Wire electric discharge machine

Patent metadata

Field	Value
Publication number	US-10646939-B2
Application number	US-201616340691-A
Country	US
Kind code	B2
Filing date	Nov 15, 2016
Priority date	Nov 15, 2016
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A wire electric discharge machine for machining a workpiece by causing a discharge between a wire electrode delivered from a wire bobbin and the workpiece. The wire electric discharge machine includes: a remaining length calculation unit that calculates a remaining length of the wire electrode based on electrode winding coefficients, bobbin draw-out radius correlation information, and a spool diameter of the wire bobbin. The electrode winding coefficients depend on a winding density of the wire electrode, an inner width of the wire bobbin, a wire diameter of the electrode wire, and a winding tension of the wire electrode. The bobbin draw-out radius correlation information is correlated with a bobbin draw-out radius that is a distance between a position at which the wire electrode wound around the wire bobbin is separated from the wire bobbin and a central axis of rotation of the wire bobbin.

First claim

The invention claimed is:

1. A wire electric discharge machine for machining a workpiece by causing a discharge between a wire electrode delivered from a wire bobbin and the workpiece, the wire electric discharge machine comprising:
a pulley in contact with the wire electrode and arranged between the wire bobbin and a tension roller; and
a wire remaining length estimating circuitry configured to calculate a remaining length of the wire electrode based on wire electrode winding coefficients, bobbin draw-out radius correlation information, and a spool diameter of the wire bobbin, the wire electrode winding coefficients representing a winding state of the wire electrode on the wire bobbin, the bobbin draw-out radius correlation information being correlated with a bobbin draw-out radius that is a distance between a position at which the wire electrode wound around the wire bobbin is separated from the wire bobbin and a central axis of rotation of the wire bobbin, wherein the wire electrode winding coefficients depend on an inner width of the wire bobbin, a wire diameter of the wire electrode, and a winding tension of the wire electrode; and
the wire remaining length estimating circuitry is further configured to calculate the bobbin draw-out radius based on a rotation angle of the pulley.

2. A wire electric discharge machine for machining a workpiece by causing a discharge between a wire electrode delivered from a wire bobbin and the workpiece, the wire electric discharge machine comprising:
a pulley in contact with the wire electrode and arranged between the wire bobbin and a tension roller;
remaining length calculation circuitry configured to calculate a remaining length of the wire electrode based on wire electrode winding coefficients, bobbin draw-out radius correlation information, and a spool diameter of the wire bobbin, the wire electrode winding coefficients representing a winding state of the wire electrode on the wire bobbin, the bobbin draw-out radius correlation information being correlated with a bobbin draw-out radius that is a distance between a position at which the wire electrode wound around the wire bobbin is separated from the wire bobbin and a central axis of rotation of the wire bobbin;
bobbin draw-out radius correlation information detection circuitry configured to detect the bobbin draw-out radius correlation information based on a rotation angle of the pulley;
a coefficient memory to store the wire electrode winding coefficients;
a spool diameter memory to store the spool diameter;
delivered length detecting circuitry configured to detect a delivered length of the wire electrode; and
a wire electrode winding coefficient calculation circuitry configured to calculate the wire electrode winding coefficients based on the delivered length and transition of the bobbin draw-out radius correlation information corresponding to the delivered length of the wire electrode, and store the wire electrode winding coefficients in the coefficient memory.

3. A wire electric discharge machine for machining a workpiece by causing a discharge between a wire electrode delivered from a wire bobbin and the workpiece, the wire electric discharge machine comprising:
a pulley in contact with the wire electrode and arranged between the wire bobbin and a tension roller;
remaining length calculation circuitry configured to calculate a remaining length of the wire electrode based on wire electrode winding coefficients, bobbin draw-out radius correlation information, and a spool diameter of the wire bobbin, the wire electrode winding coefficients representing a winding state of the wire electrode on the wire bobbin, the bobbin draw-out radius correlation information being correlated with a bobbin draw-out radius that is a distance between a position at which the wire electrode wound around the wire bobbin is separated from the wire bobbin and a central axis of rotation of the wire bobbin;
bobbin draw-out radius correlation information detection circuitry configured to detect the bobbin draw-out radius correlation information;
a coefficient memory to store the wire electrode winding coefficients;
a spool diameter memory to store the spool diameter; and
delivered length detecting circuitry configured to detect a delivered length of the wire electrode, wherein
the bobbin draw-out radius correlation information detecting circuitry is further configured to detect a rotation speed of the pulley and detect the bobbin draw-out radius correlation information based on the delivered length and the rotation speed of the pulley.

4. A wire electric discharge machine for machining a workpiece by causing a discharge between a wire electrode delivered from a wire bobbin and the workpiece, the wire electric discharge machine comprising:
a pulley in contact with the wire electrode and arranged between the wire bobbin and a tension roller;
remaining length calculation circuitry configured to calculate a remaining length of the wire electrode based on wire electrode winding coefficients, bobbin draw-out radius correlation information, and a spool diameter of the wire bobbin, the wire electrode winding coefficients representing a winding state of the wire electrode on the wire bobbin, the bobbin draw-out radius correlation information being correlated with a bobbin draw-out radius that is a distance between a position at which the wire electrode wound around the wire bobbin is separated from the wire bobbin and a central axis of rotation of the wire bobbin;
bobbin draw-out radius correlation information detection circuitry configured to detect the bobbin draw-out radius correlation information based on a rotation angle of the pulley;
a coefficient memory to store the wire electrode winding coefficients;
a spool diameter memory to store the spool diameter;
information reading circuitry configured to read the bobbin draw-out radius correlation information in an unused state displayed on the wire bobbin; and
wire electrode winding coefficient calculation circuitry configured to calculate the wire electrode winding coefficients based on a length of the wire electrode calculated from a mass per unit length of the wire electrode and a mass of the wire electrode wound around the wire bobbin, the bobbin draw-out radius correlation information in an unused state, and the spool diameter.

5. The wire electric discharge machine according to claim 4 , further comprising:
delivered length detecting circuitry configured to detect a delivered length of the wire electrode,
wherein the wire electrode winding coefficient calculation circuitry corrects the wire electrode winding coefficients based on the delivered length and transition of the bobbin draw-out radius correlation information corresponding to the delivered length of the wire electrode.

6. The wire electric discharge machine according to claim 2 , wherein the bobbin draw-out radius correlation information is a bobbin draw-out diameter that is double the bobbin draw-out radius, and
the wire electric discharge machine further includes:
a wire electrode detector to detect that the wire electrode on the wire bobbin has run out; and
spool diameter history recording circuitry configured to regard the bobbin draw-out diameter as the spool diameter once the wire electrode detector detects that the wire electrode on the wire bobbin has run out, and store the bobbin draw-out diameter in the spool diameter memory.

7. The wire electric discharge machine according to claim 2 , comprising:
filter processing circuitry configured to remove a frequency component equal to or higher than a rotational frequency of the wire bobbin from the transition of the bobbin draw-out radius correlation information corresponding to the delivered length of the wire electrode.

Assignees

• Mitsubishi Electric Corp

Inventors

• Nakagawa Takayuki
• Nii Makoto
• Izawa Satoru

Classifications

• B23H7/08 Primary

  Wire electrodes · CPC title

• B23H7/10

  Supporting, winding or electrical connection of wire-electrode · CPC title

• B23H11/00

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

• B23H7/02

  Wire-cutting · CPC title

• B23H7/20 Primary

  for program control, e.g. adaptive · CPC title