Numerical control device and computer-readable storage medium

Abstract

Provided is a numerical value control device that controls electrical discharge machining, and that has: a program path creation unit that analyzes a machining program comprising a plurality of machining processes, including rough machining, semi-finishing machining, and final-finishing machining, and that creates a program path in each machining process; a machining condition storage unit that stores a plurality of machining conditions adapted to each machining process and at least one machining condition adapted to an unmachined portion; and a machining condition modification unit that, in cases in which the unmachined portion has been generated in a previous machining process, modifies the machining condition of the current machining process to the machining condition adapted to the unmachined portion.

Description

[Technical field]

[0001] The present invention relates to a numerical control device for controlling an electric discharge machine, and a computer-readable storage medium. [Background technology]

[0002] Conventionally, there are electric discharge machines that perform machining by utilizing the discharge phenomenon between the workpiece and a traveling electrode. In electric discharge machining, after cutting out the material once, the machining is repeated by tracing the side of the workpiece two or three times, improving the shape accuracy and reducing the roughness of the machined surface. When machining is repeated, the energy of the electric discharge machining, which is determined by the voltage value (current value) and pulse width, is gradually reduced in the order of rough machining, semi-finishing, and final finishing. Because the machined surface is not flat in the rough machining stage, the voltage value (current value) and pulse width are reduced to gradually flatten the machined surface. The electrode distance at which discharge occurs is called the discharge gap, and can be predicted from machining conditions such as the current value and pulse width. In electric discharge machining, the diameter correction amount based on the predicted value is used as the machining radius to create a correction path and determine whether or not the cutting depth is excessive.

[0003] Patent Document 1 states that "a wire electric discharge machining apparatus includes a processing unit that forms a product part, which is an inner part, by cutting off an outer frame part from a workpiece, and a control device 2 that controls the processing unit. The processing unit processes a first boundary area of ​​the boundary between the outer frame part and the product part so that a part of the boundary between the outer frame part and the product part is left as an uncut part, and then, after the member that becomes the product part and the member that becomes the outer frame part are connected with a conductive member, the second boundary area, which is the uncut part of the boundary, is processed to separate the product part from the outer frame part. When processing the workpiece, the first boundary area is repeatedly processed multiple times, and the second boundary area is repeatedly processed multiple times. The control device 2 sets different processing conditions for processing the first boundary area the nth time and second processing conditions for processing the second boundary area the nth time, where n is a natural number greater than or equal to 2, based on the processing status when the first boundary area is processed." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5622977 Summary of the Invention [Problem to be solved by the invention]

[0005] As shown in Patent Document 1, in wire electric discharge machining, an uncut portion is intentionally left, and after machining the portion other than the uncut portion, the uncut portion is finally cut to separate the product portion (core). In Patent Document 1, machining accuracy is improved by changing the machining conditions before and when the core is separated.

[0006] The machining conditions are different for rough machining, semi-finishing, and final finishing. Since the machining path changes depending on the machining conditions, unmachined areas may occur depending on the machining conditions. Even if the machining conditions are set to suit each machining, if an unmachined area occurs in rough machining, the unmachined area will be machined in semi-finishing, resulting in a mismatch between the machining conditions and the machining target.

[0007] In the field of electric discharge machines, there is a demand for technology that allows machining to be performed under appropriate machining conditions. [Means for solving the problem]

[0008] A numerical control device according to one embodiment of the present disclosure is a numerical control device for controlling electric discharge machining, and includes: a program path creation unit that analyzes a machining program consisting of a plurality of machining steps including rough machining, intermediate finishing machining, and final finishing machining, and creates a program path for each machining step; a machining condition storage unit that stores a plurality of machining conditions suited to the machining steps and at least one machining condition suited to an unmachined portion; and a machining condition change unit that, when an unmachined portion occurs in a previous machining step, changes the machining conditions of the current machining step to machining conditions suited to the unmachined portion. A computer-readable storage medium according to one embodiment of the present disclosure stores computer-readable instructions that, when executed by one or more processors, analyze a machining program consisting of multiple machining steps including rough machining, intermediate finishing machining, and final finishing machining to create a program path for each machining step, store multiple machining conditions suited to the machining steps and at least one machining condition suited to an unmachined portion, and, if an unmachined portion occurs in a previous machining step, change the machining conditions for the current machining step to the machining conditions suited to the unmachined portion. Effect of the Invention

[0009] According to one aspect of the present invention, electric discharge machining can be performed under appropriate machining conditions. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram illustrating a hardware configuration of a numerical control device. [Diagram 2] FIG. 2 is a block diagram of a numerical control device. [Diagram 3] FIG. 2 is a diagram illustrating a program path. [Figure 4A] FIG. 13 is a diagram showing the relationship between the machining radius and excessive cutting depth (occurrence of excessive cutting depth). [Figure 4B] FIG. 13 is a diagram showing the relationship between the machining radius and the excessive cutting depth (without excessive cutting depth). [Diagram 5] FIG. 13 is a diagram showing an example of an avoidance route. [Figure 6] FIG. 4 is a diagram showing an example of processing conditions. [Figure 7] FIG. 11 is a diagram showing the relationship between the discharge gap and the wire diameter correction amount. [Figure 8A] FIG. 13 is a diagram showing the occurrence of unmachined parts in rough machining. [Figure 8B] FIG. 13 is a diagram showing processing of an already-processed portion in semi-finishing. [Figure 8C] FIG. 13 is a diagram showing the machining of an unmachined portion in semi-finishing. [Figure 9A] FIG. 13 is a diagram showing the outgoing path of groove machining under the machining conditions for the unmachined portion. [Figure 9B] FIG. 13 is a diagram showing the return pass of groove machining under semi-finishing machining conditions. [Figure 10A] FIG. 13 is a diagram showing the outgoing path of groove machining under semi-finishing machining conditions. [Figure 10B] FIG. 13 is a diagram showing the return pass of groove machining under semi-finishing machining conditions. [Figure 11A] FIG. 13 is a diagram showing the occurrence of unmachined parts in rough machining. [Figure 11B] FIG. 1 is a diagram showing conventional processing of an unprocessed part. [Figure 12] 11 is a flow chart illustrating a process for recording information related to an unprocessed portion. [Figure 13] 13 is a flowchart illustrating a process for changing a processing condition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The hardware configuration of a numerical control device 100 that controls a wire electric discharge machine 200 will be described with reference to Fig. 1. Note that the wire electric discharge machine 200 is given as an example of the present disclosure. The present disclosure is applicable to electric discharge machining in general, including die sinking electric discharge machining. The CPU 111 included in the numerical control device 100 is a processor that controls the entire numerical control device 100. The CPU 111 reads a system program processed in the ROM 112 via the bus 122, and controls the entire numerical control device 100 in accordance with the system program. The RAM 113 temporarily stores temporary calculation data, display data, various data input by the user via the input unit 71, etc.

[0012] The display unit 70 is a monitor or the like attached to the numerical control device 100. The display unit 70 displays an operation screen, a setting screen, and the like of the numerical control device 100.

[0013] The input unit 71 is a keyboard, a touch panel, or the like that is integrated with the display unit 70 or is separate from the display unit 70. A user operates the input unit 71 to input data to a screen displayed on the display unit 70. The display unit 70 and the input unit 71 may be a mobile terminal.

[0014] The non-volatile memory 114 is a memory that retains its stored state even when the power supply of the numerical control device 100 is turned off, for example, by being backed up by a battery (not shown). The non-volatile memory 114 stores programs read from an external device via an interface (not shown), programs input via the input unit 71, and the programs of each unit and program of the numerical control device 100. Wire Electric Discharge Machine Various data obtained from 200 etc. (e.g. Wire Electric Discharge Machine 200) is stored in the non-volatile memory 114. The programs and various data stored in the non-volatile memory 114 may be expanded in the RAM 113 when executed / used. In addition, various system programs are written in the ROM 112 in advance.

[0015] A controller 40 that controls the wire or table of the wire electric discharge machine 200 converts axis movement commands from the CPU 111 into pulse signals and outputs them to a driver 41. The driver 41 converts the pulse signals into currents to drive the servo motors of the wire electric discharge machine 200. The servo motors move the wire or table under the control of the numerical control device 100. By controlling the servo motors, it is possible to control the discharge gap and wire speed, which will be described later.

[0016] The machining power supply 202 applies a voltage between the upper and lower power feeders and the workpiece. The wire electric discharge machine 200 performs electric discharge machining on the workpiece by generating an electric discharge between the workpiece mounted on the table and the wire electrode. The voltage and current applied to the wire vary depending on the machining conditions, which will be described later.

[0017] The discharge detection unit 203 measures the waveforms of the discharge voltage and discharge current between the poles. The discharge detection unit 203 is, for example, an oscilloscope or a current sensor. The oscilloscope can grasp the discharge phenomenon occurring between the poles. The current sensor measures the discharge current flowing in the power supply line. The numerical control device 100 adjusts the wire speed based on the discharge voltage and discharge current acquired from the discharge detection unit 203 and depending on whether the discharge is normal, there is a short circuit, or the discharge is in a continuous state.

[0018] 2 is a block diagram of the numerical control device 100. The numerical control device 100 includes a machining program storage unit 11, a machining program analysis unit 12, a correction path creation unit 13, a cutting excess determination unit 14, an avoidance path creation unit 15, an unmachined path detection unit 16, a machining condition change unit 17, a machining condition storage unit 18, and an interpolation processing unit 19.

[0019] The machining program analysis unit 12 creates a program path based on the machining program stored in the machining program storage unit 11. The program path differs depending on the machining process. An example of the program path is shown in Fig. 3. The first machining process is rough machining, the second machining process is intermediate finishing (first time), the third machining process is intermediate finishing (second time), and the fourth machining process is final finishing. A finishing allowance is often set from rough machining to semi-finishing. If a finishing allowance is set in the machining program, the program path is shifted by the amount of the finishing allowance. In general, a large finishing allowance is left during rough machining, a small finishing allowance is made during semi-finishing, and the finishing allowance is set to zero during final finishing.

[0020] The correction path creation unit 13 corrects the program path based on the wire diameter correction amount. The wire diameter correction amount is the machining radius of the wire. In wire diameter correction, a path (corrected path) is created by shifting the program path by the wire diameter correction amount. The wire diameter correction amount differs depending on the machining conditions. In general, the wire diameter correction amount is large for rough machining and small for final finishing. In the case of the present disclosure, a correction path for rough machining is created in the first machining process, a correction path for intermediate finishing machining (first time) is created in the second machining process, a correction path for intermediate finishing machining (second time) is created in the third machining process, and a correction path for final finishing is created in the fourth machining process.

[0021] The excessive depth of cut determination unit 14 determines whether or not there is a portion in the path after the wire diameter correction where excessive depth of cut occurs. Figure 4 shows the relationship between machining radius and excessive cutting. In the program path in Figure 4A, machining is performed in a straight line from the right to the left of the drawing, and then machining is performed diagonally to the lower right from point A. If machining is performed according to the corrected path, excessive cutting will occur at point B. In Figure 4B, the machining conditions are changed to reduce the voltage and current, which reduces the wire machining radius. When the machining radius is reduced, excessive cutting will not occur. In rough machining, the machining radius is large and the finishing allowance is also large, so excessive cutting is likely to occur and unmachined areas are likely to occur.

[0022] The avoidance path creation unit 15 creates a path (avoidance path) that avoids excessive cutting. Fig. 5 is an example of an avoidance path. In the case of Fig. 5, excessive cutting occurs in rough machining, so an avoidance path that avoids hole machining is created. In the next machining (semi-finishing (first pass)), excessive cutting does not occur, so no avoidance path is created and a compensation path is adopted. In the subsequent machining (semi-finishing (second pass), final finishing), excessive cutting does not occur either, so no avoidance path is created and a compensation path is adopted.

[0023] The raw route detection unit 16 detects an raw route by comparing the corrected route with the avoidance route. The raw route detection unit 16 stores the raw route as information related to the raw portion (raw portion related information).

[0024] The machining condition change unit 17 reads out information related to the unmachined portion in the previous machining, and selects machining conditions that suit the machining shape of the unmachined portion. (1) to (3) are the machining condition selection procedures. When an unmachined portion occurs in the previous machining, (1) the machining condition change unit 17 compares the correction path of the current machining with the avoidance path of the previous machining, and judges the shape of the unmachined portion. (2) The machining condition change unit 17 judges whether the unmachined portion of the rough machining is machined for the first time in the current machining. (3) It is judged whether excessive cutting will occur when the machining conditions are changed and the unmachined portion is machined. The machining condition change unit 17 changes the machining conditions when all of the conditions (1) to (3) are satisfied.

[0025] The steps (1) to (3) will now be described in detail. The numerical control device 100 stores machining conditions as shown in FIG. 6. The machining conditions include normal machining conditions such as rough machining, semi-finishing (first time), semi-finishing (second time), and final finishing, and machining conditions for unmachined parts. For each machining condition, "voltage," "on time," "feed speed," "wire diameter correction amount," and the like are set. Machining conditions for unmachined parts are provided for each shape, such as "for corners" and "for grooves." The machining condition "S21" is for "corners," and the machining condition "S22" is for "grooves." The machining condition change unit 17 compares the correction path of the previous machining with the avoidance path of the previous machining to determine the machining shape, and reads out the machining conditions corresponding to the machining path. In the example of the present disclosure, the machining condition change unit 17 reads out the "groove machining" machining condition "S22."

[0026] The machining condition change unit 17 judges whether or not an excessive cut occurs under the read machining conditions. As shown in FIG. 7, there is a gap called a "discharge gap" between the wire and the machining surface. The "discharge gap" is a gap where discharge occurs. When the machining conditions are changed, the size of the "discharge gap" changes. The machining radius corresponds to the "wire diameter + discharge gap". The "wire diameter" is the radius of the wire used for machining. When the wire is changed between rough machining and finish machining, the "wire diameter" also changes. The "wire diameter correction amount", the "wire diameter + discharge gap", and the "machining radius" are approximately equal. When the machining conditions are changed, the machining radius changes, and there is a possibility that an excessive cut occurs. To avoid this, the machining condition change unit 17 judges whether or not an excessive cut occurs under the new machining conditions. If an excessive cut does not occur, the current machining conditions are changed to the machining conditions for the unmachined portion.

[0027] During electric discharge machining, the discharge gap is kept approximately constant. The numerical control device 100 performs feedback control to control the wire speed to keep the discharge gap constant. If the distance between the wire and the workpiece becomes too close, a short circuit occurs. If the wire speed decreases due to a mismatch between the machining conditions and the machining amount, the numerical control device 100 reduces the wire speed to keep the discharge gap constant.

[0028] With reference to FIG. 8, the change in processing conditions for the unprocessed portion will be described. In the rough machining, when the numerical control device 100 determines that an excessive cutting depth occurs, the numerical control device 100 creates an avoidance path to avoid the excessive cutting depth. The wire moves along the avoidance path, and an unmachined portion occurs (FIG. 8A). When the rough machining is completed, the semi-finishing (first time) is started. In the semi-finishing (first time), machining is performed under the machining condition "S2: semi-finishing (first time)" of the finishing machining (FIG. 8B). When the wire approaches the unmachined portion, the numerical control device 100 starts a process of changing the machining conditions. The numerical control device 100 compares the correction path of the previous machining with the avoidance path of the previous machining to determine the machining shape. The numerical control device 100 selects the machining condition "S22: unmachined portion (for groove)" as the machining condition corresponding to the machining shape, and determines whether or not an excessive cutting depth occurs under this machining condition. When the numerical control device 100 determines that an excessive cutting depth does not occur, it changes the machining conditions and machines the unmachined portion (FIG. 8C).

[0029] There are also methods for determining excessive cutting depth: (4), (5), and (6). (4) If the current machining is final finishing, do not change the machining conditions. During final finishing, the finishing allowance becomes zero. If the machining voltage is increased during final finishing, excessive cutting occurs. Therefore, do not change the machining conditions during final finishing.

[0030] (5) Depending on the machining shape, the machining conditions are switched between the forward and return passes. In the case of groove machining, the unmachined portion is machined on the forward pass (Fig. 9A), while the portion that has already been machined is finished on the return pass (Fig. 9B). Therefore, the machining conditions are switched between the forward and return passes. According to the machining conditions in Fig. 6, the machining condition "S22: Unmachined portion (for grooves)" is selected on the forward pass, and the machining condition is switched to "S2: Semi-finishing (first pass)" on the return pass.

[0031] (6) Do not change the machining conditions when machining is performed only twice, once for rough machining and once for final finishing. As shown in Figure 10A, when machining the unmachined part of the rough machining in the final finishing, if the voltage is increased, the length of the "wire diameter + discharge gap" will become larger than the "distance between the wire center and the workpiece", which may result in excessive cutting. In this case, do not change the machining conditions. In the case of the return pass (Figure 10B), do not change the machining conditions either, as this is not an unmachined part.

[0032] The effects of the present disclosure will be described in comparison with conventional groove machining. Figure 11 shows conventional wire EDM. As a premise, an unmachined portion occurs during rough groove machining. In the semi-finishing (first pass) following the rough machining, machining begins under the machining conditions "S2: semi-finishing (first pass)" (Figure 11A). Even when the unmachined portion is reached, the unmachined portion is machined under the specified machining conditions "S2: semi-finishing (first pass)" (Figure 11B). The machining volume of the unmachined portion is greater than the machining volume of the finishing process, causing a mismatch between the actual machining and the machining conditions, and the wire speed decreases. In addition, the distance between the wire and the workpiece becomes closer, increasing the possibility of a wire short circuit. When the distance between the wire and the workpiece becomes closer, the command speed of the feedback control also becomes slower in order to keep the discharge gap constant.

[0033] The numerical control device 100 of the present disclosure detects the occurrence of an unmachined portion in the previous machining, and when machining the unmachined portion in the current machining, changes the machining conditions to those suitable for the unmachined portion. This makes it possible to prevent a decrease in machining speed and frequent short circuits. In the present disclosure, a determination is made so that excessive cutting does not occur even if the machining radius of wire electric discharge machining increases by changing the machining conditions.

[0034] The process of recording information relating to the unprocessed portion during processing will now be described with reference to FIG. The machining program analysis unit 12 analyzes the machining program and creates a program path (step S1). In step S1, a program path for rough machining, a program path for intermediate finishing, and a program path for final finishing may be created. Here, a description will be given assuming that a program path for rough machining is created.

[0035] The corrected path creating unit 13 corrects the program path based on the wire diameter correction amount, and creates a corrected path (step S2). The excessive cut-in determination unit determines whether the corrected path includes a portion where the excessive cut-in occurs (step S3). If it is determined that the excessive cut-in occurs (step S4; Yes), the avoidance path creation unit 15 creates a path that avoids the excessive cut-in (avoidance path) (step S5).

[0036] The raw path detection unit 16 detects the raw portion by comparing the corrected path with the avoidance path. The raw path detection unit 16 stores information related to the raw portion, such as the position information of the raw portion (step S6).

[0037] If machining is to be continued (step S7; Yes), the numerical control device 100 shifts the process to step S1 and creates a program path. If machining is to be ended (step S7; No), the process of recording information related to the unmachined portion is ended.

[0038] The process of changing the machining conditions will be described with reference to the flowchart in Fig. 13. It is assumed that the previous machining has been completed before the machining conditions can be changed. The previous machining means a machining process prior to the current machining process. The machining condition change unit 17 judges whether the current machining is approaching an unmachined portion from the previous machining based on the unmachined portion related information. If the current machining is not approaching an unmachined portion (step S11; No), monitoring is continued. If the current machining is approaching an unmachined portion (step S11; Yes), the machining condition change unit 17 judges the machining shape of the unmachined portion (step S12). The machining shape includes, but is not limited to, a "groove" or a "corner". The machining condition change unit 17 judges whether the part is an unmachined part of the rough machining. Since the unmachined part of the rough machining has a large amount of machining, machining conditions that provide a larger amount of machining than those for the finish machining are suitable for the unmachined part of the rough machining. If the unmachined portion is to be roughly machined (step S13; Yes), the machining condition change unit 17 selects machining conditions suitable for the machining shape of the unmachined portion from the machining condition storage unit 18 (step S14). The machining condition change unit 17 determines whether or not excessive cutting occurs under the machining conditions according to the machining shape of the unmachined portion (step S15).

[0039] If excessive cutting occurs (step S16; Yes), the processing conditions are not changed and the process proceeds to step S11. If excessive cutting does not occur (step S16; No), the processing conditions are changed (step S17). Here, when the current machining process is completed (step S18; Yes), the process of changing the machining conditions is terminated. While the current machining process is continuing (step S18; No), the process transitions to step S11 and the process of changing the machining conditions is continued.

[0040] As described above, in wire electric discharge machining in which one workpiece is machined by repeating machining multiple times, if there is an unmachined portion in the previous machining, the numerical control device 100 of the present disclosure judges the shape of the unmachined portion, selects machining conditions suitable for the shape of the unmachined portion, and judges whether or not an overcut occurs when machining is performed under these machining conditions. If an overcut occurs, the numerical control device 100 does not change the machining conditions. If an overcut does not occur, the numerical control device 100 changes the machining conditions.

[0041] The numerical control device 100 may be provided with a function of determining whether or not the current machining is final finishing, and if it is final finishing, not changing the machining conditions. When machining involves reciprocating motion, a function may be provided that changes the machining conditions on the outward path and does not change the machining conditions on the return path. A function may be provided that does not change the machining conditions when the width of the groove in "groove machining" is equal to "wire diameter + discharge gap."

[0042] The present disclosure can be applied to electrical discharge machining in general, including die sinking electrical discharge machining. Wire electrical discharge machining is electrical discharge machining in which the tool electrode is a wire. The tool electrode may be a conductor (metal) having a shape other than a wire. In die sinking electrical discharge machining, an electrode is used instead of a wire. In die sinking electrical discharge machining, as in wire electrical discharge machining, unmachined areas may occur. In that case, the machining conditions are changed and the unmachined areas are machined under appropriate machining conditions. The correction amount for general electrical discharge machining is defined as the electrode shape correction amount. The electrode shape correction amount is the electrode shape + discharge gap amount. The wire diameter correction amount is a type of electrode shape correction amount. The electrode shape correction amount is used to correct the program path, create an avoidance path, and determine excessive cutting. [Explanation of symbols]

[0043] 100 Numerical control device 11 Machining program storage section 12 Machining program analysis section 13 Correction path creation section 16 Raw Route Detection Section 17 Machining condition change section 18 Machining condition memory section 111 CPU 112 ROM 113 RAM 114 Non-volatile memory 201 Servo motor 202 Processing power supply 203 Discharge detection unit

Claims

1. A numerical control device for controlling electric discharge machining, a program path creation unit that analyzes a machining program consisting of a plurality of machining steps including rough machining, intermediate finishing machining, and final finishing machining, and creates a program path for each machining step; a processing condition storage unit that stores a plurality of processing conditions adapted to the processing step and at least one processing condition adapted to an unprocessed portion; a processing condition changing unit that changes the processing conditions of the current processing step to processing conditions suitable for the unprocessed portion when an unprocessed portion occurs in a previous processing step; A numerical control device having the above configuration.

2. a correction path creation unit that creates a correction path by correcting the program path with an electrode shape correction amount; an excess cut determination unit that determines whether or not an excess cut occurs when machining is performed using the corrected path; an avoidance path creation unit that creates an avoidance path that is a path that avoids the excessive cutting; an unprocessed path detection unit that detects an unprocessed portion from the corrected path and the avoidance path; 2. The numerical control device according to claim 1, further comprising:

3. the processing condition storage unit stores a shape of the unmachined portion and processing conditions in association with each other; The processing condition changing unit changes the processing conditions to correspond to the shape of the unmachined portion. The numerical control device according to claim 1.

4. the machining condition change unit determines whether or not a change to the machining conditions for the unmachined portion will cause an excessive cutting depth, and if an excessive cutting depth will occur, does not change the machining conditions; The numerical control device according to claim 1.

5. the machining condition changing unit does not change the machining conditions when the current machining process is a final finishing process; The numerical control device according to claim 1.

6. When the unmachined portion is machined on a round trip path, the machining condition change unit does not change the machining conditions for the return path. The numerical control device according to claim 1.

7. When executed by one or more processors, Analyzing a machining program consisting of a plurality of machining steps including rough machining, intermediate finishing machining, and final finishing machining, and creating a program path for each machining step; storing a plurality of machining conditions adapted to the machining process and at least one machining condition adapted to the unmachined portion; When an unprocessed portion occurs in a previous processing step, the processing conditions of the current processing step are changed to processing conditions suitable for the unprocessed portion; A storage medium that stores computer-readable instructions.

8. A correction path is created by correcting the program path with an electrode shape correction amount; Determining whether or not excessive cutting occurs when machining is performed using the corrected path; Creating an avoidance path that is a path that avoids the excessive cutting depth; detecting an unprocessed portion from the corrected path and the avoidance path; A storage medium storing the computer readable instructions of claim 7.

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