POWER SUPPLY DEVICE FOR WIRE ELECTRIC DISCHARGE MACHINING

• US 20150246403A1
• Filed: 09/18/2013
• Published: 09/03/2015
• Est. Priority Date: 09/18/2012
• Status: Active Grant

• Current Assignee: Sodick Company Limited (Plustech, Inc.)
• Original Assignee: Sodick Company Limited (Plustech, Inc.)
• Inventors: Yamada, Kuniharu
• Granted Patent: US 10,730,126 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B23H 1/02 Electric circuits specially adapted therefor, e.g. power supply, control, preventing short circuits or other abnormal discharges
• CPC Class Codes: B23H 1/022 for shaping the discharge pulse train B23H1/024 takes precedence
• CPC Class Codes: B23H 7/04 Apparatus for supplying current to working gap; Electric circuits specially adapted therefor
• CPC Class Codes: B23H 7/14 Electric circuits specially adapted therefor, e.g. power supply B23H3/02 takes precedence

Abstract

A power supply device for wire electric discharge machining includes: a first DC power supply; first switching elements between the first DC power supply and a machining gap; a second DC power supply; a second switching element between the second DC power supply and the machining gap; and a pulse generator controlling the first and second switching elements. The pulse generator is configured so that, in order to generate an electric discharge in the machining gap, the second switching element is switched on and the voltage of the second DC power supply is applied to the machining gap; the first switching element is switched on intermittently at a predetermined frequency in response to an electric discharge generation detection signal, and a series of current pulses is fed to the machining gap. The feeding of the series of current pulses is discontinued when the current pulses don'"'"'t reach a reference current.

Claims

1. A power supply device for wire electric discharge machining, comprising:

a first DC power supply;

a first switching element disposed between the first DC power supply and a machining gap;

a second DC power supply;

a second switching element disposed between the second DC power supply and the machining gap;

an electric discharge generation detector generating a detection signal indicating that an electric discharge is generated in the machining gag; and

a pulse generator controlling the first switching element and the second switching element,

wherein the pulse generator switches on the second switching element and applies a voltage of the second DC power supply to the machining gap in order to generate the electric discharge in the machining gap, intermittently switches on the first switching element at a predetermined frequency in response to the detection signal and supplies a series of current pulses to the machining gap, and discontinues supply of the series of current pulses when the current pulses do not reach a reference current.

2. The power supply device for wire electric discharge machining according to claim 1, wherein a circuit where a current flows from the first DC power supply to the machining gap through the first switching element does not comprise a current limiting resistor.

3. The power supply device for wire electric discharge machining according to claim 1, wherein the predetermined frequency is 1 MHz or more.

4. The power supply device for wire electric discharge machining according to claim 1, wherein the second DC power supply is connected in parallel to the first DC power supply.