FR2650972A1 - DIGITAL CONTROL DEVICE FOR ELECTROEROSION MACHINING - Google Patents

Abstract

The invention relates to numerical control techniques for machining machines. A digital control device for a wire EDM machining machine comprises in particular data processing means which read a control program to perform a multiple machining operation in a part, and switch means with keys having at least at least three different positions. The switching means make it possible to select either the full execution of the control program, or the partial execution of this program, limited to the rough machining instructions or to the finishing machining instructions. Application to machining by electroerosion.

Description

The present invention relates to a control device

  digital for- a wire EDM machine.

  In recent years it has become common practice in a numerically controlled wire EDM machine to perform multiple machining by restricting the machining energy and changing the offset value for your dimension. the wire-shaped electrode. With multiple machining, the duration of the machining process is reduced and the machining accuracy is improved. In these multiple machining processes, various machining systems can be appropriately selected,

  in accordance with the machining conditions. -

  For example, in the case where three holes, such as those shown in FIG. 1, must all be formed by multiple machining, it can be provided in certain cases that, because the periphery along which the machining is carried out is long in each of the holes (1), (2) and (3), the machining will take a long time, and the temperature will change during the machining. In such cases, a machining system is adopted in which, firstly, the holes (1), (2) and (3) are machined using a primary machining process (roughing machining process), and then a secondary machining process and a tertiary machining process (finishing machining process), for each of the configurations,

in a short time.

  On the other hand, in the case where the periphery along which the machining is carried out for each of the holes (1), (2) and (3) is short, and the distance between the holes is large, from the point of in view of the machining efficiency, we adopt a machining system

  in which the machining of each configuration is accomplished sequentially

  in one go, the rough machining process

  wise up to the finishing machining process.

  In this way, in multiple machining, one must approx.

  sage a different machining sequence, even to machine identical shapes, and the operator must appropriately change the CNC program to conform to the system

  machining. This places a significant burden on the operator.

  Given the drawbacks of such conventional systems

  It is an object of the invention to provide a digital control device which, by actuating keys, adapts to a variety of machining systems, such as a primary machining process for machining. roughing only, a secondary machining process and a tertiary machining process for finishing machining processes only, and a total machining process, including primary, secondary and tertiary machining processes, which accomplishes all the phases from the roughing machining phase to the finishing machining process. The invention achieves these aims by using a digital control device for a wire EDM machine, comprising: data processing means intended to read a control program containing a set of instructions , and to perform a multiple machining operation in a workpiece, this machining operation comprising a roughing machining step and a finishing machining step, the reading means producing control signals, and each of them corresponding to an instruction in the control program; and key switching means having at least three different positions, which respectively produce first, second and third selection signals in their first, second and third positions; and in which the data processing means receive the first, second and third selection signals, the digital control program is executed as it is loaded when the first selection signal is received, the finishing machining instructions are neglected when the second selection signal is received, and the roughing machining instructions are neglected When the

  third selection signal is received.

  The key switching means preferably comprise

  requires a TOTAL key to produce the first signal, a FIRST key to produce the second signal, and a RESUME key to

produce the third signal.

  Because of this configuration, in the case where a multiple machining must be carried out for a configuration comprising consecutively The primary machining process, the secondary machining process and the tertiary machining process, the TOTAL key which is part of the controller is selected; if only the primary machining process has to be completed, the FIRST key is selected; and, in the case where the secondary machining process and machining processes

  must be accomplished, the RESUME key is selected

  tioned. Thus, without changing the numerical control program, the operator can select various types of machining systems for multiple machining in order to comply with the machining conditions. These aims, characteristics and advantages of the invention

  will emerge more from the following description of modes of

  preferred embodiments, and with reference to the accompanying drawings in which: FIG. 1 is an explanatory drawing showing the case in

  which multiple machining is applied to multiple configurations.

  Figure 2 is a block diagram showing an embodiment of a digital control device according to the invention.

  Figure 3 is a diagram showing electrical paths

  trode for performing a multiple machining operation

  a set of hole patterns.

  Figure 4 illustrates the machining procedures for

  multiple machining of a configuration.

  Figures 5a, 5b and 5c show a program for

  digital control usable in the invention.

  Considering FIG. 2, it will be noted that an embodiment of the digital control device for the EDM machine according to the present invention comprises an input unit 10, a data processing unit 11, a

  TOTAL 12 key, FIRST 13 key and RESUME 14 key.

  A numerical control program such as that shown in FIGS. 5a, 5b and 5c is loaded into the input unit 10 to machine the configurations 16 and 17 which are

shown in Figure 3.

  In the numerical control program, the instructions going from block number N001 (hereinafter designated by 001) to block number N039 (which is designated by 039) are intended for machining the configuration 16, and the instructions from block number 040 to block number 066 are for machining

of configuration 17.

  The data processing unit 11 reads the program for

  above numerical control to process and execute it.

  The TOTAL key 12 sends a first signal to the data processing unit 11 to indicate that the digital control program must be executed as it is (that is to say that the digital control program must be executed without any

change).

  The FIRST key 13 emits a second signal to the data processing unit 11 to indicate that the numerical control program must be executed by neglecting the instructions relating to the finishing machining, such as those going from block 015 to block 037 , and from block 054 to block 064, in the program

numerical control above.

  The RESUME button 14 emits a third signal to the data processing unit 11 to indicate that the digital control program must be executed by neglecting the instructions relating to roughing machining, such as those which go from block 002 to block 013, and from block 041 to block 052 in the

  digital control program above.

  The data processing unit 15 receives one

  conquers instruction signals from any of the

  keys 12, 13, 14. When it receives the first instruction signal,

  tion coming from the TOTAL 12 task, it executes the instructions of the numerical control program in the 4-th block numbers, without neglecting any of the instructions. When it receives the second instruction signal from the FIRST key 13, it executes the instructions of the numerical control program while neglecting the instructions relating to the finishing machining, such as those which go from block 015 to block 037. , and block 054

  at block 064 in the above numerical control program.

  When it receives the instruction signal from the RESUME button 14, it executes the instructions of the control program

  disregarding instructions for machining rough sides

  weaving, such as those going from block 002 to block 013, and from block 041 to block 052 in the above numerical control program. In operation, if the TOTAL key is selected, the instructions of the numerical control program are executed in the order of the block numbers. Consequently, primary machining (rough machining), secondary machining (finishing machining) and tertiary machining (finishing machining)

  are performed consecutively for each configuration.

  In the case where the FIRST key 13 is selected, during the execution of the instructions of the numerical control program, once the automatic thread advance code (M-66) is read, the data processing immediately jumps to the block of the code M-100 which is closest to the block of the code M-66 and which follows it, the code M-100 being a code which indicates the end of the configuration data. By way of example, in the above digital control program, the processing of the data passes from block 014 to block 038 during the processing of the data for the machining of the first configuration 16, and from block 053 to block 065 during data processing for the machining of the second configuration 17. Consequently, the primary machining for the

  configurations 16 and 17 are performed consecutively.

  In the case where the RESUME button 14 is selected, during the execution of the instructions of the numerical control program, once the automatic thread advance code (M-64) is read, the execution of the program jumps to a block corresponding to another automatic thread advance code (M-66) which is closest to and follows the block of code M-66. For example, in the above digital control program, data processing jumps from block 001 to block 014 during processing of data for machining the first configuration 16, and from block 040 to block 053 during processing data for the machining of the second configuration 17. Finishing machining (that is to say secondary and tertiary machining for

  configurations 16 and 17) are therefore carried out consecutively.

  Now considering Figure 4, we see an organi-

  gram for machining a configuration that illustrates the sequence

  from machining procedures to a tertiary machining process.

  Firstly, in step 1 (hereinafter called S1), the TOTAL key (indicated by the mention "T key"), the FIRST key (indicated by the mention "P key") or the RESUME key ( indicated by the mention "R key") is selected. When the T key or the P key is selected, the program changes to S2, i.e.

  the primary machining process; when the R key is selected

  A check is made in S3 to determine whether the finishing machining process is indicated or not. If the finishing machining process is indicated, the program goes to S5, which corresponds to the secondary machining process. If the process

  finishing machining is not indicated, it is not executed.

  In the primary machining process in S2, the wire-shaped electrode is advanced automatically, as indicated by the dotted line, the conditions for offset and machining are set, and then, after the indication of the configuration to be machined, the machining process is accomplished in accordance with the configuration. Upon completion of the primary machining process, a check is made in S4 to determine whether the process

  primary machining only is necessary, and if the F key has been.

  selected, which means that only the machining process

  primary must be completed, the machining of this hole (or configura-

  tion) is completed. If the T key was selected, the program proceeds to the secondary machining process in S5. As previously indicated, if the R key was selected, the machining process also goes to S5, in which case it is considered that the

  primary machining process is complete.

  In the secondary machining process indicated in S5, the wire-shaped electrode is advanced automatically, as in the primary machining process. Then, after the offset and machining conditions have been changed automatically to conform to the secondary machining process, the process is

  accomplished in accordance with the defined configuration (the same configuration

  ration than in the primary machining process). After completion

  ment of the secondary machining process, the program switches to the tertiary machining process in S6. In the tertiary machining process, the wire-shaped electrode is advanced automatically, as in the primary and secondary machining processes. Then, after the shift and machining conditions have been changed automatically to conform to the tertiary machining process, the process is completed according to the defined configuration

  (the same configuration as in the primary machining process).

  When the tertiary machining process has been completed, the procedures

hard machining are finished.

  As indicated above, when the FIRST key has been selected and when the primary machining process is finished, the machining of the hole considered is finished. However, in the case where the primary machining process of another configuration remains to be performed, the program proceeds to this machining process. In addition, if the restore key is selected, the program proceeds to machining another configuration, as indicated above. As the preceding explanation makes it clear, the digital control device for an electroerosion machining machine according to the invention can be adapted to a variety of machining systems, by actuating keys, these systems corresponding to machining comprising only a primary machining process (rough machining), machining comprising only a secondary machining process and a tertiary machining process (finishing machining process), and sequential machining including primary, secondary and tertiary machining processes, etc. In addition, since it is useless to make changes in a conventional program, one can obtain a very fast operation and the problem of errors in

  the program change is eliminated.

  It goes without saying that numerous modifications can be made to the device and to the process described and represented, without

depart from the scope of the invention.

Claims (3)

  1. Numerical control device for a wire EDM machine, characterized in that it comprises: data processing means (11) which read a control program comprising a set of instructions, to accomplish a multiple machining operation in a workpiece,   the machining operation comprising a rough machining step.   wise and a finishing machining step, and the processing means   data (11) producing control signals which correspond respectively to instructions in the control program; and key means (12, 13, 14) having at least three different positions, the first, second and third positions of these means respectively producing first, second and third selection signals; and in that the data processing means (11) receives the first, second and third selection signals, and, when the first selection signal is received, the digital control program is executed as it is, when the second selection signal   is received, finishing machining instructions are neglected.   and, when the third selection signal is received, the   roughing machining instructions are neglected.   2. Numerical control device for a wire EDM machine, characterized in that it comprises: data processing means (11) intended to read a control program containing a set of instructions, and to be carried out a multiple machining operation in a workpiece,   this machining operation comprising a step of machining rough sides   weaving and a finishing machining step, and the reading means (11) producing control signals each corresponding to an instruction in the control program; and key switching means (12, 13, 14) having at least three different positions, no signal being produced in the first position of these means, while first and second selection signals are produced respectively in the second and third positions; and in that the data processing means (11) receives the first selection signal or the second selection signal from the key switching means, so as to disregard roughing machining instructions or machining instructions finishing, in accordance with the signal from the switching means, the finishing machining instructions being neglected when the first selection signal is received, while the roughing machining instructions are neglected when the second selection signal is received ; whereby, in the case where a control program is introduced to perform a multiple machining operation relating to a set of configurations in a workpiece, when the first position is selected in the key switching means (12, 13, 14), the roughing and finishing machining of all the configurations are carried out, when the second position is selected in the key switching means (12, 13, 14), only the machining roughing of all the configurations is carried out, and, When the third position is - selected in the key switching means (12, 13, 14), only the finishing machining of all the configurations is performed.   3. Device according to claim 2, characterized in that the key switching means (12, 13, 14) comprise at least two switch keys, the first emitting said first selection signal, and the second emitting said second selection signal.