US Patent No. 10,024,644

WIRE ELECTRICAL DISCHARGE MACHINE


Patent No. 10,024,644
Issue Date July 17, 2018
Title Wire Electrical Discharge Machine
Inventorship Hiroyuki Abe, Yamanashi (JP)
Kaoru Hiraga, Yamanashi (JP)
Assignee FANUC CORPORATION, Yamanashi (JP)

Claim of US Patent No. 10,024,644

1. A wire electrical discharge machine having functions of relatively moving an object and a wire electrode supported by upper and lower wire guides and positioning the wire electrode or measuring the shape of the object based on a contact/non-contact state of the wire electrode and the object, the wire electrical discharge machine comprising:a voltage applying unit configured to apply a detection voltage for detecting the contact/non-contact state of the wire electrode and the object between the wire electrode and the object;
a relative movement unit for relatively moving the wire electrode and the object;
a wire electrode position detecting unit for detecting a center position of the wire electrode;
a contact state detecting unit configured to detect the voltage between the wire electrode and the object in the course of relative movement of the wire electrode toward and away from the object by the relative movement unit and detect the contact/non-contact state of the wire electrode and the object based on the detected voltage;
a wire electrode diameter storage unit for storing the diameter of the wire electrode;
a wire electrode displacement amount storage unit for storing an amount of displacement such that the wire electrode is displaceable between the upper and lower wire guides in a direction perpendicular to a line segment connecting the upper and lower wire guides;
an end face determination position detecting unit configured to detect an end face determination position in which the wire electrode is determined to be in contact with an end face of the object, based on the contact/non-contact state detected by the contact state detecting unit and the position of the wire electrode detected by the wire electrode position detecting unit;
a set number of times executing unit configured to execute a set number of times a contact detection movement where the relative movement unit moves the wire electrode and the object in the direction in which the wire electrode and an end surface of the object come into contact with each other with the movement speed slowing down and a non-contact detection movement where the relative movement unit moves the wire electrode and the object in the direction in which the wire electrode and the object come out of contact with each other with the movement speed increasing in order to shorten the detection time of the end surface determination position; and
an end face determination position compensation unit configured to obtain an average value of the end surface determination position at the time of the contact detection movement, which has been detected by the end surface determination position detection unit after the set number of times execution unit has executed the contact detection movements and the non-contact detection movements, and then obtain the end face determination position from the thus obtained average value by compensation using a compensation value obtained from the wire electrode diameter and the displacement amount,
wherein the wire electrical discharge machine positions the wire electrode or measures the shape of the object based on the position obtained by the end face determination position compensation unit as a position of the object.