WIRE ELECTRICAL DISCHARGE MACHINE CARRYING OUT ELECTRICAL DISCHARGE MACHINING BY INCLINING WIRE ELECTRODE

• US 20130186865A1
• Filed: 11/08/2012
• Published: 07/25/2013
• Est. Priority Date: 01/20/2012
• Status: Active Grant

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: HIRAGA, Kaoru, YAMAOKA, Masahide
• Granted Patent: US 8,921,729 B2
• Time in Patent Office: Days
• US Class Current: 219/69.12
• CPC Class Codes: B23H 1/024 Detection of, and response to, abnormal gap conditions, e.g. short circuits preventing short circuits or other abnormal discharges by altering machining parameters using adaptive control B23H7/16
• CPC Class Codes: B23H 1/04 Electrodes specially adapted therefor or their manufacture B23H9/00 takes precedence
• CPC Class Codes: B23H 7/065 Electric circuits specially adapted therefor
• CPC Class Codes: B23H 7/20 for programme-control, e.g. adaptive programme-control systems in general G05B19/00
• CPC Class Codes: B23H 7/30 Moving electrode in the feed direction B23H7/32 takes precedence

Abstract

A wire electrical discharge machine is capable of step machining by setting only a position located anterior to a step portion of the workpiece during a setup operation before machining, without setting an inclination finishing position of a wire electrode after passing the step portion. A machining program is read, and when a wire electrode reaches a preset inclination starting position in front of a step position, inclination control of the wire electrode is started. Then, when the wire electrode has passed the position of the step portion, the inclination control of the wire electrode is finished.

Claims

1. A wire electrical discharge machine which has a workpiece plate thickness change detection part configured to detect a change of a plate thickness in a step portion of a workpiece based on energy applied from a power source unit for machining, and machines the workpiece by relatively moving a wire electrode with respect to the workpiece with electrical discharge generated, from the power source unit for machining, between the wire electrode and the workpiece, the wire electrical discharge machine comprising:

a setting part configured to set a wire electrode inclination starting position located anterior to a step portion;

a wire electrode inclination starting position passing judgment part configured to determine whether or not the wire electrode passes the wire electrode inclination starting position set by the setting part;

a wire electrode inclination control part configured to carry out control of inclining the wire electrode within the machining plane with respect to a side where the machining plane, formed by relative movement of the wire electrode with respect to the workpiece, crosses the surface of the step portion of the workpiece when the wire electrode inclination starting position passing judgment part determined that the wire electrode has passed the wire electrode inclination starting position;

a step passing determination part configured to determine that the wire electrode has passed a position of the step portion when the plate thickness change detected by the workpiece plate thickness change detection part exceeds a preset value; and

a wire electrode inclination finishing control part configured to finish the control of inclining the wire electrode when the step passing determination part determines that the wire electrode has passed the position of the step portion.

2. The wire electrical discharge machine according to claim 1, wherein the energy applied from the power source unit for machining is a number of pulses of a pulse current applied from the power source unit for machining or a value of integral of the pulse current.

3. The wire electrical discharge machine according to claim 1, wherein the workpiece plate thickness change detection part obtains energy applied from the power source unit for machining when the wire electrode moves in a predetermined distance after passing the wire electrode inclination starting position and detects a change in the plate thickness of the workpiece by comparing the energy thus obtained with a predetermined reference energy.