Ngk Insulators, Inc.

Yuji Deguchi

Masayuki Hironaga

Yukio Miyairi

Naomi Noda

Shinichi Miwa

Hiroyuki Suenobu

Kazuhiko Kumazawa

Kazuhiko Hamatsuka

Teruyoshi Mori

Takahisa Kaneko

Masayuki Nate

Tatsuo Kawaguchi

Tomoharu Kondo

Tadato Ito

A heat/acoustic wave conversion component having a first end face and a second end face, includes a partition wall that defines a plurality of cells extending from the first end face to the second end face, inside of the cells being filled with working fluid that oscillates to transmit acoustic waves, the heat/acoustic wave conversion component mutually converting heat exchanged between the partition wall and the working fluid and energy of acoustic waves resulting from oscillations of the working fluid. Hydraulic diameter HD of the heat/acoustic wave conversion component is 0.4 mm or less, where the hydraulic diameter HD is defined as HD=4&#xd7;S/C, where S denotes a cross-sectional area of each cell perpendicular to the cell extending direction and C denotes a perimeter of the cross section, and the heat/acoustic wave conversion component has three-point bending strength of 5 MPa or more.

Heat/acoustic wave conversion component and heat/acoustic wave conversion unit

A heat/acoustic wave conversion component includes a plurality of monolithic honeycomb segments each including a partition wall that defines a plurality of cells extending between both end faces, and the plurality of monolithic honeycomb segments each mutually converts heat exchanged between the partition wall and the working fluid in the cells and energy of acoustic waves resulting from oscillations of the working fluid. In the heat/acoustic wave conversion component including the plurality of honeycomb segments each being monolithic configured, hydraulic diameter HD of the cells is 0.4 mm or less, open frontal area of the honeycomb segments is 60% or more and 93% or less, heat conductivity of the honeycomb segments is 5 W/mK or less, and a ratio HD/L of the hydraulic diameter HD to the length L of the honeycomb segment is 0.005 or more and less than 0.02.

A heat/acoustic wave conversion component includes a partition wall that defines a plurality of cells, inside of the cells being filled with fluid that oscillates to transmit acoustic waves, the heat/acoustic wave conversion component mutually converting heat exchanged between the partition wall and the fluid and energy of acoustic waves resulting from oscillations of the fluid. The plurality of cells have an average of hydraulic diameters HDs that is 0.4 mm or less in a plane perpendicular to the cell extending direction, the heat/acoustic wave conversion component has an open frontal area at each end face of 60% or more and 93% or less, and distribution of hydraulic diameters HDs of the plurality of cells has relative standard deviation that is 2% or more and 30% or less.

A heat/acoustic wave conversion unit includes a heat/acoustic wave conversion component and two heat exchangers. Hydraulic diameter HD of the cells in the heat/acoustic wave conversion component is 0.4 mm or less, and a ratio HD/L of HD to the length L of the heat/acoustic wave conversion component is from 0.005 to 0.02. One of the heat exchangers includes a heat-exchanging honeycomb structure and an annular tube that surrounds a circumferential face of the heat-exchanging honeycomb structure. The annular tube includes a structure body that is disposed in the channel to increase a contact area with the heated fluid, an inflow port into which the heated fluid flows, and an outflow port through which the heated fluid flows out. At least one of the heat-exchanging honeycomb structure and the structure body is made of a ceramic material that contains SiC as a main component.

Heat/acoustic wave conversion unit

A die was provided for forming a honeycomb body having a structure provided with groovy slits on a front face thereof, the slits being formed by cell blocks and back holes on a back surface thereof, each hole being communicatively connected with the slit. The die is made of cemented carbide having wear resistance. The cemented carbide is formed by compacting, followed by sintering at high temperature, metal carbide powder of transition metal element series with an iron group metal binder having toughness. A connection area ratio of the back hole and the cell block is 35 to 65%.

Honeycomb forming die and jig for honeycomb forming die using the same

Disclosed is a die () for forming a honeycomb body having a structure provided with groovy slits () on a front face thereof, the slits being formed by cell blocks () and back holes () on a back surface thereof, each hole being communicatively connected with the slit. The number N of the cell blocks per one side of the die is even number. According to the die for forming the honeycomb body, strain generated on an extruded face of the honeycomb body after extrusion and bending of the honeycomb body can be reduced as well as the die can maintain a stable frictional force of extrusion and is excellent in extrudability and wear resistance.

Honeycomb forming die

A heater unit comprising (1) a honeycomb heater comprising (a) a metallic honeycomb structure having a large number of passages parallel to the direction of a gas flowing through the heater unit and (b) at least one electrode for electrification of the honeycomb structure, attached to the honeycomb structure, and (2) a metallic casing for holding the honeycomb heater (1) therein via at least one metallic supporting member, in which heater unit an insulation portion is provided at least either at the connection area where the honeycomb heater and the supporting member are connected or at the connection area where the supporting member and the casing are connected, and the supporting member has such a structure as to be able to absorb the displacement of the honeycomb heater which appears in a direction substantially perpendicular to said gas flow direction, and has a function of fixing the honeycomb heater against its displacement which appears in the gas flow direction. The heater unit, when exposed to severe driving conditions of automobiles, etc. and subjected to vibration and the expansion and contraction caused by thermal shock, gives rise to neither breakage of honeycomb heater nor peeling.

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Nagoya, Japan

Yuji Deguchi