JP2020008979A - Numerical control device - Google Patents

Abstract

To provide a numerical control device and a numerical control method capable of reworking only a portion where uncut portions have occurred.SOLUTION: A numerical control device 10 includes a program storage unit 11, a program analysis unit 12, an execution control unit 13, a determination unit 15, a rework block determination unit 16, and a correspondence information storage unit 17. The program analysis unit 12 analyzes an NC program in the program storage unit 11 and extracts an operation command as a first operation command, and the execution control unit 13 controls a feed mechanism unit 2 based on the first operation command to perform a first processing on a work-piece. The determination unit 15 specifies a reworking portion that has left uncut based on the dimensions of the work-piece after the first processing, and the rework block determination unit 16 determines a block corresponding to a rework site from correspondence information in the correspondence information storage unit 17. The program analysis unit 12 extracts an operation command included in the rework block as a second operation command, and the execution control unit 13 controls the feed mechanism unit 2 based on the second operation command to rework the work-piece.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a numerical control device for numerically controlling a feed mechanism of a machine tool in accordance with an NC program, which can process a workpiece with high dimensional accuracy, and as a result, can suppress generation of defective products. About.

  2. Description of the Related Art In recent years, the material of a workpiece (cut object) processed by a machine tool has been diversified. Materials are being used. When a product using such an expensive material is processed, it is required to reduce the removal amount by the processing as much as possible in order to suppress the material cost.

  Therefore, conventionally, in order to minimize the amount of removal during processing, a material having a similar shape (near net shape) close to the product shape is manufactured by forging or casting, and this material is processed by a machine tool to A manufacturing method of obtaining a final shape has been proposed.

  When processing the near net shape type material, since the shape has a shape close to the product shape, a substantially uniform allowance (removal amount) is set for the entire surface of the material. In addition, it is necessary to accurately position (adjust) the position and attitude of attaching the material to the machine tool and the movement path of the tool set by the NC program.

  For this reason, conventionally, a method for measuring the cross-sectional shape of an object to be measured has been proposed as disclosed in Patent Document 1 below. According to this measurement method, since the cross-sectional shape of the measurement object can be accurately measured, the position and orientation of attaching the material to the machine tool and the moving path of the tool can be accurately determined based on the obtained cross-sectional shape. Can be aligned. Therefore, it is possible to set a substantially uniform allowance (removal amount) for the entire surface of the material.

JP-A-2006-95289

  By the way, even if it is a near net shape type material, it does not have a shape similar to the product shape with high accuracy, and the shape accuracy differs in each part of the material in a strict sense. Therefore, even when processing a material surface using a single tool, for example, a ball end mill, a machining portion having a large allowance and a machining portion having a small allowance are generated. In the case of (1), a large cutting force acts on the tool, and a relatively small cutting force acts on the tool when machining a portion having a small cutting allowance.

  Since the tool is not a perfect rigid body, it bends (runs away) due to the cutting force it receives. However, there are machining areas where there is a large machining allowance and large cutting forces act, and machining areas where there is little machining allowance and relatively small cutting forces act. In this case, since the amount of bending of the tool is different, the processing accuracy (in other words, the shape accuracy and the dimensional accuracy) differs depending on each processing portion.

  Therefore, although the processing accuracy falls within a predetermined allowable range at a certain processing site, the processing accuracy is out of the allowable range at a certain processing site, that is, there is a problem that the remaining machining occurs. In this case, it is conceivable to re-work the workpiece by executing the entire NC program again. However, for a machined part having a machining accuracy outside the allowable range, the machining accuracy is set within the allowable range by re-machining. Although it may be able to be accommodated, the machining accuracy of the machining part whose machining accuracy is within the allowable range may be out of the allowable range due to excessive cutting by re-machining.

  The present invention has been made in view of the above circumstances, and when a machining portion to be left uncut occurs by machining based on the NC program, rework can be performed only on the machining portion. An object of the present invention is to provide a numerical control device capable of keeping the shape accuracy of the processed portion within an allowable range by such reworking.

The present invention for solving the above problems is a numerical control device for numerically controlling a feed mechanism of a machine tool including a feed mechanism for relatively moving a tool and a work,
A program storage unit for storing the NC program;
A program analysis unit for sequentially analyzing the NC program stored in the program storage unit for each block and extracting an operation command related to the feed mechanism unit as a first operation command;
A first drive control signal is generated based on the first operation command extracted by the program analysis unit, the generated first drive control signal is transmitted to the feed mechanism unit, and the first processing is performed on the workpiece. An execution control unit to be executed;
A corresponding information storage unit for storing corresponding information of each processing part and the block corresponding to each processing part,
Based on the shape and dimensions obtained by measuring the workpiece after the first processing, determine whether there is an uncut portion, a determination unit that certifies the uncut portion as a rework portion,
When the rework portion is recognized by the determination unit, a block corresponding to the rework portion is determined with reference to the correspondence information stored in the correspondence information storage unit, and information on the determined block is determined. A re-processing block determining unit to be transmitted to the program analyzing unit,
The program analysis unit, based on the block information transmitted from the rework block determination unit, to extract the operation command included in the corresponding block as a second operation command from the program storage unit,
The execution control unit generates a second drive control signal based on the second operation command extracted by the program analysis unit, transmits the generated second drive control signal to the feed mechanism unit, The present invention relates to a numerical control device configured to execute a second process for reworking the reworked portion on a workpiece after one process.

Further, the present invention is a numerical control method for numerically controlling the feed mechanism of a machine tool having a feed mechanism for relatively moving a tool and a work,
Storing the NC program;
Sequentially analyzing the stored NC program for each block and extracting an operation command relating to the feed mechanism unit as a first operation command;
Generating a first drive control signal based on the extracted first operation command, transmitting the generated first drive control signal to the feed mechanism unit, and causing the workpiece to perform first machining;
Storing correspondence information between each processing part and the block corresponding to each processing part;
Based on the shape and dimensions obtained by measuring the workpiece after the first processing, determine whether there is an uncut portion, and certify the uncut portion as a rework portion,
When the reworked part is certified, by referring to the correspondence information, determining a block corresponding to the reworked part,
Extracting an operation command included in the determined block as a second operation command;
A second drive control signal is generated based on the extracted second operation command, and the generated second drive control signal is transmitted to the feed mechanism unit. And performing a second machining for re-machining the machining portion.

  According to the present invention, the NC program is sequentially analyzed for each block, an operation command relating to the feed mechanism is sequentially extracted as a first operation command, and a first drive control signal is generated based on the extracted first operation command. Is done. Then, the feed mechanism is numerically controlled by the generated first drive control signal, and the tool and the work relatively move, whereby the first processing based on the entire NC program is performed on the work. .

  Next, based on the shape and dimensions obtained by measuring the work after the first machining, it is determined whether or not the work has an uncut portion, and if there is an uncut portion, the uncut portion is determined. The part is certified as a rework part. Note that the uncut portion means that the portion is not sufficiently cut beyond a predetermined allowable range.

  When the reworked part is recognized, a block corresponding to the reworked part is determined with reference to the corresponding information, and the operation command included in the corresponding block is determined based on information on the determined block. The second operation command is extracted as a second operation command, and a second drive control signal is generated based on the extracted second operation command. Then, the feed mechanism section is numerically controlled by the generated second drive control signal, and the tool and the work relatively move, thereby reworking the reworked portion on the work after the first working. The second processing is performed.

  Thus, according to the present invention, when there is an uncut portion in the work after the first machining, the uncut portion is recognized (specified) as a reworked portion, and only the uncut portion is subjected to the second machining. Since the workpiece is re-worked, the shape accuracy of the remaining machined part can be kept within a predetermined allowable range without affecting other machined parts, and the work is prevented from becoming defective. be able to.

  The numerical control method according to the present invention can be executed by a computer program.

  In addition, the numerical control device according to the present invention may include a measurement unit that calculates the shape and dimension when the shape and dimension of the workpiece after the first processing are measured inside the machine tool. The shape and dimensions calculated by the measurement unit are output to the determination unit. If the shape and dimensions of the work after the first processing are measured inside the machine tool, it is not necessary to remove and attach the work when performing the measurement and the rework, so that the work In addition, it is possible to prevent a processing error from occurring due to an installation error.

  Further, the numerical control device according to the present invention, when the rework portion is recognized by the determination unit, when the rework block is determined by the rework block determination unit, analyzes the determined rework block, By recognizing a tool used in the processing corresponding to the re-machining block, analyzing the NC program, and executing the first processing and the second processing using the recognized tool, the processing by the tool is performed. A tool wear estimating unit for estimating the degree of further progress of tool wear by performing the second machining in addition to the first machining based on the estimated machining volumes. Is preferred.

  In this case, it is preferable that an output unit that outputs information on the degree of progress of the tool wear estimated by the tool wear estimation unit to the outside is provided.

  As described above, according to the present invention, if there is an uncut portion in the work after the first machining, the uncut portion is recognized as a reworked portion, and only the uncut portion is reprocessed by the second machining. Processed. Therefore, the shape accuracy of the machined part left uncut can be kept within a predetermined allowable range without affecting other machined parts. This can prevent the work from becoming defective.

1 is a block diagram illustrating a schematic configuration of a machine tool including a numerical control device according to an embodiment of the present invention. FIG. 3 is an explanatory diagram for describing a control mode in the numerical control device of the present embodiment. FIG. 3 is an explanatory diagram for describing a control mode in the numerical control device of the present embodiment. FIG. 3 is an explanatory diagram for describing a control mode in the numerical control device of the present embodiment. FIG. 3 is an explanatory diagram for describing a control mode in the numerical control device of the present embodiment. FIG. 3 is an explanatory diagram for describing a control mode in the numerical control device of the present embodiment. FIG. 3 is an explanatory diagram for describing a control mode in the numerical control device of the present embodiment. It is an explanatory view for explaining processing in a judgment part of this embodiment. FIG. 4 is an explanatory diagram showing a data table stored in a correspondence information storage unit of the embodiment.

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

  FIG. 1 is a block diagram showing a schematic configuration of a machine tool 1 according to the present embodiment. As shown in FIG. 1, the machine tool 1 of this example has a feed mechanism unit 2, a display device 3, and a numerical value. This is a so-called NC lathe including the control device 10 and the like.

  The machine tool 1 further includes a spindle device (not shown) that holds and rotates the work W (see FIGS. 3 to 7), and a tool rest (not shown) that holds the tool T. Under the control of the numerical control device 10, the feed mechanism unit 2 connects a spindle device (not shown) and a tool post (not shown), in other words, a workpiece W and a tool T to the spindle device (FIG. (Not shown) along the axis, an X-axis direction orthogonal to the Z-axis, and a Y-axis direction orthogonal to the Z-axis direction and the X-axis direction. Thereby, the workpiece W is processed by the tool T. The display device 3 is a so-called display, and can display various information.

  The numerical control device 10 includes a program storage unit 11, a program analysis unit 12, an execution control unit 13, a measurement unit 14, a determination unit 15, a rework block determination unit 16, a correspondence information storage unit 17, a tool wear estimation unit 18, and an output. It is provided with a part 19 and the like. The numerical controller 10 is composed of a computer including a CPU, a RAM, a ROM, and the like, and includes the program analysis unit 12, the execution control unit 13, the measurement unit 14, the determination unit 15, the rework block determination unit 16, the tool wear The functions of the estimating unit 18 and the output unit 19 are realized by a computer program, and execute processing described later. Further, the program storage unit 11 and the correspondence information storage unit 17 are configured from a suitable storage medium such as a RAM.

  The program storage unit 11 stores a machining program for machining the work W. In this example, for convenience of explanation, that is, in order to easily understand the present invention, the completed product shown in FIG. 2 is processed by the first to fifth steps shown in FIGS. It shall be. Then, a machining program for performing the first to fifth processes is stored in the program storage unit 11. Further, in each processing step, a predetermined allowance is set, and the work W having such an allowance is machined, and after the machining, a finished product shown in FIG. 2 is obtained. This machining program is executed in a state where the workpiece W is held by the spindle device (not shown) and the tool T is mounted on the tool rest (not shown).

  In the present example, the first step is outer diameter processing of φ70 mm, the second step is end face processing at a position of 15 mm in the Z-axis plus direction, the third step is end face processing at a position of 61.5 mm in the Z-axis plus direction, and the fourth step Is an outer diameter groove processing of φ62 mm, and the fifth step is inner diameter processing of φ53 mm. The block numbers N101 to N108 of the machining program correspond to the first step, the block numbers N201 to N208 correspond to the second step, and the block numbers N301 to N308 correspond to the third step. The block numbers N401 to N412 correspond to the fourth step, and the block numbers N501 to N508 correspond to the fifth step. The machining programs of the first step to the fifth step are successively connected in order, and these are stored in the program storage unit 11 as one machining program.

  Further, the program storage unit 11 stores a measurement program for measuring the shape and dimensions of the processed workpiece W. In this example, the workpiece W is held by the spindle device (not shown), and the measurement program is executed in a state where the tracing stylus M is mounted on the tool post (not shown), whereby the feed mechanism is provided. The tracing stylus M and the work W are relatively moved by the part 2, whereby the shape and dimensions of the work W are measured. In this example, a touch probe is used as the tracing stylus M, and outputs a detection signal when the tracing stylus M comes into contact with the workpiece W.

  The correspondence information storage unit 17 stores the correspondence (information) between each processing part set for the workpiece W and a block of a processing program for processing each processing part, in other words, a processing program corresponding to each processing part. Is stored as a data table as shown in FIG.

  The program analysis unit 12 executes a machining program and a measurement program stored in the program storage unit 11, respectively. More specifically, when executing the machining program, the program analysis unit 12 sequentially reads and analyzes the machining program for each block, extracts an operation command regarding the feed mechanism unit 2, and extracts the extracted operation command. A process of transmitting a command to the execution control unit 13 is performed. Similarly, when executing the measurement program, the program analysis unit 12 sequentially reads and analyzes the measurement program for each block, extracts a command related to the feed mechanism unit 2, and outputs the extracted command. A process for transmitting to the execution control unit 13 is performed.

  Further, when the rework block is determined by the rework block determination unit 16 described later in detail, the program analysis unit 12 receives the determined block information from the rework block determination unit 16 and stores the information in the program storage unit 11. The received target block is executed in the processed machining program. That is, the program analysis unit 12 performs a process of reading and analyzing the target block, extracting an operation command relating to the feed mechanism unit 2, and transmitting the extracted operation command to the execution control unit 13.

  As described above, the program analysis unit 12 executes the machining program, the measurement program, and the target block received from the re-machining block determination unit 16 stored in the program storage unit 11, and the operation extracted in each process. In order to distinguish commands, an operation command extracted when executing the entire machining program is referred to as a first operation command, and is extracted when executing a block (re-machining block) received from the re-machining block determination unit 16. The operation command executed is referred to as a second operation command, and the operation command extracted when the measurement program is executed is referred to as a third operation command. Processing for executing the entire processing program is referred to as first processing, and processing for executing the re-processing block is referred to as second processing.

  The execution control unit 13 generates a drive control signal based on the operation command extracted by the program analysis unit 12 and transmits the generated drive control signal to the feed mechanism unit 2 to control the operation.

  Specifically, when receiving the first operation command from the program analysis unit 12, the execution control unit 13 generates a first drive control signal based on the first operation command, and generates the generated first drive control signal. A control signal is transmitted to the feed mechanism 2 to control the feed mechanism 2. Thereby, the tool rest (not shown) on which the tool T is mounted and the work W relatively move according to the machining program, and the work W is machined by the relative movement. That is, in the present example, the processing of the first to fifth steps is performed.

  Further, when receiving the second operation command from the program analysis unit 12, the execution control unit 13 generates a second drive control signal based on the second operation command, and transmits the generated second drive control signal to the second drive control signal. The data is transmitted to the feed mechanism 2 to control the feed mechanism 2. As a result, the tool T and the work W relatively move according to the machining program, and the work W is machined by the relative movement.

  Further, when receiving the third operation command from the program analysis unit 12, the execution control unit 13 generates a third drive control signal based on the third operation command, and outputs the generated third drive control signal. The data is transmitted to the feed mechanism 2 to control the feed mechanism 2. As a result, the tracing stylus M and the work W relatively move according to the measurement program, and the shape and dimensions of the work W are measured by the relative movement.

  The measuring unit 14 receives a detection signal from the tracing stylus M, transfers the received detection signal to the execution control unit 13, and relates to a tracing stylus M obtained from the feed mechanism unit 2 when receiving the detection signal. Based on the position information, a process of calculating (calculating) a shape dimension of the work W, for example, an outer diameter dimension, an inner diameter dimension, and an end face position in the Z-axis direction, and transmitting the calculated shape dimension to the determination unit 15 is performed. . In this example, the position information of the tracing stylus M is obtained from an encoder provided in the feed mechanism unit 2. The execution control unit 13 causes the feed mechanism unit 2 to execute a measurement operation according to the measurement program while confirming that the tracing stylus M has come into contact with the workpiece W based on the detection signal transferred from the measurement unit 14. The measuring method using the measuring program, the tracing stylus M, and the measuring unit 14 is the same as the measuring method of a known so-called three-dimensional measuring device, and therefore, detailed description thereof is omitted here.

  The determination unit 15 holds information on the permissible range of each processing part as a data table as shown in FIG. 8 and recognizes that there is uncut based on the shape and dimensions transmitted from the measurement unit 14. It is determined whether or not there is a machined part to be processed, and if there is a machined part to be left uncut, the machined part is recognized as a reworked part, and information on the reworked part is sent to the rework block determination unit 16. Perform transmission processing. Note that the uncut portion means that the portion is not sufficiently cut beyond a predetermined allowable range.

  In this example, the determination unit 15 specifically includes an outer diameter processing portion of φ70 mm, an end surface processing portion of the Z-axis plus direction 15 mm position, an end surface processing portion of the Z-axis plus direction 61.5 mm position, and an outer diameter of φ62 mm If the dimension of the grooved part exceeds the allowable range in the plus direction, it is determined that there is uncut material.If the dimension of the inner diameter processing part of φ53 mm exceeds the allowable range in the minus direction. It is determined that there is an uncut portion.

  When the rework block determining unit 16 receives the information on the rework site transmitted from the determination unit 15, the correspondence information stored in the correspondence information storage unit 17 based on the received information on the rework site. , A block corresponding to the received rework portion is determined, and information relating to the determined block is transmitted to the program analysis unit 12.

  For example, when the reworked portion transmitted from the determination unit 15 is an outer diameter portion of φ70 mm, the rework block determination unit 16 refers to the correspondence information shown in FIG. Then, the blocks of the block numbers N101 to N108 are determined as the rework blocks, and information on the block numbers is transmitted to the program analysis unit 14 and the tool wear estimation unit 18.

  When the tool wear estimating unit 18 receives the information on the rework block transmitted from the rework block determination unit 16, the tool wear estimating unit 18 stores the machining program stored in the program analysis unit 11 based on the received information on the rework block. From among the rework blocks, the rework block is read and analyzed, and the tool used in the rework block is recognized. The tool wear estimating unit 18 estimates (calculates) the volume processed by the tool by the first processing and the volume processed by the tool by the second processing.

The volume (the first working volume) V ₁ which is processed by the first processing, from cutting cash d ₁ is set to the surface area S ₁ and the machined portion of the machined portion to be machined by using the tool T, the following It can be calculated by an equation.
V ₁ = S ₁ × d ₁
The volume to be processed by the second processing (second processing volume) V ₂ is the same way the surface area S ₂ and uncut allowance Rework site - from (= measured reference value) d _2, calculated by the following equation can do.
V ₂ = S ₂ × d ₂

Then, tool wear estimation unit 18, based on the first working volume V ₁ and the second machining volume V ₂ that was estimated by performing a second process in addition to the first processing, progressive wear of the tool is further The degree Lr is estimated by the following equation.
Lr = (V ₁ + V ₂ ) / V ₁

  Further, the output unit 19 causes the display device 3 to display information on the progress degree Lr of tool wear calculated by the tool wear estimation unit 18.

  According to the machine tool 1 of the present example having the above configuration, first, the entire processing program stored in the program storage unit 11 is executed by the program analysis unit 12, thereby executing the first processing. . In this example, the first processing is processing of the first to fifth steps shown in FIGS. 3 to 7, and these steps are sequentially executed.

  Then, when the first machining is completed, the measurement program stored in the program storage unit 11 is executed by the program analysis unit 12, whereby the tracing stylus M and the measurement unit 14 cause the work after the first machining to be performed. With respect to W, the shape and dimensions of each processed part are measured, and the measured data is transmitted to the determination unit 15. In this example, the outer diameter of the diameter of 70 mm, the end position of the reference position of 15 mm, the end position of the reference position of 61.5 mm, the outer diameter of the groove of 62 mm in diameter, and the inner diameter of 53 mm in diameter are measured. The dimension data obtained is transmitted to the determination unit 15.

  Next, in the determination unit 15, it is determined whether or not uncut portions are generated for each of the processed portions based on the dimensional data transmitted from the measurement unit 14. The machined part is recognized as a reworked part, and information about the reworked part is transmitted to the reworked block determination unit 16. For example, when the outer diameter of the outer diameter portion whose reference dimension is φ70 mm is +0.04 mm, it is determined that the remaining portion is left uncut, and the information for specifying the outer diameter portion of φ70 mm as the reworked portion. Is transmitted to the rework block determination unit 16.

  The re-processing block determination unit 16 determines a block corresponding to the received re-processing part by referring to the correspondence information stored in the correspondence information storage unit 17 based on the received information on the re-processing part. The information relating to the block is transmitted to the program analysis unit 12 and the tool wear estimation unit 18. For example, when the outer diameter portion of φ70 mm is recognized as the reworked part, the block numbers N101 to N108 are determined to be the blocks corresponding to the reworked part from the data table shown in FIG.

  Then, when receiving the block information related to the rework from the rework block determination unit 16, the program analysis unit 12 receives the received rework target block from the machining program stored in the program storage unit 11. Then, the blocks of the block numbers N101 to N108 are executed. Thereby, the processing part to be reprocessed is reprocessed, that is, the second processing is performed.

  On the other hand, the tool wear estimating unit 18 estimates the degree Lr of further progress of wear of the tool by executing the rework for the tool to be reworked, and outputs the estimated progress degree Lr to the output unit 19. Display on the display device 3 via the

  Thus, according to the machine tool 1 including the numerical control device 10 of the present example, when there is a machining portion where the uncut portion is left in the workpiece W after the first machining, the machining portion is set as a re-machining portion. Since it is certified and only the processing part is reworked by the second processing, the shape accuracy of the processing part left uncut can be kept within a predetermined allowable range without affecting other processing parts. In addition, the work can be prevented from becoming defective.

  In this example, in order to facilitate understanding of the present invention, a case where a simple shape is processed has been illustrated. However, as described above, in recent years, a near net shape type material has been used. . This near net shape type material does not always have a shape similar to the product shape with high accuracy, and in the strict sense its shape accuracy is different at each part of the material, so there is a lot of allowance There is a machined part and a machined part with a small margin. And, when machining a part with a large allowance, a large cutting force acts on the tool, and when machining a part with a small allowance, a relatively small cutting force acts on the tool, In a machined portion having a large allowance, uncut portions exceeding the allowable range may be left. According to the machine tool 1 of the present example, a machining portion having an uncut portion exceeding the allowable range is specified, and only the machining portion is reworked, so that the dimensional accuracy of the uncut portion is reduced to a predetermined tolerance. The present invention is particularly useful when processing an expensive near-net-shape type material, because it can be kept within the range, thereby preventing the workpiece from becoming defective.

  Further, according to the machine tool 1 of the present embodiment, since the shape and dimensions of the work W after the first processing are measured in the machine of the machine tool 1, when the work W is reworked, the work W Since there is no need to remove and attach W, it is possible to prevent processing errors from occurring due to attachment errors.

  Further, according to the machine tool 1 of the present example, by performing the second machining, which is remachining, the tool wear estimating unit 18 estimates the degree of progress Lr of how much extra wear of the tool advances. Further, since the estimated degree of progress Lr is displayed on the display device 3, the operator who operates the machine tool 1 determines how much extra wear of the tool progresses due to the rework. In other words, the effect of the rework on the life of the tool can be easily recognized.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect which this invention can take is not limited to the thing of this example at all.

  For example, in the above example, an example in which the product shown in FIG. 2 is processed by the steps shown in FIGS. 3 to 7 has been described, but the products and the steps to be processed are not limited to this. Not something. There are no restrictions on the products to which the present invention can be applied, and there are no restrictions on the processing steps that can be taken.

  Further, in the present embodiment, the dimension of the workpiece W is automatically measured in the machine tool 1 using the tracing stylus M, but the present invention is not limited to this. The work W may be measured manually inside the machine, or may be measured outside the machine. In these cases, the measurement results are input to the determination unit 15 as appropriate.

  Further, in the above example, the data table shown in FIG. 8 is held in the determination unit 15, but the present invention is not limited to this, and the data table is stored in a storage unit external to the determination unit 15. You may do it.

  Again, the description of the above embodiment is illustrative in all respects and is not limiting. Modifications and changes can be made by those skilled in the art as appropriate. The scope of the present invention is defined by the terms of the claims, rather than the embodiments described above. Further, the scope of the present invention includes modifications from the embodiments within the scope equivalent to the scope of the claims.

REFERENCE SIGNS LIST 1 machine tool 2 feed mechanism unit 3 display device 10 numerical control device 11 program storage unit 12 program analysis unit 13 execution control unit 14 measurement unit 15 determination unit 16 rework block determination unit 17 correspondence information storage unit 18 tool wear estimation unit 19 output Part M Contact point T Tool

Claims (6)

A numerical controller for numerically controlling the feed mechanism of a machine tool having a feed mechanism for relatively moving a tool and a work,
A program storage unit for storing the NC program;
A program analysis unit for sequentially analyzing the NC program stored in the program storage unit for each block and extracting an operation command related to the feed mechanism unit as a first operation command;
A first drive control signal is generated based on the first operation command extracted by the program analysis unit, the generated first drive control signal is transmitted to the feed mechanism unit, and the first processing is performed on the workpiece. An execution control unit to be executed;
A corresponding information storage unit for storing corresponding information of each processing part and the block corresponding to each processing part,
Based on the shape and dimensions obtained by measuring the workpiece after the first processing, determine whether there is an uncut portion, a determination unit that certifies the uncut portion as a rework portion,
When the rework portion is recognized by the determination unit, a block corresponding to the rework portion is determined with reference to the correspondence information stored in the correspondence information storage unit, and information on the determined block is determined. A re-processing block determining unit to be transmitted to the program analyzing unit,
The program analysis unit, based on the block information transmitted from the rework block determination unit, to extract the operation command included in the corresponding block as a second operation command from the program storage unit,
The execution control unit generates a second drive control signal based on the second operation command extracted by the program analysis unit, transmits the generated second drive control signal to the feed mechanism unit, A numerical control device configured to execute a second process for reworking the reworked portion on a workpiece after one process.   2. The numerical control device according to claim 1, further comprising: a measurement unit that calculates a shape and a dimension of the workpiece after the first processing, and outputs the calculation result to the determination unit.   When the rework portion is recognized by the determination unit and the rework block is determined by the rework block determination unit, the determined rework block is analyzed and used in processing corresponding to the rework block. By recognizing the tool, analyzing the NC program, and performing the first processing and the second processing using the recognized tool, the processing volumes processed by the tool were estimated and estimated, respectively. 3. A tool wear estimating unit for estimating a degree of further progress of tool wear by executing a second machining in addition to the first machining based on the machining volume. Numerical control device.   4. The numerical control device according to claim 3, further comprising an output unit that outputs information on the degree of progress of tool wear estimated by the tool wear estimation unit to the outside. A numerical control method for numerically controlling a feed mechanism of a machine tool including a feed mechanism for relatively moving a tool and a work,
Storing the NC program;
Sequentially analyzing the stored NC program for each block and extracting an operation command relating to the feed mechanism unit as a first operation command;
Generating a first drive control signal based on the extracted first operation command, transmitting the generated first drive control signal to the feed mechanism unit, and causing the workpiece to perform first machining;
Storing correspondence information between each processing part and the block corresponding to each processing part;
Based on the shape and dimensions obtained by measuring the workpiece after the first processing, determine whether there is an uncut portion, and certify the uncut portion as a rework portion,
When the reworked part is certified, by referring to the correspondence information, determining a block corresponding to the reworked part,
Extracting an operation command included in the determined block as a second operation command;
A second drive control signal is generated based on the extracted second operation command, and the generated second drive control signal is transmitted to the feed mechanism unit. Performing a second machining for re-machining the machining portion.   A computer program for causing a computer to execute the numerical control method according to claim 5.

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