Method and device for identifying a spark-erosion wire on a coil, and application to machining by a wire spark-erosion machine

Abstract

A device for identifying a spark-erosion wire conditioned on a coil includes a radio tag, rigidly connected to the coil and accessible for reading data that it supports, identification data of the wire, supported by the radio tag, a data-reading device, associated with a wire spark-erosion machine, capable of reading the identification data supported by the radio tag of the coil, and capable of transmitting the identification data to the wire spark-erosion machine, an acquisition device for generating and recording over time as identification data, in the radio tag, historical data selected from the group that consists of historical usage data describing usage conditions of the wire supported by the coil and historical constraint data describing physical constraints to which the wire supported by the coil is subjected.

Claims

1. A device for identifying a spark-erosion wire packaged on a spool, comprising: an RFID tag, fastened to the spool and accessible for reading identification data that the RFID tag carries, identification data of said wire, carried by the RFID tag, and including a number of turns of wire initially present on the spool, an onboard accelerometer on the RFID tag or on the spool, wherein: the RFID tag is configured to communicate with a data reader device associated with a wire spark-erosion machine for reading and writing the identification data carried by the RFID tag of the spool, the RFID tag is of an active or semi-active type, provided with an onboard electrical power supply and an onboard storage circuit to receive and to store said identification data, the RFID tag comprises a processor electronic circuit controlled by a program, said program includes a storage sequence for scrutinizing and storing, in the storage circuit, signals produced by the onboard accelerometer on the RFID tag or on the spool, said program includes a number of revolutions computation sequence, for computing a number of turns effected by the spool about its axis as a function of acceleration signals received from the onboard accelerometer, and for computing a quantity of wire remaining on the spool as a function of said computed number of turns.

2. The device as claimed in claim 1 for identifying a spark-erosion wire packaged on a spool, wherein: the RFID tag is associated with onboard ambient temperature or humidity sensors, said program includes a storage sequence for scrutinizing and storing, in the storage circuit, signals produced by the onboard temperature or humidity sensors, said signals constituting stress historical data describing the physical stresses to which the spark-erosion wire carried by the spool is subjected.

3. The device as claimed in claim 1 for identifying a spark-erosion wire packaged on a spool, wherein the device further comprises a data reader device, associated with a wire spark-erosion machine, configured to read the identification data carried by the RFID tag of the spool, and configured to transmit the identification data to the wire spark-erosion machine, the data reader device is a radio-frequency communication device configured to communicate with the RFID tag.

4. The device as claimed in claim 1 for identifying a spark-erosion wire packaged on a spool, wherein: the spark-erosion machine comprises a control circuit including a computer program, the computer program comprises at least one acquisition sequence for generating and storing on the fly in the RFID tag, via a radio-frequency communication device, use historical data describing conditions of use of the spark erosion wire by said spark-erosion machine.

5. The device as claimed in claim 1, for identifying a spark-erosion wire packaged on a spool, wherein the identification data comprises threading or machining alarms encountered previously with the wire carried by the spool.

6. The device as claimed in claim 1, for identifying a spark-erosion wire packaged on a spool, wherein the identification data comprises nature or height of the parts machined previously with the wire carried by the spool.

7. A method of identifying a spark-erosion wire packaged on a spool including an RFID tag carrying identification data of said wire and associated with an onboard accelerometer on the RFID tag or on the spool, including: scrutinizing and storing, in the RFID tag, signals produced by the onboard accelerometer on the RFID tag or on the spool, computing, in the RFID tag, a number of turns effected by the spool about its axis as a function of acceleration signals received from the onboard accelerometer, and computing a quantity of wire remaining on the spool.

8. The method as claimed in claim 7 for identifying a spark-erosion wire packaged on a spool, wherein the RFID tag carrying identification data of said wire is associated with onboard ambient temperature or humidity sensors, said method including scrutinizing and storing, in the RFID tag, signals produced by the onboard ambient temperature or humidity sensors on the RFID tag.

9. The method as claimed in claim 7 for identifying a spark-erosion wire packaged on a spool, wherein: the spool including the RFID tag carrying identification data is associated with a spark-erosion machine, the method includes generating and storing on the fly in the RFID tag, from said spark-erosion machine, use historical data describing conditions of use of the spark erosion wire by said spark-erosion machine.

10. A spark-erosion machining device, comprising: a wire spark-erosion machine, a spark-erosion wire packaged on a spool, an RFID tag, fastened to the spool and accessible for reading identification data that the RFID tag carries, identification data of said wire, carried by the RFID tag, an onboard accelerometer on the RFID tag or on the spool, a data reader device, associated with the wire spark-erosion machine, configured to read the identification data carried by the RFID tag of the spool, and configured to transmit the identification data to the wire spark-erosion machine, the RFID tag is of an active or semi-active type, provided with an onboard electrical power supply and a storage circuit to receive and to store said identification data, the RFID tag comprises a processor electronic circuit controlled by a program, said program includes a storage sequence for scrutinizing and storing, in the storage circuit, signals produced by the onboard accelerometer on the RFID tag or on the spool, said program includes a number of revolutions computation sequence, for computing a number of turns effected by the spool about its axis as a function of acceleration signals received from the onboard accelerometer, and for computing a quantity of wire remaining on the spool.

11. The spark-erosion machining device of claim 10, further comprising onboard ambient temperature or humidity sensors, said program including scrutinizing and storing, in the RFID tag, signals produced by the onboard ambient temperature or humidity sensors on the RFID tag.

12. The spark-erosion machining device of claim 10, configured to execute a stored computer program comprising an acquisition sequence which generates, transmits and stores on the fly, in the RFID tag, historical data on use of the wire by the wire spark-erosion machine, said use historical data of the wire including threading or machining alarms encountered by the wire spark-erosion machine with the wire carried by the spool.

13. The spark-erosion machining device of claim 10, configured to execute a stored computer program comprising an acquisition sequence which generates, transmits and stores on the fly, in the RFID tag, historical data on use of the wire by the wire spark-erosion machine, said use historical data of the wire including nature or height of the parts machined by the wire spark-erosion machine with the wire carried by the spool.

14. A method of machining by spark erosion on a wire spark-erosion machine by means of a spark-erosion wire packaged on a spool including an RFID tag carrying identification data of said wire and associated with an onboard accelerometer on the RFID tag or on the spool, the method including: scrutinizing and storing, in the RFID tag, signals produced by the onboard accelerometer on the RFID tag or on the spool, computing, in the RFID tag, a number of turns effected by the spool about its axis as a function of acceleration signals received from the onboard accelerometer, and computing a quantity of wire remaining on the spool.

15. The method according to claim 14 of machining by spark erosion on a wire spark-erosion machine by means of a spark-erosion wire packaged on a spool including an RFID tag carrying identification data of said wire, said RFID tag been associated with onboard ambient temperature or humidity sensors on the RFID tag, the method including: scrutinizing and storing, in the RFID tag, signals produced by the onboard ambient temperature or humidity sensors on the RFID tag or on the spool.

16. The method according to claim 14 of machining by spark erosion on a wire spark-erosion machine by means of a spark-erosion wire packaged on a spool including an RFID tag carrying identification data of said wire, the method including: downloading, into the wire spark-erosion machine, identification data contained in the RFID tag, adapting machining parameters of the spark-erosion machine depending on identification data downloaded from the RFID tag of the spool used for the machining.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other aims, features and advantages of the present invention will emerge from the following description of particular embodiments given with reference to the appended figures, in which:

(2) FIG. 1 is a diagram showing a spark-erosion machine that is machining a part by means of a wire packaged on a spool according to one embodiment of the present invention;

(3) FIG. 2 is a diagram showing a passive RFID tag type identification data medium according to a first embodiment of the present invention communicating by radio with a data reader device associated with or implemented in a spark-erosion machine; and

(4) FIG. 3 is a diagram showing an active or semi-active RFID tag type identification data medium according to a second embodiment of the present invention communicating by radio with a data reader device associated with or implemented in a spark-erosion machine.

DESCRIPTION OF PREFERRED EMBODIMENTS

(5) Consider first of all FIG. 1, showing a wire spark-erosion machining device according to one embodiment of the present invention.

(6) Generally speaking, the machining device comprises a wire spark-erosion machine 1 in which there is a machining zone 2 filled with an appropriate liquid dielectric. The machining zone 2 is conformed and structured to receive and to hold a part 3 to be machined. A spark-erosion wire 4, packaged on a spool 5, is paid out from the spool 5 and passes over guides 6 of the spark-erosion machine 1 that hold it in position and drive it in longitudinal movement as shown by the arrow 7. The spark-erosion wire 4 passes through the machining zone 2, in which it is held in the vicinity of the part 3 to be machined.

(7) The wire spark-erosion machine 1 further includes an electrical current generator 8, connected between the spark-erosion wire 4 and the part 3 to be machined, to produce electrical arcs between the spark-erosion wire 4 and the part 3 to be machined.

(8) In operation, the electrical arcs cause wear of the spark-erosion wire 4 and of the part 3 to be machined. The continuous longitudinal movement 7 of the spark-erosion wire 4 in the machining zone 2 makes it possible to prevent rupture of the spark-erosion wire 4 because of the wear caused by the electrical arcs on the wire. On the other hand, the wear caused on the part 3 by the electrical arcs constitutes a removal of material that makes it possible, by progressive relative movement of the spark-erosion wire 4 toward the part 3, for example as shown by the arrow 9, to make a cut 10 on the part 3 to be machined.

(9) In the machining zone 2, the spark-erosion wire 4 must be tensioned by longitudinal mechanical traction effected by the guides 6, in order to preserve a defined and stable geometrical position that guarantees good geometry of the cut 10 made on the part 3 to be machined.

(10) At the start of machining, it is necessary to introduce the free end of the spark-erosion wire 4 into the guides 6 and into the machining zone 2. Generally speaking, the spark-erosion machine 1 comprises a sequence of operations providing automatic introduction of the wire. However, this necessitates that the spark-erosion wire 4 has satisfactory properties of straightness and stiffness so that its free end can be guided when the guides 6 hold the wire only by intermediate sections away from the free end of the wire.

(11) According to the invention, the machining device further comprises a device for identifying the spark-erosion wire 4 packaged on the spool 5.

(12) This identification device comprises in particular an identification data medium 11 fastened to the spool 5 and identification data 12 of the wire carried by the identification data medium 11.

(13) The identification data medium 11 cooperates with a data reader device 13 associated with the wire spark-erosion machine 1, via a wireless link 100 enabling communication between the identification data medium 11 and the data reader device 13.

(14) FIGS. 2 and 3 show, by way of example, two embodiments of the identification device according to the invention.

(15) In FIG. 2, the identification data medium 11 is a passive RFID tag, comprising an antenna 11a, a power supply circuit 11b able to use some of the electrical energy captured by the antenna 11a to generate a power supply voltage powering the other electronic circuits of the RFID tag. A processor electronic circuit 11c receives the request electronic signals 14c captured by the antenna 11a, communicates with a storage circuit 11d containing the identification data 12, and, as a function of the request electronic signals 14c, generates response electronic signals 14d that it transmits via the antenna 11a. For example, on reception of request electronic signals 14c requesting the communication of an identification, the passive RFID tag returns response signals 14d containing said identification extracted from the identification data 12 of the wire.

(16) In this case, the data reader device 13 is an active device, emitting radio frequencies that enable remote activation of the RFID tag 11. It comprises an antenna 13d and an electronic circuit 13e enabling on the one hand generation of the request signals 14c to be transmitted via the antenna 13d to the RFID tag 11 and on the other hand to process the response signals 14d received from the RFID tag 11 and captured by the antenna 13d. The wireless link 100 is a radio link.

(17) One RFID tag and data reader device embodiment is described in the document U.S. Pat. No. 4,724,427.

(18) In FIG. 3 the identification data medium 11 is an active or semi-active RFID tag, in which there are found again the principal elements of the FIG. 2 embodiment, and in particular: an antenna 11a, a power supply circuit 11b, a processor electronic circuit 11c, a storage circuit 11d, having the same functions as those of the FIG. 2 embodiment. In FIG. 3, the identification data medium 11 further comprises an onboard electrical power supply able to supply electrical energy to the processor electronic circuit 11c and the storage electronic circuit 11d instead of or in addition to the electrical energy captured by the antenna 11a.

(19) In this case, the identification data medium 11 further comprises onboard sensors, for example four onboard sensors 16a, 16b, 16c, 16d respectively supplying to the processor electronic circuit 11c signals imaging the acceleration of the carrying the wire 4 and the identification data medium 11, signals imaging the ambient temperature, signals imaging the ambient relative humidity, signals imaging the weight of the spool 5.

(20) The processor electronic circuit 11c is controlled by a program including a storage sequence for scrutinizing and storing, in the storage circuit 11d, the signals produced by the onboard sensors 16a, 16b, 16c and 16d.

(21) The program of the processor electronic circuit 11c can advantageously include a number of revolutions computation sequence, for computing the number of revolutions of the spool 5 around its axis as a function of the signals imaging the accelerations of the spool 5, those signals being received from an accelerometer type onboard sensor 16a.

(22) In this FIG. 3 embodiment, the data reader device 13 is also an active device emitting radio frequencies that where applicable make it possible to activate remotely the RFID tag 11, and comprising an antenna 13d and an electronic circuit 13e for on the one hand generating request signals 14c sent to the RFID tag 11 and on the other hand processing the response signals 14d received from the RFID tag 11 and captured by the antenna 13d. The wireless link 100 is a radio link.

(23) Referring again to FIG. 1, the control circuit 17 of the spark-erosion machine 1 includes a computer program.

(24) The computer program of the control circuit 17 of the spark-erosion machine 1 comprises at least one acquisition sequence for generating and storing on the fly by way of identification data 12, in the identification data medium 11, historical data chosen from the group consisting of use historical data describing conditions of use of the spark-erosion wire 4 carried by the spool 5 and stress historical data describing physical stresses to which the spark-erosion wire 4 carried by the spool 5 is subjected.

(25) The use historical data is in principle generated in the wire spark-erosion machine 1, and sent in the form of messages 14c to the identification data medium 11.

(26) The stress historical data is in principle generated by the sensors 16a, 16b, 16c and 16d associated with the identification data medium 11.

(27) The computer program of the control circuit 17 of the spark-erosion machine 1 comprises at least one sequence for downloading some or all of the identification data 12 carried by the identification data medium 11. The downloading sequence controls the data reader device 13 so that it generates request signals 14c and sends them no the identification data medium 11, which then sends back to it in the form of messages 14d some or all of the identification data 12 which, after reception by the data reader device 13, is introduced into the control circuit 17 of the spark-erosion machine 1.

(28) The computer program of the control circuit 17 of the spark-erosion machine 1 comprises at least one sequence for adaptation of the machining parameters, taking into account in particular identification data 12 coming from the identification data medium 11 of the spool 5 used for the machining. As a result, the device according no the invention enables automation of the adaptation of the spark-erosion parameters in the wire spark-erosion machine 1 as a function of the inherent capacities of the spark-erosion wire 4 used. For example, the adaptation sequence can modify or limit parameters comprising the mechanical tension in the spark-erosion wire 4 in the machining zone 2, the electrical current in the spark-erosion wire 4 in the machining zone 2, the speed of longitudinal movement 7 of the spark-erosion wire 4 in the machining zone 2, the agitation of the dielectric in the machining zone 2, the transverse movement 9 of the spark-erosion wire 4 in the machining zone 2.

(29) Additionally, the adaptation sequence can include a sequence for generation of alarms detectable by an operator, by which an alarm is generated when the machining conditions programmed by the operator conform to machining conditions stored in the identification data medium 11 and having previously caused defective machining using the same spark-erosion wire 4.

(30) The data relating to the spark-erosion wire 4 can be downloaded directly, merely by interrogation of the identification data medium 11 if the latter contains ail of the necessary data.

(31) Alternatively, the downloading of the data can be in part indirect, the downloading sequence then comprising the downloading of at least the identity of the manufacturer of the wire 4 and the number of the spool 5 by interrogation of the identification data support 11, and a sequence for automatic downloading of data relating to the spool 5 of wire 4 from a computer server of the manufacturer by interrogating the computer server of the manufacturer via the Internet using information on the identity of the manufacturer of the wire 4 and the serial number of the spool 5.

(32) In operation, the computer program of the spark erosion machine 1 therefore enables use of a wire spark-erosion machining method in which some or all of the identification data 12 of the wire 4 is downloaded from an identification data medium 11 carried by the spool 5 on which the spark-erosion wire 4 used for the machining method is packaged. The identification data 12 is, then used by the computer program of the spark erosion machine 1 to adapt the machining parameters taking account of the identification data 12.

(33) The present invention is not limited to the embodiments that have been explicitly described, but includes the various variants and generalizations thereof within the scope of the following claims.