A wire electrical discharge machining apparatus capable of improving the shape precision of a continuous corner part includes a corner speed coefficient calculation device calculating a machining speed ratio between a middle corner section and a straight part from a machining volume ratio between the straight part and the middle corner section in which machining volume becomes a constant value. A corner speed coefficient interpolation device interpolates a speed coefficient calculated by the corner speed coefficient calculation device in a pre-corner section and a post-corner section. A speed reference calculation device calculates a machining speed reference based on a representative speed and the corner speed coefficient, and a drive control device controls a drive device. A continuous corner detection device determines whether continuous corner sections overlap each other when the length of the straight part connecting two corner parts is shorter than the length of the pre-corner section.

A wire electrical discharge machining system includes: an electrode motion control unit for moving a wire electrode while keeping the wire electrode parallel to Z.sub.1-axis and bring the wire electrode into contact with a reference piece, and moving the wire electrode while keeping the wire electrode inclined with respect to the Z.sub.1-axis and bring the wire electrode into contact with the reference piece; an electrode position acquiring unit for acquiring a position of the wire electrode in an X.sub.1Y.sub.1Z.sub.1 orthogonal coordinate system when the wire electrode touches the reference piece; a piece position acquiring unit for acquiring a piece position of the reference piece in an X.sub.2Y.sub.2Z.sub.2 orthogonal coordinate system when the wire electrode touches the reference piece; and a relative positional relationship calculator for calculating a coordinate system relative positional relationship, based on the acquired positions.

A wire electrical discharge machine for performing electrical discharge machining on a workpiece by applying voltage across an electrode gap between a wire electrode stretched between an upper nozzle and a lower nozzle and the workpiece to generate electrical discharges, includes a lifting mechanism configured to move the workpiece in the travelling direction of the wire electrode.

A wire electric discharge machine according to the present invention includes a multijoint robot including a wire crossing mechanism for crossing a wire electrode on its tip end, a robot controller for controlling the multijoint robot, a numerical controller for controlling the wire electric discharge machine, and a transmission unit for transmitting a coordinate position when the multijoint robot is driven and controlled to move the wire crossing mechanism from the robot controller to the numerical controller, and the numerical controller synchronizes a position of each shaft of the wire electric discharge machine with a movement of the wire crossing mechanism with reference to the coordinate position transmitted by the transmission unit.

A multiwire electric discharge machine includes: a plurality of guide rollers; a machining power supply that applies a voltage between each of a plurality of cutting wire sections and a workpiece; a dummy workpiece including a contact surface curved in such a way as to be capable of coming into contact with a curved surface of the workpiece except for an end point, the end point being to be reached by each of the plurality of cutting wire sections when machining of the workpiece is completed, the dummy workpiece supporting the workpiece from one side in a first direction, the first direction being a direction in which the workpiece moves; and a pressing mechanism including a pressing portion, the pressing mechanism pressing the workpiece against the dummy workpiece by bringing the pressing portion into contact with the workpiece from another side in the first direction.

A device .[.(340, 440, 540).]. is connected to an output terminal of a controller.[.(330).]., having a single input terminal connected to a first power terminal of an external power source .[.(305).]. which outputs an AC voltage between the first power terminal and a second power terminal. The device includes a bleeding circuit.[.(342, 442, 542).]., and a switching arrangement .[.(344/346, 444/446, 544/546).]. to detect whether the controller powers a load .[.(320.]. or disables the load. When the controller is in an OFF state, the switching arrangement connects the bleeding circuit between the output terminal of the controller and the second power terminal to provide a current path between the output terminal of the controller and the second power terminal. When the controller is in an ON state, the switching arrangement disconnects the bleeding circuit between the output terminal of the controller and the second power terminal.

A machining program creation apparatus for a wire electrical discharge machine for creating a machining program for cutting a predetermined machining shape in an object to be machined includes a first unit defining the machining shape; a second unit defining a shape of the object to be machined; a third unit designating a reference position to be used when the machining shape is machined; a fourth unit for generating a first machining path for cutting the machining shape based on the machining shape, the shape of the object to be machined, and the machining reference position; a fifth unit for generating the shape of the object to be machined as a second machining path based on the shape of the object to be machined and the machining reference position; and a sixth unit for drawing the first and the second machining paths on the same screen.

A wire electrical discharge machine machines a workpiece so as to have different machined shapes on a top surface and a bottom surface of the workpiece. The wire electrical discharge machine includes: a distance measuring sensor for moving within a machining area of the wire electrical discharge machine and measuring a distance between the distance measuring sensor and an object to be measured; and a vertical position calculating unit for calculating a distance between a reference surface and the top surface and a distance between the reference surface and the bottom surface, from a distance between the reference surface and the distance measuring sensor, a distance between the top surface and the distance measuring sensor, and a distance between the bottom surface and the distance measuring sensor, measured by the distance measuring sensor.

A measurement program for sequentially measuring measurement points, which are to be measured with a touch sensor, is created on the basis of a machining program, which is read in, for machining a turning tool. Then, the rake face height is measured on each of the measurement points and the measurement data is stored. Subsequently, a calculation method of a correction amount is selected so as to calculate the correction amount, and whether or not the calculated correction amount is smaller than a regulation value is determined. The machining program is modified on the basis of the correction amount when the correction amount is not smaller than the regulation value, while the machining program is modified on the basis of the correction amount in accordance with the selected method when the correction amount is smaller than the regulation value.

In wire electric discharge machining performed with a wire electrode moved relative to a workpiece based on a desired shape, a command speed is controlled so that the discharge densities per unit distance in circular-arc and straight portions of the desired shape are equal, in consideration of the difference in arc length between a circular-arc portion in a desired shape and the corresponding portion of a machining path, whereby the shape accuracy of the circular-arc portion is improved.