Abstract:
A method of and an apparatus for electrical-machining a conductive workpiece with an axially traveling wire electrode displaced transversely to the workpiece along a predetermined cutting path to advance electroerosion effected across the machining gap supplied with a machining liquid, wherein the rate of supply of the machining liquid to the gap is controlled as a function of the shape of the cutting path.
Abstract:
An improved machining method and electrode for use in the traveling-wire EDM process utilizing an aqueous machining fluid medium which is decomposed by erosive electrical discharges into gaseous oxygen and hydrogen. Breakage of the traveling-wire electrode is reduced or eliminated through the use of an improved electrode element comprising a continuous electrode wire substrate and a layer of a polymeric substance having a temperature of thermal decomposition of 100.degree. to 500.degree. C. attached thereto in a distributed manner such as to partially cover the surface of the substrate. The improved electrode element traveling in machining juxtaposition with the workpiece is subjected to the electrical discharges to cause a thermal decomposition of the polymeric substance to form carbon and to allow the gaseous oxygen and hydrogen at least partially to be chemically combined therewith and to reduce the amount of the oxygen gases in the machining gap which tend to cause a continuous arc discharge or explosion as a cause of the wire breakage. The improved elongate element should preferably contain a hydrogen active catalytic metal, e.g. Li, Cs or Sm, having a spectrographic wavelength of 300 to 600 nm to facilitate chemical reaction of carbon with oxygen and hydrogen in the gap.
Abstract:
An improved apparatus for magnetically filtering a magnetically susceptible component in a fluid with a matrix of magnetizable material which, when magnetized, provides a multiplicity of regions of high magnetic field gradient. A sequence of time-spaced impulsive magnetic fluxes are produced in an electromagnetic coil by periodically charging and discharging capacitor connected to the coil, the fluxes being concentrated across the magnetic matrix to magnetically collect the magnetically susceptible component in the regions of high field gradient therein. A static magnetic flux may also be provided in the magnetic matrix by a permanent magnet included in a magnetic circuit with the matrix.
Abstract:
A mechanical member employs an inclined ring body having a frustoconical profile and comprising a multiplicity of tough and elastic, inclined ring elements each individually having a frustoconical profile and formed with a centrally located opening for slidably accepting therethrough a first member which is cylindrical and an outer peripheral edge adapted for engagement with a second member. The ring element has a plurality of outer slits extending radially inwardly from the outer peripheral edge towards the centrally located opening and a plurality of inner slits extending radially outwardly from the edge defining the centrally located opening towards the outer peripheral edge. An inclination adjusting member is carried by one of the first and second members so as to maintain a bearing contact with the inclined ring body and adapted to be displaced on the one member to change a given angle of the frustocone, thereby regulating the state of engagement of the ring body with the first and second members.
Abstract:
A travelling-wire electro-erosion machine which has a head assembly comprising a tubular support formed with a plurality of roller guides positioned to define a path for a travelling wire forming an electrode for electroerosion. Above the tubular support, there is provided a boxlike housing with a supply wheel and a takeup wheel for the wire and a bevel gear on the tubular support cooperates with a pinion on a motor which enables rotation of the entire assembly. A worm-gear arrangement may be used instead of the bevel gears and a different construction of the guide rollers may be provided as well, e.g. on the downwardly extending projection from the tubular body.
Abstract:
An EDM method and apparatus wherein a tool electrode is spacedly juxtaposed with a conductive workpiece across a machining gap filled with a dielectric liquid and a succession of localized, time-spaced, repetitive and randomly dispersed machining electrical discharges are effected between the tool electrode and the workpiece across the machining gap to remove stock from the workpiece uniformly over the surface thereof juxtaposed with the tool electrode. The surface finish of the stock-removed surface of the workpiece is improved by discharging electrical charge stored due to a stray capacitance across the tool electrode and the workpiece, through an electrical shunt circuit in parallel with the machining gap immediately prior to initiation of each of the machining electrical discharges across the machining gap.
Abstract:
A capacitor-type pulse generator is provided for wire-cutting EDM. The generator includes a capacitor connected on one hand to a DC source in series with a charging switch and on the other hand to the EDM gap in series with a discharging switch. A first sensing circuit turns the discharging switch into conduction when the charging voltage on the capacitor reaches a predetermined level. The charging switch is normally in its conductive state and is turned into its nonconductive state when a second sensing circuit senses that the EDM gap voltage exceeds a preselected value. In a modified generator, parallel-connected discharging switches are triggered in sequence when the capacitor voltage reaches the predetermined level.
Abstract:
A device for conducting a machining current to a traveling wire-electrode tool in a wire-cutting electroerosion machine comprises a rotary brush block (e.g. of cylindrical shape) having a planar current-conducting surface disposed in a wire-travel path for making sliding electrical contact with the moving wire-electrode tool. A motor rotates the brush block about the rotary axis thereof to rotationally move the current-conducting surface in tangential sliding electrical contact with the moving wire-electrode tool. A scraper is provided downstream of the workpiece machining zone and upstream of the brush block to remove abrasive particles and machining chips and other products (e.g. tar) adherent on the wire tool fed from the machining zone, thus to prevent them from being carried onto the brush surface.
Abstract:
An electroerosive wire-cutting method and apparatus wherein a high-velocity stream of the cutting liquid medium produced through a small-opening nozzle is injected into a low-velocity stream of the cutting liquid medium produced through a large-opening nozzle and directed towards the region of the gap. The high-velocity cutting-liquid stream has a thickness substantially equal to the thickness of the cutting slot being formed behind the advancing wire electrode in the workpiece and is directed at a region of the cutting gap behind the advancing wire electrode. Gases (e.g. oxygen or ozone) and/or abrasive particles may be entrained in the high velocity cutting-liquid stream.