Abstract: An extracellular potential measurement device includes multiple insulating films each of which is made from an electric insulating material, the insulating films being stacked and bonded to each other; and multiple electrode wires each of which is made from an electroconductive material, the electrode wires being arranged in multiple heights. Each of the electrode wires is interposed between an upper insulating film and a lower insulating film. Each of the insulating films, except for a lowermost insulating film, has an opening penetrating the insulating film. The opening in a lower insulating film has a size that is less than that of the opening in an upper insulating film, the openings in the insulating films being overlapped to form a recess having a size reducing downward, the recess being adapted to store a collection of cells. Each of the electrode wires has an end that is located near an opening in an insulating film that is immediately below the electrode wire, the ends being exposed in the recess.

Abstract: A plurality of inlet-side octagonal cells and outlet-side quadrangular cells partitioned by partition walls on an upper surface and a lower surface are opened in a green honeycomb molded body in which a plurality of through-holes partitioned from each other by the partition walls are open in an end surface of a columnar body. Four outlet-side quadrangular cells having a smaller opening area adjoin around one inlet-side octagonal cell through the partition walls. The partition walls are joined together and the inlet-side octagonal cells are opened while closing the outlet-side quadrangular cells on the inlet side and the outlet-side quadrangular cells are opened while closing the inlet-side octagonal cells on the outlet side in a particulate-matter-removing filter such as a diesel particulate filter.

Abstract: This particulate filter 200 has a columnar ceramic honeycomb structure 201 including first flow channels 210 and second flow channels 220. Adjacently to each of the first flow channels 210, the second flow channel 220 and the other first flow channel 210 are arranged through a partition wall portion forming each of the first flow channels 210. A sum total of areas of the inner faces of the first flow channels 210 per apparent unit volume of the ceramic honeycomb structure 201 is 1.5 to 2.5 m2/L; a number density of a total of the first flow channels 210 and the second flow channels 220 is 150 to 350 per unit square inch in a cross section perpendicular to an axis of the ceramic honeycomb structure 201; and a hydraulic diameter of each of the first flow channels 210 is 0.5 to 1.0 mm.

Abstract: An integrated closing tool is inserted into a part of hexagonal cells in a green honeycomb molded body including a plurality of hexagonal cells that open in an upper surface and a lower surface of a columnar body and are mutually partitioned by partition walls to join the partition walls together, thereby closing the hexagonal cells. A part of the integrated closing tool is separated, and tool separated pieces separated from a part of the hexagonal cells into which the closing tool has been inserted are removed.

Abstract: A plurality of inlet-side octagonal cells and outlet-side quadrangular cells partitioned by partition walls on an upper surface and a lower surface are opened in a green honeycomb molded body in which a plurality of through-holes partitioned from each other by the partition walls are open in an end surface of a columnar body. Four outlet-side quadrangular cells having a smaller opening area adjoin around one inlet-side octagonal cell through the partition walls. The partition walls are joined together and the inlet-side octagonal cells are opened while closing the outlet-side quadrangular cells on the inlet side and the outlet-side quadrangular cells are opened while closing the inlet-side octagonal cells on the outlet side in a particulate-matter-removing filter such as a diesel particulate filter.

Abstract: A plurality of inlet-side octagonal cells and outlet-side quadrangular cells partitioned by partition walls on an upper surface and a lower surface are opened in a green honeycomb molded body in which a plurality of through-holes partitioned from each other by the partition walls are open in an end surface of a columnar body. Four outlet-side quadrangular cells having a smaller opening area adjoin around one inlet-side octagonal cell through the partition walls. The partition walls are joined together and the inlet-side octagonal cells are opened while closing the outlet-side quadrangular cells on the inlet side and the outlet-side quadrangular cells are opened while closing the inlet-side octagonal cells on the outlet side in a particulate-matter-removing filter such as a diesel particulate filter.

Abstract: The extrusion-molding device of the invention includes a flow passage for transporting a paste raw material composition; a screw provided at an upstream side of the flow passage to knead the raw material composition and transport it to a downstream side; a die provided at a downstream side of the flow passage to extrude a molded body composed of the raw material composition therefrom; a resistive tube for connecting the flow passage and the die; and a current plate provided between the screw and the die. The current plate comprises a plurality of through-holes that penetrate from a upstream end side to a downstream end side, and an opening of the through-hole on the upstream end side has a larger open area than an opening on the downstream end side.

Abstract: This particulate filter 200 has a columnar ceramic honeycomb structure 201 including first flow channels 210 and second flow channels 220. Adjacently to each of the first flow channels 210, the second flow channel 220 and the other first flow channel 210 are arranged through a partition wall portion forming each of the first flow channels 210. A sum total of areas of the inner faces of the first flow channels 210 per apparent unit volume of the ceramic honeycomb structure 201 is 1.5 to 2.5 m2/L; a number density of a total of the first flow channels 210 and the second flow channels 220 is 150 to 350 per unit square inch in a cross section perpendicular to an axis of the ceramic honeycomb structure 201; and a hydraulic diameter of each of the first flow channels 210 is 0.5 to 1.0 mm.

Abstract: An integrated closing tool is inserted into a part of hexagonal cells in a green honeycomb molded body including a plurality of hexagonal cells that open in an upper surface and a lower surface of a columnar body and are mutually partitioned by partition walls to join the partition walls together, thereby closing the hexagonal cells. A part of the integrated closing tool is separated, and tool separated pieces separated from a part of the hexagonal cells into which the closing tool has been inserted are removed.

Abstract: The columnar honeycomb structure 10 extending along a central axis CL, including a first end surface 10a and a second end surface 10b, and a partition wall 10c forming a plurality of first flow passages Ra and a plurality of second flow passages Rb, in which the first flow passages Ra are opened at the side of the first end surface 10a and plugged at the side of the second end surface 10b, the second flow passages Rb are plugged at the side of the first end surface 10a and opened at the side of the second end surface 10b, and the honeycomb structure includes a circular row W formed by arranging the second flow passages Rb adjoining and partitioned by the partition wall 10c in a circular pattern.

Abstract: Regular hexagonal cells at both an top surface and a bottom surface of a green honeycomb molded body are closed at the same time. Therefore, the regular hexagonal cells can be closed effectively. In addition, the regular hexagonal cells of the green honeycomb molded body are closed by welding partition walls with each other, by inserting each of closing protrusions of a closing jig into the plurality of regular hexagonal cells. Therefore, a closing paste like the conventional method is not required. In a case where a honeycomb structure is used for a diesel particulate filter, turbulence of exhaust gas flow, at the end surface of the side to supply the exhaust gas and/or the side to discharge the exhaust gas, is reduced, and pressure drop can be reduced.

Abstract: A closing jig for a green honeycomb molded body includes closing protrusions which are arranged at positions corresponding to regular hexagonal cells and are inserted into the regular hexagonal cells to weld partition walls to each other for closing. Each of the closing protrusions includes a conical tip end portion that has a conical shape, and a triangular pyramidal base portion with a truncated triangular pyramidal shape having an apex angle larger than an apex angle of the conical tip end portion. The conical tip end portion has the conical shape with an acute apex angle. The triangular pyramidal base portion has the truncated triangular pyramidal shape having the large apex angle.

Abstract: A method for manufacturing a honeycomb structure in which some of a plurality of through-holes that are opened at the end face of the cylinder, and mutually divided by partitions, have been closed, wherein a closing jig is inserted into some of the plurality of hexagonal cells of a green honeycomb molded body which has a plurality of hexagonal cells mutually divided by partitions and is open at the end face of the cylinder, thereby contact bonding together the partitions to close the hexagonal cells. Thus, it is possible to close hexagonal cells in a very simple manner during manufacture of the honeycomb molded body.

Abstract: A closing jig for a green honeycomb molded body includes closing protrusions which are arranged at positions corresponding to regular hexagonal cells and are inserted into the regular hexagonal cells to weld partition walls to each other for closing. Each of the closing protrusions includes a conical tip end portion that has a conical shape, and a triangular pyramidal base portion with a truncated triangular pyramidal shape having an apex angle larger than an apex angle of the conical tip end portion. The conical tip end portion has the conical shape with an acute apex angle. The triangular pyramidal base portion has the truncated triangular pyramidal shape having the large apex angle.

Abstract: Regular hexagonal cells at both an top surface and a bottom surface of a green honeycomb molded body are closed at the same time. Therefore, the regular hexagonal cells can be closed effectively. In addition, the regular hexagonal cells of the green honeycomb molded body are closed by welding partition walls with each other, by inserting each of closing protrusions of a closing jig into the plurality of regular hexagonal cells. Therefore, a closing paste like the conventional method is not required. In a case where a honeycomb structure is used for a diesel particulate filter, turbulence of exhaust gas flow, at the end surface of the side to supply the exhaust gas and/or the side to discharge the exhaust gas, is reduced, and pressure drop can be reduced.

Abstract: The extrusion-molding device of the invention is for producing a green honeycomb molded body with a cell structure, and the device includes a housing, a screw, a die with slits, a resistance tube and a fragmenting board having through-passages through which a raw material composition passes from the upstream end side to the downstream end side. The through-passages of the fragmenting board have upstream channels composed of a plurality of flow passages extending downstream from the upstream end side, and downstream channels extending up to the downstream end side and having flow passage cross-sectional shapes different from those of the upstream channels.

Abstract: Obtaining computer-tomography images of a first section at a distance Z1 from one end surface 112d of a honeycomb structure 100 and a second section at a distance Z2 larger than the distance Z1 from the end surface 112d of the honeycomb structure, determining the existence/nonexistence of a plugging portion 114 in at least one of the plurality of passages based on the computer-tomography image of the first section, determining the existence/nonexistence of the plugging portion in the at least one passage based on the computer-tomography image of the second section, and determining the length of the plugging portion based on the result of determination of the existence/nonexistence of the plugging portion based on the computer-tomography image of the first section and the result of determination of the existence/nonexistence of the plugging portion based on the computer-tomography image of the second section.

Abstract: The tunnel kiln according to the present invention includes a tunnel kiln main body having an inner wall constituted by a furnace material, and having a debinding zone and a sintering zone wherein respectively debinding and sintering of a body to be fired containing an organic component are performed; a conveying unit for conveying the body to be fired from an inlet side to an outlet side of the tunnel kiln main body; and a lining provided so that at least an inner wall of the debinding zone of the inner wall of the tunnel kiln main body is covered therewith.