Institute of Technology Precision Electrical Discharge Work's

Ngk Insulators, Inc.

Bridgestone Tire Company Limited

Bridgestone Corporation

Bridgeport Tire Co. Ltd.

Hoden Seimitsu

Shoji Futamura

Satoru Inoue

Sei Ozaki

Noboru Higuchi

Koichi Hirano

Kenichi Takahashi

Seisuke Sueyasu

Yasutada Yoda

Michihiro Orikawa

Masaru Kojima

Masaki Kurihara

An extrusion die for extruding ceramic honeycomb structural bodies includes body discharge channels having a desired honeycomb arrangement and independent body supply holes communicating with the body discharge channels. The body supply holes are so designed that each of them has inner peripheral surface zones of different inner dimensions and the inner peripheral surface zones may be coaxially arranged.

Die for extruding honeycomb structural bodies

Dies for extruding honeycomb structures are disclosed, which comprise wear resistant alloy plates, a die base body having a coefficient of thermal expansion different from that of the wear resistant alloy plates, forming channels having a sectional shape conforming to that of honeycomb structural bodies to be extruded and a given depth from a front face of the die toward a rear face thereof, and a plurality of opening holes independently formed from the die near face toward the die front face and communicating with the forming channels. The die base body and the wear resistant alloy plates are bonded together such that the forming channels may communicate with the opening holes. A method for producing such dies is also disclosed, which is characterized in that slits are preliminarily formed in one of machined faces of the die base before the wear resistive alloy plates are bonded to the die base portion, and are located at a predetermined width in an arrangement conforming to the forming channels.

Method for producing dies for extruding honeycomb structures

Dies for extruding honeycomb structures are disclosed, which comprise wear resistant alloy plates, a die base body having a coefficient of thermal expansion different from that of the wear resistant alloy plates, forming channels having a sectional shape conforming to that of honeycomb structural bodies to be extruded and a given depth from a front face of the die toward a rear face thereof, and a plurality of opening holes indepndently formed from the die rear face toward the die front face and communicating with the forming channels. The die base body and the wear resistant alloy plates are bonded together such that the forming channels may communicate with the opening holes. A method for producing such dies is also disclosed, which is characterized in that slits are preliminarily formed in one of machined faces of the die base before the wear resistive alloy plates are bonded to the die base portion, and are located at a predetermined width in an arrangement conforming to the forming channels.

Dies for extruding honeycomb structure

A honeycomb structure forming die has a forming section provided with at least forming channels and a plurality of opening holes. The forming channels have a sectional shape conforming to that of honeycomb structural bodies to be extruded by the die, and have a given depth from a front face of the die toward a rear face thereof. The opening holes are independently formed from the die rear face toward the die front face and communicate with the forming channels. The honeycomb structure forming die is further provided with communicating holes which communicate with the opening holes of the forming section.

Super hard alloy dies for extruding honeycomb structures

A wire-cut electrical discharge machining apparatus having upper and lower tables which are disposed on a bed and movable in such directions as to intersect orthogonally with each other, and a wire electrode which is movably stretched so that a workpiece placed on the upper table can be machined by an electrical discharge produced between the electrode and the workpiece, and characterized in that a through hole is provided at least in the upper table, and upper and lower wire guides are provided above and below the through hole respectively, or inside the same, so that the wire electrode can be discharged via the lower wire guide.

Wire-cut electrical discharge machining equipment

A discharge machining apparatus adapted to permit the supply of discharge current to be cut off without increasing electrode consumption. Arrangements are made to gradually increase the level of discharge current, rather than maintaining the current level of discharge pulse. By doing so, electrode consumption becomes independent of the pulse width of the discharge pulse, so the discharge current can be cut off immediately after an abnormal state such as short circuiting or an instantaneous interruption of the discharge current occurs, eliminating the danger of deteriorating the quality of the machining surface of a workpiece.

Electrical discharge machining apparatus with discharge current control

An electrical discharge machining apparatus having an electrode and a work table on which a workpiece is placed for machining the workpiece by causing an electric discharge between the electrode and the workpiece. A shielding cover for forming a substantially enclosed predetermined space around main structural members comprising the electrical discharging apparatus is provided. A gas is introduced into the space formed by the shielding cover so as to keep the temperature in the space at a constant level.

Electrical discharge machining apparatus including a shield for

Ceramic honeycomb structural body-extruding dies are disclosed which each comprise a plurality of die-constituting members. The die-constituting members are bonded together with a bonding layer, and the bonding layer is composed of an acid-resisting metal.

Dies for extrusion-shaping ceramic honeycomb structural bodies

An extrusion die having on the front surface thereof a bearing opening of the shape of a given section; a bearing surface corresponding to the section of the bearing opening formed over a length from the front surface to the rear surface of the die; and a draft formed from the bearing surface toward the rear surface; the bearing surface at each position on the inner circumferential line of the bearing opening being formed in such a fashion as to have a bearing length which is substantially determined in accordance with the shape of the bearing opening at that position wherein, when viewed with respect to a sectional face orthogonal to the inner circumferential line, a straight line corresponding to the bearing surface and a straight line corresponding to the draft intersect at a depth position substantially equal to or larger than the bearing length at that position, and the depth position where the intersection point exists is in a depth position which is substantially determined in accordance with the shape of the bearing opening at the respective positions on the inner circumferential line of the bearing opening, and a method of making the same.

Extrusion die and manufacturing method of same

Disclosed herein is a die for extruding honeycomb structural body, which comprises a die base body made of an alloy steel and a plate of a wear resistant alloy which is joined to the front face side of the die base body. In the wear resistant alloy plate are formed forming slits having a sectional profile conforming to that of a honeycomb structural body to be shaped and having a given depth from the front face of the die toward the rear face thereof, and a plurality of openings are formed independently of each other in the die base body from the rear face of the die toward the front face thereof to communicate with the forming slits. The wear resistant alloy plate may be joined to the die base body through an alloy steel plate having the same as or thinner than the thickness of the wear resistant alloy plate. A method of manufacturing such a honeycomb structural body-extruding die is also disclosed.

Method of manufacturing a die for extruding honeycomb body

A tire manufacturing mold comprising a profile ring having a contour corresponding to the outer profile of a tire being molded, including at least the tread thereof, and a net ring having a faying surface for making contact with the contour surface and consisting of ribs and/or lugs for forming the grooves of the tire being molded. The net ring is disposed on the contour surface of the profile ring. The profile ring and/or the net ring has gas vent members embedded so as to form gas vent gaps on the periphery thereof; and the gas vent gaps formed on the periphery of the gas vent members being constructed as gas vent passages.

Tire manufacturing mold

A die for extruding honeycomb structural bodies includes a plurality of ceramic batch exhaust grooves and a plurality of ceramic batch supply apertures. Tubes are fitted in at least some of the ceramic batch supply apertures to improve or make constant the surface roughness and dimensions of inner surfaces of ceramic batch supply apertures through which the ceramic batch passes, thereby producing perfect ceramic honeycomb stuctural bodies. The adjustment of flow of ceramic batch is so simplified that any other controlling plate which would be required in the prior art is not needed for controlling the flow. When the supply apertures have been worn off, the tubes are exchanged by new ones to restore the required inner surfaces easily.

Die for extruding ceramic honeycomb structural bodies

Die for extruding honeycomb structural body

A tire manufacturing mold comprises a mold body having an inner circumferential surface corresponding to the contour of a tire being molded, and includes at least the tread thereof. The body has a mold attachment for molding recesses of the tire being molded and a joint surface with the inner circumferential surface of the mold body. The mold attachment is detachably fitted to the inner circumferential surface of the mold body.

Vented tire molding mold

A tire molding mold comprising a profile ring having an inner circumferenl surface corresponding to the outer profile of a tire being molded, including at least the tread surface thereof, and a net ring having a faying surface fitted and joined to the inner circumferential surface of the profile ring and consisting of a network of ribs and/or lugs for forming the grooves of the tire being molded; the net ring being disposed on the profile ring wholly, or with the part thereof removed.

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Kawasaki, Japan

Shoji Futamura