JP5749691B2 - 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 perpendicularity 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 (see, for example, Patent Document 1). Moreover, about the honeycomb structure manufactured by such a method, the dimension inspection about an external dimension, a contour, a squareness, a curvature, a cylindricity, etc. is performed. For example, a dimensional inspection is performed as to whether or not the outer diameter dimension of the manufactured honeycomb structure satisfies a reference outer diameter dimension tolerance. And what passed such a dimension inspection is shipped as a product.

  On the other hand, when manufacturing a honeycomb structure having an outer diameter of 150 mm or more, a step of separately manufacturing an outer wall may be added (for example, see Patent Document 2). 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 3).

JP 2002-046856 A JP-A-3-275309 JP 2006-231475 A

  However, in the conventional method for manufacturing a honeycomb structure, the perpendicularity of one end face and the other end face of the honeycomb structure to be obtained (hereinafter, “the perpendicularity of one end face and the other end face” is simply referred to as “the perpendicularity”. There is a problem that it is insufficient. In particular, in the manufacturing method by integral molding described above, the decrease in the perpendicularity becomes significant. In recent years, the allowable range for the perpendicularity of the honeycomb structure has become strict, and improvement of the perpendicularity of the honeycomb structure is required. The permissible range of perpendicularity means a range that satisfies the standard value of perpendicularity required for a ceramic honeycomb structure as a product. For example, in the processing method described in Patent Document 3, after the honeycomb structure is held by the clamp, the shape of the honeycomb structure is measured, and the posture of the honeycomb structure is corrected to perform the finishing process. . However, since the honeycomb structure has irregularities or the like on its outer wall, the clamp described above may not be stable. Further, in the processing method described in Patent Document 3, shape measurement for correcting the posture of the honeycomb structure is performed at four points of 0 °, 45 °, 90 °, and 135 ° in the circumferential direction. For this reason, there are problems that the measurement points are rough and the processing accuracy is low.

  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 using integral molding, the perpendicularity of the honeycomb structure is more significantly reduced. For example, when a large honeycomb structure is manufactured by a conventional manufacturing method using integral molding, the perpendicularity yield may be less than 50%. 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 squareness 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] The ceramic honeycomb fired body is subjected to dimensional inspection, and passes a product that satisfies the inspection standard, a rejected product that does not satisfy the inspection standard, and a perpendicularity that does not satisfy the inspection standard only among the rejected products. An inspection step for selecting the rejected product, and a grinding step for grinding one end surface and the other end surface of the ceramic honeycomb fired body selected as a reject product of only the perpendicularity, and In the grinding step, the contour measurement start point P1 and the contour measurement start point P2 are two positions spaced apart in the direction from the one end face toward the other end face of the outer wall surface of the ceramic honeycomb fired body. In the first measurement portion Q1 that goes around in the circumferential direction including the measurement start point P1, the contour of the outer diameter of the ceramic honeycomb fired body is In the second measurement portion Q2 measured at a plurality of measurement points while shifting the measurement position in the circumferential direction from the contour measurement start point P1, and in the second measurement portion Q2 that goes around in the circumferential direction including the contour measurement start point P2, the ceramic The contour of the outer diameter of the honeycomb fired body is measured at a plurality of measurement points while shifting the measurement position in the circumferential direction from the contour measurement start point P2, and the contour is measured at the first measurement point P1x of the first measurement portion Q1. And the contour measured at the second measurement point P1y existing at a position deviated from the first measurement point P1x of the first measurement portion Q1 by the contour C1x. The contour measured at the third measurement point P2x existing at the same phase position as the first measurement point P1x of the second measurement part Q2 And over C2x, the contour measured at the fourth measurement point P2y at the position of the said second measurement point P1y same as the phase of the second measurement portion Q2, as contour C2y, for each of the measuring points, 4 The sum of the absolute values of the differences between the values of the two contours C1x, C1y, C2x, C2y is obtained based on the following formula (1), and the contours C1x, C1y, C2x, the measuring point absolute value sum of the four as the minimum of the differential value of c2y, while supported by the first receiving tray and a second receiving tray, the one end surface and the said ceramic honeycomb fired body A method for manufacturing a ceramic honeycomb structure, wherein the other end face is ground.

[2] the contour C1x, C1y, C2x, said second measurement point P1y in the absolute value of four of the measurement points total is the smallest of the difference values of C2y, the phase of the contour measurement start point P1 , when the optimum chuck angle, the ceramic honeycomb fired bodies prior to supporting said first receiving tray and a second receiving tray, wherein the ceramic honeycomb fired body to the [1] to rotate by the optimum chuck angle A method for manufacturing a ceramic honeycomb structure.

[ 3 ] The method for manufacturing a ceramic honeycomb structure according to [1] or [2] , wherein the first measurement point P1x and the second measurement point P1y are shifted by 60 to 120 ° in the circumferential direction. .

[ 4 ] The ceramic honeycomb structure according to any one of [1] to [ 3 ], wherein the ceramic honeycomb fired body is placed on a measurement table so that the one end surface is a bottom surface, and the contour is measured. Body manufacturing method.

[5] said measuring table, the contour C1x, C1y, C2x, said second measurement point P1y in four of the measurement points the sum of the absolute value is minimum of the differential value of C2y, the contour measurement starting point the phases of the P1, when the optimum chuck angle, prior to supporting the ceramic honeycomb fired body to the first cradle and the second cradle, according to [4], which is rotated by said optimum chuck angle A method for manufacturing a ceramic honeycomb structure.

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

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

[ 8 ] The method for manufacturing a ceramic honeycomb structure according to any one of [1] to [ 7 ], wherein a one-sided dimensional difference in outer diameter dimensional tolerance of the ceramic honeycomb fired body is larger than a squareness.

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

[ 10 ] The ceramic honeycomb structure according to any one of [1] to [ 9 ], wherein the ceramic honeycomb fired body is made of a raw material containing at least one selected from the group consisting of cordierite, silicon carbide, and alumina. Manufacturing method.

  According to the method for manufacturing a ceramic honeycomb structure of the present invention, a ceramic honeycomb structure having an excellent perpendicularity can be manufactured regardless 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 manufacturing 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 contour in a grinding process. It is a side view which shows typically the state which mounted the ceramic honeycomb fired body in the 1st cradle and the 2nd cradle. It is the top view which looked at FIG. 2B from the one end surface side of the ceramic honeycomb fired body. It is a perspective view showing typically the 1st cradle and the 2nd cradle shown in Drawing 2B. It is a side view which shows typically an example of the grinding process in a grinding process. It is a graph which shows an example of the result of having measured a contour, and is a graph for demonstrating the calculation method of the total value of an absolute value. It is a graph which shows distribution of the optimal chuck angle of a ceramic honeycomb fired body. It is a schematic diagram for explaining the perpendicularity, and is a side view of the ceramic honeycomb structure viewed from the side. It is a top view which shows the state immediately after mounting the ceramic honeycomb fired body on the 1st cradle and the 2nd cradle.

  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 a method for manufacturing a ceramic honeycomb structure according to the present invention is a method for manufacturing a ceramic honeycomb structure including an inspection step C and a grinding step D as shown in FIG. In addition, in the manufacturing method of the ceramic honeycomb structure of this embodiment, you may further provide the finishing process A and the baking process B as shown in FIG. Here, FIG. 1 is a perspective view schematically showing a process of manufacturing a ceramic honeycomb structure in one embodiment of the 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 of firing the finished ceramic honeycomb dried body 70 obtained in the finishing step A to obtain a ceramic honeycomb fired body 80. Inspecting step C is a dimensional inspection of ceramic honeycomb fired body 80 obtained in firing step B, a passing product that satisfies the inspection criteria, a rejected product that does not meet the inspection criteria, and a perpendicularity among the rejected products. Is a process of selecting rejected products having only perpendicularity that do not satisfy the inspection standard. By this inspection step C, a ceramic honeycomb fired body 80B (hereinafter, also referred to as “failed product of only the right angle”) in which only the right angle does not satisfy the inspection standard is selected. The grinding process D is a process of grinding one end surface 91 and the other end surface 92 of the ceramic honeycomb fired body 80B selected as a rejected product having only a right angle. The ceramic honeycomb structure 100 obtained through such a grinding step D has an excellent perpendicularity. In addition, the ceramic honeycomb structure that has passed the inspection standard in the inspection step C is also a product (that is, a ceramic honeycomb structure). In the conventional manufacturing method, when the above-described inspection process is performed, a rejected product having only a right angle may be disposed of in the same manner as other rejected products. In the method for manufacturing a ceramic honeycomb structure according to the present embodiment, by performing the grinding step D, a rejected product having only a right angle (that is, the ceramic honeycomb fired body 80B) is a ceramic that satisfies the inspection standard for the right angle. It can be revived as a honeycomb fired body.

  Hereinafter, the ceramic honeycomb fired body 80B having only a defective perpendicularity may be referred to as “ceramic honeycomb fired body 80B” or simply “ceramic honeycomb fired body 80B”.

  In the method for manufacturing the ceramic honeycomb structure of the present embodiment, the grinding process D is performed by the following method. Here, FIG. 2A is a perspective view schematically showing an example of the contour measuring method in the grinding process.

  In the method for manufacturing the ceramic honeycomb structure of the present embodiment, as shown in FIG. 2A, the contour of the outer diameter of the ceramic honeycomb fired body 80B having a defective perpendicularity is measured. Specifically, first, two positions separated in the direction from one end face 91 to the other end face 92 on the surface of the outer wall 93 of the ceramic honeycomb fired body 80B are set as a contour measurement start point P1 and a contour measurement start point P2. . Two points, the contour measurement start point P1 and the contour measurement start point P2, serve as reference points for the contour measurement. Contour measurement is performed at a plurality of measurement points while shifting the measurement position in the circumferential direction from the respective contour measurement start points P1 and P2 to the entire circumferential direction including the contour measurement start points P1 and P2. Is called. That is, in the first measurement portion Q1 that goes around the circumferential direction R including the contour measurement start point P1, the contour of the outer diameter size of the ceramic honeycomb fired body 80B is shifted from the contour measurement start point P1 in the circumferential direction R. Measure at multiple measuring points. Further, in the second measurement portion Q2 that goes around the circumferential direction R including the contour measurement start point P2, the contour of the outer diameter of the ceramic honeycomb fired body 80B is shifted from the contour measurement start point P2 in the circumferential direction R. Measure at multiple measuring points. “Circumferential direction R” refers to the “cross section” along the surface of the outer wall 93 of the ceramic honeycomb fired body 80B in a cross section substantially perpendicular to the direction from the one end face 91 to the other end face 92 of the ceramic honeycomb fired body 80B. It is the direction that goes around the periphery of the. FIG. 2A shows an example in which the ceramic honeycomb fired body 80B is placed on a measurement table 65 on which a measurement object can be placed horizontally and the contour is measured. In FIG. 2A, the ceramic honeycomb fired body 80B placed on the measuring table 65 is rotated in the rotation direction indicated by reference numeral 88 to measure the contour. In FIG. 2A, reference numeral 81 denotes a partition wall of the ceramic honeycomb fired body, and reference numeral 82 denotes a cell partitioned by the partition wall 81.

From the measurement result of the contour measured in this way (for example, see FIG. 3), the support positions of the first cradle and the second cradle on which the ceramic honeycomb fired body is placed are determined in the grinding process. Here, FIG. 3 is a graph showing an example of the result of measuring the contour, and is a graph for explaining a method of calculating the sum of absolute values. Specifically, the sum of absolute values of differences between the values of “four contours C1x, C1y, C2x, C2y” shown below is obtained based on the following formula (1) .

  “Contour C1x” is a contour measured at the first measurement point P1x of the first measurement portion Q1. The “contour C1y” is a contour measured at the “second measurement point P1y existing at a position deviated from the first measurement point P1x by a certain phase” in the first measurement portion Q1. On the other hand, the “contour C2x” is a contour measured at the “third measurement point P2x existing at the same phase position as the first measurement point P1x” of the second measurement portion Q2. The “contour C2y” is a contour measured at the “fourth measurement point P2y existing at the same phase position as the second measurement point P1y” of the second measurement portion Q2.

  As can be seen from the measurement results shown in FIG. 3, the ceramic honeycomb fired body 80 </ b> B has a deformed outer peripheral shape or a bend in a direction from one end surface 91 toward the other end surface 92. When such a ceramic honeycomb fired body 80B is placed on the first cradle 68a and the second cradle 68b as shown in FIGS. 2C and 2D, the ceramic honeycomb fired body 80B becomes the first cradle 68a and the second cradle 68a. It is conceivable that the base 68b moves. That is, when the outer peripheral shape of the ceramic honeycomb fired body 80B is deformed, it cannot be placed on the first receiving tray 68a and the second receiving tray 68b in a stable state. Therefore, when the ceramic honeycomb fired body 80B is fixed by the auxiliary receiving base 69 after being placed on the first receiving base 68a and the second receiving base 68b, the ceramic honeycomb fired body 80B may move and tilt. When grinding is performed in a state where the ceramic honeycomb fired body 80B is inclined, the perpendicularity of the ceramic honeycomb fired body 80B is deteriorated. In the method for manufacturing the ceramic honeycomb structure of the present embodiment, the positions supported by the first cradle 68a and the second cradle 68b are determined from the above-described contour measurement result, and grinding is performed. When the ceramic honeycomb fired body 80B is placed on the first cradle 68a and the second cradle 68b, the point on the first measurement portion Q1 of the ceramic honeycomb fired body 80B is the grinding tool 75a of the first cradle 68a. Is supported at the end on the side where is disposed. The point on the second measurement portion Q2 of the ceramic honeycomb fired body 80B is supported by the end of the second cradle 68b on the side where the grinding tool 75b is disposed. Thus, in the method for manufacturing the ceramic honeycomb structure of the present embodiment, the “grinding tool 75a of the first cradle 68a is disposed in the direction L from the one end face 91 of the ceramic honeycomb fired body 80B toward the other end face 92. The “supported position at the end to be performed” is present in the first measurement portion Q1. Similarly, the “position supported at the end on the side where the grinding tool 75b of the second cradle 68b is disposed” in the direction L from the one end surface 91 to the other end surface 92 of the ceramic honeycomb fired body 80B is “the first position”. Exists in the second measurement part Q2 ". With this configuration, the ceramic honeycomb fired body 80B is placed on the first cradle 68a and the second cradle 68b at a position where the “total absolute value of contours” is the smallest. Furthermore, the right angle property is further enhanced by placing the first cradle 68a on the grinding tool 75a side and the second cradle 68b on the grinding tool 75b side. The distances n1, n2 between the first cradle 68a and the second cradle 68b and the grinding tool are preferably minimized within a range where the grinding tool and the cradle do not buffer, and specifically, within 10 mm. It is preferable.

The above-mentioned “total of absolute values of differences between the values of the contours C1x, C1y, C2x, C2y” is calculated by the following equation (1). Hereinafter, “the sum of the absolute values of the differences of the values of the contours C1x, C1y, C2x, C2y” calculated by the following formula (1) may be simply referred to as “the sum of the absolute values of the contours”. The calculation of the sum of the absolute values of the differences of the contours calculated by the following formula (1) is performed by all the measured contours.

Next, for each measurement point, the “sum of the absolute values of the differences of the contours” calculated by the above formula (1) is compared, and the “sum of the absolute values of the differences of the contours” is the smallest position. Find out.

  Next, as shown in FIGS. 2B to 2E, four measurement points on the surface of the outer wall 93 of the ceramic honeycomb fired body 80 </ b> B, at which the sum of absolute values of the differences in the respective contour values is minimized, It supports with 68a and the 2nd receiving stand 68b. Then, one end face 91 and the other end face 92 of the ceramic honeycomb fired body 80B are ground in a state where the ceramic honeycomb fired body 80B is supported by the first cradle 68a and the second cradle 68b. 2B to 2E, the four measurement points at which the sum of the absolute values of the differences of the contour values are the minimum are the support positions indicated by the symbols C1xnx and C1yny of the first cradle 68a and the second cradle. It is supported at the support positions indicated by reference numerals C2xnx and C2yny of 68b.

  The first cradle 68a and the second cradle 68b sideways the ceramic honeycomb fired body 80B so that the direction L from the one end surface 91 of the ceramic honeycomb fired body 80B toward the other end surface 92 is parallel to the substantially horizontal direction. It supports in the state of. That is, the first support position (C1yny) at the lowest point in the vertical direction of the first cradle 68a is the contour C1y among the four measurement points at which “the sum of the absolute values of the differences of the contours” is the smallest. Supports the second measurement point P1y "measured. Further, the second support position (C1xnx) shifted by a certain phase in the circumferential direction from the first support position at the lowest point in the vertical direction of the first cradle 68a is “the sum of the absolute values of the differences of the contours”. The first measurement point P1x where the contour C1x among the four measurement points that are the smallest is measured is supported. Similarly, the third support position (C2yny) at the lowest point in the vertical direction of the second cradle 68b is the contour of the four measurement points at which “the sum of the absolute values of the respective contour differences” is minimized. The fourth measurement point P2y where C2y is measured is supported. Further, the fourth support position (C2xnx) shifted by a constant phase in the circumferential direction from the third support position at the lowest point in the vertical direction of the second cradle 68b is “the sum of the absolute values of the differences of the contours”. The third measurement point P2x where the contour C2x is measured among the four measurement points that are the smallest is supported. In the “first support position C1yny”, “C1y” represents the value of the contour, and “ny” represents the contour measurement angle. In “second support position C1xnx”, “C1x” represents the value of the contour, and “nx” represents the contour measurement angle. In “the third support position C2yny”, “C2y” represents the value of the contour, and “ny” represents the contour measurement angle. In “fourth support position C2xnx”, “C2x” represents the value of the contour, and “nx” represents the contour measurement angle. The contour measurement angle is an angle at the measurement point of each contour when the contour measurement start point (P1, P2) is 0 ° and 360 ° when the side surface of the ceramic honeycomb fired body is measured once.

  Here, the phase of the two support positions (the first support position and the second support position) of the first cradle 68a may be referred to as the “receiving angle” of the first cradle 68a. That is, when the phase of the first measurement point P1x and the second measurement point P1y is 90 °, the receiving angle of the first receiving stand 68a is 90 °. 2B to 2D, the shapes of the first cradle 68a and the second cradle 68b are such that the position of the lowest point in the vertical direction on the outer wall 93 of the ceramic honeycomb fired body 80B in the lateral direction and the circumferential direction from the position. It is an L-shape configured to support two points 90 ° apart. Therefore, the phase between the first measurement point and the second measurement point when calculating “the sum of the absolute values of the differences of the contour values” is also 90 °. 2B to 2D, the ceramic honeycomb fired body 80 </ b> B is supported by the first cradle 68 a and the second cradle 68 b described above and the auxiliary cradle 69. The auxiliary cradle 69 has an outer wall on the opposite side across the center and a position 90 ° apart in the circumferential direction in a cross section perpendicular to the direction L from the one end face 91 to the other end face 92 of the ceramic honeycomb fired body 80B. It is something to support. Such auxiliary cradle 69 can prevent the ceramic honeycomb fired body 80B from rolling.

  Next, as shown in FIG. 2E, one end surface 91 and the other end surface 92 of the ceramic honeycomb fired body 80B are ground. FIG. 2E shows an example in which one end surface 91 and the other end surface 92 of the ceramic honeycomb fired body 80B are ground by the grinding tools 75a and 75b. Examples of the grinding tools 75a and 75b include a cutting grindstone and a grinding cup grindstone, and a grindstone that does not chip during processing is selected. When the grinding process is performed, “dry processing” that does not require drying after the processing is more preferable. By performing the grinding process in this way, the surplus portions 80a and 80b having an adverse effect on the perpendicularity of the one end face 91 and the other end face 92 of the ceramic honeycomb fired body 80B are scraped, and the ceramic having the excellent perpendicularity. A honeycomb structure can be manufactured.

  The smaller the distance n1 from the grinding tool 75a to the first support position C1yny of the first cradle 68a and the distance n2 from the grinding tool 75b to the third support position C2yny of the second cradle 68b, the shorter the ceramic honeycomb structure obtained. The perpendicularity of is improved. However, the cutting edges of the grinding tools 75a and 75b may be shaken by the vibrations of the grinding tools 75a and 75b. For this reason, it is preferable to ensure the lengths n1 and n2 described above so that the first cradle 68a and the second cradle 68b do not come into contact with the cutting edges of the grinding tools 75a and 75b. The distances n1 and n2 are preferably within 10 mm.

  In the finishing process of the method for manufacturing a ceramic honeycomb structure, the end face of the ceramic honeycomb dried body is simply cut and the lengths are simply cut. In such a cutting process in which the end face of the dried ceramic honeycomb body is simply cut, the perpendicularity of one end face and the other end face of the finished finished ceramic honeycomb dried body may be deteriorated. The ceramic honeycomb fired body 80B selected as a rejected product is subjected to the above-described grinding process on the ceramic honeycomb fired body 80B selected as a rejected product having only a right angle by the inspection process. It can be revived as meeting inspection standards. Thereby, the number of ceramic honeycomb fired bodies discarded as rejected products can be reduced, and a ceramic honeycomb structure having an excellent perpendicularity can be manufactured with a high yield.

  In addition, when grinding is performed on the ceramic honeycomb fired body 80B selected as a rejected product having only a perpendicularity, the perpendicularity is not necessarily improved unless grinding is performed by the grinding method as described above. It is not always done. That is, the contour of the ceramic honeycomb fired body is not constant in the circumferential direction of the ceramic honeycomb fired body. Further, the contour for each ceramic honeycomb fired body is not constant. For this reason, even if the ceramic honeycomb fired body selected as a rejected product of only perpendicularity is placed on the first cradle and the second cradle and simply ground, the squareness is not improved, The current state may be maintained, or conversely, the squareness may deteriorate. For example, in the state shown in FIG. 2E, if the four points where the contour values of the ceramic honeycomb fired body 80B greatly differ become support points for the first cradle 68a and the second cradle 68b, the ceramic honeycomb fired body 80B. May move and tilt. When grinding is performed in a state where the ceramic honeycomb fired body 80B is inclined, the perpendicularity of the ceramic honeycomb fired body 80B is deteriorated.

  In the method for manufacturing the ceramic honeycomb structure of the present embodiment, four measurement points at which “the sum of the absolute values of the differences of the contour values” is minimized are supported by the first cradle and the second cradle. Grinding is performed in this state. Thereby, in the manufacturing method of the ceramic honeycomb structure of the present embodiment, the grinding process is performed so that the perpendicularity becomes the best for each ceramic honeycomb fired body selected as a rejected product having only the perpendicularity. In the method for manufacturing a ceramic honeycomb structure of the present embodiment, the squareness can be satisfactorily improved by the above-described grinding process even for a ceramic honeycomb structure having a large outer diameter. Further, the manufacturing method of the ceramic honeycomb structure according to the present embodiment can manufacture a large-sized ceramic honeycomb structure at a high frequency without performing a complicated process as in the manufacturing method using the outer periphery coat. Also excellent.

  “Contour” means the magnitude of the actual contour deviation from the geometric contour defined by the theoretically exact dimensions. Therefore, the contour measured in the method for manufacturing the ceramic honeycomb structure of the present embodiment shown in FIG. 3 is the ceramic honeycomb fired body from the standard outer diameter dimension (corresponding to “0” on the vertical axis in FIG. 3). That is the size of the gap. By measuring such a contour, the variation of the line elements constituting the curved surface can be defined in a two-dimensional planar tolerance range. That is, the variation of the line elements constituting the outer peripheral surface of the ceramic honeycomb fired body can be defined by a two-dimensional planar tolerance range.

  The “squareness” will be described with reference to FIG. FIG. 5 is a schematic view for explaining the perpendicularity, and is a side view of the ceramic honeycomb structure 200 as viewed from the side. When obtaining the perpendicularity of the ceramic honeycomb structure 200, first, an imaginary line 115 perpendicular to the one end face 111 is drawn from any one point 111 a on the periphery of the one end face 111 of the ceramic honeycomb structure 200. An intersection 118 between the virtual line 115 and the virtual surface 116 of the other end surface 112 is obtained. Then, a length Y1 connecting the intersection point 118 and the end point 112a on the periphery of the other end surface 112 is obtained. The “length Y1” is the squareness of any one point. The squareness of the ceramic honeycomb structure 200 is a squareness having a maximum value obtained by measuring the “length Y1” over the entire circumference.

  The ceramic honeycomb fired body is obtained by firing a finished ceramic honeycomb dried body in which one end face and the other end face of the ceramic honeycomb dried body are finished so as to have a finished size. The “finished dimension” of the dried ceramic honeycomb body means 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. The finishing process of the dried ceramic honeycomb body can be performed according to a conventionally known method for manufacturing a ceramic honeycomb structure. The finished ceramic honeycomb dried body is cut so that the length from one end face to the other end face is the finish dimension, but the perpendicularity is that all the inspection standards of the dimension inspection are satisfied. Do not mean.

  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, the ceramic honeycomb dried body is not particularly limited as to its production method as long as the length in the cell extending direction is before finishing so as to be the finished dimension.

  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 raw material containing a ceramic material and a forming aid is kneaded and a clay is formed by a vacuum 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 the raw material mentioned above, In the manufacturing method of a conventionally well-known ceramic honeycomb structure, the ceramic material used as a forming raw material can be used. 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 FIG. 1, 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. That is, the finishing process refers to a process of cutting an excess portion from the finished dimension m of one end face 61 and the other end face 62 of the honeycomb dried body 50.

  There is no restriction | limiting in particular about the method of finishing, It can carry out according to the method of finishing in the manufacturing method of a conventionally well-known ceramic honeycomb structure. For example, although not shown, a method for cutting one end face and the other end face of the ceramic honeycomb dried body by placing the ceramic honeycomb dried body on a finishing cradle and using the finishing cutting tool Can be mentioned. Examples of the finishing cutting tool include a grindstone.

(1-3) Firing step:
In the method for manufacturing the ceramic honeycomb structure of the present embodiment, the finished ceramic honeycomb dried body obtained through the finishing process is fired to obtain a ceramic honeycomb fired body.

  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 fired body. 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) Inspection process:
In the method for manufacturing the ceramic honeycomb structure of the present embodiment, the obtained ceramic honeycomb fired body is subjected to dimensional inspection, and “accepted product that satisfies the inspection standard”, “failed product that does not satisfy the inspection standard”, Among rejected products, “failed products having only perpendicularity in which only the perpendicularity does not satisfy the inspection standard” is selected. The inspection standard is a standard value required for a ceramic honeycomb structure as a final product. The dimensional inspection can include a dimensional inspection for at least perpendicularity, and may further include, for example, dimensional inspections such as external dimensions, contours, bends, cylindricity, and the like. That is, the rejected product having only the perpendicularity satisfies the inspection standard other than the above-mentioned perpendicularity and is a rejected product that does not satisfy the inspection standard of the perpendicularity. In addition, the above-mentioned “failed product that does not satisfy the inspection standard” means a rejected product other than the rejected product having only the right angle, and failing to satisfy at least one inspection standard other than the right angle. It is a product.

  As described above, in the method for manufacturing a ceramic honeycomb structure according to the present embodiment, the ceramic honeycomb fired body in which only the perpendicularity is defective is selected from the obtained ceramic honeycomb fired body by this dimensional inspection. Then, the ceramic honeycomb fired body selected as a rejected product having only a right angle is subjected to the grinding process as described above, and the perpendicularity of one end face and the other end face of the ceramic honeycomb fired body is performed. To improve.

  There is no particular limitation on the specific method of dimensional inspection, and in a conventionally known method for manufacturing a ceramic honeycomb structure, it can be performed in accordance with various dimensional inspections performed on the final ceramic honeycomb structure. it can. In the conventional method for manufacturing a ceramic honeycomb structure, those that have not passed the dimensional inspection are usually treated as a rejected product, such as disposal. In this dimensional inspection, not only the perpendicularity but also other inspections such as external dimensions and bends did not pass, so it is difficult to make all improvements in the grinding process in the present embodiment. Appropriate treatments such as disposal are considered as acceptable products.

(1-5) Grinding process:
In the method for manufacturing the ceramic honeycomb structure of the present embodiment, as shown in FIGS. 2A to 2E, one end surface 91 of the ceramic honeycomb fired body 80B selected as a rejected product having only a right angle in the inspection step, and The other end surface 92 is ground. At this time, as described above, the contour of the outer diameter of the ceramic honeycomb fired body 80B selected as a rejected product having only a right angle is measured.

  There is no particular limitation on the method for measuring the contour. For example, the contour can be measured by a laser displacement meter 67 as shown in FIG. 2A. 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 contour of the ceramic honeycomb fired body 80B.

  There is no particular limitation on the number of measurement points in the circumferential contour of the ceramic honeycomb fired body 80B. However, if the number of measurement points increases, there is a greater possibility that a measurement point where the sum of the absolute values of the differences between the four contour values is smaller is obtained. Thereby, it is possible to obtain a ceramic honeycomb structure having an excellent perpendicularity.

  When measuring the contour of the ceramic honeycomb fired body 80B, measurement is performed in this circumferential direction from the contour measurement start point P1 to the entire circumferential direction including the contour measurement start point P1 (that is, the first measurement portion Q1). While shifting the position, the contour is measured at a plurality of measurement points of the first measurement portion Q1. Similarly, the measurement position of the second measurement portion Q2 is shifted from the contour measurement start point P2 over the entire circumferential direction including the contour measurement start point P2 (that is, the second measurement portion Q2) while shifting the measurement position in this circumferential direction. The contour is measured at a plurality of measurement points.

  As shown in FIG. 2A, the measurement of the contour is preferably performed by placing the ceramic honeycomb fired body 80B on a measurement table 65 on which a measurement object can be placed horizontally. When such a measuring table 65 is used, the contours of the first measurement portion Q1 and the second measurement portion Q2 can be easily measured. For example, when the laser displacement meter 67 is fixed, it is preferable to arrange two laser displacement meters 67 and simultaneously measure the contours of the first measurement portion Q1 and the second measurement portion Q2. The contour of the first measurement portion Q1 and the second measurement portion Q2 can be continuously measured by rotating the measurement table 65 on which the ceramic honeycomb fired body 80B is placed once in a horizontal plane. The laser displacement meter 67 may be a movable type. The ceramic honeycomb fired body 80B has a certain degree of squareness by the finishing process described above. Therefore, the ceramic honeycomb fired body 80B can measure the contour with high accuracy by placing the measurement object as it is on the measurement table 65 that can be placed horizontally.

  At the time when the measurement of the contour is completed, “the sum of the absolute values of the differences between the values of the four contours” is obtained, and the support positions supported by the first cradle 68a and the second cradle 68b are determined. Further, the measurement table 65 may be rotated by a predetermined angle. More specifically, first, “the sum of the absolute values of the differences of the contours” calculated for each measurement point is compared, and the position where the sum is the smallest is found. When there are a plurality of such “minimum values of total values”, for example, the closest measurement point from the contour measurement start point P1 is selected. By selecting the measurement points in this way, the time for rotating by a predetermined angle can be shortened. Next, the phase between the second measurement point P1y and the contour measurement start point P1 at the four measurement points at which “the sum of the absolute values of the differences of the four contour values” is minimized is referred to as “optimal chuck angle”. To do. Then, the measuring table 65 is rotated by the phase from the contour measurement start point P1 to the optimum chuck angle. As a result, the ceramic honeycomb fired body 80B on the measurement table 65 rotates by the optimum chuck angle, and the ceramic honeycomb fired body 80B in this state is chucked by the transport chuck, and the first receiving table 68a and the second receiving table 68b. Transport to. By configuring in this way, the four measurement points at which “the sum of the absolute values of the differences of the four contour values” is minimized are defined as described above, as described above. The support is performed at the support position C1yny and the second support position C1xnx, and at the third support position C2yny and the fourth support position C2xnx of the second cradle 68b.

  When the ceramic honeycomb fired body 80B is transported to the first cradle 68a and the second cradle 68b, as shown in FIG. 6, the ceramic honeycomb fired body 80B, the first cradle 68a and the second cradle 68b, It is preferable to provide a clearance f for preventing a collision. Here, FIG. 6 is a plan view showing a state immediately after the ceramic honeycomb fired body is placed on the first cradle and the second cradle. As shown in FIG. 6, after the ceramic honeycomb fired body 80B is placed on the first cradle 68a and the second cradle 68b, when the auxiliary cradle 69 moves to the left side of the page, the ceramic honeycomb fired body 80B rotates counterclockwise. Rotate to. By this rotation, the ceramic honeycomb fired body 80B is supported at each of two locations of the first cradle 68a and the second cradle 68b. However, as described above, when the ceramic honeycomb fired body 80B rotates, the optimum chuck angle after the shape measurement shifts and is supported by the first cradle 68a and the second cradle 68b. Therefore, in the case of transporting the ceramic honeycomb fired body 80B with the clearance f provided between the first cradle 68a and the second cradle 68b, the rotation at the time of fixing the ceramic honeycomb fired body 80B is considered. It is necessary to make corrections. Specifically, after the shape measurement shown in FIG. 2A is completed, when the measuring table 65 is rotated by the optimum chuck angle, the rotation angle at the time of fixing (that is, the rotation angle corresponding to the clearance f) is corrected. To do. By configuring in this way, the four measurement points at which “the sum of the absolute values of the differences of the four contour values” is minimized are defined as the first support position C1yny and the second support position of the first cradle 68a. C1xnx and the third support position C2yny and the fourth support position C2xnx of the second cradle 68b can be supported.

  As shown in FIG. 2A, when the measurement table 65 on which the ceramic honeycomb fired body 80B is placed is rotated once in a horizontal plane, the rotation center of the measurement table 65 and one end face of the ceramic honeycomb fired body 80B are changed to the other. The central axis in the direction toward the end surface may be slightly deviated. What is necessary is just to be within a measurement allowable range of the laser displacement meter and within a range where the ceramic honeycomb fired body 80B does not move when the measurement table 65 rotates. If the measurement of each contour is performed under the same conditions at a position that coincides with the direction from one end face to the other end face, the above-mentioned optimum chuck is obtained from "the sum of the absolute values of the differences of each contour". You can find the corner. The contour is a shape obtained by performing a best-fit process on the reference outer diameter by a least square method, a spline interpolation (interpolation method), or the like. The measured contour data (that is, the measurement result) is stored in XY coordinates. That is, the contour measurement of the ceramic honeycomb fired body 80B is (1) set at an arbitrary place on the measurement table 65, and the measurement coordinate data is different individually. (2) The ceramic honeycomb fired body 80B is bent. Although the outer diameter dimensions of the measurement part Q1 and the second measurement part Q2 can be measured, the measurement coordinate data is stored in a shifted manner such that the measurement coordinates of the first measurement part Q1 and the second measurement part Q2 are different. Accordingly, the measurement coordinate data of the first measurement portion Q1 and the measurement coordinate data of the second measurement portion Q2 are individually subjected to a best fit process with respect to the reference outer diameter dimension by the least square method. As a result, the contours of the first measurement portion Q1 and the second measurement portion Q2 can be processed with the same coordinates, and the “sum of the absolute values of the differences of the contours” can be calculated.

  When the sum of the absolute values of the differences between the four contour values is obtained for each measurement point, the first measurement point P1x and the second measurement point P1y of the first measurement portion Q1 are arranged in the circumferential direction. It is preferable that it exists in the range of 60-120 degrees. In other words, the phase between the first measurement point P1x and the second measurement point P1y is preferably 60 to 120 °. Similarly, the third measurement point P2x and the fourth measurement point P2y of the second measurement portion Q2 are also in the range of 60 to 120 ° in the circumferential direction. The first measurement point P1x and the second measurement point P1y serve as support points for the first cradle when the ceramic honeycomb fired body is supported by the first cradle. If the phase between the first measurement point P1x and the second measurement point P1y is less than 60 ° or more than 120 ° in the circumferential direction, it may be difficult to stably support the ceramic honeycomb fired body. More preferably, the phase of the first measurement point P1x and the second measurement point P1y is 90 °.

  As shown in FIGS. 2B to 2E, a specific example of the case where the outer wall 93 of the ceramic honeycomb fired body 80B is supported by the first cradle 68a and the second cradle 68b and grinding is performed in this state is as follows. explain. In the following specific example, an example in which the receiving angles of the first cradle 68a and the second cradle 68b are 90 ° is shown. The first cradle 68a and the second cradle 68b have the same shape, and the first cradle 68a and the second cradle 68b have horizontal support positions at their lowest points, and the first cradle 68a and the second cradle 68b. The cradle 68a and the second cradle 68b are disposed so as to be parallel to each other. Further, the first cradle 68a and the second cradle 68b and the grinding tools 75a and 75b are arranged in parallel. That is, one end surface 91 and the other end surface 92 of the ceramic honeycomb fired body 80B ground by the grinding tools 75a and 75b are parallel to the first cradle 68a and the second cradle 68b. As the first cradle 68a and the second cradle 68b used in the grinding process, for example, the same cradle used in the finishing process can be used.

  Here, an example of the result of measuring the contour is shown in FIG. In FIG. 3, the vertical axis represents the contour (mm), and the horizontal axis represents the contour measurement angle (°). The contour measurement angle (°) is the angle at the measurement point of each contour when the contour measurement start points P1 and P2 are 0 ° and the side of the ceramic honeycomb fired body is measured once. . In FIG. 3, the measurement result of the contour in the first measurement part Q1 and the measurement result of the contour in the second measurement part Q2 are shown. In the first measurement portion Q1 and the second measurement portion Q2, the contour is measured at 3000 points.

  As shown in FIG. 3, the contour measured at the first measurement point P1x of the first measurement portion Q1 is referred to as “contour C1x”. In addition, the measurement was performed at the second measurement point P1y existing at a position 90 ° out of phase with the first measurement point P1x of the first measurement portion Q1 (in other words, the position where the contour measurement angle was 90 ° apart). The contour is called “Contour C1y”. Similarly, the contour measured at the third measurement point P2x existing at the same phase position as the first measurement point P1x of the second measurement portion Q2 is referred to as “contour C2x”. The contour measured at the fourth measurement point P2y existing at the same phase as the second measurement point P1y of the second measurement portion Q2 is referred to as “contour C2y”. Here, the measurement point present at a position 90 ° out of phase from the first measurement point P1x is defined as the second measurement point P1y because the receiving angle of the first cradle and the second cradle is 90 °. Because. For this reason, when the receiving angles of the first cradle and the second cradle are different angles, the phase of the second measurement point P1y (in other words, the second measurement point P1y, according to the angle). Is determined).

  A solid line k1 and a broken line k2 shown in FIG. 3 are lines drawn at positions where the contour measurement angle is 90 ° apart. For example, the values of four points existing on the solid line k1 and the broken line k2 when moved over the entire circumference of the graph shown in FIG. 3 while maintaining the position where the solid line k1 and the broken line k2 are separated by 90 °. Are the contour C1x, the contour C1y, the contour C2x, and the contour C2y. The contour C1x is a contour measured at the first measurement point P1x, the contour C1y is a contour measured at the second measurement point P1y, and the contour C2x is measured at the third measurement point P2x. The contour C2y is a contour measured at the fourth measurement point P2y.

  Here, a method of calculating the sum of the absolute values of the differences between the four contour values when the contours C1x, C1y, C2x, and C2y shown in FIG. 3 are selected will be described. The sum of the absolute values of the differences of the contour values can be obtained by the above equation (1). The values of C1x, C1y, C2x, and C2y in the above formula (1) are the values (mm) of the contours C1x, C1y, C2x, and C2y in FIG.

  For the sum of the absolute values of the differences of the contour values, first, the absolute values of the differences of the four contour values to be calculated are obtained. As described above, when the contours C1x, C1y, C2x, and C2y are selected, the absolute value obtained by C1x-C2x, the absolute value obtained by C1y-C2y, the absolute value obtained by C1x-C1y, and C2x− The absolute values obtained by C2y are respectively obtained.

  In the example shown in FIG. 3, when the contour measurement angle is around 90 ° and 180 °, the sum of the absolute values of the differences between the values of the four contours is minimized. Therefore, as shown in FIGS. 2B to 2D, when the ceramic honeycomb fired body 80B is placed on the L-shaped first cradle 68a and the second cradle 68b, the contour measurement angle is 180 °. The positions are supported at the first support position C1yny of the first cradle 68a and the third support position C2yny of the second cradle 68b. On the other hand, when the contour measurement angle is 90 °, the angle is automatically supported at the second support position C1xnx of the first cradle 68a and the fourth support position C2xnx of the second cradle 68b. For example, even if the shape of the first cradle and the second cradle is V-shaped, if the receiving angle is 90 °, the same concept is used. As described above, by performing the grinding process in a state where the measurement point corresponding to the optimum chuck angle of the ceramic honeycomb fired body 80B is supported by the first cradle 68a and the second cradle 68b, only the perpendicularity is defective. The perpendicularity of the ceramic honeycomb fired body 80B thus selected can be improved.

  Here, FIG. 4 shows the calculation result of the optimum chuck angle of the ceramic honeycomb fired body. FIG. 4 is a graph showing the distribution of the optimum chuck angle of the ceramic honeycomb fired body. In FIG. 4, the vertical axis represents the optimum chuck angle, and the angle (°) at which the lowest point of the first support position C1yny of the first cradle 68a and the third support position C2yny of the second cradle 68b is supported. The horizontal axis indicates the number of measurements (pieces). As shown in FIG. 4, the optimum chuck angle of the ceramic honeycomb fired body has a different value for each ceramic honeycomb fired body over the entire circumferential direction. When a plurality of ceramic honeycomb fired bodies having different optimum chuck angles are always ground at a constant angle, the squareness deteriorates. In the method for manufacturing a ceramic honeycomb structure of the present embodiment, the squareness can be improved by grinding the ceramic honeycomb fired body after obtaining the optimum chuck angle by the above-described method.

  As shown in FIG. 2B and FIG. 2C, there is no particular limitation on the method for placing the ceramic honeycomb fired body 80B on the first cradle 68a and the second cradle 68b. After the contour is measured by the method as shown in FIG. 2A, the angle at which the measurement table 65 is supported at the lowest point of the first support position C1yny of the first receiving table 68a and the third support position C2yny of the second receiving table 68b. It is preferable that the ceramic honeycomb fired body 80B in this state is transported to the first cradle 68a and the second cradle 68b by a transport chuck (not shown). Note that, as described above, the first support position C1yny at the lowest point of the first cradle 68a is the contour C1y of the four measurement points at which “the sum of the absolute values of the differences of the contours” is the smallest. Supports the second measurement point P1y "measured. The third support position C2yny at the lowest point of the second cradle 68b is the first position where the contour C2y of the four measurement points at which “the sum of the absolute values of the differences of the contours” is the smallest is measured. Supports “four measurement points P2y”. That is, the measurement of the contour is finished, and the ceramic honeycomb fired body 80B in a state of rotating once to the contour measurement start point is further rotated by the optimum chuck angle. By rotating the optimum chuck angle, the measured ceramic honeycomb fired body 80B is always supported by the first cradle 68a and the second cradle 68b at the optimum chuck angle. Such a contour measurement is performed on all the ceramic honeycomb fired bodies 80B selected as rejected products having only perpendicularity. As described above, in the method for manufacturing the ceramic honeycomb structure of the present embodiment, the first cradle 68a, the second cradle 68b, the grinding tools 75a and 75b, and the like with respect to the difference in the shape of each ceramic honeycomb fired body 80B. The optimum chuck angle of each ceramic honeycomb fired body 80B is determined by the contour.

  Thereafter, the end faces of the ceramic honeycomb fired body 80B placed on the first cradle 68a and the second cradle 68b are ground by the grinding tools 75a and 75b.

  As described above, the fired ceramic honeycomb body having only a defective perpendicularity can be revived as a fired ceramic honeycomb body satisfying the perpendicularity inspection standard. In the method for manufacturing a ceramic honeycomb structure of the present embodiment, a ceramic honeycomb fired body obtained by grinding and a ceramic honeycomb fired body selected as an acceptable product that satisfies the inspection standard by the above-described dimensional inspection are manufactured. A ceramic honeycomb structure is obtained. In the method for manufacturing a ceramic honeycomb structure of the present embodiment, a ceramic honeycomb structure having an excellent perpendicularity can be manufactured with high frequency regardless of the outer diameter of the ceramic honeycomb fired body. For this reason, the method for manufacturing the ceramic honeycomb structure of the present embodiment is suitable when the outer diameter of the ceramic honeycomb fired body is 100 mm or more, and the outer diameter of the ceramic honeycomb fired body is 150 mm or more. More preferred in some cases. Ceramic honeycomb fired bodies with a ceramic honeycomb fired body with an outer diameter size of 100 mm or more have a large contour on the outer wall surface. Many honeycomb fired bodies are manufactured. That is, the perpendicularity yield is lowered. In addition, the method for manufacturing a ceramic honeycomb structure of the present embodiment is more suitable when the one-side dimensional difference of the outer diameter dimensional tolerance of the ceramic honeycomb fired body is larger than the squareness. That is, even if the allowable range for the perpendicularity is stricter, according to the method for manufacturing the ceramic honeycomb structure of the present embodiment, a good perpendicularity can be realized. The outer diameter dimension tolerance is a product standard of the outer diameter dimension, and is a difference between the maximum dimension and the minimum dimension of an error allowed in each manufacturing stage.

  In the above-described dimensional inspection of the ceramic honeycomb fired body, in addition to the contour measurement start points P1 and P2 that are separated from the one end face of the outer wall surface of the ceramic honeycomb fired body toward the other end face, the contour measurement start is also started in the central portion. Dots are provided. Of these, the contour data of Q1 and Q2 measured at the measurement start points P1 and P2 can be used as chuck angle calculation data. That is, an acceptable product that satisfies the inspection standard in dimensional inspection, an unacceptable product that does not satisfy the inspection standard, and an unacceptable product that has only a perpendicularity are selected, and the contours C1x, C1y, and C2x are rejected. , C2y, it is possible to calculate the four measurement points that minimize the sum of the absolute values of the respective differences. The method described above can be applied to the post-calculation step. There is no need to measure the shape again, which is an efficient method. However, in order to perform grinding in the process of performing a precise dimensional inspection, it is necessary to improve the environment.

  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 ceramic honeycomb dried body was produced. 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, one end face and the other end face of the obtained ceramic honeycomb dried body were finished to obtain a finished ceramic honeycomb dried body. The length (namely, finished dimension) from one end face to the other end face of the finished ceramic honeycomb dried body was 200 mm.

  The obtained finished ceramic honeycomb dried body was degreased and fired to prepare a ceramic honeycomb fired body. Degreasing and firing were performed in an oxidizing atmosphere. The maximum temperature during firing was 1430 ° C. By such a method, 100 lots of ceramic honeycomb fired bodies were manufactured with 100 lots. The outer diameter of the ceramic honeycomb fired body was 150 mm. Table 1 shows the “outer diameter dimension” of the ceramic honeycomb fired body and the “finish dimension” of the finished ceramic honeycomb dried body.

  Next, the obtained ceramic honeycomb fired body was subjected to dimensional inspection to select an acceptable product that satisfies the inspection standard and an unacceptable product that does not satisfy the inspection standard and has only a perpendicularity. Thereafter, the ceramic honeycomb fired body selected as a rejected product having only a perpendicularity was subjected to a grinding process by the following method. In addition, the ceramic honeycomb fired body selected as an acceptable product satisfying the inspection standard by the above-described dimension inspection was not subjected to a grinding process, and the ceramic honeycomb fired body was made a ceramic honeycomb structure for manufacturing purposes.

  As shown in FIG. 2A, the ceramic honeycomb fired body 80B selected as a rejected product having only a right angle was placed on a measurement table 65 that can rotate in a horizontal plane. Thereafter, the contour in the circumferential direction on the surface of the outer wall 93 of the ceramic honeycomb fired body 80 </ b> B was continuously measured by a laser displacement meter 67. Specifically, first, two positions separated in the direction from one end face 91 to the other end face 92 on the surface of the outer wall 93 of the ceramic honeycomb fired body 80B are set as a contour measurement start point P1 and a contour measurement start point P2. . Then, in the first measurement portion Q1 that goes around the circumferential direction R including the contour measurement start point P1, the contour of the outer diameter dimension of the ceramic honeycomb fired body 80B is shifted from the contour measurement start point P1 in the circumferential direction R. However, measurement was performed at a plurality of measurement points. In the second measurement portion Q2 that goes around the circumferential direction R including the contour measurement start point P2, the contour was measured at a plurality of measurement points while shifting the measurement position in the circumferential direction R from the contour measurement start point P2. As the laser displacement meter 67, a reflective non-contact laser displacement meter was used. The measurement of the contour was performed at 3000 points in one circumferential direction. That is, the contour at each point on the surface of the outer wall 93 of the ceramic honeycomb fired body 80B was measured in increments of 0.12 ° from the contour measurement start point. In Example 1, as a first cradle and a second cradle for performing a grinding process, a cradle with a receiving angle of 90 ° was used.

  From the obtained measurement results, the total of the absolute values of the differences between the four contour values was determined for each of the 3000 measurement points by the following method. Here, the contour measured at the contour measurement start point P1 is referred to as “Contour C1 (0 °)”, and the contour measured at the contour measurement start point P2 is referred to as “Contour C2 (0 °)”. Further, a contour measured at a measurement point moved by n ° in the circumferential direction from the contour measurement start point P1 is defined as “contour C1 (n °)”. The “n °” is the contour measurement angle (°) when the contour measurement start point P1 is set to 0 ° (see FIG. 3). Similarly, a contour measured at a measurement point shifted by n ° in the circumferential direction from the contour measurement start point P2 is defined as “contour C2 (n °)”. For example, the contour measured at the measurement point moved by 0.12 ° in the circumferential direction from the contour measurement start point P1 is “Contour C1 (0.12 °)”.

First, the total N ₀ of the absolute values of the differences between the four contour values of the contour C1 (0 °), the contour C1 (90 °), the contour C2 (0 °), and the contour C2 (90 °) was obtained. . “The total absolute value N ₀ of each difference of the contour values” means the contour measurement start point P1 and “the first measurement point P1x for calculating the total absolute value of the differences of the contour values” Means you have selected. In addition, the calculation of “the total of the absolute values of the differences of the contour values N ₀ ” was performed using the contour values of the contour measurement angles of 0 ° and 90 ° for the first cradle and the second cradle. This is because the receiving angle is 90 °.

Next, the difference of each of the four contour values of contour C1 (0.12 °), contour C1 (90.12 °), contour C2 (0.12 °), and contour C2 (90.12 °) The absolute total N _0.12 was determined. From this point onward, sequentially find the sum of the absolute values of the differences of the four contour values while moving the measurement points for the sum of the absolute values of the differences of the four contour values in the circumferential direction. It was. Hereinafter, “the sum of the absolute values of the differences between the values of the four contours” may be simply referred to as “the sum of the differences of the contours”.

  Next, all the obtained “sum of contour differences” are compared, and the smallest total value having the smallest “sum of contour differences” is found. Here, an angle obtained by adding 90 ° to the contour measurement angle at which “the total difference of contours” is minimum was defined as “optimum chuck angle”. The four contours used to calculate the minimum total value with the smallest “total contour difference” are “Contour C1 (n °)”, “Contour C1 ((n + 90) °)”, “Contour C2 ( n ”) and“ Contour C2 ((n + 90) °) ”, the values of each contour are as follows. That is, “Contour C1 (n °)” is defined as “Contour C1x measured at the first measurement point P1x”. “Contour C1 ((n + 90) °)” is defined as “Contour C1y measured at the second measurement point P1y”. “Contour C2 (n °)” is defined as “Contour C2x measured at the third measurement point P2x”. “Contour C2 ((n + 90) °)” is defined as “Contour C2y measured at the fourth measurement point P2y”. Next, as shown in FIG. 2B and FIG. 2C, the ceramic honeycomb fired body 80B for which measurement was completed was placed on the first cradle 68a and the second cradle 68b. The ceramic honeycomb fired body 80B was transported to the first cradle 68a and the second cradle 68b by the following method. First, the measurement of the contour was completed, and the ceramic honeycomb fired body 80B in a state of being rotated once to the contour measurement start point was further rotated by the optimum chuck angle. The ceramic honeycomb fired body 80B described above was rotated by rotating the measuring table 65. Next, the ceramic honeycomb fired body 80B is transferred to the first support position C1yny and the second support position C1xnx of the first cradle 68a and the third support position C2yny of the second cradle 68b by the transport chuck (not shown). Installed at the four support positions C2xnx.

  Next, as shown in FIG. 2E, the one end face 91 and the other end face 92 of the ceramic honeycomb fired body 80B placed on the first cradle 68a and the second cradle 68b are ground by the grinding tools 75a and 75b. The ceramic honeycomb structure was obtained by processing. As the grinders 75a and 75b, cup grindstones having a grindstone particle size of # 100 were used. The taper angle of the cup grindstone was 15 degrees. The peripheral speed of the cup grindstone was 30 m / sec. The distance n1 from the grinding tool 75a to the first support position C1yny and the distance n2 from the grinding tool 75b to the third support position C2yny were 6 mm.

  The defect rate of the ceramic honeycomb fired body 80B selected as a rejected product having only a perpendicularity is 21%. Grinding is performed by the above-described method, and the defect rate of the obtained ceramic honeycomb structure with respect to the perpendicularity ( %). That is, the squareness of all the ceramic honeycomb structures obtained in Example 1 was measured, and those satisfying the tolerance of perpendicularity were regarded as acceptable, and those not satisfying the tolerance of perpendicularity were rejected. did. From this measurement result, the defect rate (%) for the perpendicularity in Example 1 (that is, “the defect rate of only the perpendicularity (%)”) was obtained. Table 1 shows the defect rate (%) of the perpendicularity of Example 1 only.

(Example 2)
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 finished dimensions were as shown in Table 1. A ceramic honeycomb structure was manufactured in the same manner as in Example 1. The defect rate of the ceramic honeycomb fired body 80B selected as a rejected product having only a perpendicularity is 49%, and grinding was performed by the method described above, and the ceramic honeycomb structure obtained by the same method as in Example 1 was used. The defect rate (%) of only the perpendicularity of the body was determined. The results are shown in Table 1.

(Comparative Examples 1 and 2)
In Examples 1 and 2, Comparative Example 1 and 2 were those in which the above-described grinding process was not performed on a rejected product with only a right angle selected by dimensional inspection. Since the above-described grinding process is not performed on a rejected product having only a right angle selected by dimensional inspection, Comparative Example 1 has a failure rate of 21% and Comparative Example 2 has a failure rate of 49%.

(Result 1)
As shown in Table 1, according to the manufacturing methods of Examples 1 and 2, compared with the manufacturing methods of Comparative Examples 1 and 2, the defect rate (%) of only perpendicularity is drastically reduced. I understand. In Comparative Examples 1 and 2, when the ceramic honeycomb dried body is finished, the ceramic honeycomb dried body placed on the finishing cradle may move and tilt. When finishing is performed in a state where the ceramic honeycomb dried body is inclined, the perpendicularity of the ceramic honeycomb dried body is deteriorated. Such deterioration of the perpendicularity of the ceramic honeycomb dried body is directly reflected in the perpendicularity of the ceramic honeycomb structure. On the other hand, in Examples 1 and 2, as in Comparative Examples 1 and 2, the squareness may deteriorate in finishing, but the perpendicularity deteriorated by performing the shape measurement and grinding process described above. The perpendicularity of the ceramic honeycomb fired body can be improved. For this reason, in Examples 1 and 2, it was possible to obtain a result that the defect rate of only perpendicularity was 0%.

  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 an excellent perpendicularity.

50: Ceramic honeycomb dried body, 51: Partition wall, 52: Cell, 61: One end surface, 62: The other end surface, 65: Measuring table, 67: Laser displacement meter, 68a: First receiving table, 68b: Second receiving table 70: Auxiliary cradle, 70: Finished ceramic honeycomb dried body, 75a, 75b: Grinding tool, 80: Ceramic honeycomb fired body, 80B: Ceramic honeycomb fired body (ceramic honeycomb fired body in which only perpendicularity is defective), 80a 80b: surplus portion, 81: partition wall, 82: cell, 88: rotational direction, 91: one end face, 92: the other end face, 93: outer wall, 100, 200: ceramic honeycomb structure, 111: one end face, 111a: point (one point on the periphery of one end surface), 112: the other end surface, 112a: end point (the end point on the other end surface), 115: virtual line, 116: temporary Surface, 118: intersection, A: finishing process, B: firing process, C: inspection process, D: grinding process, C1x, C1y, C2x, C2y: contour, f: clearance, k1: solid line, k2: broken line, L : Direction from one end face to the other end face, m: finishing dimension, n1: distance (distance from the grinding tool to the first support position), n2: distance (distance from the grinding tool to the third support position), P1 , P2: contour measurement start point, C1yny: first support position, C1xnx: second support position, C2yny: third support position, C2xnx: fourth support position, P1x: first measurement point, P1y: second measurement point, P2x: third measurement point, P2y: fourth measurement point, R: circumferential direction, Q1: first measurement portion, Q2: second measurement portion, Y1: length (perpendicularity).

Claims (10)

The ceramic honeycomb fired body is subjected to dimensional inspection, a passing product that satisfies the inspection standard, a non-accepting product that does not satisfy the inspection standard, and a non-acceptance of only a perpendicularity that does not satisfy the inspection standard. An inspection process for selecting products,
A grinding step of grinding one end face and the other end face of the ceramic honeycomb fired body selected as a rejected product of only the perpendicularity, and
In the grinding step, two positions separated in the direction from the one end face to the other end face of the outer wall surface of the ceramic honeycomb fired body are set as a contour measurement start point P1 and a contour measurement start point P2.
In the first measurement portion Q1 that goes around in the circumferential direction including the contour measurement start point P1, the contour of the outer diameter of the ceramic honeycomb fired body is shifted from the contour measurement start point P1 in the circumferential direction while shifting the measurement position. Measure at multiple measuring points, and
In the second measurement portion Q2 that goes around in the circumferential direction including the contour measurement start point P2, the contour of the outer diameter size of the ceramic honeycomb fired body is shifted from the contour measurement start point P2 in the circumferential direction. Measure at multiple measuring points,
A contour measured at the first measurement point P1x of the first measurement portion Q1 is defined as a contour C1x, and a second measurement point existing at a position deviated from the first measurement point P1x of the first measurement portion Q1 by a certain phase. The contour measured at P1y is defined as contour C1y, and the contour measured at the third measurement point P2x existing at the same phase as the first measurement point P1x of the second measurement portion Q2 is defined as contour C2x. The contour measured at the fourth measurement point P2y existing at the same phase position as the second measurement point P1y of the second measurement portion Q2 is defined as contour C2y.
For each of the measurement points, a total of absolute values of differences between the four contours C1x, C1y, C2x, C2y is obtained based on the following formula (1) :
The ceramic of the outer wall surface of the honeycomb fired body, wherein the contour C1x, C1y, C2x, the absolute value the measurement point total of four as the minimum of the differential value of C2y, first receiving tray and a second receiving tray A method for manufacturing a ceramic honeycomb structure in which the one end surface and the other end surface of the ceramic honeycomb fired body are ground while being supported by the above.

The contour C1x, C1y, C2x, said second measurement point P1y in the absolute value total of four of the measuring point as the minimum of the differential value of C2y, the phase of the contour measurement start point P1, the optimum chuck If it is a corner,
Wherein prior to supporting the ceramic honeycomb fired body to the first cradle and the second cradle method for producing a ceramic honeycomb structure according to claim 1 for rotating the ceramic honeycomb fired body by the optimum chuck angle. Wherein the first measurement point P1x and a second measurement point P1y, method for producing a ceramic honeycomb structure according to the circumferential direction in claim 1 or 2 which is 60 to 120 ° shifted position. The method for manufacturing a ceramic honeycomb structure according to any one of claims 1 to 3 , wherein the ceramic honeycomb fired body is placed on a measurement table so that the one end surface is a bottom surface, and the contour is measured. . Said measuring table, the contour C1x, C1y, C2x, said second measurement point P1y in the absolute value total of four of the measuring point as the minimum of the differential value of C2y, with the contour measurement start point P1 5. The ceramic honeycomb structure according to claim 4 , wherein when the phase is an optimum chuck angle, the ceramic honeycomb fired body is rotated by the optimum chuck angle before the ceramic honeycomb fired body is supported on the first cradle and the second cradle. Manufacturing method. The method for manufacturing a ceramic honeycomb structure according to any one of claims 1 to 5 , wherein the contour 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 6 , wherein the ceramic honeycomb fired body has an uneven surface on an outer periphery. The method for producing a ceramic honeycomb structure according to any one of claims 1 to 7 , wherein a one-sided dimensional difference of an outer diameter dimensional tolerance of the ceramic honeycomb fired body is larger than a squareness. The method for manufacturing a ceramic honeycomb structure according to any one of claims 1 to 8 , wherein an outer diameter of the ceramic honeycomb fired body is 100 mm or more. The method for manufacturing a ceramic honeycomb structure according to any one of claims 1 to 9 , wherein the ceramic honeycomb fired body is made of a raw material containing at least one selected from the group consisting of cordierite, silicon carbide, and alumina.

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