POWER SOURCE DEVICE FOR ELECTRIC DISCHARGE FINISHING MACHINE

• Main Authors: SATOU SEIJI, YAMADA HISASHI
• Format: Patent
• Language: English
• Published: 14.09.1998
• Edition: 6
• Subjects: MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL; TRANSPORTING; WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OFELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKESTHE PLACE OF A TOOL

PROBLEM TO BE SOLVED: To restrain generation of discharge by a negative polarity voltage pulse by providing a pulse control means to control a voltage impressing means so that a period of a positive polarity voltage impressing condition, a period of a negative polarity voltage impressing condition and a negative polarity voltage impression resting condition are repeatedly generated in prescribed order. SOLUTION: When a period after an impression of a negative side voltage pulse is set to time sufficiently longer than positive negative voltage pulse impressing time, negative voltage is maintained because of capacitance of a maching clearance during a period when semiconductor switching elements 102 and 105 are turned off. On the other hand, after semiconductor switching elements 103 and 104 are turned off by impressing positive voltage, since negative voltage is immediately impressed, voltage of the machining clearance immediately reverses to negative polarity from positive polarity. Therefore, a negative side voltage pulse impressing period can be shortened more than positive side voltage pulse impressing time.