Patents by Inventor Takeshi Tokunaga

Takeshi Tokunaga has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8048508
    Abstract: A honeycomb structure comprising porous partition walls which form, by surrounding, a plurality of cells extending between the two ends faces of the honeycomb structure, and an outer wall formed integrally with the partition walls. The cells consist of partial cells of outermost peripheral portion, having incomplete cell sections, which are located at the outermost peripheral portion of the honeycomb structure and are in partial contact with the outer wall, and complete cells having a complete cell section, other than the partial cells of outermost peripheral portion. In the complete cells, a plugged part is formed at one end of each complete cell so that each end face of the honeycomb structure shows a checkerwise plugging pattern. In the partial cells of outermost peripheral portion to be plugged according to the above-mentioned plugging pattern, part of them is plugged in the entire length and formed integrally with the outer wall and remaining cells have each a plugged part only at one end.
    Type: Grant
    Filed: May 22, 2009
    Date of Patent: November 1, 2011
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihito Ichikawa, Koichi Ito, Takeshi Tokunaga
  • Patent number: 8003035
    Abstract: A method of manufacturing a plugged honeycomb structure has a plugging process which includes the steps of: immersing one end (a first end) of a honeycomb base material in a plugging slurry while vibrating the plugging slurry; after bringing an internal part of a cell into a negative pressure and then returning it into an atmospheric pressure, vibrating the plugging slurry to make the plugging slurry enter a first open end of the cell; and drying the plugging slurry having entered the first open end of the cell to form a first plugging portion at the first end.
    Type: Grant
    Filed: July 27, 2009
    Date of Patent: August 23, 2011
    Assignee: NGK Insulators, Ltd.
    Inventors: Koichi Ito, Takeshi Tokunaga
  • Patent number: 8000516
    Abstract: A manufacturing method of a plugged honeycomb structure including attaching a transparent sheet to an end face of a honeycomb structure; picking up an image of the end face; with respect to cells positioned at other than outermost peripheral portion of a honeycomb structure (usual cells), subjecting the picked-up image to image processing, recognizing positions to be plugged on said sheet, and with respect to cells positioned at outermost peripheral portion (outermost peripheral cells), positions of the cells are recognized based on an average cell pitch calculated from the positions of the cells, subjecting to a perforation treatment based on the recognized positions of the sheet, submerging an end portion into a plugging slurry in which a material of the plugging portions is slurried, filling holes made at the respective sheet with the slurry to form the plugging portions.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: August 16, 2011
    Assignee: NGK Insulators, Ltd.
    Inventors: Koichi Ito, Takeshi Tokunaga
  • Patent number: 7972677
    Abstract: There is provided a honeycomb structure including: porous partition walls separating and forming a plurality of cells extending between two end faces, and an outer peripheral wall formed unitarily with the partition walls. The cells include outermost peripheral portion partial cells each locating in an outermost peripheral portion of the honeycomb structure and having an incomplete cell cross section, a part of which is brought into contact with the outer peripheral wall, and complete cells each having a complete cell cross section other than the outermost peripheral portion partial cells. The complete cells and the outermost peripheral portion partial cells having plugging portions formed on one end portion so that an entire end face of the honeycomb structure shows a checkerwise plugging pattern, and the depth of the plugging portions in the outermost peripheral partial cells is smaller than that of the plugging portions in the complete cells.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: July 5, 2011
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihito Ichikawa, Koichi Ito, Takeshi Tokunaga
  • Patent number: 7858168
    Abstract: There is disclosed a honeycomb structure in which while sufficiently maintaining a collection efficiency and a bonding strength of a plugging portion, a thermal shock resistance is improved. A plugging portion 32 is formed in the end of each cell 3 of a honeycomb structure 1, and a gap 34 having a size of 20 ?m or more is formed between the plugging portion 32 and each partition wall 2. Moreover, the length of the gap 34 in the axial direction is 50% or more and less than 95% of the length of the plugging portion 32 in the axial direction, the length of the gap in a face vertical to the axial direction is 20% or more and 50% or less of the length of the inner peripheral surface of the cell 3, and the gaps are formed in at least ? of the plugging portions 32.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: December 28, 2010
    Assignee: NGK Insulators, Ltd.
    Inventors: Toshio Yamada, Takeshi Tokunaga, Makoto Furutani
  • Patent number: 7807085
    Abstract: A manufacturing apparatus of a plugged honeycomb structure includes a table portion having a through hole into which the end of a honeycomb structure is inserted, positioning means for positioning and holding the honeycomb structure in the through hole of the table portion in such a manner that its end face appears on the side of a first face of the table portion, and a film holding portion fixing the remaining portion of a film on the side of a second face of the table portion. After or before fixing the film, holes corresponding to openings of cells of the honeycomb structure are formed in the film, and a plugging material is filled into the holes, to manufacture the plugged honeycomb structure using the apparatus.
    Type: Grant
    Filed: March 23, 2009
    Date of Patent: October 5, 2010
    Assignee: NGK Insulators, Ltd.
    Inventors: Hiroyuki Tsuji, Yoshimasa Kondo, Takeshi Tokunaga, Toshio Oda, Shinya Yoshida, Takayuki Ogata
  • Patent number: 7736581
    Abstract: A method is provided for manufacturing a plugged honeycomb structure 30 including a honeycomb substrate 1 and plugging portions 15 arranged so as to form complementary checkered patterns at both end surfaces 11 and 21 of the honeycomb substrate 1. The method includes attaching a first mask film 4a to the first end surface 11 of the honeycomb substrate 1, making slurry permeation holes 3a to introduce a plugging slurry 6, attaching a second mask film 4b to the second end surface 21 of the honeycomb substrate 1, making slurry permeation holes 3b, allowing air to flow into the cells 2 so as to discharge air giving a pressure of 0.05 to 5 MPa between the first mask film 4a and the honeycomb substrate 1; and filling cell opening end portions 7 with the plugging slurry 6 to fire the resultant slurry filled substrate 20.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: June 15, 2010
    Assignee: NGK Insulators, Ltd.
    Inventors: Koichi Ito, Takeshi Tokunaga
  • Publication number: 20100108242
    Abstract: The film sticking apparatus includes: a gripping member; a pressing member pressing the adhesive face of the film being held in a planar state against one end face of a cylindrical honeycomb structure having a plurality of cells, and thus sticking the film to the one end face; and a folding member having an opening portion formed that allows an end of the honeycomb structure on the side to which the film is stuck to be inserted, wherein the folding member folds a protruding portion of the film protruding from the one end face of the honeycomb structure by inserting the honeycomb structure into the opening portion, toward a side face of the honeycomb structure, and simultaneously presses at least a part of the folded protruding portion against a part of the side face of the honeycomb structure to stick the film to the side face.
    Type: Application
    Filed: October 5, 2009
    Publication date: May 6, 2010
    Applicant: NGK INSULATORS, LTD.
    Inventors: Takeshi TOKUNAGA, Koichi MIYASHITA
  • Publication number: 20100109198
    Abstract: The apparatus for injecting slurry contains the first member having the cavity therein; and the second member having a plurality of convex sections, each of the convex sections having the injection hole formed therein communicating with the cavity, wherein the protrusion length of the convex section is in a range from 3 to 5 mm, and the distance between centers of adjacent convex sections is in a range from 3 to 13 mm.
    Type: Application
    Filed: October 7, 2009
    Publication date: May 6, 2010
    Applicant: NGK INSULATORS, LTD.
    Inventor: Takeshi Tokunaga
  • Patent number: 7638086
    Abstract: A manufacturing method of a plugged honeycomb structure 30 which comprises a honeycomb substrate 1 and plugging portions 15 arranged so as to form complementary checkered patterns alternately at both end surfaces 11 and 21 of the honeycomb substrate 1. The method comprises attaching mask films 4a and 4b to both end surfaces 11 and 21 of the honeycomb substrate 1, respectively; forming slurry permeation holes 3a at portions of the mask films 4a and 4b corresponding to cell opening end portions 7, respectively; forming deaeration holes 3b at portions of the mask films 4a and 4b facing the portions provided with the slurry permeation holes 3a via cells 2; submerging both end surfaces 11 and 21 of the honeycomb substrate 1 to which the mask films 4a and 4b have been attached into a plugging slurry 6, respectively; and firing the resultant slurry filled substrate 20.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: December 29, 2009
    Assignee: NGK Insulators, Ltd.
    Inventors: Koichi Ito, Takeshi Tokunaga
  • Publication number: 20090283928
    Abstract: A method of manufacturing a plugged honeycomb structure has a plugging process which includes the steps of: immersing one end (a first end) of a honeycomb base material in a plugging slurry while vibrating the plugging slurry; after bringing an internal part of a cell into a negative pressure and then returning it into an atmospheric pressure, vibrating the plugging slurry to make the plugging slurry enter a first open end of the cell; and drying the plugging slurry having entered the first open end of the cell to form a first plugging portion at the first end.
    Type: Application
    Filed: July 27, 2009
    Publication date: November 19, 2009
    Applicant: NGK INSULATORS, LTD.
    Inventors: Koichi ITO, Takeshi TOKUNAGA
  • Publication number: 20090246458
    Abstract: There is disclosed a honeycomb structure in which while sufficiently maintaining a collection efficiency and a bonding strength of a plugging portion, a thermal shock resistance is improved. A plugging portion 32 is formed in the end of each cell 3 of a honeycomb structure 1, and a gap 34 having a size of 20 ?m or more is formed between the plugging portion 32 and each partition wall 2. Moreover, the length of the gap 34 in the axial direction is 50% or more and less than 95% of the length of the plugging portion 32 in the axial direction, the length of the gap in a face vertical to the axial direction is 20% or more and 50% or less of the length of the inner peripheral surface of the cell 3, and the gaps are formed in at least ? of the plugging portions 32.
    Type: Application
    Filed: March 25, 2009
    Publication date: October 1, 2009
    Applicant: NGK Insulators, Ltd.
    Inventors: Toshio YAMADA, Takeshi TOKUNAGA, Makoto FURUTANI
  • Publication number: 20090243139
    Abstract: A manufacturing apparatus of a plugged honeycomb structure includes a table portion 11 having a through hole 11h into which the end of a honeycomb structure 1 is inserted, positioning means for positioning and holding the honeycomb structure 1 in the through hole 11h of the table portion 11 in such a manner that its end face 8 appears on the side of a first face 11a of the table portion, and a film holding portion 13 fixing the remaining portion of a film 25 on the side of a second face 11b of the table portion 11. After or before fixing the film 25, holes corresponding to openings of cells 3 of the honeycomb structure 1 are formed in the film, and a plugging material 31 is filled into the holes, to manufacture the plugged honeycomb structure 1, and the method of manufacturing the plugged one using the apparatus.
    Type: Application
    Filed: March 23, 2009
    Publication date: October 1, 2009
    Applicant: NGK Insulators, Ltd.
    Inventors: Hiroyuki Tsuji, Yoshimasa Kondo, Takeshi Tokunaga, Toshio Oda, Shinya Yoshida, Takayuki Ogata
  • Publication number: 20090239031
    Abstract: There is provided a honeycomb structure including: porous partition walls separating and forming a plurality of cells extending between two end faces, and an outer peripheral wall formed unitarily with the partition walls. The cells include outermost peripheral portion partial cells each locating in an outermost peripheral portion of the honeycomb structure and having an incomplete cell cross section, a part of which is brought into contact with the outer peripheral wall, and complete cells each having a complete cell cross section other than the outermost peripheral portion partial cells. The complete cells and the outermost peripheral portion partial cells having plugging portions formed on one end portion so that an entire end face of the honeycomb structure shows a checkerwise plugging pattern, and the depth of the plugging portions in the outermost peripheral partial cells is smaller than that of the plugging portions in the complete cells.
    Type: Application
    Filed: May 27, 2009
    Publication date: September 24, 2009
    Applicant: NGK INSULATORS, LTD.
    Inventors: Yukihito ICHIKAWA, Koichi ITO, Takeshi TOKUNAGA
  • Publication number: 20090239032
    Abstract: A honeycomb structure comprising porous partition walls which form, by surrounding, a plurality of cells extending between the two ends faces of the honeycomb structure, and an outer wall formed integrally with the partition walls. The cells consist of partial cells of outermost peripheral portion, having incomplete cell sections, which are located at the outermost peripheral portion of the honeycomb structure and are in partial contact with the outer wall, and complete cells having a complete cell section, other than the partial cells of outermost peripheral portion. In the complete cells, a plugged part is formed at one end of each complete cell so that each end face of the honeycomb structure shows a checkerwise plugging pattern. In the partial cells of outermost peripheral portion to be plugged according to the above-mentioned plugging pattern, part of them is plugged in the entire length and formed integrally with the outer wall and remaining cells have each a plugged part only at one end.
    Type: Application
    Filed: May 22, 2009
    Publication date: September 24, 2009
    Applicant: NGK INSULATORS, LTD.
    Inventors: Yukihito ICHIKAWA, Koichi ITO, Takeshi TOKUNAGA
  • Publication number: 20090146350
    Abstract: A process for producing a honeycomb structure includes: a mixing step where forming raw materials including a ceramic raw material are mixed to obtain a forming blended material, a kneading step where the forming blended material is kneaded to obtain kneaded clay, a forming step where the kneaded clay is formed into a honeycomb shape to obtain a honeycomb formed article, and a firing step where the honeycomb formed article is fired to obtain a honeycomb structure. The ceramic raw material is a cordierite forming raw material, and a magnetic powder contained in the kneaded clay is at a ratio of 400 ppm or less with respect to solid content conversion mass of the whole kneaded clay. There is provided a honeycomb structure capable of improving trapping efficiency, in particular, initial trapping efficiency by reducing the number of coarse pores in the partition walls.
    Type: Application
    Filed: February 9, 2009
    Publication date: June 11, 2009
    Applicant: NGK INSULATORS, LTD.
    Inventors: Yasushi NOGUCHI, Takehiko WATANABE, Takeshi TOKUNAGA, Yukari NAKANE
  • Publication number: 20080280064
    Abstract: A marking composition comprises an inorganic pigment having an average diameter of o.1 to 5 ?m and a titanium-containing ceramic resin. The composition exhibits excellent concealing properties and heat resistance and produces a high definition marking with high contrast and excellent discrimination capability when applied to the surface of an article.
    Type: Application
    Filed: June 12, 2008
    Publication date: November 13, 2008
    Applicant: NGK INSULATORS, LTD.
    Inventors: Takeshi TOKUNAGA, Sadaaki HIRAI
  • Publication number: 20080251978
    Abstract: A method for manufacturing a plugged honeycomb structure 30 which comprises attaching a mask film 4 to an end surface 11; making holes 3 at selected portions corresponding to the predetermined cell opening end portions 7; applying a pretreating agent 20 containing at least one component compatible with a dispersion medium for slurry for plugging the predetermined cell opening end portions 7 to partition walls 10 at the predetermined cell opening end portions 7, then submerging, in a plugging slurry 6, the end surface 11 of the material to which the perforated mask film 4 has been attached to fill the predetermined cell opening end portions 7 with the plugging slurry 6.
    Type: Application
    Filed: December 12, 2007
    Publication date: October 16, 2008
    Applicant: NGK INSULATORS, LTD.
    Inventors: Koichi ITO, Takeshi TOKUNAGA
  • Patent number: D604046
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: November 17, 2009
    Assignee: Yasuo Hutagawa
    Inventor: Takeshi Tokunaga
  • Patent number: D604512
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: November 24, 2009
    Inventor: Takeshi Tokunaga