Wire electrical discharge machine and control method for wire electrical discharge machine

Patent metadata

Field	Value
Publication number	US-10864587-B2
Application number	US-201815910066-A
Country	US
Kind code	B2
Filing date	Mar 2, 2018
Priority date	Mar 3, 2017
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A wire electrical discharge machine machines a workpiece so as to have different machined shapes on a top surface and a bottom surface of the workpiece. The wire electrical discharge machine includes: a distance measuring sensor for moving within a machining area of the wire electrical discharge machine and measuring a distance between the distance measuring sensor and an object to be measured; and a vertical position calculating unit for calculating a distance between a reference surface and the top surface and a distance between the reference surface and the bottom surface, from a distance between the reference surface and the distance measuring sensor, a distance between the top surface and the distance measuring sensor, and a distance between the bottom surface and the distance measuring sensor, measured by the distance measuring sensor.

First claim

What is claimed is:

1. A wire electrical discharge machine configured to machine a workpiece so as to have different machined shapes on a top surface and a bottom surface of the workpiece, comprising:
a distance measuring sensor configured to move within a machining area of the wire electrical discharge machine and measure a distance from the distance measuring sensor to an object to be measured; and
a calculating unit configured to set a reference surface in the machining area, wherein the reference surface is an upper surface or a lower surface of the worktable, and calculate a distance between the reference surface and the top surface of a workpiece and a distance between the reference surface and the bottom surface of a workpiece by measuring, with the distance measuring sensor, a distance between the reference surface and the distance measuring sensor, measuring from above the workpiece, with the distance measuring sensor, a distance between the top surface of the workpiece and the distance measuring sensor, and measuring from below the workpiece, with the distance measuring sensor, a distance between the bottom surface of the workpiece and the distance measuring sensor, and subtracting the distance measured between the top surface or bottom surface of the workpiece and the distance measuring sensor from the distance measure between the reference surface and the distance measuring sensor.

2. The wire electrical discharge machine according to claim 1 , wherein the calculating unit is configured to calculate a thickness of the workpiece from the distance between the reference surface and the top surface and the distance between the reference surface and the bottom surface.

3. The wire electrical discharge machine according to claim 1 , further comprising:
a wire electrode configured to perform electrical discharge machining on the workpiece;
a wire electrode driving unit configured to change a tilt of the wire electrode with respect to a thickness direction of the workpiece to be machined by the wire electrode; and
a control unit configured to control the wire electrode driving unit, wherein
the control unit is configured to set the tilt of the wire electrode depending on the distance between the reference surface and the top surface and the distance between the reference surface and the bottom surface.

4. The wire electrical discharge machine according to claim 1 , further comprising:
a bottom side reference surface member attached on the upper surface of the worktable so as to protrude from an outer periphery of the worktable, wherein
a portion of the bottom side reference surface member that protrudes from the outer periphery of the worktable includes a downward-facing plane that is flush with the upper surface of the worktable.

5. The wire electrical discharge machine according to claim 1 , wherein:
the distance measuring sensor is configured to measure a vertical distance from the distance measuring sensor to the object to be measured; and
the calculating unit is configured to calculate a vertical distance between the reference surface and the top surface and a vertical distance between the reference surface and the bottom surface, from a vertical distance between the reference surface and the distance measuring sensor, a vertical distance between the top surface and the distance measuring sensor, and a vertical distance between the bottom surface and the distance measuring sensor, measured by the distance measuring sensor.

6. A control method for a wire electrical discharge machine configured to machine a workpiece so as to have different machined shapes on a top surface and a bottom surface of the workpiece, comprising:
a distance measuring step of moving a distance measuring sensor within a machining area of the wire electrical discharge machine and measuring, with the distance measuring sensor, a distance from the distance measuring sensor to an object to be measured; and
a calculating step of setting a reference surface in the machining area, wherein the reference surface is an upper surface of a lower surface of the worktable, and calculating a distance between the reference surface and the top surface of a workpiece and a distance between the reference surface and the bottom surface of the workpiece by measuring, with the distance measuring sensor, a distance between the reference surface and the distance measuring sensor, measuring from above the workpiece, with the distance measuring sensor, a distance between the top surface of the workpiece and the distance measuring sensor, and measuring from below the workpiece, with the distance measuring sensor, a distance between the bottom surface of the workpiece and the distance measuring sensor, and subtracting the distance measured between the top surface or bottom surface of the workpiece and the distance measuring sensor from the distance measure between the reference surface and the distance measuring sensor.

7. The control method for the wire electrical discharge machine according to claim 6 , wherein the calculating step is effected to calculate a thickness of the workpiece from the distance between the reference surface and the top surface and the distance between the reference surface and the bottom surface.

8. The control method for the wire electrical discharge machine according to claim 6 , wherein the wire electrical discharge machine includes:
a wire electrode configured to perform electrical discharge machining on the workpiece;
and a wire electrode driving unit configured to change a tilt of the wire electrode with respect to a thickness direction of the workpiece to be machined by the wire electrode,
the control method further comprising a wire electrode drive control step of controlling the wire electrode driving unit so as to set the tilt of the wire electrode depending on the distance between the reference surface and the top surface and the distance between the reference surface and the bottom surface.

9. The control method for the wire electrical discharge machine according to claim 6 , wherein
the distance measuring step is effected to measure, with the distance measuring sensor, a vertical distance from the distance measuring sensor to the object to be measured; and
the calculating step is effected to calculate a vertical distance between the reference surface and the top surface and a vertical distance between the reference surface and the bottom surface, from a vertical distance between the reference surface and the distance measuring sensor, a vertical distance between the top surface and the distance measuring sensor, and a vertical distance between the bottom surface and the distance measuring sensor, measured by the distance measuring sensor.

Assignees

• Fanuc Corp

Inventors

• Hashimoto Taiju

Classifications

• B23H11/00

  Auxiliary apparatus or details, not otherwise provided for · CPC title

• B23H7/02 Primary

  Wire-cutting · CPC title

• B23H7/065 Primary

  Electric circuits specially adapted therefor · CPC title

• B23H2500/20

  Methods or devices for detecting wire or workpiece position · CPC title

• G05B2219/45043

  EDM machine, wire cutting · CPC title