Device and method for confirming that a wire electrode for a wire cutting discharge machine has penetrated a wire guide section on a wire take-out side

• US 4,978,828 A
• Filed: 06/21/1989
• Issued: 12/18/1990
• Est. Priority Date: 06/21/1988
• Status: Expired due to Term

• Current Assignee: Amada Company Limited, Amada Wasino Co. Ltd. (Amada Company Limited)
• Original Assignee: Amada Company Limited, Amada Wasino Co. Ltd. (Amada Company Limited)
• Inventors: Matsuda, Morikatsu, Umetsu, Masahito
• Primary Examiner(s): Evans, Geoffrey S.
• Application Number:
  US07/369,524
• Time in Patent Office: 545 Days
• Field of Search: 219/69.12, 219/69.17, 226/108
• US Class Current: 219/69.12
• CPC Class Codes: B23H 7/10 Supporting, winding or electrical connection of wire-electrode

Abstract

A wire cutting electric discharge machine that has wire supply rollers 17A and 17B feed the wire at a first speed and a wire feed out section that conveys the wire to a scrap box at a second speed that is greater than the first speed. Detection of the wire successfully reaching a wire guide section on the wire take out side is accomplished by detecting the speed of movement of a wire supply roller to see when it exceeds a preset fixed speed of movement.

Claims

1. A device for confirming that a wire electrode for a wire cutting discharge machine has penetrated a wire guide section on a wire take-out side comprising:

a speed detection means for detecting the delivery speed of the wire electrode by detecting the speed of movement of a wire supply means for supplying the wire electrode;

a speed setting means for presetting a fixed speed of movement larger than the wire delivery speed of the wire supply means;

a comparison means for comparing the value detected by the speed detection means with the set value of the speed setting means; and

a decision means for deciding from the output of the comparison means whether or not the wire electrode has penetrated the wire guide section on a wire take-out side.

2. A device according to claim 1, further comprising a step motor for driving said wire supply means, wherein said speed detection means outputs a pulse signal according to the speed of movement of the wire supply means;

said speed setting means sets a value by multiplying a number of pulses to be output to the step motor by a fixed number; and

said comparison means compares the number of pulses output from the speed detection means with the value set by the speed setting means.

3. A device according to claim 1, wherein said speed detection means outputs a voltage according to the speed of movement of the wire supply means;

said speed setting means sets a predetermined voltage; and

said comparison means compares the voltage output by the speed detection means with the predetermined voltage set by the speed setting means.

4. A method for confirming that a wire electrode for a wire cutting discharge machine has penetrated a wire guide section on a wire take-out side, comprising the steps of:

detecting the delivery speed of the wire electrode by detecting the speed of movement of a wire supply means for supplying the wire electrode;

setting a fixed speed of movement larger than the wire delivery speed of the wire supply means;

comparing the delivery speed of the wire electrode with the fixed speed of movement; and

deciding from the result of said comparing whether of not the wire electrode has penetrated the wire guide section on the wire take-out side.