Machining program correction method and information processing device

Abstract

To more easily obtain cutting point information used for correcting a machining program. [Solution] The method for correcting a machining program comprises step S12 of creating first machining information including tool path information that represents the path of a tool, step S13 of creating a first machining program based on the first machining information, step S16 of calculating an error between a machined product manufactured by executing the first machining program on an NC machine tool and a target shape of the machined product, step S17 of creating second machining information by correcting the first machining information based on the calculated error, and step S18 of creating a second machining program for operating the NC machine tool based on the second machining information. In addition to the tool path information, the first machining information includes cutting point information that represents cutting points where the tool corresponding to each point data of the tool path information meets the target shape.

Description

[Technical Field]

[0001] The present invention relates to a method for correcting a machining program and an information processing device for executing the correction of the machining program. [Background technology]

[0002] A method for correcting a machining program executed by a numerically controlled machine tool (NC machine tool) is disclosed in Patent Document 1, for example.

[0003] The machining program correction method of Patent Document 1 cuts a workpiece at multiple cross sections, compares the measured shape of each cross section with a target shape, and calculates an error. Specifically, the error is calculated as follows: The machining program correction unit associates point cloud data of the measured shape with point cloud data of the target shape. The point cloud data of the target shape uses point cloud data representing cutting points where the tool and workpiece come into contact, calculated from information representing the tip point position of the tool in the machining program. The machining program correction unit compares each point data of the cutting points with the corresponding point data of the measured shape, and corrects the machining program to reduce the error. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7286860 Summary of the Invention [Problem to be solved by the invention]

[0005] In the machining program correction method of Patent Document 1, point cloud data of cutting points in the machining program, which is used to calculate the error between the measured shape and the target shape, is calculated from information representing the tip point position of the tool in the machining program. In other words, the point cloud data of cutting points is obtained by performing some kind of arithmetic processing on the information representing the tip point position of the tool.

[0006] An object of the present invention is to more easily obtain cutting point information used for correcting a machining program. [Means for solving the problem]

[0007] The method for correcting a machining program of the present invention is a method for correcting a machining program executed by an NC machine tool, and includes the steps of: creating first machining information including tool path information representing a tool path when machining a workpiece into a target shape based on target shape information representing a target shape of the workpiece to be manufactured by the NC machine tool; creating a first machining program for operating the NC machine tool based on the first machining information; and comparing the measured workpiece with the target shape of the workpiece based on measurement information representing the shape of the workpiece obtained by actually measuring the workpiece manufactured by executing the first machining program on the NC machine tool. a step of creating second machining information by correcting the first machining information based on the calculated error; and a step of creating a second machining program for operating an NC machine tool based on the second machining information, wherein the first machining information includes, in addition to the tool path information, cutting point information that indicates cutting points where the tool corresponding to the tool path information and the target shape meet, and in the step of calculating the error, an error between the measured machined workpiece and the target shape of the machined workpiece is calculated based on each cutting point data in the cutting point information and measurement point data corresponding to each cutting point data in the measurement information. [Effects of the Invention]

[0008] When an NC machine tool processes a workpiece, it does so by numerically controlling the tool spindle to which the tool is attached and the workpiece spindle to which the workpiece is attached, etc. Therefore, the machining program for controlling the NC machine tool contains control codes for the equipment equipped on the machine tool, such as the tool spindle.

[0009] On the other hand, before creating a machining program for an NC machine tool, the way in which the tool will be placed and moved relative to the workpiece in order to machine the workpiece into the target shape, i.e., the tool path, is considered. This consideration is carried out using design support software such as CAM. As a result of this consideration, machining information including tool path information is created. Because this machining information does not directly describe the information for operating the tool spindle and other parts of the NC machine tool, it is converted into a machining program that the NC machine tool can understand, for example, using design support software.

[0010] As described above, since a machining program is a program for controlling the tool spindle of an NC machine tool, the machining program does not include cutting point information. However, the machining information that forms the basis of the machining program is created by considering the tool movement path relative to the workpiece. Therefore, when considering the tool movement path, the cutting point, which is the contact point between the workpiece and the tool, is taken into consideration. In other words, although cutting point information is not required for creating a machining program for an NC machine tool and is not output, it is inherent in the design support software. The machining program correction method of the present invention is characterized by outputting and utilizing cutting point information that is inherent in the design support software and not normally output. In this way, the machining program correction method of the present invention outputs the cutting point information inherent in the design support software at the time the first machining information is created, by including it in the first machining information. The machining program correction method of the present invention compares the output cutting point information with actually measured measurement information to calculate the error between the target shape and the actually measured shape. With this method, it is not necessary to calculate the cutting point information based on other information that is normally output (e.g., information on the tool path, tool shape, etc.). Therefore, according to the machining program correcting method of the present invention, cutting point information used for correcting the machining program can be obtained more easily. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of a machining system that executes a machining program correction method according to this embodiment. [Figure 2]FIG. 2 is a schematic diagram showing the configuration of an NC machine tool. [Figure 3] FIG. 3 is a functional block diagram showing the configuration of the information processing device. [Figure 4] FIG. 4 is a flowchart of a method for correcting a machining program. [Figure 5] FIG. 5 is a conceptual diagram for explaining the first processing information creating step. [Figure 6] FIG. 6 is a conceptual diagram for explaining the error calculation step. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] FIG. 1 is a schematic diagram of a machining system that executes the machining program correction method of this embodiment. The machining system 100 includes an NC machine tool 1 and an information processing device 2. The NC machine tool 1 is configured to be able to communicate with the information processing device 2. The communication method may be wired communication or wireless communication. In the machining system 100, various machining processes for machining a workpiece are designed in the information processing device 2, and the information is sent to the NC machine tool 1, which then performs machining of the workpiece. Each device will be described in detail below.

[0014] FIG. 2 is a schematic diagram showing the configuration of an NC machine tool. In this embodiment, a five-axis machine is used as the NC machine tool 1. The NC machine tool 1 is not limited to being able to machine one type of workpiece W. In this embodiment, the NC machine tool 1 is configured to be able to perform gear cutting on the workpiece W to be machined. Note that when viewed from the front of the NC machine tool 1, the left-right direction, the front-rear direction, and the up-down direction are referred to as the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively.

[0015] The NC machine tool 1 includes a tool spindle 11 to which various tools are attached, and a swing table 12 on which a workpiece W is placed. The tool spindle 11 is provided on the ceiling side of a machining chamber. The tool spindle 11 is configured to be able to translate in three axial directions: the X-axis, the Y-axis, and the Z-axis. The tool spindle 11 is also configured to be able to rotate a tool T attached via a tool holder around a rotation axis (the central axis of the tool spindle) parallel to the Z-axis. The swing table 12 is provided on the bottom side of the machining chamber. The swing table 12 is configured to be able to rotate around a rotation axis (C-axis) parallel to the Z-axis and a rotation axis (A-axis) parallel to the Y-axis.

[0016] The NC machine tool 1 is provided with a tool magazine (not shown) that is located outside the machining chamber and that houses multiple devices. The NC machine tool 1 is configured so that devices are exchanged between the tool magazine and the tool spindle 11 by an automatic tool change mechanism (not shown). The devices housed in the tool magazine include tools used to machine the workpiece as well as measuring devices that measure the shape of the workpiece. Examples of measuring devices include touch probes and laser scanner units.

[0017] The NC machine tool 1 is equipped with a control device 13 that controls each piece of equipment such as the tool spindle 11, oscillating table 12, etc. The control device 13 is composed of a computer including a CPU, a recording medium, etc. The control device 13 controls the operation of each component by executing a computer program stored in the recording medium. The control device 13 transmits control signals to each piece of equipment such as the tool spindle 11 and oscillating table 12 in accordance with a machining program (NC program). The machining program is written in G-code or the like, and is a program that can be read by the NC machine tool 1 (control device 13). The machining program may be stored in advance on a recording medium, or may be input when the NC machine tool 1 is operated.

[0018] 3 is a functional block diagram showing the configuration of an information processing device. The information processing device 2 is configured as a computer including a CPU, a recording medium, etc. The information processing device 2 realizes each process by executing a computer program stored in the recording medium. The information processing device 2 includes a design information acquisition unit 21, a machining information creation unit 22, a machining program creation unit 23, an output unit 24, a measurement information acquisition unit 25, an error calculation unit 26, and a memory unit 27.

[0019] The design information acquisition unit 21 acquires information necessary to create machining information. Examples of the information necessary to create machining information include target shape information that represents a target shape of a workpiece to be manufactured by the NC machine tool 1, workpiece shape information that represents the shape of the workpiece, and tool information that represents the type and shape of one or more tools used to machine the workpiece. The information acquired by the design information acquisition unit 21 may be created by the information processing device 2, or may be created by a device separate from the information processing device 2. The design information acquisition unit 21 transmits the acquired information to the machining information creation unit 22.

[0020] The machining information creation unit 22 creates first machining information based on the information received from the design information acquisition unit 21. The first machining information includes tool path information that represents the path of the tool when machining the workpiece into a target shape. The machining information creation unit 22 calculates the path of the tool so that the difference between the workpiece shape and the target shape can be removed (cut) by the tool. At this time, the machining information creation unit 22 creates tool path information so that the cutting point, which is the contact point between the tool and the workpiece, is aligned with the target shape. That is, the machining information creation unit 22 also creates cutting point information that represents the cutting point along with the creation of the tool path information. The machining information creation unit 22 transmits the created first machining information to the machining program creation unit 23. The machining information creation unit 22 also stores the created first machining information and cutting point information in the memory unit 27.

[0021] The machining program creation unit 23 creates a first machining program based on the first machining information received from the machining information creation unit 22. The first machining program is an NC program that can be read by the NC machine tool 1, such as G-code. That is, the machining program creation unit 23 converts the first machining information into a first machining program, which is a program for operating the NC machine tool 1. The machining program creation unit 23 transmits the created first machining program to the NC machine tool 1 via the output unit 24. Thereafter, as will be described later, the NC machine tool 1 machines the workpiece according to the first machining program and measures the shape of the machined product.

[0022] The measurement information acquisition unit 25 acquires measurement information representing the shape of a workpiece obtained by actually measuring the workpiece manufactured by the NC machine tool 1. The measurement information is created by a measuring device provided in the NC machine tool 1. The measurement information acquisition unit 25 transmits the acquired measurement information to the error calculation unit 26.

[0023] When the error calculation unit 26 receives measurement information from the measurement information acquisition unit 25, it acquires cutting point information from the storage unit 27. The error calculation unit 26 calculates the error between the shape of the workpiece measured based on the measurement information and the cutting point information and the target shape. If the calculated error is less than a predetermined threshold value, the error calculation unit 26 causes the display unit 28 to display a message that processing has been completed. If the calculated error is equal to or greater than the predetermined threshold value, the error calculation unit 26 creates error information representing the calculated error and transmits it to the processing information creation unit 22.

[0024] When the machining information creation unit 22 receives the error information from the error calculation unit 26, it acquires the first machining information from the memory unit 27. The machining information creation unit 22 corrects the first machining information based on the error information and creates second machining information. The machining information creation unit 22 transmits the created second machining information to the machining program creation unit 23. The machining program creation unit 23 converts the second machining information into a second machining program. The machining program creation unit 23 transmits the second machining program to the NC machine tool 1 via the output unit 24.

[0025] Next, a method for correcting a machining program according to this embodiment will be described. The method for correcting a machining program corrects an executed machining program in order to reduce an error between the target shape of a workpiece manufactured by executing the machining program on an NC machine tool.

[0026] 4 is a flowchart of a method for correcting a machining program. The method for correcting a machining program includes a modeling step S11, a first machining information creation step S12, a first machining program creation step S13, an actual machining step S14, an actual measurement step S15, an error calculation step S16, a second machining information creation step S17, and a second machining program creation step S18.

[0027] The modeling step S11 is a step of creating a three-dimensional model of a workpiece to be manufactured by an NC machine tool. The modeling step S11 may be executed by the information processing device 2 or by a device separate from the information processing device 2. The modeling step S11 is executed, for example, by CAD (Computer Aided Design) software. The modeling step S11 is executed, for example, by CAD software dedicated to gears. In the modeling step S11, specification information of the gear is input into the CAD software. The CAD software creates a three-dimensional model of the gear based on the input specification information. This three-dimensional model corresponds to the target shape of the workpiece (gear) to be manufactured by the NC machine tool. The three-dimensional model is composed of target shape information that represents the target shape as CAD data.

[0028] After the modeling step S11 is executed, a first processing information creation step S12 is executed. The first processing information creation step S12 is executed by the processing information creation unit 22 of the information processing device 2. The first processing information creation step S12 is executed by, for example, CAM (Computer Aided Manufacturing) software. The first processing information creation step S12 is executed by, for example, CAM software dedicated to gears. Note that the CAM function and the CAD function may be executed by separate software or may be executed by the same software.

[0029] 5 is a conceptual diagram for explaining the first machining information creation step. The first machining information creation step S12 is a step of creating a path along which a tool will pass in order to machine a workpiece into a machined product having a target shape. In the first machining information creation step S12, the first machining information is created by CAM software. The first machining information includes coordinate data (X, Y, Z) that represents the coordinates of the tool path in three dimensions, vector data (Vx, Vy, Vz) that represents the movement direction and movement speed of the tool at each coordinate of the tool path in three dimensions, cutting point data that represents the cutting points where the tool and the target shape meet in three dimensions, and normal vector data that represents the normal vector at each cutting point.

[0030] The CAM software acquires target shape information created by the CAD software. The CAM software creates data (cutting point information) of multiple cutting points along the outer shape of the target shape based on the CAD data in the target shape information. Each point data in the cutting point information is expressed as cutting point coordinate data (Px, Py, Pz). All or part of the multiple cutting point data included in the cutting point information may be set on the outer surface of the target shape represented by the CAD data (target shape information). All or part of the multiple cutting point data may not be set on the outer surface of the target shape. The multiple cutting point data only need to substantially represent the outer shape of the target shape.

[0031] Information about tools used in NC machine tools to machine a workpiece into a target shape is input to the CAM software. The tool information includes the type of tool, the tool shape, and information that allows the tool shape to be calculated (such as the overall length and diameter of the cutting tool). The CAM software calculates a command point corresponding to certain point data (certain cutting point) in the cutting point information based on the tool information. In this embodiment, the command point is set to the position (coordinates) of the tip point of the tool. The CAM software calculates a command point corresponding to each point data in the cutting point information and creates three-dimensional data of multiple command points. This three-dimensional data of multiple command points corresponds to coordinate data (X, Y, Z) that represents the coordinates of the tool path.

[0032] The CAM software calculates vector data (Vx, Vy, Vz) from the coordinate data, which represents the tool movement direction and movement speed at each coordinate. These coordinate data (X, Y, Z) and vector data (Vx, Vy, Vz) correspond to tool path information, which represents the tool path. Each piece of coordinate data and each piece of vector data in the tool path information is calculated from each piece of cutting point data in the cutting point information, and therefore corresponds to each piece of cutting point data in the cutting point information. In other words, one data set (coordinate data and vector data) in the tool path information is paired with one piece of cutting point data (coordinates of the cutting point) in the cutting point information.

[0033] The CAM software further calculates normal vector information including normal vector data (Nx, Ny, Nz) for each cutting point in the cutting point information. The normal vector data is expressed as a three-dimensional vector of the normal at the cutting point set on the outer shape of the target shape. The normal vector information is composed of normal vector data for each cutting point, i.e., multiple normal vector data. The normal vector information is calculated based on the target shape information and cutting point information.

[0034] The CAM software outputs the calculated tool path information (X, Y, Z, Vx, Vy, Vz), cutting point information (Px, Py, Pz), and normal vector information as first machining information. The CAM software outputs the first machining information as CL data (Cutter Location Data).

[0035] Here, the machining information (CL data) output by the CAM software is sent to a post-processor. The post-processor converts the received machining information into an NC program written in G-code so that the machine tool can understand it. Therefore, the machining information output by the CAM software usually includes tool path information (X, Y, Z, Vx, Vy, Vz) but does not include cutting point information (Px, Py, Pz). In other words, the CAM software is set not to output cutting point information (Px, Py, Pz), which is information unnecessary for creating an NC program. In contrast, the machining program correction method of this embodiment is characterized in that the CAM software outputs cutting point information (Px, Py, Pz). This point will be described later.

[0036] Referring to FIG. 4, after the first machining information creating step S12 is executed, a first machining program creating step S13 is executed. The first machining program creating step S13 is executed by the machining program creating unit 23 of the information processing device 2. The first machining program creating step S13 is executed by, for example, post-processor software. In the first machining program creating step S13, a first machining program for operating an NC machine tool is created based on the tool path information (X, Y, Z, Vx, Vy, Vz) output by the CAM software in the first machining information creating step S12. The first machining program is a computer program written in G-code. That is, the post-processor software converts the first machining information, which is CL data, into an NC program. Note that the cutting point information (Px, Py, Pz) and normal vector information (Nx, Ny, Nz) are not used in the first machining information creating step S12. The post-processor software is configured to ignore the cutting point information (Px, Py, Pz) and the normal vector information (Nx, Ny, Nz) included in the first machining information. The post-processor software transmits the created first machining program to the NC machine tool.

[0037] After the first machining program creation step S13 is executed, an actual machining step S14 is executed. The actual machining step S14 is a step in which the NC machine tool executes the first machining program and machines the workpiece into a machined piece. That is, the actual machining step S14 is executed by the NC machine tool 1.

[0038] After the actual machining step S14 is executed, the actual measurement step S15 is executed. The actual measurement step S15 is a step for measuring the shape of the workpiece manufactured by the NC machine tool in accordance with the first machining program. The actual measurement step S15 is executed by the NC machine tool 1. The actual measurement step S15 is executed, for example, using a measuring tool (such as a probe) attached to the tool spindle of the NC machine tool. The measuring tool transmits data obtained by measuring the shape of the workpiece at multiple points to, for example, measurement CAM software. The measurement CAM software creates measurement information that represents the received shape of the workpiece as point cloud data (data of multiple measurement points).

[0039] After the actual measurement step S15 is executed, an error calculation step S16 is executed. The error calculation step S16 is a step for calculating an error between the actually measured workpiece and the target shape of the workpiece. The error calculation step S16 is executed by the error calculation unit 26 of the information processing device 2. The error calculation step S16 is executed by, for example, measurement CAM software.

[0040] FIG. 6 is a conceptual diagram for explaining the error calculation step. In addition to measurement information, the measurement CAM software acquires cutting point information and normal vector information. Each point data in the cutting point information is set on the outer shape of the target shape. Therefore, the measurement CAM software treats the cutting point information as information that pseudo-represents the target shape.

[0041] The measurement CAM software identifies measurement point data in the measurement information corresponding to a cutting point (Px, Py, Pz) based on the cutting point (Px, Py, Pz) and the normal vector (Nx, Ny, Nz) at the cutting point. More specifically, the measurement CAM software determines the measurement point data on the normal vector (Nx, Ny, Nz) or an extension of the normal vector as the measurement point data corresponding to the cutting point (Px, Py, Pz). If there is no measurement point data on the normal vector (Nx, Ny, Nz) or an extension of the normal vector, the measurement CAM software associates the measurement point data closest to the point on the measured surface that intersects with the normal vector (Nx, Ny, Nz) or an extension of the normal vector with the cutting point (Px, Py, Pz). The measured surface is a virtual outer surface of the workpiece calculated from the measurement information.

[0042] The measurement CAM software calculates the error between the cutting point and the measurement point corresponding to that cutting point. This error is calculated as error information indicating the difference between the cutting point and the corresponding measurement point in each of the X, Y, and Z directions. In other words, the error is calculated as three-dimensional information. The measurement CAM software calculates a corrected cutting point based on the error information. Specifically, the CAM software calculates a point that is point-symmetric to the measurement point, with the cutting point as the center, as the corrected cutting point. The measurement CAM software performs this process for each cutting point data in the cutting point information. As a result, the measurement CAM software calculates corrected cutting point information that includes multiple corrected cutting points. The measurement CAM software sends the corrected cutting point information to the CAM software.

[0043] After the error calculation step S16 is executed, a second machining information creation step S17 is executed. The second machining information creation step S17 is a step of creating second machining information by correcting the first machining information based on the calculated error information (corrected cutting point information). The second machining information creation step S17 is executed by the machining information creation unit 22 of the information processing device 2. The second machining information creation step S17 is executed by, for example, CAM software.

[0044] The CAM software creates corrected tool path information that passes through each corrected cutting point based on each corrected cutting point data and tool information in the acquired corrected cutting point information. More specifically, the CAM software corrects the tool path information (X, Y, Z, Vx, Vy, Vz) in the first machining information before correction to corrected tool path information (Xrev, Yrev, Zrev, Vx, Vy, Vz). In this embodiment, the CAM software corrects the tool coordinate data (X, Y, Z), but does not correct the tool vector data (Vx, Vy, Vz). However, the CAM software may correct the tool vector data.

[0045] The CAM software corrects the cutting point information (Px, Py, Pz) in the first processing information before correction to corrected cutting point information (Pxrev, Pyrev, Pzrev). In this embodiment, the CAM software does not correct the normal vector information (Nx, Ny, Nz). However, the CAM software may correct the normal vector information.

[0046] As a result of this processing, the CAM software creates second machining information (Xrev, Yrev, Zrev, Vx, Vy, Vz, Nx, Ny, Nz, Pxrev, Pyrev, Pzrev) by correcting the first machining information. The CAM software then sends the created second machining information to the post processor.

[0047] After the second machining information creation step S17 is executed, the second machining program creation step S18 is executed. The second machining program creation step S18 is executed by the machining program creation unit 23 of the information processing device 2. The second machining program creation step S18 is executed, for example, by post-processor software. In the second machining program creation step S18, a second machining program for operating the NC machine tool is created based on the corrected tool path information (Xrev, Yrev, Zrev, Vx, Vy, Vz, Nx, Ny, Nz, Pxrev, Pyrev, Pzrev) output by the CAM software in the second machining information creation step S17. The second machining program is a computer program written in G-code. Note that the corrected cutting point information (Pxrev, Pyrev, Pzrev) and normal vector information (Nx, Ny, Nz) are not used in the second machining information creation step S17. These pieces of information are used when further correction is required. The post-processor software sends the created second machining program to the NC machine tool.

[0048] The NC machine tool executes the received second machining program and further processes the workpiece manufactured in actual machining step S14. That is, the NC machine tool executes the second machining program to perform correction machining of the workpiece.

[0049] As described above, the machining program correction method of this embodiment compares the cutting point information included in the first machining information with the measurement information of the actually measured workpiece to calculate error information and correct the machining program. The cutting point information used in this case is information inherent in the CAM software. The machining program correction method of this embodiment outputs and uses the cutting point information inherent in the CAM software.

[0050] More specifically, a machining program (NC program) executed by an NC machine tool is created based on tool path information. Therefore, CAM software typically outputs tool path information and does not output cutting point information that is unnecessary for creating an NC machining program. However, cutting point information is information used when creating tool path information in the CAM software. In other words, cutting point information is information used in internal processing when creating tool path information in the CAM software. A feature of the machining program correction method of this embodiment is that the cutting point information used in this internal processing is intentionally output to the CAM software and used to correct the machining program.

[0051] For example, suppose that the CAM software outputs tool path information as usual but does not output cutting point information. In this case, if you want to correct the machining program (tool path information) using the cutting point information, some software must calculate the cutting point information from the tool path information and tool information output from the CAM software. In addition, a process is required to associate the calculated cutting point information with the tool path information.

[0052] In contrast, the machining program correction method of this embodiment uses cutting point information inherent in the CAM software. In the CAM software, cutting point information is created as an internal process based on input target shape information. In the CAM software, tool path information is created as an internal process based on the created cutting point information. That is, in the CAM software, the tool path information and cutting point information are associated with each other at the stage when the tool path information is created. The machining program correction method of this embodiment uses cutting point information that has been associated with the tool path information in advance in this way. Therefore, there is no need to calculate the cutting point information from the tool path information output from the CAM software. Furthermore, there is no need to associate the tool path information with the cutting point information. Therefore, according to the machining program correction method of this embodiment, the cutting point information used to correct the machining program can be more easily obtained.

[0053] The above-described embodiments are illustrative in all respects and are not limiting. Modifications and variations are possible for those skilled in the art. The scope of the present invention is defined not by the above-described embodiments but by the claims. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope of the claims and their equivalents.

[0054] For example, in the above embodiment, the NC machine tool is a five-axis machining tool. However, the NC machine tool is not limited to a five-axis machining tool. The NC machine tool may be any machine tool that has the function of performing cutting work.

[0055] In the above embodiment, the command point, i.e., the tool coordinate data (X, Y, Z) is set to the position (coordinates) of the tip point of the tool. However, the command point is not limited to this. The command point may be set to any position on the tool.

[0056] In the above-described embodiment, the first machining information and the second machining information include normal vector information. However, the first machining information and the second machining information do not have to include normal vector information. For example, in the error calculation step, a vector perpendicular to the tool movement vector from the cutting point or measurement point data on (or in the vicinity of) the extension of the vector may be used as the measurement point data corresponding to the cutting point. In other words, normal vector information may be replaced with other information.

[0057] In the above-described embodiment, the machining program correction method has been described as including the modeling step S11, the actual machining step S14, and the actual measurement step S15. However, the machining program correction method does not have to include these steps. For example, the modeling step may be executed on another computer or at another location. The machining program correction method only needs to be able to acquire target shape information created in the modeling step. The actual machining step and the actual measurement step may be executed at another location. The machining program correction method only needs to be able to acquire measurement information obtained by actually measuring a workpiece manufactured by executing the first machining program. [Explanation of symbols]

[0058] 100: Processing system 1:NC machine tool 11: Tool spindle 12: Oscillating table 13: Control device 2: Information processing equipment 21: Design information acquisition department 22: Processing information creation section 23: Machining program creation section 24: Output section 25: Measurement information acquisition unit 26:Error calculation section 27: Storage section 28:Display section S11: Modeling step S12: First processing information creation step S13: First machining program creation step S14: Actual machining step S15: Measured step S16: Error calculation step S17: Second processing information creation step S18: Second machining program creation step

Claims

1. A method for correcting a machining program executed by an NC machine tool, comprising: a step of creating first machining information including tool path information representing a tool path when machining a workpiece into a target shape based on target shape information representing a target shape of the workpiece to be manufactured by an NC machine tool; creating a first machining program for operating an NC machine tool based on the first machining information; a step of calculating an error between the actually measured shape of a workpiece manufactured by executing the first machining program in an NC machine tool and a target shape of the workpiece based on measurement information representing the shape of the workpiece obtained by actually measuring the workpiece; creating second processing information by correcting the first processing information based on the calculated error; creating a second machining program for operating an NC machine tool based on the second machining information; The first processing information is In addition to the tool path information, cutting point information representing a cutting point where the tool corresponding to the tool path information contacts the target shape is included, In the step of calculating the error, A method for correcting a machining program, which calculates an error between a measured workpiece and a target shape of the workpiece based on each cutting point data in the cutting point information included in the first machining information and measurement point data corresponding to each cutting point data in the measurement information.

2. The machining program correction method according to claim 1, The step of creating the first processing information includes: acquiring the target shape information; creating the tool path information and the cutting point information based on the target shape information, and outputting each cutting point data in the cutting point information and the tool path information associated with each cutting point data.

3. The machining program correction method according to claim 2, The step of creating the first processing information includes: Executed in CAM software that creates the target shape information, The CAM software includes: A machining program correction method that outputs the cutting point information and the tool path information.

4. An information processing device that corrects a machining program executed by an NC machine tool, a process of creating first machining information including tool path information representing a tool path when machining a workpiece into a target shape based on target shape information representing a target shape of the workpiece to be manufactured by an NC machine tool; a process of creating a first machining program for operating an NC machine tool based on the first machining information; a process of calculating an error between the actually measured shape of a workpiece manufactured by executing the first machining program in an NC machine tool and a target shape of the workpiece, based on measurement information representing the shape of the workpiece obtained by actually measuring the workpiece; A process of creating second processing information by correcting the first processing information based on the calculated error; a process of creating a second machining program for operating an NC machine tool based on the second machining information, The first processing information is In addition to the tool path information, cutting point information representing a cutting point where the tool corresponding to the tool path information contacts the target shape is included, The information processing device includes: In the process of calculating the error, an information processing device calculates the error between the measured workpiece and the target shape of the workpiece based on each cutting point data in the cutting point information included in the first processing information and measurement point data corresponding to each cutting point data in the measurement information.

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