Denso Corporation

Toyota Jidosha Kabushiki Kaisha

Cataler Corporation

Denso Corpora Tion

Masakazu Murata

Hiromasa Suzuki

Hiroyuki Matsubara

Oji Kuno

Naohiro Hayashi

Kenichi Taki

Akimasa Hirai

Tomoaki Nakano

Shingo Nakata

Masakazu Tanaka

Keiji Ito

Yuji Yabuzaki

Takeshi Ueda

Nobutoshi Matsui

Takashi Obata

Toshiaki Tanida

Yoshiyasu Andou

Seiichi Fukaya

Yoshiyasu Andoh

Hironao Kawai

A honeycomb structure has a cylindrical outer skin and a partition wall and a plurality of cells and a separator. A plurality of intersections intersecting the two partition walls each other are disposed in the outer skin. Some of the intersections are reinforced by the reinforcing part. Two angles &#x3b8;and &#x3b8;are formed by a radial direction of the outer skin and respective two partition walls intersecting with each other. A smaller of two angles &#x3b8;and &#x3b8;is larger than a predetermined angle &#x3b8;. Further, some of the reinforcing parts are respectively formed only on some of the intersections which are disposed in a vicinity of the separator.

Honeycomb structure

A honeycomb structural body is made of cordierite ceramic and composed of partition walls and cells. A cell density is changed continuously or step by step from a central section to an outer peripheral section in a radial direction. The honeycomb structural body has a relationship of M1&#x3e;M2&#x3e;M3, and a relationship of K1&#x3c;K2. M1 is an average cell density of a first section formed from a center to not more than &#x2153; R from the center. M2 is an average cell density of a second section formed within a range from &#x2153; R to &#x2154; R. M3 is an average cell density of a third section formed of more than &#x2154; R from the center to an outer peripheral surface. K1 and K2 are average cell density change rates of the first and second sections, respectively. R is a radius of the honeycomb structural body.

Honeycomb structural body

A honeycomb structural body has plural cell density sections having a cell density which is changed stepwise in a radial direction. A partition wall is formed between adjacent cell density sections. The cell density sections have a high cell density section having a maximum cell density, excepting an outermost cell density section formed at an outermost side, and a low cell density section having a minimum cell density, excepting an innermost cell density section formed at an innermost side. A relationship of V&#x2212;Va&#x2267;Vb+Vs is satisfied, where V indicates a volume of the honeycomb structural body if the overall honeycomb structural body is composed of the high cell density section, Va indicates a volume of the high cell density section, Vb indicates a volume of the cell density section, and Vs indicates a volume of the boundary wall which separates the low cell density section from the cell density section formed immediately inside of the low cell density section.

A honeycomb structural body has cells surrounded by cell walls arranged in a lattice-like shape. A cross section is divided into a central section and an outer peripheral section. The outer peripheral section surrounds the central section through a boundary partition wall. The outer peripheral section is lower in a cell density than the central section. The cells contain imperfectly shaped cells in contact directly with the boundary partition wall. In the imperfectly shaped cells, first specific imperfectly shaped cells are smaller in opening area than second specific imperfectly shaped cells. Each first specific imperfectly shaped cells has an opening area of not more than a predetermined area S=(P&#x2212;T)/8. P and T indicate a cell pitch and a thickness of each cell wall, respectively. The opening section of the first specific imperfectly shaped cells is closed by the same raw material of the cell walls.

In a cross section, perpendicular to an axial direction of a honeycomb structural body having partition walls and cells, a plurality of sections having a different cell density is formed from a central area toward an outer peripheral area, and a partition wall is formed between the sections adjacent to each other. The boundary section has boundary partition walls and plural boundary cells having a polygonal shape different in shape from the cells in the sections formed adjacent to the boundary section. The partition walls in the sections adjacent to the boundary section are connected by the boundary partition walls. A part of the boundary cell is surrounded by at least the boundary partition walls. A relationship of &#x3c6;1/&#x3c6;2&#x2267;1.25 is satisfied, where &#x3c6;1 indicates an average hydraulic diameter of the boundary cells and &#x3c6;2 indicates an average hydraulic diameter of the cells.

A hexagonal-cell honeycomb catalyzer is for purifying an exhaust gas. The catalyzer comprising a support that has a plurality of cells and a purification layer that has an HC absorption layer and a three-way catalyst layer. The HC absorption layer is formed on the honeycomb-formed surface of each wall of the support. The three-way catalyst layer is formed on the surface of the HC absorption layer. Provided that the HC absorption layer has a thickness aand the three-way catalyst layer has a thickness bat a thin portion of the purification layer of which thickness is minimum and the HC absorption layer has a thickness aand the three-way catalyst layer has a thickness bat a thick portion of the purification layer of which thickness is maximum, a ratio of a/band a ratio of a/bare both within a range of 1/20 to 5/1.

Hexagonal-cell honeycomb catalyzer for purifying exhaust gas

With the recent yearly increase in cell density, use of the same slurry as a conventional one for forcibly depositing a solid, e.g., alumina for supporting, on the surface of cell walls has come to arouse a trouble that the resultant coat layer is thick and cell clogging is more apt to occur. When a slurry whose viscosity has been reduced by reducing the binder amount is used, the slurry which has flowed into cells is discharged without leaving a solid adherent to the surface of the cell walls. Namely, it is difficult to secure a desired solid deposition amount. A honeycomb structure for slurry coating is provided which is made of a porous object, wherein the surface of cell walls formed in the structure has fine pores dispersedly formed therein and having a pore diameter of 2 &#x3bc;m or smaller. Preferably, the total volume of the fine pores is 0-0.17 ml, excluding 0 ml, per g of the structure.

Honeycomb structure for slurry coating

A process for producing a honeycomb structure, comprising the steps of: providing a substrate having cell walls in a honeycomb form and comprising SiO , Al O and MgO as the main chemical components, applying to said substrate a mixture of a component for lowering the cordierite crystal phase crystallization temperature of said substrate with a liquid medium, and firing said substrate with said mixture applied to form a honeycomb structure comprising a crystalline cordierite phase, said crystalline cordierite phase comprising 42-56% by mass of SiO 30-42% by mass of Al O and 12-18% by mass of MgO as the main chemical components.

Process for producing honeycomb structure

There is provided a honeycomb structural body with a lower-than-conventional heat capacity and excellent durability. A honeycomb structural body (,) having partition walls composed mainly of cordierite arranged in a honeycomb fashion is provided with fortified section (,) with a higher strength than the general section (,) at one end or both ends (,) in the direction of length of the partition walls (,). The fortified section (,) is given improved strength by having increased density with respect to the general section.

Honeycomb structural body and process for production of the same

Apparatus for forming a honeycomb structure capable of adjusting a shaping speed of an outer skin of the honeycomb structure, thereby preventing a defect in the skin. The shaping device is constructed by a die (10) having slits (11) for formation of a honeycomb structure and a guide ring (2) arranged downstream of the die (11). The guide ring includes an opening with an inner edge (21) and includes at a location upstream from the edge a pool portion (22) for the formation of a skin of the honeycomb structure. A temperature controller (3) is arranged in the guide ring for controlling a heating on a cooling of a ceramic material held in the pool portion (22).

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Obu, Japan

Masakazu Murata