Ngk Insulators, Inc.

Masayuki Hironaga

Yuji Deguchi

Yukio Miyairi

Naomi Noda

Shinichi Miwa

Hiroyuki Suenobu

Kazuhiko Kumazawa

Kazuhiko Hamatsuka

Teruyoshi Mori

Hironori Takahashi

Takahisa Kaneko

Masayuki Nate

Tatsuo Kawaguchi

Yoshimasa Kondo

Seiichiro Hayashi

Masanari Iwade

Hirofumi Hosokawa

Takahiro Inoue

Masaaki Koishikura

Masahiro Fujiyama

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 method for manufacturing a die to be used for formation of honeycomb structure, the die having a die base having two faces, honeycomb-shaped slitsbeing formed in one face and back holes communicating with the slitsbeing formed in the other face in order to introduce a forming material thereinto, at least the slit portions of the die being made of a super had alloy, wherein slitsare formed by grinding or electric discharge machining, then a discharging electrodehaving a square-shaped section is disposed near each crossing portion of slits, and electric discharge machining is conducted from the upper side of slittoward the depth direction of slit.

Method of manufacturing die for forming honeycomb structure and die for forming honeycomb structure

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

A die for forming a honeycomb structure includes a die base having a first plate-like member and a second plate-like member, the first plate-like member is provided with groove portions on the side of a bonding surface between the first plate-like member and the second plate-like member, and a depth y (mm) of the groove portions satisfies:&#xb7;(1&#xd7;1+2&#xd7;2)/(1&#xd7;2&#xd7;1&#xd7;2)where t1 is a thickness (mm) obtained by subtracting the depth (mm) of the groove portions from a thickness (mm) of the first plate-like member, E1 is an apparent volume elasticity (GPa) of the first plate-like member at 25&#xb0; C. in consideration of a state in which back holes are formed, t2 is a thickness (mm) of the second plate-like member, E2 is a volume elasticity (GPa) of the second plate-like member at 25&#xb0; C., and a is a coefficient determined based on conditions during manufacturing.

Die for forming honeycomb structure

A die for forming a honeycomb structure may realize a sophisticated formability and superior resistance to wear. The die may be provided with a die base including two surfaces, one being provided with slits of honeycomb shape, and the other being provided with back holes through which a forming material may be introduced. The die base may include: a die precursor obtained by stacking and bonding a first member (one surface of the die base) and of tungsten carbide-based super hard alloy and a second member (the other surface of the die base) and of a metal material that causes at least up to three phase transformation of martensite transformation, bainite transformation, and pearlite transformation by cooling of an austenite phase together. Tensile and compressive stresses in a mutually bonded surface of the two plate-like members are 1000 MPa or less.

Die for forming honeycomb structure and method of manufacturing the same

A process for producing a die for forming a honeycomb structure having slits having hexagonal honeycomb cell shapeat one of surfacesof a plate-like base material for die, and backside holeseach communicating with respective slitsat the other surface, which comprises the steps of forming holesfor dielectric fluid each having an opening diameter smaller than the width of the slitin a predetermined depth at the one of surfacesthereof, and holescommunicating with holesat the rest surface; and then passing a dielectric fluidfor electrical discharge machining from the surfaceto the surfacevia holesanduntil the machining proceeds to a position communicating with each hole; thereby, the slitsare formed at the surfaceof the base material

Process for production of die usable for formation of honeycomb structure

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

Disclosed is a wire electric discharge machining apparatus comprising a wire-driving system for feeding a wire electrode while opposing it to a workpiece, and a power supply unit for supplying electric power to the wire electrode, wherein electric discharge is effected between the wire electrode and the workpiece to machine the workpiece to have an arbitrary shape. The wire electrode is allowed to approach the workpiece to effect the electric discharge between the wire electrode and the workpiece so that the workpiece is machined to have an arbitrary shape, while a suction mechanism is used to remove undesirable matters including sludge together with a working fluid via cylindrical members from holes formed in the workpiece. Accordingly, it is possible to easily form, by means of wire electric discharge machining, a machining groove having a narrow width and a large depth under a condition deviated from the general standard machining condition for the wire electric discharge machining, for example, even for a workpiece having a large thickness.

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Nagoya, Japan

Masayuki Hironaga