Abstract: A discharge machining apparatus adapted to quickly absorb the energy, which has been accumulated by an inductance component during discharge machining, during the non-discharge period. The accumulated energy is absorbed as it is caused to flow as a current in an equivalent resistor having a resistance varying function. With this invention, it becomes possible to increase the frequency of discharges per unit time since the energy is quickly absorbed without residue as the change in the resistance value of the equivalent resistor causes the current flowing in it to shift from an oscillating state to a normal damping state.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A tire manufacturing mold having a contour surface consisting of a predetermined curved surface corresponding to the outer circumferential surface of a tire being molded, a plurality of bone portions and blade portions, both protruding on the contour surface, and a manufacturing method of the same are disclosed. The tire manufacturing mold is manufactured by discharge machining in such a manner that the blade portions are caused to protrude essentially vertically to the contour surface, and that the contour surface, the bone portions and the blade portions are integrally formed.

Abstract: A method of making a mold which is utilized to manufacture a tire, the mold having a contour curved surface with broad bone portions and narrow blade portions extending therefrom, comprises a first machining stage utilizing a plurality of electrical discharge machining electrodes for approaching a workpiece used to make the mold, at different angles. Each of the electrodes used in the first machining stage are shaped to avoid the removal of excessive metal from the mold so that both the bone portions and the blade portions can extend normally from the contour curved surface. The method includes a second machining stage utilizing a further electrical discharge machining electrode which has recesses for receiving bone portions and blade portions formed by the first stage electrodes, and is movable laterally of the contour surface to form well-defined edges of the bone and blade portions.

Abstract: A ring-shaped mold of the split mold type constructed by assembling into an annular shape a plurality of sectorial separate blocks formed by cutting a ring-shaped workpiece haveing a mold surface on the annular circumference thereof, and the method and apparatus for making the same are disclosed. Sector lines interfacing adjoining the separate blocks on the mold surface intersect the circumference of the ring-shaped mold at angles not perpendicular to said circumference.

Abstract: A system for manufacturing tire molding metal molds with electrical discharge machining is disclosed, which makes possible the rotation, longitudinal and cross feeding of a work table on which a workpiece to be machined into a tire molding metal mold is placed and the rotation, lifting and lowering of a machining head, whereby the workpiece is discharge-machined by feeding a discharge machining electrode in a plurality of different directions corresponding to a plurality of projections protruding essentially vertical to the tire molding surface of the tire molding metal mold to be machined, and by changing electrodes having such profiles as to prevent the excess metal removal of the projections in accordance with each of the electrode feeding directions.

Abstract: A die for extruding a honeycomb structural body, all parts of which are uniform in mechanical strength, is disclosed. The die is provided with guide grooves between discharge slits and feed inlets for raw stock, said discharge slits having a cross-sectional shape corresponding to that of the honeycomb structural body and said guide grooves having a cross-sectional area larger than that of the discharge slits.

Abstract: A die for extruding a honeycomb structural body which comprises a throttle portion having a plurality of openings where the forcedly supplied raw stock flow is throttled at the rear surface side of the die, a reservoir portion provided with a plurality of guide channels, an opening portion having a plurality of openings and guide slots, and discharge slits.

Abstract: Extrusion dies for extruding honeycomb structural bodies which comprise a plurality of cell blocks having a cross sectional shape conforming to cells of the honeycomb structural body, a spoke supporter, and spokes, one end of which is fixed to the cell blocks and another end of which is integrally secured to the spoke supporter, said adjacent cell blocks forming discharge slits conforming to the cross sectional shape of the honeycomb structure, and said spoke supporter being provided with a plurality of feed inlets having a larger diameter, which are perforated from one end surface of the spoke supporter toward the cell blocks and a plurality of openings having a smaller diameter, which are perforated from another end surface of the spoke supporter to the feed inlet and connect to the feed inlet.