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US 6,723,941 B2Granted
Wire electric-discharge machining apparatus
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsTatsushi Sato, Junichi Shibata
Life of this patent
Estimating the term…
Abstract
In the wire electric-discharge machining apparatus, when a measured voltage exceeds a proportional constant switching voltage that is set higher than a short circuit reference voltage, a relative feed rate determining unit outputs a relative feed rate based on a preliminarily set proportional constant A according to an increase in the measured voltage. When the measured voltage is equal to a reference voltage, the relative feed rate determining unit outputs a target feed rate that becomes a target value, and also outputs a relative feed rate that follows a preset proportional constant B (<A) and that is a positive value when the measured voltage exceeds the short circuit reference voltage but is below the proportional constant switching voltage.
Claims15
A wire electric-discharge machining apparatus which comprises:
- a relative feed rate determining unit that decides a relative feed rate between a wire electrode and a workpiece based on a measured voltage between the wire electrode and the workpiece, and which carries out machining on the workpiece by generating a discharge between the wire electrode and the workpiece and relatively moving the wire electrode and the workpiece at the relative feed rate decided by the relative feed rate determining unit,
- wherein the relative feed rate determining unit outputs an target feed rate as a target value when the measured voltage is equal to a preset reference voltage, and outputs a positive relative feed rate according to preset conditions, when the measured voltage exceeds a predetermined short circuit reference voltage but is below a switching voltage that is preliminarily set between the short circuit reference voltage and the reference voltage.
A wire electric-discharge machining apparatus which comprises:
- a relative feed rate determining unit that decides a relative feed rate between a wire electrode and a workpiece based on a measured voltage between the wire electrode and the workpiece, and which carries out machining on the workpiece by generating a discharge between the wire electrode and the workpiece and relatively moving the wire electrode and the workpiece at the relative feed rate decided by the relative feed rate determining unit,
- wherein when the measured voltage exceeds a predetermined short circuit reference voltage, the relative feed rate determining unit outputs a positive relative feed rate in which an amount of change per unit voltage change becomes smaller as a difference between the measured voltage and the short circuit reference voltage decreases.
A wire electric-discharge machining apparatus comprising:
- a machining power supply which applies a pulse-like voltage between a wire electrode and a workpiece;
- an average voltage measurement unit which measures an average voltage between the wire electrode and the workpiece;
- a control parameter switching unit which sets a reference voltage and a target feed rate based on predetermined machining conditions;
- a relative feed rate determining unit which decides a relative feed rate between the wire electrode and the workpiece based on a measured voltage between the wire electrode and the workpiece, and which carries out machining on the workpiece by generating a discharge between the wire electrode and the workpiece and relatively moving the wire electrode and the workpiece at the relative feed rate decided by the relative feed rate determining unit;
- a control parameter setting unit which sets a reference voltage and a target feed rate based on predetermined conditions;
- and
- a control unit which moves the wire electrode and the workpiece by a feed rate calculated by a driving unit.
4 more elements
A wire electric-discharge machining apparatus comprising:
- a wire electrode;
- a machining power supply which applies a pulse-like voltage between the wire electrode and a workpiece to carry out machining on the workpiece;
- a driving unit which moves the wire electrode and the workpiece relatively to each other during the machining;
- a control unit which calculates a feed rate at which the wire electrode is fed relative to the workpiece and controls the driving unit so that the wire electrode and the workpiece move relatively to each other at the feed rate;
- a voltage measurement unit which measures a voltage between the wire electrode and the workpiece while the wire electrode and the workpiece move relatively to each other;
- an average voltage calculating unit which calculates an average voltage from voltages measured by the voltage measurement unit at different locations due to the relative movement of the wire electrode and the workpiece;
- a relative feed rate determining unit which decides a target relative feed rate between the wire electrode and the workpiece based on the average voltage according to predetermined conditions;
- a control parameter setting unit which sets a reference voltage, a shortcircuit reference voltage, and a switching voltage that is set between the shortcircuit reference voltage and the reference voltage based on predetermined conditions;
- and
- a control parameter switching unit which switches the target relative feed rate to a positive relative feed rate according to predetermined conditions, when the average voltage exceeds the short circuit reference voltage but is below the switching voltage.
7 more elements
A wire electric-discharge machining apparatus comprising:
- a wire electrode;
- a machining power supply which applies a pulse-like voltage between the wire electrode and a workpiece to carry out machining on the workpiece;
- a driving unit which moves the wire electrode and the workpiece relatively to each other during the machining;
- a control unit which calculates a feed rate at which the wire electrode is fed relative to the workpiece and controls the driving unit so that the wire electrode and the workpiece move relatively to each other at the feed rate;
- an average voltage measurement unit which measures a voltage between the wire electrode and the workpiece while the wire electrode and the workpiece move relatively to each other, and calculates an average voltage from the voltages measured;
- a relative feed rate determining unit which decides a target relative feed rate between the wire electrode and the workpiece based on the average voltage according to predetermined conditions;
- a control parameter setting unit which sets a reference voltage, a shortcircuit reference voltage, and a switching voltage that is set between the shortcircuit reference voltage and the reference voltage based on predetermined conditions;
- and
- a control parameter switching unit which switches the target relative feed rate to a positive relative feed rate according to predetermined conditions, when the average voltage exceeds the short circuit reference voltage but is below the switching voltage.
6 more elements
Dependencies are inferred from the claim text.