JPS63174105A - Control method for safety of automatic machine tool - Google Patents

Abstract

PURPOSE:To heighten the safety of an operator, by comparing an n-th execution time Tn with an execution time T1 processed and stored at a first execution time, outputting an alarm when it is Tn>T1, and stopping a machine tool. CONSTITUTION:A first process is performed with punch press by turning ON the timer of a watchdog timer part 11 when an NC device 5 is set at a tape memory mode. At an arithmetic processing part 17, the first execution time T1 is compared with a fixed value (alpha), and when it is T1>alpha, a stop signal is sent to the NC device 5 by outputting the alarm, which stops a press 1. When it is not T1>alpha, the timer 11 is turned OFF, and also, the first timer value T1 is stored in a memory 15. Next, a second execution time T2 is fetched and compared, and when it is T2>T1, the alarm is outputted, which stops the press 1. When it is not T2>T1, the timer value T1 is canceled, and an operation advances to the next process, then, the n-times of processes are performed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a method for controlling the safety of an automatic machine tool, and more specifically, to a method for controlling the safety of an automatic machine tool that improves worker safety. Concerning safety control methods.

(Prior Art) Generally, automatic machine tools perform sequential operations by transmitting the completion of one operation to the numerical control equipment and proceeding to the next sequence operation.

Conventionally, when detecting abnormalities in operating conditions using this method, it is usually done by assuming a time that cannot actually occur due to the nature of the machine tool.
The estimated time To is set with a timer, the actual machining time Ti is compared with the estimated time To, and when Ti>To, an abnormality is determined and an alarm signal is issued to stop the machine tool.

(Problems to be Solved by the Invention) However, in the conventional safety II+ control method described above, the assumed time is unreasonable, and there are cases where it is completely meaningless under conditions where the driving time is short. Additionally, if things go wrong for some reason, there will be a stoppage, and with conventional methods, it is not possible to discover the cause of this stoppage, and the safety of the 2028 system has not yet been improved. It is.

The purpose of the present invention is to improve the above-mentioned problems by using it during actual machining, to help investigate the cause of stopped parts when things go wrong for some reason, and to improve worker safety. The object of the present invention is to provide a safe control method for automatic machine tools.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention has an objective of achieving the above-mentioned object. Execution time T stored after processing the first execution time Tn to the first or (n-1) time
1 or Tn −1, Tn>T+ or T
In the case of n-1, an alarm is output and the machine tool is stopped to constitute a safety control method for an automatic machine tool.

(Function) By adopting the automatic machine tool safety control method of the present invention, safety suitable for actual machining can be achieved. moreover,
When an abnormality is detected, it helps in investigating the cause, and the cause can be found more easily than in the past.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

Referring to FIG. 1, an NC device 5 is connected to, for example, a punch press 1 as an automatic machine tool via a sequencer 3. As shown in FIG. The NC device 5 has a built-in NC program for driving and controlling the punch press 1, and its NO.
The sequencer 3 is operated by the Canadian program. This sequencer 3 includes an M code decoding section 7. M
Code processing section 9. Watchdog timer section 11 and fixed value position memory 13 of the timer section 11. Store value memory 15. It has a built-in arithmetic processing section 17.

The sequence operation that operates this sequencer 3 includes:
In addition to functions called MF (auxiliary functions) such as nibbling operation, workpiece unloading operation, and program end, there is also a TFBm function that rotates the turret.

Additionally, external operation functions EF such as a PFi function for starting the press and an optional tapping operation are provided.

To explain the MF (auxiliary function) among these various operations as an example, in FIG.
9 is input to the M code decoding section 7 of the sequencer 3. Output signals from the M code decoding section 7h1 and others enter the M code processing section 9 and are sent to the punch breath 1 as a mechanical control signal 21.

At the same time, the output signal from the M code decoding section 7 is input to the watchdog timer section 11 to start the timer.

For example, when the punch press 1 completes a nibbling operation based on the mechanical control signal 21, a mechanical completion signal 23 is sent to the NC as an auxiliary completion signal 25 via the M code processing section 9.
At the same time as being sent to the device 5, the mechanical completion signal 23 is also sent to the watchdog timer section 11, and the execution time T1 is taken into the wA calculation processing section 17. A fixed value memory 13 of the watchdog timer unit 11 stores in advance a fixed time α for comparing the first execution time of machining.

The fixed time α stored in the fixed value memory 13 is taken into the arithmetic processing unit 17, and a judgment process is performed to determine whether T+>α. If TI>α, it is output as an alarm and a stop signal 27 is sent from the arithmetic processing section 17 to the NC device H5 to stop the punch press 1. If T+ > α, the first execution time T1 is stored in the store value memory 15 and the operation is continued, the second machining is started, and the above-described operation is performed.

Then, the second mechanical completion signal 23 is sent to the watchdog timer section 11, and the second execution time T2 is taken into the arithmetic processing section 17. The first execution time T1 stored in the store value memory 15 is taken into the arithmetic processing unit 17, and a judgment process is performed to determine whether T2>TI. In this judgment process, if T2 > TI, an alarm is output and a stop signal 27 is sent to the NC from the arithmetic processing unit 17.
The punch press 1 is sent to the device 5 and stopped. T2 > T
If not +, the second execution time T2 is stored in value memory 1.
5, and the first execution time T that was stored last time
1 is canceled and the same product program continues to be executed until the Nth operation is completed while being checked.

In this way, the store value memory 15 in the watchdog timer section 11 stores the previous execution time Tn-1, and the arithmetic processing section 17 stores the current execution time Tn.
and the previous execution time Tn-1, l'-n > T
If n -1, it is output as an alarm and sent to the NC device 5 to stop the punch press 1. the result,
Reasonable safety control suitable for actual machining is performed, and even if an alarm is output and the punch press 1 stops, the cause can be easily investigated.

In the above operation, the previous execution time Tn-1 is stored in the store value memory 15, and the execution time 7'n-1 and the current execution time Tn are compared in the arithmetic processing section 17. This can be handled by storing the first execution time T1 in the store value memory 1, and comparing the execution time T1 with the current execution time Tn in the arithmetic processing 117.

Next, the operation of this embodiment will be explained based on the flowchart shown in FIG.

In FIG. 2, first, at step 101, it is determined whether or not the tape memory mode is set, and if the tape memory mode is not set, the process ends without execution. If the tape memory mode is selected, the process proceeds to step 103, where it is determined whether or not to perform the first processing. In this case, since it is the first machining, the watchdog timer section 1 is set at the 105th stage.
Turn on timer 1. At the 107th stage, the first machining is performed by the pan de press 1, and the arithmetic processing unit 17 compares the first execution time T1 with the fixed value α, and if TI>α, an alarm is output at the 109th stage. , sends a stop signal to NCH station 5, stops pande press 1, and ends the process.

If TI>α, it is determined whether M2O<program end) at stage 111, and if it is not the program end, the process returns to the front of stage 107, and if it is the program end, it advances to stage 113 and the watchdog The timer 11 is turned off, and the first timer value T1 is stored in the store value memory 1 at the 115th stage. Next, it is determined in step 117 whether or not the machining is complete, and if it is determined that the machining has been completed, the process ends at that point. In this case, processing is to be performed N times, so the 103rd
Returning to the front of the stage, it is determined at the 103rd stage whether or not it is the first machining.

Since this is not the first machining, the process proceeds to step 119, where the machining is continued with the Pande Press 1 and the timer of the watchdog timer unit 11 is turned on. At the 121st stage, for example, the second execution time T2 is taken into the arithmetic processing unit 17, and T
A process is performed to determine whether 2>TI. If T2 > TI, an alarm is output at the 109th stage and sent to the NCB device to stop the punch press 1.

If T2 > TI, it is determined whether it is M2O (program end) at the 123rd stage, and if it is not M2O, the process returns to the front of the 121st stage, and if it is M2O (program end), it proceeds to the 113th stage, The timer of the watchdog timer section 11 is turned off, the timer value is stored in the store value memory 15 in the 115th stage, and the previous timer value TI is
cancel. At step 117, it is determined whether or not the process has ended, and if it is determined that the process has ended, the process ends at that point. If the machining is to be performed N times, it is determined that the machining has not been completed, and the process returns to the stage 103, and the process described above is repeated until the N machining is completed.

Note that the present invention is not limited to the above-described embodiments, but can be implemented in other embodiments by making appropriate changes. For example, although the description has been given using a punch press as an example, it is also applicable to press brakes and other machine tools.

[Effect of the invention] As can be understood from the description of the embodiments above, when processing is repeated N times using the same product program, the n-th execution time Tn is the first or (n-1)th execution time. The timer section compares the time T1 or Tn-1 and Tn
＞TI or Tn＞Tn-1, an alarm is output and the machine is stopped, so it is possible to perform reasonable safety control that matches the actual machining, and the safety of workers is improved compared to conventional methods. This has the effect of further improving the performance.

Furthermore, alarm inspection during repeated processing can be carried out effectively.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention;
FIG. 2 is a flowchart explaining the operation of this embodiment. (Explanation of symbols representing main parts of drawings) 1... Punch breath 3... Sequencer 5... NC device
5...M code decoding section 9...M code processing section 11...Watchdog timer section 15...Store value memory 17...Multiple processing section Agent Patent attorney Yasuo Miyoshi Figure 2

Claims (1)

[Claims] When machining is repeated N times with the same product program of the NC device that drives and controls the machine tool, the n-th execution time T
Compare n with execution time T_1 or Tn-1 stored after processing the first time or (n-1) time, and calculate Tn
>T_1 or Tn>Tn-1, an alarm is output and the machine tool is stopped.