WIRE-CUT ELECTRIC DISCHARGE MACHINE HAVING WORKPIECE MEASURING MECHANISM

• US 20120031879A1
• Filed: 05/20/2011
• Published: 02/09/2012
• Est. Priority Date: 08/06/2010
• Status: Active Grant

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: ABE, Hiroyuki, SUZUKI, Koji, TAKAYAMA, Yushi
• Granted Patent: US 8,637,785 B2
• Time in Patent Office: Days
• US Class Current: 219/69.12
• CPC Class Codes: B23H 2500/20 Methods or devices for detecting wire or workpiece position
• CPC Class Codes: B23H 7/065 Electric circuits specially adapted therefor

Abstract

A machining program used for machining a workpiece with a wire-cut electric discharge machine is used for measuring a shape of the workpiece. A wire electrode moved in a direction away from the workpiece by an offset command for machining is moved close to the workplace in workplace measurement after the machining. In other words, the wire electrode is moved in an opposite direction to an offset direction for the machining. Then, an end face position of the machined workpiece detected by a position of the wire electrode when the wire electrode comes in contact with the workpiece.

Claims

1. A wire-cut electric discharge machine including analysis means for analyzing a block of a machining program and means for carrying out on/off control of application of machining power supply voltage to a wire electrode to machine a workpiece in accordance with a machining program, the machine comprising:

calculating means for calculating a measuring point and a measuring direction by using an analysis result of the block of the machining program by the analysis means;

storage means for storing the measuring point and the measuring direction calculated by the calculating means;

means for relatively moving the wire electrode with respect to the workpiece in a state in which the application of the machining power supply voltage to the wire electrode is turned off in accordance with the block of the machining program analyzed by the analysis means;

determining means for determining whether or not the wire electrode has moved with respect to the workpiece and reached the measuring point;

means for relatively moving the wire electrode with respect to the workpiece in the measuring direction stored in the storage means, in a case where it is determined by the determining means that the wire electrode has reached the measuring point;

contact detecting means for detecting that the wire electrode has come in contact with the workpiece; and

position detecting means for detecting a position of the wire electrode when the contact detecting means detects contact between the wire electrode and the workplace.

2. The wire-cut electric discharge machine according to claim 1, wherein the measuring point is a midpoint between a starting point and an end point of the block in the machining program, an equally dividing point, or a position a predetermined distance away from the starting point of the block.

3. The wire-cut electric discharge machine according to claim 1, wherein the measuring direction is obtained from a relative moving direction of the wire electrode with respect to the workplace and an offset command described in the block in the machining program.

4. The wire-cut electric discharge machine according to claim 1, wherein faint voltage is applied to the wire electrode by a voltage applying device and the contact detecting means detects the contact by utilizing a fact that the wire electrode becomes equal to the workpiece in potential when the wire electrode comes in contact with a machined end face of the workpiece.

5. The wire-cut electric discharge machine according to claim 1, further comprising a measuring probe which comes in contact with the workplace to detect the contact with the workpiece, in a position having a predetermined positional relationship to the wire electrode, wherein

the position detecting means detects a position of the measuring probe when the measuring probe comes in contact with the workpiece instead of detecting the position of the wire electrode when the wire electrode comes in contact with the workpiece.