Numerical controller

Abstract

A numerical controller (10) is provided with a program storage unit (16), a display device (21), an automatic operation control unit (13), a pause processing unit (12), a program operation unit (15), an automatic operation monitoring unit (14), and the like. The automatic operation monitoring unit (14) monitors the execution state of the automatic operation control unit (13), when the execution of the NC program is restarted after the execution of the NC program is suspended by the suspension processing unit (12), the automatic operation monitoring unit (14) confirms whether or not a restart block including a character specified by the program operation unit (15) before restart is a predetermined restart block, and if the restart block is a restart block, the automatic operation monitoring unit (14) stops the execution state of the automatic operation control unit (13). When the block is a resume block, the processing from the resume block in the automatic operation control unit (13) is resumed, and when the block is not a resume block, the processing is stopped.

Description

Technical Field

[0001] The present invention relates to a numerical control device for numerically controlling a motion mechanism of a machine tool. Background Art

[0002] The numerical control device of a machine tool is configured to numerically control a motion mechanism portion of the machine tool by executing an NC program created for machining.

[0003] As for such NC programs, almost all the programs created initially have room for improvement, and usually, they are changed to more appropriate tool paths or processing conditions proved by trial processing or subsequent operation. At this time, as for the NC programs stored in the numerical control device, the contents are modified (edited) by the program editing function provided in the numerical control device under the operation performed by the operator.

[0004] Furthermore, for example, during trial machining, if an error in the tool path is found or if machining conditions need to be reset, the NC program is corrected as needed, and then machining is restarted from the corrected machining portion. In this case, the operator needs to restart machining from an appropriate portion of the NC program, but if machining is restarted from an inappropriate portion due to operator negligence, for example, serious problems such as interference between the tool and the workpiece may occur.

[0005] Therefore, a midway start method disclosed in, for example, Japanese Patent Publication No. 5-158518 (reference document 1 below) has been proposed. The midway start method is configured to select a specific block from the blocks constituting the machining program (NC program) as a midway start block, and execute the machining program from the midway start block. Then, when the midway start block is selected, a tool instruction block describing a tool exchange instruction is extracted from the machining program, and the tool number or tool offset number indicated in the extracted tool instruction block is displayed for each tool instruction block. Thereafter, a specific tool number or a specific tool offset number is selected from the displayed tool numbers or tool offset numbers, thereby selecting a tool instruction block indicating the selected specific tool number or specific tool offset number as the midway start block.

[0006] According to this previous midway start method, it is possible to select the tool number or tool offset number of the tool used in the processing step to be processed from the tool number or tool offset number displayed on the screen using the cursor keys, and perform midway start from the tool instruction block indicating the selected tool number or tool offset number, that is, the starting block of the processing step to be processed.

[0007] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Laid-Open No. 5-158518 Summary of the invention Problems to be solved by the invention However, the above-mentioned conventional midway start method has the following problems. That is, in the above-mentioned conventional midway start method, when restarting processing from the middle of a processing program, the following processing needs to be performed: 1) extracting a tool instruction block describing a tool exchange instruction from the processing program, 2) displaying a tool number or a tool offset number indicated in the extracted tool instruction block for each tool instruction block, and then, 3) selecting a specific tool number or a specific tool offset number from the displayed tool number or tool offset number. Not only is the processing in the control device for midway start excessive, but there is also a problem that the operator must be familiar with the tools used in each processing step.

[0008] Some operators who operate machine tools are not fully familiar with machining processes. Such operators may not be able to select a correct tool when resuming machining after pausing machining and operating the machining program.

[0009] On the other hand, an operator who is not sufficiently familiar with the machining process can operate the machining program after pausing the machining and putting the control device into the editing mode of the machining program. Thereafter, as long as it is possible to determine whether the machining should be restarted, for example, whether the machining program block executed when the machining was paused is a block that can be restarted, without relying on the operator's judgment, interference between the tool and the workpiece can be reliably avoided, which is beneficial.

[0010] The present invention has been created in view of the above actual situation, and an object of the present invention is to provide a numerical control device that can reliably avoid interference between a tool and a workpiece even when an operator who is not fully familiar with the machining process restarts the machining operation.

[0011] Technical solutions to solve problems The present invention for solving the above-mentioned problems is a numerical control device for numerically controlling a motion mechanism of a machine tool, comprising: a program storage unit storing an NC program composed of a plurality of blocks describing NC codes; A display device that at least displays the NC program in characters; an automatic operation control unit that executes the NC program stored in the program storage unit under numerical control to operate the motion mechanism unit; a pause processing unit, which, when the automatic operation control unit executes the NC program, resumes the execution of the NC program after pausing the execution of the NC program; A program operation unit, when the processing of the automatic operation control unit is suspended by the suspension processing unit, for the NC program being executed and displayed on the display device, the program operation unit can operate the character display on the display device in a state of specifying the displayed characters, or can edit the NC program, wherein: An automatic operation monitoring unit is provided, which monitors the execution status of the automatic operation control unit. When the execution of the NC program is restarted after being suspended by the pause processing unit, it is confirmed whether the restart block containing the characters specified in the program operation unit before the restart is a predetermined restartable block. If it is a restartable block, the processing in the automatic operation control unit starting from the restart block is restarted, and if it is not a restartable block, the processing is terminated.

[0012] According to the numerical control device, the automatic operation control unit executes the NC program stored in the program storage unit to numerically control the motion mechanism of the machine tool. In addition, when the automatic operation control unit executes the NC program, the pause processing unit can pause the execution of the NC program by the automatic operation control unit, and can restart the execution of the NC program by the automatic operation control unit. In addition, when the processing of the automatic operation control unit is paused by the pause processing unit, for the NC program being executed and displayed on the display device, the program operation unit can operate the character display on the display device in the state of specifying the displayed characters, or can edit the NC program.

[0013] Moreover, the automatic operation monitoring unit monitors the execution status of the automatic operation control unit, and when the execution of the NC program is restarted after being suspended by the pause processing unit, it is confirmed whether the restart block containing the characters specified in the program operation unit before the restart is a predetermined restartable block. If it is a restartable block, the processing in the automatic operation control unit starting from the restart block is restarted, and if it is not a restartable block, the processing is terminated.

[0014] Thus, according to the numerical control device of the present invention, the automatic operation monitoring unit monitors the execution state (operation state) of the automatic operation control unit, and when the execution of the NC program is restarted after the execution of the NC program is suspended, it is confirmed whether the restart block is a restartable block, and the processing is restarted only when it is a restartable block. Therefore, even if there is an operator's erroneous operation, it is possible to reliably avoid interference between the tool and the workpiece. In addition, since it is possible to determine whether it is a restartable block without relying on the operator's judgment, the operator does not need to be fully familiar with the processing process executed by the machine tool.

[0015] In addition, the numerical control device of the present invention can also include a storage unit, which stores blocks that are predetermined for the executed NC program and can restart automatic operation. In this case, the automatic operation monitoring unit can adopt the following method: when the execution of the NC program is restarted by the automatic operation control unit, the restartable block stored in the storage unit is compared with the restart block, and when the restart block is consistent with the restartable block stored in the storage unit, it is determined that the restart block is a restartable block.

[0016] According to the numerical control device of this aspect, since the restartable block is set in advance, it is possible to quickly perform a confirmation process of whether the restart block is a restartable block.

[0017] Alternatively, the numerical control device of the present invention may further include a storage unit, which stores NC codes predetermined for the executed NC program and defined as NC codes that can restart automatic operation. In this case, the automatic operation monitoring unit may be configured to confirm whether the restart block contains the NC code stored in the storage unit when the execution of the NC program is restarted by the automatic operation control unit, and when the restart block is a block containing the NC code stored in the storage unit, determine that the restart block is a restartable block.

[0018] According to the numerical control device of this aspect, since the restartable block is set in advance via the NC code, it is also possible to quickly perform a confirmation process on whether the restart block is a restartable block.

[0019] Furthermore, in the present invention, it is preferable that the automatic operation monitoring unit is configured to output an alarm to the outside when the restart block is not a restartable block.

[0020] According to the numerical control device of this aspect, since an alarm is output to the outside when the restart block is not a restartable block, the operator can instantly understand his own erroneous operation. In this case, the operator can take measures such as implementing it from the beginning of the machining program.

[0021] Effects of the Invention As described above, according to the numerical control device of the present invention, when the execution of the NC program is restarted after being suspended, it is confirmed whether the restart block is a restartable block, and the processing is restarted only when it is a restartable block. Therefore, even if there is an operator's erroneous operation, interference between the tool and the workpiece can be reliably avoided.

[0022] Furthermore, since it is possible to determine whether or not a block is a restartable block without relying on the judgment of the operator, even a highly specialized operator who does not have sufficient knowledge of the machining process executed by the machine tool can operate the machine tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] [ Figure 1 ] is a block diagram showing a schematic structure of a machine tool according to an embodiment of the present invention; [ Figure 2 ] is a flowchart showing the processing in the automatic operation monitoring unit of the present embodiment; [ Figure 3 ] is an explanatory diagram showing data stored in the restartable condition storage unit of the present embodiment; [ Figure 4 ] is an explanatory diagram showing an example of an NC program according to the present embodiment; [ Figure 5 ] is an explanatory diagram showing the data stored in the restartable condition storage unit of a modified example of the present invention. DETAILED DESCRIPTION

[0024] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0025] like Figure 1 As shown, the machine tool 1 of this example is composed of a numerical control device 10, an input / output device 20, a motion mechanism 25, etc. In addition, the machine tool 1 includes all kinds of machine tools known in the past having a structure in which the numerical control device 10 numerically controls the motion mechanism 25, and as an example, a lathe, a machining center, etc. can be cited, but it is not limited to this.

[0026] The motion mechanism unit 25 is a mechanism unit controlled by the numerical control device 10. For example, in the case of a lathe, it includes a spindle mechanism composed of a spindle motor and a spindle rotated by the spindle motor, a feed device composed of a feed motor and a reciprocating table and a tool holder moved by the feed motor, and a turntable mounted on the tool holder. In addition, in the case of a machining center, it also includes a spindle mechanism composed of a spindle motor and a spindle driven by the spindle motor, a feed motor and a spindle head moved by the feed motor, and a feed device composed of a feed motor and a reciprocating table and a table moved by the feed motor.

[0027] The input / output device 20 is composed of a display device 21 and an input device 22. The display device 21 includes a display for displaying characters or images, and the input device 22 also includes a device using a keyboard or a pointer displayed on the display, but these display devices 21 and input devices 22 may not be completely separated, for example, they may include a method in which the display unit and the input unit are integrated, such as a touch panel, and the input / output device 20 may include a method in which independent display units and input units are mixed, in addition to such an integrated method.

[0028] The numerical control device 10 is composed of an input / output control unit 11, a pause processing unit 12, an automatic operation control unit 13, an automatic operation monitoring unit 14, a program operation unit 15, a program storage unit 16, and a restartable condition storage unit 17. In addition, this structure is ultimately only a structure required to realize the present invention, and of course, the numerical control device 10 can include other functional parts.

[0029] The numerical control device 10 is composed of a computer including a CPU, a RAM, a ROM, etc. The input / output control unit 11, the pause processing unit 12, the automatic operation control unit 13, the automatic operation monitoring unit 14, and the program operation unit 15 realize their functions through computer programs and execute the processing described below. In addition, the program storage unit 16 and the restartable condition storage unit 17 are composed of appropriate storage media such as a RAM.

[0030] The input / output control unit 11 is a functional unit that controls the input / output of the input / output device 20. For example, the input / output control unit 11 stores data on the restartable condition input from the input device 20 in the restartable condition storage unit 17, and displays the restartable condition stored in the restartable condition storage unit 17 on the display device 21. In addition, the NC program input from the input device 20 is stored in the program storage unit 16 under the processing performed by the program operation unit 15 described in detail later, and the NC program stored in the program storage unit 16 is displayed on the display device 21.

[0031] The program storage unit 16 is a functional unit for storing NC programs created for machining, and stores NC programs input via the input device 22 and the input / output control unit 11 as described above. In addition, the NC program is composed of a plurality of blocks describing NC codes, such as Figure 4 In addition, each block is defined with a serial number as shown in the sequential number following N.

[0032] The restart condition storage unit 17 is a functional unit for storing a sequence number of a block that can be executed from the middle of the NC program after the execution is suspended, and stores the data inputted via the input device 22 and the input / output control unit 11 in a data table format. An example of the data table stored in the restart condition storage unit 17 is shown in FIG. Figure 3 .exist Figure 3 In the NC program, a restartable block (sequence number) is set in advance for each NC program. In addition, O0001 and O0002 are program numbers.

[0033] In addition, the input / output control unit 11 selectively sends the operation signal input from the input device 22 to the corresponding processing unit, that is, any one of the pause processing unit 12 , the automatic operation control unit 13 , the automatic operation monitoring unit 14 and the program operation unit 15 .

[0034] The program operation unit 15 receives an operation signal input from the input device 22 and the input / output control unit 11 and performs a process. For example, if an operation signal for inputting an NC program from the input device 22 and the input / output control unit 11 is received, a process for storing the NC program input from the input device 22 and the input / output control unit 11 in the program storage unit 16 is then performed.

[0035] In addition, if the program operation unit 15 receives a signal for operating the NC program from the input device 22 and the input / output control unit 11, the corresponding NC program is displayed on the display device 21 via the input / output control unit 11, and the character display on the display device 21 in the state of specifying the displayed characters can be operated, or the NC program can be edited, and when the NC program is changed, the NC program stored in the program storage unit 16 is updated by the changed NC program. In addition, the program operation can be performed when the processing by the automatic operation control unit 13 is not executed or when the processing by the automatic operation control unit 13 is suspended.

[0036] When the automatic operation control unit 13 receives an operation signal for executing the NC program displayed on the display device 21 via the input device 22 and the input / output control unit 11 under the processing performed by the program operation unit 15, the corresponding NC program is read and executed in the order of blocks from the program storage unit 16, so that the motion mechanism unit 25 operates under numerical control. At this time, the executed blocks are displayed on the display device 21 in a recognizable manner via the input / output control unit 11. As an example of this method, a method of underlining the blocks being executed or displaying them in black and white inversion with respect to the NC program displayed on the display device 21 is illustrated.

[0037] When the automatic operation control unit 13 executes the NC program, if the pause processing unit 12 receives a signal for suspending the execution of the NC program from the input device 22 via the input / output control unit 11, the pause processing unit 12 sends a pause signal to the automatic operation control unit 13 to suspend the processing in the automatic operation control unit 13. In addition, if the automatic operation restart signal (instruction) is received from the input device 22 via the input / output control unit 11, the automatic operation restart signal is sent to the automatic operation control unit 13 to restart the processing in the automatic operation control unit 13. In addition, the pause signal and the automatic operation restart signal input from the input device 22 are also sent to the automatic operation monitoring unit 14 described later via the input / output control unit 11.

[0038] The automatic operation monitoring unit 14 performs the following processing: monitoring the execution status of the automatic operation control unit 13, and when the execution of the NC program is restarted after being suspended by the pause processing unit 12, confirming whether the restart block containing the characters specified in the program operation unit 15 before the restart is a predetermined restartable block, and if it is a restartable block, restarting the processing in the automatic operation control unit 13 from the restart block, and terminating the processing if it is not a restartable block.

[0039] Specifically, the automatic operation monitoring unit 14 executes Figure 2 That is, the automatic operation monitoring unit 14 starts the processing by starting the numerical control device 10, and monitors whether the processing by the automatic operation control unit 13 has started (step S1). And, if the processing by the automatic operation control unit 13 has started, it monitors whether a pause signal is input from the input device 22, in other words, whether a pause signal is sent from the input device 22 to the pause processing unit 12 to pause the processing in the automatic operation control unit 13 (step S2).

[0040] Furthermore, in step S2, if it is confirmed that the pause signal has been input, the automatic operation monitoring unit 14 sends a pause maintenance instruction (signal) to the automatic operation control unit 14 (step S3), so that the automatic operation control unit 14 maintains the pause state. That is, the automatic operation control unit 14 maintains the pause state by receiving the pause maintenance instruction, and during this period, the automatic operation restart instruction is input from the input device 22, and even if the automatic operation restart instruction is input via the input / output control unit 11 and the pause processing unit 12, the pause state is maintained.

[0041] Next, the automatic operation monitoring unit 14 monitors whether a restart automatic operation signal has been input from the input device 22 via the input / output control unit 11 (step S4). If it is confirmed that the restart automatic operation signal has been input (step S4), then it is confirmed whether the automatic operation control unit 13 has operated the program being executed based on the processing status of the program operation unit 15 (step S5). If the program has not been operated, the restart automatic operation signal is sent to the automatic operation control unit 13 to restart the processing by the automatic operation control unit 13 (step S7).

[0042] On the other hand, in the above-mentioned step S5, when it is confirmed that the operation has been performed on the executing program, the restart block when the automatic operation restart signal is input is then identified based on the display status of the display device 21, that is, the block including the characters specified on the display device 21 is identified as the restart block under the processing performed by the above-mentioned program operation unit 15, and it is confirmed with reference to the data stored in the above-mentioned restartable condition storage unit 17 whether the identified restart block is a block set as a restartable block (step S6). If it is a restartable block, the processing of the above-mentioned step S7 is executed. If it is a non-restartable block, an alarm is displayed on the above-mentioned display device 21 via the above-mentioned input / output control unit 11 (step S9).

[0043] For example, the automatic operation control unit 13 executes Figure 4 A pause signal is input in the middle of the NC program shown in FIG. 1 to pause the processing by the automatic operation control unit 13. During the pause, under the processing by the program operation unit 15, if the NC program being executed is operated, the NC program is stopped. Figure 4 When the NC program is restarted at position (1) in the automatic operation monitoring unit 13, the automatic operation monitoring unit 13 refers to the restartable condition storage unit 17. Figure 3 The data shown confirms (discriminates) whether "sequence number N0001" is a restartable block. In this case, since "sequence number N0001" is a restartable block, the automatic operation performed by the automatic operation control unit 13 is restarted.

[0044] exist Figure 3 In the example shown, in addition to the above, since "serial number N0012", "serial number N0020", "serial number N0051" and the like are restartable blocks, for example, the automatic operation monitoring unit 14 allows automatic restart. Figure 4 On the other hand, since "sequence number N0025", "sequence number N0026" and the like are non-restartable blocks, for example, the automatic operation monitoring unit 14 refuses to restart the automatic operation. Figure 4The automatic operation is restarted from the blocks shown in (4) and (5). In addition, since "sequence number N0001" is the start block of the NC program, it is a block that can be restarted without interruption.

[0045] After executing step S7 , the automatic operation monitoring unit 14 repeatedly executes the processing after step S1 until the machining is completed. After the machining is completed, the automatic operation monitoring unit 14 repeatedly executes the processing after step S1 until the processing in the numerical controller 10 is completed.

[0046] According to the numerical controller 10 of the present example configured as above, when an operation signal regarding an execution command is input from the input device 22, the automatic operation control unit 13 executes the NC program displayed on the display device 21 by the processing performed by the program operation unit 15. Furthermore, the input status of the operation signal input from the input device 22 and the processing status in the automatic operation control unit 13 are monitored by the automatic operation monitoring unit 14.

[0047] Moreover, when the NC program is executed by the automatic operation control unit 13, a pause signal is sent from the input device 22 to the pause processing unit 12. If the processing in the automatic operation control unit 13 is paused by the pause processing unit 12, the automatic operation monitoring unit 14 then sends a maintain pause instruction (signal) to the automatic operation control unit 14, so that the automatic operation control unit 14 maintains the pause state.

[0048] Moreover, in this state, the automatic operation monitoring unit 14 monitors via the input / output control unit 11 whether a command (signal) to restart the automatic operation has been input from the input device 22. If it is confirmed that the command to restart the automatic operation has been input, it then confirms whether the executing program has been operated by the automatic operation control unit 13 based on the processing status of the above-mentioned program operation unit 15. If the program has not been operated, the command to restart the automatic operation is sent to the above-mentioned automatic operation control unit 13 to restart the processing by the automatic operation control unit 13.

[0049] On the other hand, when it is confirmed that an operation has been performed on the executing program, the automatic operation monitoring unit 14 identifies the restart block when the automatic operation restart instruction is input based on the display status of the display device 21, and confirms whether the identified restart block is a block set as a restartable block with reference to the data stored in the restartable condition storage unit 17. If it is a restartable block, the automatic operation restart instruction is sent to the above-mentioned automatic operation control unit 13 to restart the processing performed by the automatic operation control unit 13. If it is a non-restartable block, the above-mentioned display device 21 is displayed with an alarm via the above-mentioned input / output control unit 11.

[0050] In this way, according to the numerical control device 10 of this example, the automatic operation monitoring unit 14 monitors the execution status of the automatic operation control unit 13. When the execution of the NC program is restarted after being suspended, the automatic operation monitoring unit 14 confirms whether the restart block is a restartable block. Since processing is restarted only when it is a restartable block, even if there is an error in the restart processing operation performed by the operator, interference between the tool and the workpiece can be reliably avoided.

[0051] In addition, according to the numerical control device 10 of this example, since it is possible to determine whether it is a restartable block without relying on the judgment of the operator, the operator does not need to be familiar with the machining process executed by the machine tool 1. In addition, according to the numerical control device 10, since the display device 21 displays (outputs) an alarm when the restart block is not a restartable block, the operator can instantly understand that he or she has made an erroneous operation, and in this case, the operator can take measures such as implementing it from the beginning of the NC program.

[0052] Furthermore, according to the numerical control device 10 of this example, since information on the restartable block is preset and stored in the restartable condition storage unit 17, the automatic operation monitoring unit 14 can quickly perform a confirmation process on whether the restart block is a restartable block.

[0053] As mentioned above, a specific embodiment of the present invention has been described, but the present invention can be implemented in any way.

[0054] For example, in the above example, each time a restartable block is set, the serial number (N number) of the definition block itself, i.e., the characteristic value of the block, is used, but it is not limited to this, and a specific NC code may be used as a reference to identify whether it is a restartable block. Figure 5 .exist Figure 5 In the example shown, M codes such as “M1” are used as NC codes for defining the restartable block, and information on the NC codes thus set is set for each NC program and stored in the restartable condition storage unit 17 .

[0055] In this case, the automatic operation monitoring unit 14 identifies the restart block when the automatic operation restart instruction is input based on the display status of the display device 21, and confirms whether the NC code set as the restartable NC code in the identified restart block is included in the restart block with reference to the data stored in the restartable condition storage unit 17. In the case of a block containing a restartable NC code, a restart automatic operation instruction is sent to the above-mentioned automatic operation control unit 13 to restart the processing performed by the automatic operation control unit 13. In the case of a block that does not contain a restartable NC code, that is, a non-restartable block, an alarm is displayed on the above-mentioned display device 21 via the above-mentioned input-output control unit 11.

[0056] In addition, "M1" means selective stop, and in the operation mode that makes the selective stop "M1" effective, the automatic operation is suspended. Therefore, even if the automatic operation is restarted from this "M1", the interference between the tool and the workpiece can be avoided. Therefore, in this example, "M1" is used to define the NC code that can be restarted. In addition, the NC code that can be defined as restartable is not limited to this M1, and of course, other NC codes can also be used.

[0057] In the above example, the automatic operation monitoring unit 14 and the restartable condition storage unit 17 are configured as different functional units, but they may be configured so as to be regarded as one functional unit.

[0058] Although repeated, the description of the above embodiments is only illustrative in all aspects and is not restrictive. Those skilled in the art may appropriately make modifications and changes. The scope of the present invention is represented by the claims rather than the above embodiments. Moreover, the scope of the present invention includes changes according to the embodiments within the claims and within the scope of equivalents.

[0059] Description of Reference Numerals 1 Machine tools 10 Numerical control device 11 Input and output control unit 12 Suspension Processing Department 13 Automatic operation control unit 14 Automatic operation monitoring unit 15. Program Operation Department 16 Program storage unit 17 Restartable condition storage unit 20 Input and output devices 21 Display device 22 Input Devices 25 Sports Mechanism Department

Claims

1. A numerical control device that performs numerical control on the motion mechanism of a machine tool. in, have: a program storage unit storing an NC program composed of a plurality of blocks describing NC codes; A display device that at least displays the NC program in characters; an automatic operation control unit that executes the NC program stored in the program storage unit under numerical control to operate the motion mechanism unit; a pause processing unit, which, when the automatic operation control unit executes the NC program, resumes the execution of the NC program after pausing the execution of the NC program; A program operation unit, wherein when the processing of the automatic operation control unit is suspended by the suspension processing unit, the program operation unit can operate the character display in the display device in a state of specifying the displayed characters, or can edit the NC program, for the NC program being executed and displayed on the display device, and is characterized in that: An automatic operation monitoring unit is provided, which monitors the execution status of the automatic operation control unit. When the execution of the NC program is restarted after being suspended by the pause processing unit, it is confirmed whether the restart block containing the characters specified in the program operation unit before the restart is a predetermined restartable block. If it is a restartable block, the processing in the automatic operation control unit starting from the restart block is restarted, and if it is not a restartable block, the processing is terminated.

2. The numerical control device according to claim 1, It is characterized in that A storage unit is further provided, in which a block predetermined for the executed NC program and capable of restarting the automatic operation is stored. The automatic operation monitoring unit is configured to compare the restartable block stored in the storage unit with the restart block when the automatic operation control unit restarts the execution of the NC program, and to determine that the restart block is a restartable block when the restart block is consistent with the restartable block stored in the storage unit.

3. The numerical control device according to claim 1, It is characterized in that A storage unit is further provided, in which an NC code predetermined for the executed NC program and defined as an NC code capable of resuming automatic operation is stored. The automatic operation monitoring unit is configured to confirm whether the restart block contains the NC code stored in the storage unit when the automatic operation control unit restarts the execution of the NC program, and if the restart block is a block containing the NC code stored in the storage unit, determine that the restart block is a restartable block.

4. The numerical control device according to any one of claims 1 to 3, It is characterized in that The automatic operation monitoring unit is configured to output an alarm to the outside when the restart block is not a restartable block.

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