ELECTRIC DISCHARGE MACHINE HAVING WIRE ELECTRODE CUTTING FUNCTION, AND WIRE ELECTRODE CUTTING METHOD

• US 20090101627A1
• Filed: 09/02/2008
• Published: 04/23/2009
• Est. Priority Date: 10/18/2007
• Status: Abandoned Application

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: FURUKAWA, Hiroyuki, KAWAHARA, Akiyoshi
• Application Number:
  US12/202,523
• Publication Number:
  US 20090101627A1
• Time in Patent Office: Days
• US Class Current: 219/69.120
• CPC Class Codes: B23H 7/04 Apparatus for supplying current to working gap; Electric circuits specially adapted therefor
• CPC Class Codes: B23H 7/08 Wire electrodes
• CPC Class Codes: B23H 7/102 Automatic wire threading

Abstract

A wire electric discharge machine and a wire electrode cutting method capable of carrying out a wire electrode cutting process without need for an operator to input information on material or a diameter of a wire electrode. An electric current measuring device measures a value of an electrical current flowing through a wire electrode to which a voltage is applied. An electrical resistance of the wire electrode is detected based on the applied voltage and the measured value of the electrical current. A plurality of cutting conditions predetermined and stored for electrical resistances of different types of wire electrodes. A cutting condition for the wire electrode is determined based on the detected electrical resistance of the wire electrode and the stored plurality of cutting conditions, and the wire electrode is fusion-cut on the thus determined cutting condition.

Claims

1. A wire electric discharge machine having a function of fusion-cutting a wire electrode, comprising:

a voltage applying device for applying a voltage to the wire electrode;

an electric current measuring device for measuring a value of an electrical current flowing through the wire electrode to which the voltage is applied;

electrical resistance detecting means that detects an electrical resistance of the wire electrode based on the applied voltage and the measured value of the electrical current;

storage means that stores a plurality of cutting conditions predetermined for electrical resistances of different types of wire electrodes;

cutting condition determining means that determines a cutting condition for the wire electrode based on the electrical resistance of the wire electrode detected by said electrical resistance detecting means and the plurality of cutting conditions stored in said storage means; and

means for fusion-cutting the wire electrode on the cutting condition determined by said cutting condition determining means.

2. A wire electric discharge machine according to claim 1, wherein said storage means stores a table indicating cutting conditions respectively for different electrical resistances of the wire electrodes.

3. A wire electric discharge machine according to claim 1, wherein said storage means stores a first table indicating types of wire electrodes respectively for electrical resistances of the wire electrodes, and a second table indicating cutting conditions respectively for the types of the wire electrodes.

4. A wire electrode cutting method for a wire electric discharge machine having a function of fusion-cutting a wire electrode, comprising the steps of:

applying a voltage to the wire electrode;

measuring a value of an electrical current flowing through the wire electrode to which the voltage is applied;

detecting an electrical resistance of the wire electrode based on the applied voltage and the measured value of the electrical current;

determining a wire electrode cutting condition based on the detected electrical resistance of the wire electrode and a plurality of cutting conditions which are predetermined for electrical resistances of different types of wire electrodes; and

fusion-cutting the wire electrode on the determined cutting condition.