that is a molding aid or the like in the molding raw material and the amount added. As said organic substance, an organic binder, a dispersing agent, a pore making material etc. can be mentioned. Since the firing conditions (temperature and time) vary depending on the type of the forming raw material, an appropriate condition may be selected according to the type. For example, the firing temperature is generally about 1400 to 1600 ° C., but is not limited thereto. Degreasing and main baking may be separate steps. Degreasing and main baking can be performed using an electric furnace, a gas furnace, or the like.

(1-4) Plugging portion manufacturing process:
The method for manufacturing the ceramic honeycomb structure of the present embodiment may further include a plugging portion manufacturing step. The plugging portion manufacturing step is a step of filling the sealing material into the cells of the finished ceramic honeycomb dried body or the ceramic honeycomb structure. By providing such a plugged portion manufacturing step, it is possible to manufacture a plugged ceramic honeycomb structure in which the plugged portions are arranged in a checkered pattern at the opening ends of the cells of the ceramic honeycomb structure. it can.

  The plugged ceramic honeycomb structure can be used as a filter for removing impurities in the fluid. Examples of such a filter include an exhaust gas purification filter for removing particulate matter in the exhaust gas. Examples of the exhaust gas purifying filter include a diesel particulate filter for removing particulate matter in exhaust gas discharged from a diesel engine.

  About the plugging part preparation process, it can carry out according to the process similar to the plugging part preparation process in the manufacturing method of a conventionally well-known plugged ceramic honeycomb structure. The plugging portion manufacturing step is preferably performed after the finishing step or after the firing step.

  Hereinafter, an example in which the plugged portion manufacturing step is performed on the finished ceramic honeycomb dried body after the finishing step will be described. First, a slurry-like sealing material is filled into one open end of a predetermined cell of the finished ceramic honeycomb dried body and the other open end of the remaining cell. When filling the opening material of the cell of the finished ceramic honeycomb dried body with the sealing material, first, the sealing material is filled into one opening edge, and then the sealing material is filled into the other opening edge. To do.

  Examples of a method for filling one opening end with a sealing material include the following methods. First, a sheet is bonded to one end face of the finished ceramic honeycomb dried body. Next, holes for filling the sealing material are formed in the sheet at positions where a checkered pattern is formed. The hole for filling the sealing material is located at a position where a cell in which a plugging portion is to be formed exists. The finished ceramic honeycomb dried body to which the sheet is attached is press-fitted into a container in which the sealing material is stored. That is, the end portion of the finished ceramic honeycomb dried body to which the sheet is attached is press-fitted into the container. Thereby, the sealing material is filled into a predetermined cell through the hole of the sheet.

  After the sealing material is filled into one open end of the cell, the remaining cells at the other open end of the cell are filled with the sealing material in the same manner as described above. That is, a sheet is attached to the other end face of the finished ceramic honeycomb dried body similarly to the one end face, and the sealing material is filled in the same manner as described above.

  A plugging portion can be formed by drying the sealing material filled in the cells of the finished ceramic honeycomb dried body. In addition, you may perform the drying of a sealing material for every one opening edge part. Usually, the sealing material filled in the cell is dried and then fired to produce a diesel particulate filter.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
First, a dried ceramic honeycomb body for performing the finishing process was prepared. In order to produce a ceramic honeycomb dried body, a cordierite forming raw material was used as a ceramic raw material. A predetermined amount of a molding aid was added to the cordierite forming raw material, and water was added to prepare a mixed powder.

  Next, the obtained mixed powder was extruded using a mold for forming a ceramic honeycomb formed body. Extrusion molding was performed by continuous molding to produce a cylindrical ceramic honeycomb molded body in which a plurality of cells extending from one end face to the other end face were partitioned. Next, the ceramic honeycomb formed body was cut so that the length in the cell extending direction was longer than the finished dimension in the cell extending direction.

  Next, the ceramic honeycomb formed body was dried to produce a ceramic honeycomb dried body. Drying was performed by combining dielectric drying and hot air drying.

  Next, as shown in FIG. 3A, the obtained ceramic honeycomb dried body 50 was placed on a measuring table 65 that can rotate in a horizontal plane. The outer circumferential shape of the surface of the outer wall 63 of the dried ceramic honeycomb body 50 was continuously measured by a laser displacement meter 67. As the laser displacement meter 67, a reflective non-contact laser displacement meter was used. The measurement of the outer peripheral shape was performed by measuring 3000 points in one peripheral direction, and the outer peripheral shape in the peripheral direction was obtained from the obtained measurement result. In Example 1, the outer peripheral shape was measured without arranging the spacer 66 in FIG. 3A between the measuring table 65 and one end face 61 of the ceramic honeycomb dried body 50.

In Example 1, (A) In the first outer peripheral shape measurement step, the outer peripheral shapes A ₁ , A ₂ , A ₃ , and A ₄ were measured at four locations at 10 mm intervals. Further, (B) in the second outer peripheral shape measuring step, the outer peripheral shapes B ₁ , B ₂ , B ₃ , B ₄ are measured at intervals of 10 mm, and (C) the outer peripheral shape C in intervals of 10 mm in the third outer peripheral shape measuring step. ₁ , C ₂ , C ₃ , C ₄ were measured. In the dried ceramic honeycomb body 50, the length from one end face 61 to the other end face 62 is 50 mm longer than the finished dimension. The finished dimension of the dried ceramic honeycomb body 50 in Example 1 was 150 mm. The outer diameter of the ceramic honeycomb dried body 50 was 150 mm. Table 1 shows the “outer diameter” of the dried ceramic honeycomb body and the “finished dimension” of the finished ceramic honeycomb dried body.

Next, as (D) cylindricity calculation step, first, the outer peripheral shape A ₁ , A ₂ , A ₃ , A ₄ , B ₁ , B ₂ , B ₃ , B ₄ , C ₁ , C ₂ , C ₃ , C ₄ was divided into the following first group to fourth group. The first set is the outer peripheral shape A ₁ , the outer peripheral shape B ₁ , and the outer peripheral shape C ₁ , the second set is the outer peripheral shape A ₂ , the outer peripheral shape B ₂ , and the outer peripheral shape C _2, and the third set is the outer periphery The shape A ₃ , the outer shape B ₃ , and the outer shape C ₃ were used, and the fourth set was the outer shape A ₄ , the outer shape B ₄ , and the outer shape C ₄ . The cylindricity of the dried ceramic honeycomb body 50 was calculated for each set from the outer peripheral shapes of the first to fourth sets. When calculating the cylindricity, the inclination amount of the ceramic honeycomb dried body at the time of measurement was corrected. Then, a group having the smallest cylindricity is obtained, and (A) the measurement position of the first outer periphery shape measurement and (C) the measurement position of the third outer periphery shape measurement of the group having the smallest cylindricity are set as the finishing positions. .

  Next, as shown in FIGS. 4A to 4C, the ceramic honeycomb dried body 50 was placed on the first cradle 68a and the second cradle 68b. At this time, as shown in FIG. 4C, the first cradle 68a and the second pedestal 68a and the second pedestal 68a are finished so that the finishing processing by the cutting tools 75a and 75b is performed at the finishing processing position determined by the (D) cylindricity calculation step. The position of the ceramic honeycomb dried body 50 placed on the two receiving boards 68b was adjusted. And the end surface of the ceramic honeycomb dried body 50 was finish-processed with the cutting tools 75a and 75b, and the finished ceramic honeycomb dried body was obtained. As the cutting tools 75a and 75b, disc-shaped grindstones were used.

The resulting finished ceramic honeycomb dried body was degreased and fired to produce a ceramic honeycomb structure. Degreasing and firing were performed in an oxidizing atmosphere. The maximum temperature during firing was 1430 ° C. The ceramic honeycomb structure of Example 1 has a cell density of 62 cells / cm ² and a partition wall thickness of 150 μm.

  Ten ceramic honeycomb structures were manufactured by such a method (the method of Example 1). Then, the cylindricity of each of the obtained ceramic honeycomb structures was measured, and the average cylindricity (mm) of 10 ceramic honeycomb structures was obtained. Table 1 shows the average cylindricity (mm). The average cylindricity (mm) is an arithmetic average of cylindricity of ten ceramic honeycomb structures.

(Examples 2 to 4)
A ceramic honeycomb dried body in which the outer diameter size, the cell density after firing, and the thickness of the partition walls after firing have the values shown in Table 1 was prepared, and the ceramic honeycomb dried body was manufactured in the same manner as in Example 1. A honeycomb structure was manufactured by determining the finishing position of one end face and the other end face. Thereafter, the average cylindricity (mm) of the obtained ceramic honeycomb structure was determined in the same manner as in Example 1. The results are shown in Table 1. In Examples 2 and 3, a dried ceramic honeycomb body in which the length of the ceramic honeycomb dried body in the cell extending direction was 50 mm longer than the finished dimensions shown in Table 1 was produced. That is, the length from one end face to the other end face of the dried ceramic honeycomb bodies of Examples 2 and 3 is 250 mm. In Example 4, a dried ceramic honeycomb body having an outer diameter of 200 mm and a length in the cell extending direction of the ceramic honeycomb dried body that was 50 mm longer than the finished dimensions shown in Table 1 was produced. That is, the length from one end face of the dried ceramic honeycomb body of Example 4 to the other end face is 250 mm. In Example 4, the partition wall thickness is 100 μm.

(Comparative Examples 1-4)
In Comparative Examples 1 to 4, first, ceramic honeycomb drying was performed in the same manner as in Example 1 so that the outer diameter, the cell density after firing, and the partition wall thickness after firing had the values shown in Table 1. The body was made. Next, the outer peripheral shape was not measured, and finish processing was performed so that the lengths of the end portions on one end face side of the ceramic honeycomb dried body and the end portions on the other end face side were the same. . The average cylindricity (mm) of the obtained ceramic honeycomb structure was determined in the same manner as in Example 1. The results are shown in Table 1.

(result)
According to the manufacturing methods of Examples 1 to 4, the average cylindricity of the ceramic honeycomb structures obtained when the ceramic honeycomb structures having the same finished dimensions are manufactured as compared with the manufacturing methods of Comparative Examples 1 to 4. It is understood that is superior. That is, in the manufacturing methods of Comparative Examples 1 to 4 such as the conventional manufacturing method, the cylindricity of the ceramic honeycomb structure may be deteriorated by finishing. In the manufacturing methods of Examples 1 to 4, in the surplus portion from the finished dimensions, the machining position where the cylindricity is further improved is selected and the finishing process is performed, so that the ceramic honeycomb structure having excellent cylindricity is obtained. Could be manufactured.

  The method for manufacturing a ceramic honeycomb structure of the present invention can be used in a method for manufacturing a ceramic honeycomb structure having excellent cylindricity.

50: Ceramic honeycomb dried body, 50a, 50b: Surplus part, 51: Partition wall, 52: Cell, 61: One end face, 62: The other end face, 63: Outer wall, 65: Measuring stand, 66: Spacer, 67: Laser Displacement meter, 68a: first cradle, 68b: second cradle, 69: auxiliary cradle, 70: dried ceramic honeycomb dried body, 75a, 75b: cutting tool, 80: rotating direction, 100: ceramic honeycomb structure, A: Finishing process, B: Firing process, A ₁ , A ₂ , A ₃ , A ₄ , B ₁ , B ₂ , B ₃ , B ₄ , C ₁ , C ₂ , C ₃ , C ₄ : Peripheral shape, L : Direction from one end face to the other end face, m, m ₁ , m ₂ , m ₃ , m ₄ : finish dimensions, P1, P2, P3, P4: measurement start point, R: circumferential direction.

Claims (10)

A finishing step of finishing the one end face and the other end face of the cylindrical ceramic honeycomb dried body having one end face and the other end face to obtain a finished ceramic honeycomb dried body;
Firing the finished ceramic honeycomb dried body to obtain a ceramic honeycomb structure, and
The finishing positions of the one end face and the other end face of the ceramic honeycomb dried body in the finishing step are as follows: (A) first outer peripheral shape measuring step, (B) second outer peripheral shape measuring step, and (C) first. A method for manufacturing a ceramic honeycomb structure, which is determined by three outer peripheral shape measurement steps and (D) a minimum cylindricity calculation step.
(A) First outer peripheral shape measurement: In the end portion on the one end face side of the ceramic honeycomb dried body, the ceramic honeycomb drying is performed at a plurality of locations separated in a direction from the one end face toward the other end face. The outer peripheral shape of the outer wall surface of the body is measured.
(B) Second outer peripheral shape measurement: In the central part of the ceramic honeycomb dried body from the one end face toward the other end face, the (A) first end face in the direction from the one end face toward the other end face. The outer peripheral shape of the outer wall surface of the dried ceramic honeycomb body is measured at a plurality of locations spaced apart from each measurement location of one outer peripheral shape measurement by a certain distance.
(C) Third outer peripheral shape measurement: Distance corresponding to the finished dimension of the ceramic honeycomb dried body from each measurement location of the (A) first outer peripheral shape measurement at the end portion on the other end face side of the ceramic honeycomb dried body. The outer peripheral shape of the outer wall surface of the ceramic honeycomb dried body is measured at a plurality of spaced locations.
(D) Cylindricity calculation step: From (A) one outer peripheral shape of the outer peripheral shapes measured in the first outer peripheral shape measurement, and (B) from the measurement location of the one outer peripheral shape in the second outer peripheral shape measurement. The outer peripheral shape measured at the measurement points spaced apart by a certain distance, and the measurement at a distance corresponding to the finished dimension of the dried ceramic honeycomb body from the measurement point of the first outer peripheral shape in the (C) third outer peripheral shape measurement. The measured outer peripheral shapes are grouped so that the three outer peripheral shapes measured at the locations are one set, and the ceramics for each set are separated from the outer peripheral shapes of the groups. A cylindricity of the dried honeycomb body is calculated, and from the calculated cylindricity, a set of the outer peripheral shape having the smallest cylindricity is obtained, and a set having the smallest cylindricity is obtained. The measurement points of the (A) measurement point and said first outer circumferential shape measurement (C) a third outer circumferential shape measurement, and the finishing position.   In the (A) first outer peripheral shape measuring step, (B) second outer peripheral shape measuring step, and (C) third outer peripheral shape measuring step, the ceramic honeycomb dried body is measured so that the one end surface is a bottom surface. The method for manufacturing a ceramic honeycomb structure according to claim 1, wherein the outer peripheral shape is measured by mounting on a table.   The method for manufacturing a ceramic honeycomb structure according to claim 2, wherein spacers are arranged at least at three positions between the ceramic honeycomb dried body and the measurement table.   The method for manufacturing a ceramic honeycomb structure according to claim 2 or 3, wherein when the ceramic honeycomb dried body is placed on the measurement table, a difference in inclination of a bottom surface of the ceramic honeycomb dried body with respect to a horizontal plane is 4 mm or less. .   The method for manufacturing a ceramic honeycomb structure according to any one of claims 1 to 4, wherein the outer peripheral shape is measured by a reflective non-contact laser displacement meter.   The method for manufacturing a ceramic honeycomb structure according to any one of claims 1 to 5, wherein a temperature of the ceramic honeycomb dried body when the outer peripheral shape is measured is 20 to 150 ° C.   The method for manufacturing a ceramic honeycomb structure according to any one of claims 1 to 6, wherein the dried ceramic honeycomb body has irregularities on an outer periphery.   The method for manufacturing a ceramic honeycomb structure according to any one of claims 1 to 7, wherein an outer diameter of the ceramic honeycomb dried body is 100 mm or more.   The method for manufacturing a ceramic honeycomb structure according to any one of claims 1 to 8, wherein the dried ceramic honeycomb body is made of a forming raw material that is fired to become cordierite.   The ceramic honeycomb structure according to any one of claims 1 to 9, further comprising a plugging portion manufacturing step of filling a sealing material at an end of a cell of the finished ceramic honeycomb dried body or the ceramic honeycomb structure. Production method.

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