WORKING FLUID SUPPLY CONTROL APPARATUS FOR WIRE ELECTRIC DISCHARGE MACHINE

• US 20150202704A1
• Filed: 01/22/2015
• Published: 07/23/2015
• Est. Priority Date: 01/23/2014
• Status: Abandoned Application

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: YOSHIDA, Masayuki, KAWAHARA, Akiyoshi, NAKASHIMA, Yasuo
• Application Number:
  US14/602,782
• Publication Number:
  US 20150202704A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B23H 1/10 Supply or regeneration of working media
• CPC Class Codes: B23H 7/101 Supply of working media

Abstract

A working fluid supply control apparatus for a wire electric discharge machine including a first pump supplying a working fluid through an upper nozzle and a second pump that supplies the working fluid through a lower nozzle independently of each other is provided. A supply amount of the working fluid supplied through the first pump is controlled such that the actual pressure of the working fluid supplied through the upper nozzle follows a preset target value. Control over the supply amount of the working fluid supplied through the lower nozzle is performed similarly to and independently of the control over the supply amount of the working fluid supplied through the upper nozzle.

Claims

1. A working fluid supply control apparatus for a wire electric discharge machine including a first pump that supplies a working fluid to a gap between a wire electrode and a workpiece through an upper nozzle and a second pump, provided independently of the first pump, that supplies a working fluid to the gap through a lower nozzle, the working fluid supply control apparatus comprising:

a pressure setting section that sets a target value for a pressure of the working fluid supplied through each of the upper and lower nozzles in accordance with an electric discharge machining condition;

a pressure detection section that detects the pressure of the working fluid supplied through each of the upper and lower nozzles; and

a working fluid supply control section that controls a supply amount of the working fluid supplied by each of the pumps through each of the upper and lower nozzles independently so that a value of the pressure of the working fluid through each of the upper and lower nozzles detected by the pressure detection section follows the target value for the pressure of the working fluid through each of the upper and lower nozzles set by the pressure setting section.

2. The working fluid supply control apparatus for the wire electric discharge machine according to claim 1, wherein the pressure setting section is configured to set the pressure of the working fluid supplied through each of the upper and lower nozzles based on number of discharge pulses per unit time or unit distance during electric discharge machining.

3. The working fluid supply control apparatus for the wire electric discharge machine according to claim 2, wherein the pressure setting section is configured to set the value of the pressure smaller as the number of discharge pulses per unit time or unit distance during the electric discharge machining is smaller, and to set the value of the pressure larger as the number of discharge pulses per unit time or unit distance during the electric discharge machining is larger.

4. The working fluid supply control apparatus for the wire electric discharge machine according to claim 1, wherein the pressure setting section is configured to set the pressure of the working fluid supplied through each of the upper and lower nozzles based on a mean value of a discharge pulse current per unit time or unit distance during electric discharge machining.

5. The working fluid supply control apparatus for the wire electric discharge machine according to claim 4, wherein the pressure setting section is configured to set the value of the pressure smaller as the mean value of the discharge pulse current per unit time or unit distance during the electric discharge machining is smaller, and to set the value of the pressure larger as the mean value of the discharge pulse current per unit time or unit distance during the electric discharge machining is larger.

6. The working fluid supply control apparatus for the wire electric discharge machine according to claim 1, wherein the pressure setting section is configured to set the pressure of the working fluid supplied through each of the upper and lower nozzles based on the value of the pressure of the working fluid controlled during electric discharge machining.

7. The working fluid supply control apparatus for the wire electric discharge machine according to claim 6, wherein the pressure setting section is configured to set the value of the pressure smaller when the value of the pressure of the working fluid controlled during the electric discharge machining is smaller, and to set the value of the pressure larger when the value of the pressure of the working fluid controlled during the electric discharge machining is larger.

8. The working fluid supply control apparatus for the wire electric discharge machine according to claim 1, wherein the pressure setting section is configured to set the pressure of the working fluid supplied through each of the upper and lower nozzles based on an amount of the working fluid controlled during electric discharge machining.

9. The working fluid supply control apparatus for the wire electric discharge machine according to claim 8, wherein the pressure setting section is configured to set the value of the pressure smaller as the amount of working fluid controlled during the electric discharge machining is larger, and to set the value of the pressure larger as the amount of working fluid controlled during the electric discharge machining is smaller.