Abstract: A broken wire electrode 3 of a wire electrode electric discharge machining device is automatically repaired at the wire breaking position. After the used portion is cut away, the wire electrode 3 is fed toward the work 1. Upon detection of contact of the wire electrode 3 with the work 1, the feeding of the wire electrode 3 is stopped. A predetermined amount of deflection is obtained when the feeding of the wire electrode 3 is stopped. The wire electrode 3 is then moved horizontally relative to the work 1 within a predetermined range, until the end of the wire electrode 3 eventually falls into the machined groove 14 and the wire electrode 3 comes out of contact with the work 1. Thereafter the feeding of the wire electrode 3 is resumed to span the wire electrode 3 across the feeding-side wire guide unit 4 and the receiving-side wire guide unit 5.

Abstract: A machining solution filtration apparatus for a machining device which includes: a filter, a filter medium which is arranged separately from the filter and supplied continuously; a unit for supplying a contaminated machining solution to the filter medium; a unit for generating a difference in pressure between the upper surface and lower surface of the filter medium; a unit for returning a machining solution filtered via the pressure difference to a filtered solution vessel; a unit for selecting the filter to allow the machining solution to be filtered only thereby for a predetermined period of time; a unit for detecting the presence/absence and/or remaining amount of the filter medium; and a unit for controlling the speed of supplying the filter medium.

Abstract: Rust inhibitors for electrical discharge machining solutions. Each preventive is composed of a fatty acid amide which has been obtained by dehydrating and condensing at least one fatty acid and at least one alkanolamine.

Abstract: A wire electrode supplying apparatus for a wire electric discharge machine to effect the machining of a workpiece by inserting a wire electrode through the workpiece and allowing electric discharge to take place between the workpiece and the wire electrode. In this apparatus, a wire electrode feeding section is provided for inserting the wire electrode through the workpiece, as well as a feeding-side guide section and a receiving-side guide section are provided with the workpiece placed therebetween for the positioning of the wire electrode. The wire electrode is formed of a small-diameter wire, and the feeding-side guide section and the receiving side guide section are respectively provided with small openings for constraining the direction of its movement. The passage of the wire electrode through the small openings is aided by reducing the speed of feeding the wire electrode when the wire electrode passes through the small openings.

Abstract: A travelling wire electro-erosion machine in which an electrical discharge is generated in a narrow gap between a wire electrode and a work piece through a processing liquid so as to erossively remove material from the work piece. A wire guide device is provided for supporting and guiding the wire electrode wherein the wire guide device comprises a V-shaped guide member including coplanar intersecting guide surfaces, each of which have a single, continuous, convex arcuate wire engaging surface so as to prevent the wire from experiencing excessive stress.

Abstract: A method and apparatus for detecting breakage of a wire electrode in an electric discharge machining apparatus, and an apparatus for carrying out this method, whereby breakage of the wire electrode is detected by detecting a change in a current from a detection power source provided separately from the main power source. Current from the detection power source is applied through the wire electrode by a roller in contact therewith. When the wire electrode is unbroken, current passes from the detection power source, through the wire electrode, to an optical coupling circuit, the secondary of the latter driving and indicating circuit. When the wire electrode breaks, the power flow to the primary of the optical coupling circuit is interrupted, thereby indicating breakage of the wire electrode.

Abstract: A wire electrode for use in wire-cut electrical discharge machining which can be used under a high machining tension and which produces no appreciable deposit on the workpiece it is used to machine. The wire of the invention may be made of an amorphous metal or amorphous alloy composed primarily of iron, cobalt, or copper, and coated on its surface with a layer of a metal such as zinc, magnesium, tin, lead, cadmium or alloys thereof. Alternatively, the wire electrode may be a wire of highly fine crystalline particles fabricated by super-quenching from a pure metal or an alloy of a pure metal in a molten state at a cooling rate of 10.sup.3 to 10.sup.5 .degree.C./sec in a super-quenching process such as a spinning process which forms a wire in a rotating liquid layer.

Abstract: A device for feeding an electrode wire 2 automatically from a wire supply reel 1 to a work hole 77 in the material 38 to be machined, and therefrom to a recovery system for the electrode wire includes a cleaning device for injecting a fluid against a guide member 40 for the electrode wire to blow away dust or any other contaminant matter to ensure that the electrode can be successfully supplied for a long period of time.

Abstract: In an electric discharge machine having a main switching circuit 24 for supplying a current high in current peak value between which are an electrode 10 and a workpiece 12, and an auxiliary switching circuit 26 for supplying a current low in current peak value between the electrodes, to intermittently cause electric discharge between the electrodes which are the electrode 10 and the workpiece; a voltage is applied across the electrodes by the auxiliary switching circuit 26, and when no electric discharge occurs between the electrodes before a decision set time of 1 to 4 .mu.

Abstract: In an electric discharge machining apparatus with a wire-shaped electrode for machining a workpiece by causing electrical discharge in a gap between the wire-shaped electrode and the workpiece and controlling a machining feed speed so that the voltage across the gap is constant, the machining area of the workpiece is detected from the machining feed speed. The thus detected data representative of the machining area are applied to an arithmetic unit which operates to instruct optimum electrical machining conditions according to the machining area, whereby the workpiece is machined under the optimum electrical conditions at all times.

Abstract: A command average machining current It(n) corresponding to change of a workpiece thickness is given by the following equations: ##EQU1## wherein the reference Ia(n) designates an actual average machining current Ia(n) at the workpiece thickness (Tn); It(n) designates an average machining current of the control command; Fn designates an actual machining feed rate; Ia(o) designates an actual average machining current at the initiation of the machining; S(o) designates a machining width; and To designates a workpiece thickness.The command average machining current It(n) is compared with the actual average machining current and the electric condition is changed and controlled to approach the actual average machining current to the command average machining current It(n) thereby controlling the work groove width to be constant in an electric discharge machining of the workpiece with a wire electrode.

Abstract: An electric discharge machining apparatus for cutting and shaping a workpiece into an article having a desired configuration in which the period of time required until the speed of a table carrying the workpiece becomes constant is made quite short. Comparator means compares a gap voltage between a wire-shaped electrode and a workpiece with a reference voltage to produce an error voltage. In one embodiment, a non-linear amplifier is disposed between the output of the comparator means and the input of an integrator. In the integrator, a clamping diode is coupled across an integrating capacitor so as to prevent the output of the integrator from becoming negative.

Abstract: In an electric discharge machine, a pulse voltage is applied between a wire electrode and a workpiece to cause electric discharge between said wire electrode and said workpiece in a work liquid, and said workpiece is moved to said wire electrode depending upon the configuration of said workpiece and the degree of said electric discharge work to obtain a desired configuration. The movement of said workpiece can be controlled depending upon the speed signal corresponding to a gap voltage and the degree of the signal. The size of the work area is detected by the speed signal and a sharp corner work is carried out under a low energy by controlling the power source and the thickness variation work is carried out by increasing the energy in the case that the work area is increased and by decreasing the energy in the case that the work area is decreased.