JPH0356859B2 - - Google Patents

Description

[Detailed description of the invention]

(Technical Field of the Invention) The present invention relates to a method for controlling skip operation when a tool abnormality is detected in a numerically controlled machine tool having a device for detecting tool abnormality. (Technical background of the invention and its problems) In a numerically controlled tool machine equipped with a tool abnormality detection device, when a tool abnormality is detected such as a tool breaking or the tool reaching the end of its life, conventionally the abnormality is detected. Methods such as stopping machining or preparing a spare tool in a tool storage magazine in advance and switching to that spare tool have been used. However, when using the former method, it is necessary to immediately stop machining when a tool abnormality is detected, and when using the latter method, it is necessary to prepare a spare tool in the tool storage magazine in advance. When there is not enough time, or when there is no spare tool for a special tool, machining must be interrupted, and in both cases machining cannot be continued. (Purpose of the Invention) This invention was made in view of the above-mentioned circumstances, and when a tool abnormality is detected, it is possible to prevent the abnormality from occurring during machining using the tool in which the abnormality was detected or during machining using a tool with a lower machining order than the abnormal tool. The object of the present invention is to provide a skip operation control method that allows machining to continue even after a tool abnormality is detected by performing empty cutting with a plugged tool or an empty tool instead of the commanded tool and performing skip operation. It is said that (Summary of the Invention) The present invention relates to a skip operation control method in a numerically controlled machine tool having a device for detecting tool abnormalities. During machining with a tool in which an abnormality has been detected, or when machining with a tool that belongs to the same machining group as the abnormal tool and has a lower machining order, perform dry cutting with a plugged tool or an empty tool instead of the commanded tool. By performing skip operation, machining can be continued without interruption. (Embodiment of the Invention) Fig. 1 is a schematic configuration diagram of a skip operation control device for a numerically controlled machine tool to which the control method of the present invention is applied. By inputting the tool abnormality detection signal DAN to the gate 11, the tool number ATn at the time the abnormality was detected is stored in the memory 2 via the gate 11. TNN and GN are the command value signals read from the tape reader or operation panel, where TNN is the tool number and GN
Each indicates the machining group number to which the tool belongs. The command value TNN of the tool number ATn is input to the discrimination circuit 3, the gate 13, and the comparison circuit 7, and the discrimination circuit 3 checks whether the tool number ATn in which an abnormality has been detected is stored in the memory 2. The inspection result SKIPA is input to the NOT circuit 15 and the OR circuit 17 included in the tool changeover circuit 8, and the output of the NOT circuit 15 is input to the gate 14. In addition, the machining group number GN to which the tool indicated by the tool number ATn belongs is input to the gate 14, and the output of the NOT circuit 15 is
When it is ON, it is input to the memory read circuit 5. The memory 4 stores tool numbers TN1,..., TNn belonging to the machining group corresponding to each machining group number, and the memory readout circuit 5 stores the tool numbers TN1,..., TNn belonging to the machining group in correspondence with the machining group number. The tool numbers TN1, . . . , TNn belonging to are read out and sent to the discrimination circuit 6. The abnormal tool number is extracted from the tool numbers TN1, ..., TNn by the discrimination circuit 6 with reference to the memory 2, and is inputted to the comparison circuit 7, where it is compared with the tool number TNN, and the comparison result is SKIP- B is input to the OR gate 17. Furthermore, the memory 4 stores a plugging tool number (empty tool number) TD, and this plugging tool number TD is read out and inputted to the gate 12.
The output of the OR gate 17 is input to the gate 12 and the NOT circuit 16, and the output of the NOT circuit 16 is input to the gate 13. OR circuit 17, NOT circuit 1
6. A circuit including gates 12 and 13 is a tool changeover circuit 8, which outputs a plugging tool number (empty tool number) TD or a tool number TNN. A method for controlling skip operation of a numerically controlled machine tool in such a configuration will be explained with reference to the following drawings. First, before starting the machine tool, the machining group number GN and related related tools belonging to that group are arranged in order of highest machining order, that is, in the order of machining steps, and input into the memory 4, and are stored for each machining group. Also, the plugging tool number (empty tool number) TD is similarly registered in the memory 4. When the machine tool is started in this state, a numerical control device (not shown) generates a tool number TNN and a machining group number GN to which the tool belongs, and input them to the discrimination circuit 3 and gate 14, respectively. Here, if all the tools are normal, the abnormality detection circuit 1 does not output the abnormality detection signal DAN, so the gate 11 remains closed, and the tool number
Since ATn is not stored in memory 2, the contents of memory 2 remain empty. Also, since there is no tool number in memory 2 that matches the input tool number TNN, discrimination circuit 3 sets SKIPA="0". Output. NOT circuit 15 is set by SKIP-A="0"
Outputs SKIPA="1", which causes gate 14
is opened, and the input machining group number GN is input to the memory readout circuit 5. However, no matter what tool number the memory read circuit 5 reads, the discrimination circuit 6 does not output the tool number because the memory 2 is empty. Therefore, the comparator circuit 7 makes SKIPB=
“0” is output, and SKIPA+ is output from OR circuit 17.
Since SKIPB="0" is output, gate 12 is closed and gate 13 is opened. Therefore, the tool number TNN is output from the tool change circuit 8, the plugged tool number (empty tool number) TD is not output, and the commanded tool number TNN itself is selected and normal machining proceeds with that tool. It will be done. On the other hand, if an abnormality occurs in the tool, the abnormality signal TAB
is input to the tool abnormality detection circuit 1, and since the abnormality detection signal DAN is detected from the abnormality detection circuit 1, the tool number ATn of the abnormal tool is stored in the memory 2 through the gate 11. The tool number ATn of the tool in which the abnormality was detected in this way is stored in memory 2.
If the input tool number TNN is stored in the memory 2, the discrimination circuit 3
SKIPA becomes “1”, and SKIPA becomes “1” by OR circuit 17.
+SKIPB="1", gate 12 opens, and gate 13 closes. Therefore, the tool change circuit 8 outputs the plugging tool number (empty tool number) TD, and a skip operation is performed using the plugging tool or the empty tool. On the other hand, when the input tool number TNN does not exist in the memory 2, the output SKIPA of the discrimination circuit 3 becomes "0", the output of the NOT circuit 15 becomes "1", and the gate 14 is opened. Then, the machining group number GN is input to the memory readout circuit 5. The memory reading circuit 5 reads out the tool numbers TN1, . Discrimination circuit 6 is tool number TN1,
..., Check whether TNn exists in memory 2 in the order in which it was sent, and select the first tool number that exists.
Send TNm to comparison circuit 7. The comparison circuit 7 compares the machining order of tool number TNN and the machining order of tool number TNm, and sets SKIPB="1" if the machining order of tool number TNN is lower. in this case,
The output of the OR circuit 17 becomes SKIPA+SKIPB="1", the plugging tool number TD is output, and a skip operation is performed. Also, if the machining order of tool number TNN is higher, SKIPA + SKIPB
= "0", the tool number TNN is output, and normal machining can proceed. The skip operation is controlled in the above manner, and the control of the skip operation will be specifically explained using the tap hole machining process as an example. The process for drilling tapped holes is as follows. T1 (center fir) → T2 (prepared hole drilled) → T5
(Chamfering hole) → T7 (tap) First, before starting the machine tool, based on the above machining process, arrange the related tools as machining group G1 in the order of the highest machining order, that is, in the machining process order, and then store them in memory 4. Enter as follows. Machining group G1; T1, T2, T5, T7 Figure 2 shows an outline of the machining program in this example. First, T1 and G1 indicate the tool number T1 to be used in the next machining and the machining group number G1 of that tool. is instructed, and the tool instructed by tool change command MO6 is installed. After installing the tool,
Immediately, the tool number T2 and machining group number G1 to be used in the next machining are instructed, and then the program for the center fir, which is the first machining, is executed. After the center fir program ends, the tool number T2 that was previously instructed by tool change command MO6
The tool is installed, and after installation, the tool number T5 and machining group number G1 are used in the next machining.
is instructed. After this, a program for drilling the pilot hole is executed, and after this program is finished, a tool change command is issued.
Tool number T5 that was previously specified by MO6
tools are installed. Furthermore, the program includes instructions for tool number T7 and machining group number G1, execution of a chamfering program, tool change command MO6, and execution of a tap machining program. For example, assume that an abnormality is detected in the tool with tool number T2, which is used in the process of drilling a pilot hole, and the abnormality is stored in the memory 2 as an abnormal tool. In this case, if tool number T5 is specified, even if this tool T5 does not have a tool abnormality, the tool with the higher machining order, tool number T2, has a tool abnormality.
A skip operation instruction signal is generated. As a result, a plugging tool (empty tool) TD is prepared in place of tool number T5. Therefore, when the tool exchange command MO6 is issued next, the plugging tool (empty tool) is attached and the chamfering drill program is executed, which is the same as if the program had been skipped. When an abnormal tool number is detected and stored in this way, a skip operation is performed during machining using a tool lower in machining order than the abnormal tool, as shown in FIG. 3, for example. Incidentally, in the above explanation, the skip operation is controlled by wire logic, but it is also possible to control this by software control by a microcomputer. FIG. 4 is a schematic configuration diagram of a control system that controls skip operation by the microcomputer 20. Tool abnormality is detected by the tool abnormality detection circuit 1 in the same manner as described above, and the tool abnormality detection signal DAN is transmitted to the microcomputer 20. 20, the microcomputer 2
Interrupts 0. By being interrupted, the microcomputer 20 reads and stores the tool number ATn in which the abnormality has been detected. The tool number TNN and machining group number GN are command value signals read from a tape reader or operation panel, and when these are input, the microcomputer 20 executes the software based on the memory of the tool number ATn in which the abnormality was detected. Calculations are performed based on the wear, and the plugging tool number (empty tool number)) TD or tool number TNN
The operation will be explained with reference to the flowchart of FIG. First, before starting the machine tool, the machining group number GN and related tools belonging to that group are arranged in the highest machining order and input into a storage device (not shown) in the microcomputer. Also, the plugging tool number (empty tool number) TD is similarly set in the storage device within the microcomputer. When the machine tool is started in this way, the numerical control device (not shown)
As a result, the tool number TNN and the machining group number GN to which the tool belongs are generated and input to the microcomputer 20. (Step S1). next,
Microcomputer 20 is the processing group number
From GN, the number of the related tool belonging to that group.
TN1, . . . , TNn are extracted from the stored data in the order of their processing order (step S2). On the other hand, when the abnormality detection circuit 1 outputs the abnormality detection signal DAN, an interrupt routine is started, and in the interrupt routine, the abnormality detection signal DAN is first checked to confirm that it is turned ON. If the abnormality detection signal DAN is ON, the abnormal tool number ATn is read and stored in the storage device in the microcomputer 20, and the process returns from the interrupt routine. The tool number of the tool in which the abnormality was detected is thus stored in the storage device. In the main routine, the related tool numbers TN1,...,TNn of the group number GN are compared with the number of the tool in which the abnormality was detected stored in the storage device, and the tool in which the abnormality was detected is selected from among TN1,...,TNn. Extract (step S3). Next, if the tool in which the abnormality was detected is not extracted, the tool with a higher machining order is set as TNm, and if it is extracted, the tool is set as TNm (step S4).
Compare tool numbers TNN and TNm, TNN>TN
In the case of m, the tool number TNN is output, but the plugged tool number (empty tool number) TD is not output, so that normal machining can proceed with the tool. Also, TNN≦
In case of TNm, plug tool number (empty tool number)
TD is output and skip operation is performed using a plugging tool or an empty tool. As described above, the microcomputer 20 can realize a function equivalent to the wire logic described above. In the above configuration, a skip operation control device is provided separately from the control device of the numerically controlled machine tool. However, if the control device of the machine tool is constituted by a microcomputer, the skip operation control function may be provided by incorporating the skip operation control routine described above into the software of the control device. (Effects of the Invention) As described above, according to the present invention, when an abnormality is detected in a tool, the tool in which the abnormality was detected and the tool that belongs to the same machining group as that tool and has a lower machining order than that tool, , execute skip operation. Therefore, even after an abnormality is detected, machining can be continued without interruption.
A machining process unrelated to a machining process using a tool in which an abnormality has been detected can be continued normally. Therefore, the effect is particularly great during unmanned operation.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the skip operation control device.
FIG. 2 is a schematic diagram of a machining program for a numerically controlled machine tool to which the present invention is applied; FIG. 3 is a diagram showing the relationship between abnormal tool numbers and tool numbers that result in skip operation;
FIG. 4 is a schematic configuration diagram of a skip operation control device using a microcomputer, and FIG. 5 is a flowchart of skip operation control using a microcomputer. 1... Abnormality detection circuit, 2, 4... Memory, 3, 6...
Discrimination circuit, 5...Memory reading circuit, 7...Comparison circuit,
8... Tool change circuit, 20... Microcomputer.

Claims (1)

[Scope of Claims] 1. In a numerically controlled machine tool equipped with a device for detecting tool abnormalities, when a tool abnormality due to tool breakage or tool life is detected, when the tool in which the abnormality is detected is used during machining. Numerical control machining characterized in that machining can be continued without interruption by performing a skip operation in which dry cutting is performed using a plugged tool or an empty tool instead of the commanded tool. Skip operation control method in machinery. 2. In a numerically controlled machine tool equipped with a tool abnormality detection device, when a tool abnormality due to tool breakage or tool life is detected, a tool that belongs to the same machining group as the abnormal tool and has a lower machining order The present invention is characterized in that during machining, machining can be continued without interruption by performing a skip operation in which idle cutting is performed using a plugged tool or an empty tool instead of the commanded tool. Skip operation control method for numerically controlled machine tools.