Fujitsu Fanuc Limited

Fanuc Corporation

Kanemasa Okuda

Yoshiyuki Nomura

Masatoyo Sogabe

Gotaro Gamo

Hisao Ishii

Hideo Katsube

Keiji Sakamoto

Shunsuke Matsubara

Mitsuo Kinoshita

Tomonaga Yamamoto

Optical encoder with grounded coding plate

Digital servo system

When cutting workpiece into a desired number of closed loop configurations by means of a wire-cut, electric discharge machine provided with an automatic wire feed mechanism, electric discharge machining is started from a machining start hole made in the workpiece corresponding to each closed loop configuration and is performed to a point where the electric discharge machining operation is stopped, thus a part of the closed loop configuration is left uncut. After fixing at least one portion of each closed loop configuration to the workpiece and inserting the wire electrode into the machining start hole by the automatic wire feed mechanism, the electric discharge machining operation is resumed to cut off the remaining uncut part. In the case of the wire electrode breaking during the electric discharge machining operation, the wire electrode is inserted by the automatic wire feed mechanism into the machining start hole and is moved to the position where it breaks along the route where the machining operation has already been performed, and then the electric discharge machining operation is resumed.

Wire-cut, electric discharge machining method

A wire electrode pull-up mechanism in a wire-cut electric discharge machine having an energized wire electrode stretched between upper and lower guides for machining a workpiece wherein the wire electrode pull-up mechanism pulls up a wire electrode which has been passed through a bore in the workpiece until the upper end of the wire electrode protrudes from the upper side of the workpiece, and includes a gripping member for gripping the wire electrode. The gripping member includes an arm having a bearing wall at the distal end thereof; a clamping member pivotally provided on the arm and having a cam body and a restraining portion for abutting against the bearing wall of the arm; a spring member for urging the clamping member in such a manner that the restraining portion thereof abuts against the bearing wall; and an operating member pivotally provided on the arm and having a cam operating portion abutting against the cam body of the clamping member for pivoting the clamping member, the operating member being pivoted owing to pressured contact with the upper surface of the workpiece. The clamping member is pivoted as the operating member abuts against the workpiece, in such a manner that the clamping member causes a gap to be formed between the restraining portion and the bearing wall, and the operating member separates from the workpiece when the arm is raised.

Wire electrode pull-up mechanism in wire-cut electric discharge machine

A wire-cut, electric discharge machining method in which a wire is inserted into a machining start hole made in a workpiece to start electric discharge machining from the machining start hole, a bushing of a conductive material is pressed into a hole made in the workpiece to provide the machining start hole.

A wire-cut, electric discharge machine in which a pair of rollers are provided in the vicinity of each of the upper and lower guides of a wire running system for gripping therebetween a wire with constant pressure. When the wire breaks, the pairs of rollers hold the wire to prevent it from coming off the running system.

Wire-cut, electric discharge machine

A wire-cut, electric discharge machine which is provided with auxiliary wire feed means for feeding a wire in a backward direction when the wire is broken, and a wire detector for detecting, at a predetermined position, the extreme end of the broken wire fed in the backward direction. When detecting the extreme end of the broken wire by the wire detector, the feed of the broken wire by the auxiliary wire feed means is stopped to position the extreme end of the broken wire at a predetermined position.

A wire or band electrode type electric discharge machine for machining hard metals by an electric spark generated between the metal workpiece and a wire electrode which is fed longitudinally to provide a fresh supply thereof while a prescribed relative motion is established between the workpiece and the wire electrode. The invention provides a clamping mechanism on the wire supply side of the workpiece for clamping the wire electrode if it breaks during operation, and a wire electrode feed mechanism for automatically guiding the broken end of the wire through the opening that has been machined in the workpiece. A wire electrode pull-up mechanism is provided on the other side of the workpiece for gripping and pulling up the wire electrode. If the electrode wire breaks during a machining operation, the clamping mechanism immediately clamps the wire electrode and prevents it from falling under its own weight. Thereafter the wire electrode feed mechanism draws the broken wire electrode away from the surface of the workpiece and then reinserts the broken end through the opening until the end of the wire emerges from the opposite side. The wire electrode pull-up mechanism the grips the end of the wire and pulls it to a new position to restore operation after it has been released by the clamping mechanism.

Electric discharge machine

A method and apparatus for restoring a broken wire electrode in a wire electrode-type electric discharge machine for machining a workpiece into a desired shape while the workpiece is moved relative to the wire electrode on the basis of machining command data. For effecting the restoration of the wire electrode, memory means are provided for storing the relative machining starting position of the workpiece and the wire electrode at the machining starting point, and the relative wire electrode breakage position of the workpiece and the wire electrode when the wire electrode breaks. After the wire electrode breaks the relative position of the workpiece and the wire electrode is brought into coincidence with the machining starting position on the basis of information indicative of the machining starting position and the wire electrode breakage position. After the wire electrode is returned to a feed system therefor, the workpiece is again moved relative to the wire electrode from the machining starting point on the basis of the machine command data. The relative position of the workpiece and the wire electrode is made to coincide with the wire electrode breakage position, after which the discharge machining operation is resumed.

Growing community of inventors

Hino, Japan

Kanemasa Okuda