Information processing device, information processing method, and program

Abstract

To provide a machine tool control device and the like that can set the tool rotation speed taking into account changes in material properties.SOLUTION: An information processing device controls a machine tool that cuts a workpiece using a tool, and includes: a storage unit that stores physical property value information indicating physical property values related to the past cutting processing in association with material information indicating the material of the workpiece and tool type information indicating the type of tool; an acquisition unit that acquires the material information, the tool type information, tool diameter information indicating a tool diameter of the tool, and cutting speed information of the workpiece; a rotation speed calculation unit that calculates a rotation speed of the tool based on the tool diameter information and the cutting speed information; a correction value calculation unit that refers to the storage unit and calculates a correction value for the rotation speed by using the physical property value information at a previous time and the time before that correspond to the same material information and tool type information as the newly acquired material information and tool type information; and a correction unit that corrects the rotation speed of the tool with the correction value of the rotation speed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an information processing device, an information processing method, and a program. [Background technology]

[0002] Patent document 1 discloses a technology in which a machine tool equipped with a control system having a CNC (Computerized Numerical Control) device that executes NC calculations using an NC program retracts a tool from a workpiece when an abnormality occurs during machining. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-024443 Summary of the Invention [Problem to be solved by the invention]

[0004] When cutting a workpiece using a machine tool, a pre-calculated tool rotation speed is set. The set rotation speed is a calculated ideal value. Meanwhile, as cutting is performed on the workpiece, the physical property values ​​of the tool and the like related to the cutting change over time. For this reason, a discrepancy occurs between the tool rotation speed corresponding to the actual physical property values ​​and the ideal value of the rotation speed. As a result, it becomes impossible to cut the workpiece at the tool rotation speed corresponding to the actual physical property values. Patent Document 1 is a technology for dealing with abnormalities during processing, and does not solve the above-mentioned problem.

[0005] According to one aspect, the present invention has an object to provide an information processing device and the like capable of setting the rotation speed of a tool taking into account changes in physical property values. [Means for solving the problem]

[0006] An information processing device according to one embodiment of the present invention is an information processing device that controls a machine tool that performs cutting processing on a workpiece using a tool, and includes: an acquisition unit that acquires, from a memory unit that stores physical property value information indicating physical property values ​​related to the past cutting processing performed on the workpiece in correspondence with material information indicating the material of the workpiece and tool type information indicating the type of the tool, the material information, the tool type information, tool diameter information indicating the tool diameter of the tool, and cutting speed information indicating the cutting speed when cutting the workpiece; a rotation speed calculation unit that calculates the rotation speed of the tool based on the tool diameter information and the cutting speed information; a correction value calculation unit that refers to the memory unit, reads out the physical property value information before last and the previous physical property value information that correspond to the same material information and tool type information as the newly acquired material information and tool type information, and calculates a rotation speed correction value of the rotation speed using the read out physical property value information before last and the previous physical property value information; and a correction unit that corrects the rotation speed of the tool with the rotation speed correction value.

[0007] A machining control method according to one aspect of the present invention is a machining control method for controlling a machine tool that performs cutting processing on a workpiece using a tool, the method comprising: acquiring, from a memory unit that stores physical property information indicating physical property values ​​related to the past cutting processing performed on the workpiece in correspondence with material information indicating the material of the workpiece and tool type information indicating the type of the tool, the material information, the tool type information, tool diameter information indicating the tool diameter of the tool, and cutting speed information indicating the cutting speed when cutting the workpiece; calculating a rotation speed of the tool based on the newly acquired tool diameter information and cutting speed information; referring to the memory unit, reading out the physical property value information before last and the previous physical property value information that correspond to the same material information and tool type information as the newly acquired material information and tool type information; calculating a rotation speed correction value for the rotation speed using the read physical property value information before last and the previous physical property value information; and correcting the rotation speed of the tool with the rotation speed correction value.

[0008] A program according to one aspect of the present invention is a program to be executed by a computer of an information processing device that controls a machine tool that performs cutting processing on a workpiece using a tool, the program causing the computer to acquire, from a memory unit that stores physical property value information indicating physical property values ​​related to the past cutting processing performed on the workpiece in correspondence with material information indicating a material of the workpiece and tool type information indicating a type of the tool, the material information, the tool type information, tool diameter information indicating a tool diameter of the tool, and cutting speed information indicating a cutting speed when cutting the workpiece, calculate a rotation speed of the tool based on the newly acquired tool diameter information and cutting speed information, refer to the memory unit to read out the physical property value information before last and the previous physical property value information that correspond to the same material information and tool type information as the newly acquired material information and tool type information, calculate a rotation speed correction value for the rotation speed using the read out physical property value information before last and the previous physical property value information, and correct the rotation speed of the tool with the rotation speed correction value. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates an example of a conversion control system. [Diagram 2] FIG. 2 is a block diagram illustrating an example of a server. [Diagram 3] FIG. 2 is a block diagram showing an example of a machine tool control device. [Figure 4] FIG. 1 illustrates an example of a machine tool. [Diagram 5] FIG. 13 is a diagram illustrating an example of a tool table. [Figure 6] FIG. 4 is a diagram illustrating an example of a physical property table. [Figure 7] FIG. 11 is a diagram showing an example of supplementary information of drawing data; [Figure 8] An example of a flow of processing related to tool data will be described. [Figure 9] 13 is a diagram showing an example of a change in a tool table. [Figure 10] 13 is a flowchart showing an example of a processing flow relating to physical property information. [Figure 11] 13 is a flowchart showing an example of a process flow of a physical property storage process. [Figure 12] FIG. 11 is a diagram showing an example of a change in a physical property table. [Figure 13] 10 is a flowchart showing an example of the flow of a correction process. [Figure 14] FIG. 4 is a diagram illustrating an example of calculation of a rotation speed control value. [Figure 15] 14 is a flowchart continuing from FIG. 13. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the present embodiment will be described with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and duplicated explanations are omitted. In addition, all of the configurations described in the present embodiment are not necessarily essential configurations of the present disclosure.

[0011] 1 is a diagram showing an example of a machining control system 100. The machining control system 100 includes a server 101, a plurality of orderer computers 102 (102A, 102B, 102C, ...), a plurality of machine tool controllers 103 (103A, 103B, 103C, ...), and a plurality of machine tools 104 (104A, 104B, 104C, ...). There may be only one orderer computer 102, one machine tool controller 103, and one machine tool 104.

[0012] The server 101, each orderer computer 102, and each machine tool control device 103 are connected via a network NW such as the Internet. Each machine tool control device 103 is connected to a machine tool 104. A plurality of machine tools 104 may be connected to one machine tool control device 103.

[0013] The server 101 is an information processing device that controls machining when the machine tool 104 performs cutting machining on a workpiece. The server 101 is, for example, a cloud server. The server 101 controls each machine tool control device 103 via a network NW. Hereinafter, cutting machining will be simply referred to as machining.

[0014] The orderer computer 102 is a computer belonging to a company that places an order for the processing of a workpiece. The orderer computer 102 is, for example, a personal computer. The orderer computers 102A to 102C are, for example, computers that belong to different companies. A plurality of orderer computers 102 may belong to a single company.

[0015] The ordering computer 102 transmits drawing data of an object (workpiece) to be machined to the server 101. The drawing data is generated, for example, by an operator of the ordering company operating and editing the ordering computer 102. The drawing data is data representing the shape of the workpiece, such as STL (Standard Triangulated Language) data, OBJ data, CAD data, etc. The drawing data may also include information representing the material of the workpiece.

[0016] The machine tool control device 103 is a computer that controls the machine tool 104. The machine tool 104 in this embodiment is an NC (Numerical Control) machine tool that performs predetermined machining on a workpiece in accordance with the control of the machine tool control device 103. The machine tool control device 103 communicates with the server 101, and controls the machine tool 104 based on the machining control from the server 101.

[0017] The machine tool 104 is provided with a tool, and the tool is used to perform a predetermined processing on a workpiece. In the following description, the predetermined processing is assumed to be cutting processing, but the present embodiment is also applicable to processing other than cutting processing.

[0018] Fig. 2 is a block diagram showing an example of the server 101. The server 101 includes a control unit 201, a communication unit 202, a storage unit 203, an operation unit 204, and a display unit 205. The server 101 is not limited to the configuration shown in Fig. 2, and may include other elements, or some elements may be omitted.

[0019] The control unit 201 includes a processor and a memory. The processor is, for example, a CPU (Central Processing Unit). The processor executes a program (a set of multiple instructions) stored in the memory, thereby realizing various controls performed by the control unit 201. The processor may be a GPU (Graphics Processing Unit) or the like.

[0020] The communication unit 202 is a network interface connected to the network NW, and transmits and receives data via the network NW in response to instructions from the control unit 201.

[0021] The storage unit 203 is configured with an information recording medium such as a hard disk, a ROM, or a RAM. The storage unit 203 stores a physical property table (physical property information) indicating physical property values ​​related to cutting processes previously performed on a workpiece, in association with material information indicating the material of the workpiece and tool type information indicating the type of tool. The storage unit 203 also stores a tool table related to tools. Details of each table will be described later.

[0022] The operation unit 204 is composed of interfaces such as a keyboard, a mouse, and buttons, and outputs the contents of a user's instruction operation to the control unit 201 in response to the user's instruction operation. The display unit 205 is, for example, a liquid crystal display, a CRT display, or an organic EL display. The display unit 205 displays information in accordance with instructions from the control unit 201.

[0023] The control unit 201 includes an acquisition unit 211, a rotation speed calculation unit 212, a feed speed calculation unit 213, a cutting depth calculation unit 214, a wear amount calculation unit 215, a correction value calculation unit 216, and a correction unit 217. The functions of the control unit 201 are software functions realized by the above-mentioned processor executing a plurality of instruction sets stored in the memory.

[0024] The acquisition unit 211 acquires various information including material information of the workpiece, tool type information of the tool, tool diameter information indicating the tool diameter of the tool, and cutting speed information indicating the cutting speed when cutting the workpiece. For example, the acquisition unit 211 acquires the material information of the workpiece from the additional information attached to the drawing data. When the file name of the drawing data includes the name of the workpiece as the additional information, the acquisition unit 211 may acquire the material information of the workpiece from the file name of the drawing data. Also, for example, when a new tool is introduced to the machine tool 104, the server 101 receives the tool type information, tool diameter information, and cutting speed information from the machine tool control device 103, and stores each of the received information in a tool table (described later) of the storage unit 203. The acquisition unit 211 may acquire the tool type information, tool diameter information, and cutting speed information from the tool table of the storage unit 203. The acquisition of each information will be described later in detail.

[0025] The rotation speed calculation unit 212 calculates the rotation speed of the tool based on the tool diameter information and cutting speed information acquired by the acquisition unit 211. The feed speed calculation unit 213 calculates the feed speed of the tool based on the tool diameter indicated by the tool diameter information and the calculated rotation speed. The cutting depth calculation unit 214 calculates the Z-axis cutting depth of the tool (hereinafter simply referred to as cutting depth) based on the calculated rotation speed.

[0026] A wear amount calculation unit 215 calculates the amount of wear of the tool based on the change in the tool diameter over time. A correction value calculation unit 216 calculates correction values ​​for the number of rotations, the feed rate, and the amount of cutting in, using the tool diameter information and tool type information newly acquired by the acquisition unit 211 and the previous physical property value information and the physical property value information before the previous one stored in the storage unit 203. A correction unit 217 corrects the calculated number of rotations, the feed rate, and the amount of cutting in with the correction values.

[0027] Fig. 3 is a block diagram showing an example of machine tool control device 103. Machine tool control device 103 includes a control unit 301, a communication unit 302, a storage unit 303, an operation unit 304, a display unit 305, an output unit 206, a machine information acquisition unit 307, and an image acquisition unit 308. Machine tool control device 103 is not limited to the configuration in Fig. 2, and may include other elements, or some elements may be omitted.

[0028] The control unit 301 includes a processor and a memory. The processor executes a program (a set of multiple instructions) stored in the memory to realize various controls of the control unit 301. The processor may be a GPU or the like. The communication unit 302 is a network interface connected to the network NW, and transmits and receives data via the network NW in response to instructions from the control unit 301.

[0029] The storage unit 303 is configured with, for example, an information recording medium such as a hard disk, a ROM, a RAM, etc. The storage unit 303 is an information recording medium that holds a program executed by the processor of the control unit 301.

[0030] Operation unit 304 is composed of interfaces such as a keyboard, a mouse, buttons, etc., and outputs the contents of a user's instruction operation to control unit 301 in response to the instruction operation. Display unit 305 is, for example, a liquid crystal display, a CRT display, or an organic EL display. Display unit 305 displays information in accordance with instructions from control unit 301. Output unit 306 outputs control information for controlling machine tool 104 to machine tool 104.

[0031] The machine information acquisition unit 307 acquires machine information related to the machine tool 104 (machine) from the machine tool 104. The machine tool 104 is provided with an encoder that measures the coordinate position of a tool. The machine information acquisition unit 307 acquires coordinate information indicating the coordinate position of the tool from the encoder.

[0032] The machine tool 104 is provided with an ammeter that measures the spindle current value (additional current value) when the tool spindle comes into contact with the workpiece. The machine information acquisition unit 307 acquires the spindle current value from the ammeter. The machine tool 104 is provided with a hardness tester (e.g., a Rockwell hardness tester) that measures the hardness of the workpiece. The machine information acquisition unit 307 acquires workpiece hardness information indicating the hardness of the workpiece from the hardness tester.

[0033] Furthermore, the machine tool 104 is provided with a thermometer (e.g., a non-contact thermometer) that measures the temperature of the workpiece. The machine information acquisition unit 307 acquires workpiece temperature information indicating the temperature of the workpiece from the thermometer. The machine tool 104 is provided with a thermometer (e.g., a chiller thermometer) that indicates the temperature of the coolant. The machine information acquisition unit 307 acquires coolant temperature information indicating the temperature of the coolant from the thermometer.

[0034] As described later, a camera that photographs the tool (particularly, the portion that processes the workpiece) is provided on the machine tool 104. The image acquisition unit 308 acquires an image of the portion that is processed by the tool from the camera.

[0035] Fig. 4 is a diagram showing an example of machine tool 104. Machine tool 104 has a tool 401, a workpiece mounting table 402, an X-axis driving mechanism 403, a Y-axis driving mechanism 404, a Z-axis driving mechanism 405, and a B-axis driving mechanism 406. The configuration of machine tool 104 is not limited to the example in Fig. 4.

[0036] The tool 401 is a tool used for cutting the workpiece W. The tool 401 is, for example, a square end mill or a center drill. The tool 401 may be another tool.

[0037] The workpiece placement table 402 is a table for placing the workpiece W on. The workpiece placement table 402 is rotated by drive control of a rotation drive mechanism and a B-axis drive mechanism 406 (not shown). In addition, the tool 401 moves in three orthogonal axes, the X-axis, the Y-axis, and the Z-axis, by drive control of an X-axis drive mechanism 403, a Y-axis drive mechanism 404, and a Z-axis drive mechanism 405. The tool 401 descends along the Z-axis, coming into contact with the workpiece W, and cutting of the workpiece W is performed.

[0038] 4 shows an example in which a workpiece W is machined using a tool 401 driven along five axes, including three linear axes and two rotational axes. The machine tool 104 may perform machining using drive axes other than the five-axis machining. For example, the machine tool 104 may perform cutting on the workpiece W using a tool 401 driven along three linear axes.

[0039] The camera 407 captures an image of the tool 401 (particularly, a processing portion for cutting the workpiece W). The captured image is output to the image acquisition unit 308 in Fig. 3. From the image of the tool 401, the tool diameter of the tool 401 is acquired.

[0040] FIG. 5 is a diagram showing an example of a tool table. The tool table includes items such as tool ID, tool information, tool diameter, manufacturer, rotation speed, feed rate, cutting depth, cutting speed, wear amount before last, and wear amount last time. The tool table may include other items. The tool table is stored in the storage unit 203. The tool table is updated when a new tool 401 is introduced into the machine tool 104 or when machining is performed on a workpiece W. Details of updating the tool table will be described later with reference to FIG. 9.

[0041] The tool ID is an ID that identifies the tool type of the machine tool 104. The tool information is information that indicates the tool type identified by the tool ID. The tool ID and the tool information may be integrated into one piece of information. The tool diameter is information that indicates the diameter of the tool. The manufacturer is information that indicates the manufacturer that produced the tool.

[0042] Both tools with tool IDs "001" and "002" represent square end mills. However, the square end mill with tool ID "001" and the square end mill with tool ID "002" are made by different manufacturers. Even if the tools are of the same tool type, the tool diameter, etc. may differ depending on the manufacturer. Therefore, the tool IDs "001" and "002" are assigned to tools of the same tool type.

[0043] The rotation speed N is information that indicates the rotation speed of the tool. The rotation speed N is calculated by the following formula 1. "Rotation speed N = (1000 x cutting speed VC) / (3.14 x tool diameter DC)" (Formula 1)

[0044] As described above, the cutting speed information indicating the cutting speed VC and the tool diameter information indicating the tool diameter DC are acquired, for example, from the machine tool control device 103. The rotation speed calculation unit 212 calculates the rotation speed N by applying the acquired information on the cutting speed VC and the tool diameter DC to the above formula 1.

[0045] The feed rate VF is information that indicates the feed rate of the tool. The feed rate VF is calculated by the following formula 2. "Feed rate VF = Feed amount per tooth FZ × Rotation speed N × Number of tool teeth ZN" (Formula 2)

[0046] In the above formula 2, the feed amount (feed amount) FZ per blade is calculated, for example, by the following formula 3. In the following formula 3, a and b are predetermined values ​​and are stored, for example, in the storage unit 203. a and b may be calculated, for example, by performing linear regression analysis on values ​​input by a craftsman based on experience for each tool type and tool diameter. "Feed per tooth FZ=a*Dc+b" (Equation 3)

[0047] In addition, in the above formula 2, the number of tool teeth ZN is acquired as, for example, half the value of the tool diameter DC. The feed speed calculation unit 213 calculates the feed amount FZ using the above formula 3. The rotation speed N is obtained by the above formula 1. The feed speed calculation unit 213 calculates the feed speed VF by taking the half value of the tool diameter DC as the number of tool teeth ZN and applying the feed amount FZ, the rotation speed N, and the number of tool teeth ZN to the above formula 3.

[0048] The cutting depth F is information that represents the Z-axis cutting depth of the tool. The cutting depth F is calculated using the following formula 4. "Cutting depth F = tool diameter DC" (Equation 4)

[0049] The cutting depth calculation unit 214 applies the acquired information on the tool diameter DC to the above formula 4 to calculate the cutting depth F. The information on the tool diameter, manufacturer, rotation speed, feed rate, cutting depth, and cutting speed obtained as described above is stored in the tool table in association with a new tool ID when a new tool is introduced to the machine tool 104, for example. Details will be described later.

[0050] Next, the amount of wear will be described. The tool 401 wears out every time the workpiece W is machined. The amount of wear before last indicates the amount of wear of the tool 401 caused by the machining before last performed on the workpiece W. The amount of wear from the previous time indicates the amount of wear of the tool 401 caused by the machining last performed on the workpiece W.

[0051] The wear amount calculation unit 215 calculates the amount of wear of the tool diameter of the tool 401 based on the change over time in the tool diameter of the tool 401. As shown in the example of Fig. 4, the camera 407 captures an image of the tool 401 at a machining portion where the workpiece W is machined. The image acquisition unit 308 acquires an image of the tool 401 from the camera 407. The machine tool control device 103 transmits the acquired image of the tool 401 to the server 101 every time machining is performed on the workpiece W.

[0052] Wear amount calculation unit 215 performs image analysis on the acquired image of tool 401, calculates the tool diameter value DC(i-1) of tool 401, and stores the calculated tool diameter value DC(i-1) in memory unit 203. When machine tool 104 uses tool 401 to machine workpiece W, machine tool control device 103 transmits an image of tool 401 after machining to server 101. As a result, server 101 acquires an image of tool 401 after machining.

[0053] The wear amount calculation unit 215 performs image analysis on the acquired image of the post-machining tool 401, calculates the tool diameter value DC(i-2) of the post-machining tool 401, and stores the calculated tool diameter value DC(i-2) in the memory unit 203. The wear amount calculation unit 215 calculates the wear amount by the following formula 5 using the pre-machining tool diameter value DC(i-1) stored in the memory unit 203 and the calculated post-machining tool diameter value DC(i-2). "Wear volume Wdia = DC(i-1) - DC(i-2)" (Equation 5)

[0054] The wear amount calculation unit 215 stores the wear amount Wdia2 (Wdia2A, 2B, 2C, etc.) calculated when the workpiece W was previously machined in the item of the previous wear amount in the tool table. In this case, the previous wear amount Wdia2 can be obtained by applying the tool diameter DC before and after the previous machining of the workpiece W to the above formula 5.

[0055] Assume that after the previous wear amount is stored in the tool table, new machining of the workpiece W is performed. In this case, the server 101 acquires an image of the tool 401 after the new machining. Then, the wear amount calculation unit 215 stores Wdia2, which was stored in the previous wear amount item corresponding to the tool ID in the tool table, as Wdia1 in the item of the wear amount before last.

[0056] The wear amount calculation unit 215 calculates the wear amount Wdia2 by applying the tool diameter DC before and after machining when machining a new workpiece W to the above formula 5. The wear amount calculation unit 215 stores the calculated wear amount Wdia2 in the previous wear amount item corresponding to the tool ID in the tool table. As described above, each time machining of the workpiece W is performed, the wear amount before last and the previous wear amount in the tool table are updated.

[0057] FIG. 6 is a diagram showing an example of a physical property table. The physical property table includes items of material ID, tool ID, compliance value, spindle load rate, tool hardness, tool toughness, workpiece hardness, workpiece toughness, workpiece temperature, and coolant temperature. In the physical property table, the compliance value, spindle load rate, tool hardness, tool toughness, workpiece hardness, workpiece toughness, workpiece temperature, and coolant temperature correspond to physical property values. The physical property table may include other items. In addition, the physical property table is stored in the storage unit 203. Details of updating the physical property table will be described later with reference to FIG. 12.

[0058] The material ID is information that identifies the material of the workpiece W. The material ID "001" indicates that the material of the workpiece W is aluminum. The material ID "002" indicates that the material of the workpiece W is copper. The material ID "003" indicates that the material of the workpiece W is stainless steel. In the physical property table, the material ID and the material information indicating the material may be provided as separate items, as in the tool table of FIG. 5.

[0059] The tool ID corresponds to the tool ID in the tool table. The compliance value, spindle load rate, tool hardness, tool toughness, workpiece hardness, workpiece toughness, workpiece temperature, and coolant temperature indicate physical property values ​​related to past machining performed on the workpiece W. In the physical property value table, information indicating each physical property value is stored in association with a material ID indicating the material of the workpiece W and a tool ID indicating the type of tool.

[0060] Each physical property item includes a previous item and a previous-before-last item. The previous item stores a physical property value related to the previous processing performed on the workpiece W. The previous-before-last item stores a physical property value related to the processing performed on the workpiece W before last.

[0061] Each physical property value will be described. The compliance value is the first information indicating the mechanical compliance value of the machine tool 104. The mechanical compliance value Cp of the machine tool 104 can be obtained by the following formula 6. In formula 6, x represents the amount of displacement, and f represents the applied force. “Cp=x / f” (Formula 6)

[0062] The displacement amount x is obtained from the difference between the coordinate position when the spindle of the tool 401 comes into contact with the workpiece W and the specified coordinate position. As described above, the machine information acquisition unit 307 of the machine tool control device 103 acquires the coordinate position of the tool 401 from the encoder provided in the machine tool 104.

[0063] The machine tool control device 103 controls the machine tool 104 based on CNC data. The CNC data includes a specified coordinate position where the tool 401 is located. The control unit 301 of the machine tool control device 103 calculates the difference between the coordinate position of the tool 401 acquired from the encoder and the specified coordinate position included in the CNC data as a displacement amount x. The displacement amount x is also the amount of deviation of the position of the tool 401 from the specified coordinate position of the tool 401.

[0064] The applied force f can be calculated based on the spindle current meter when the spindle of the tool 401 comes into contact with the workpiece W. As described above, the machine information acquisition unit 307 of the machine tool control device 103 acquires the spindle current value from the spindle current meter provided in the machine tool 104. In addition, the above CNC data includes the rated current value of the spindle.

[0065] The control unit 301 of the machine tool control device 103 calculates the applied force f by dividing the spindle current value acquired from the spindle current meter by the rated current value. The control unit 301 of the machine tool control device 103 calculates the compliance value Cp by applying the above displacement amount x and applied force f to Equation 6. The machine tool control device 103 transmits the calculated compliance value Cp to the server 101. As a result, the acquisition unit 211 of the server 101 acquires the compliance value Cp.

[0066] The compliance value Cp may be calculated by the server 101. In this case, the acquisition unit 211 of the server 101 acquires the coordinate position, spindle current value, and CNC data of the tool 401 acquired from the encoder from the machine tool control device 103. Then, the control unit 201 of the server 101 applies the above-mentioned displacement amount x and applied force f to Equation 6 to calculate the compliance value Cp.

[0067] The spindle load factor LM is second information indicating a load factor for the spindle of the machine tool 104. The spindle load factor LM of the machine tool 104 can be obtained by dividing the spindle current value acquired from the above-mentioned spindle ammeter by the rated current value. In this case, the spindle load factor LM of the machine tool 104 has the same value as the above-mentioned applied force f. The calculation of the spindle load factor LM may be performed by the server 101. In this case, the acquisition unit 211 of the server 101 acquires the spindle current value and the CNC data from the machine tool control device 103.

[0068] The tool hardness is third information indicating the hardness of the tool 401. Moreover, the tool toughness is fourth information indicating the toughness of the tool 401. The information on the tool hardness TH and the information on the tool toughness TT are included in, for example, catalog data of the tool. The catalog data may be stored in, for example, a server of a company that manufactures the tool. In this case, the server 101 acquires the catalog data including the tool hardness TH and the tool toughness TT from the server of the company.

[0069] The workpiece hardness is fifth information indicating the hardness of the workpiece W. As described above, the machine tool 104 is provided with a hardness meter that measures the hardness of the workpiece W. The machine information acquisition unit 307 acquires workpiece hardness information indicating the hardness of the workpiece from the hardness meter. The machine tool control device 103 transmits the acquired workpiece hardness information to the server 101. As a result, the acquisition unit 211 of the server 101 acquires the workpiece hardness information indicating the hardness of the workpiece W.

[0070] The workpiece toughness is sixth information indicating the toughness of the workpiece W. Information on the workpiece toughness is included, for example, in additional information that is included in the drawing data acquired by the server 101 from the ordering computer 102. The additional information may be included in the metadata of the drawing data, or may be included in the file name of the drawing data.

[0071] The acquisition unit 211 of the server 101 acquires information on the workpiece toughness of the workpiece W from the additional information of the drawing data. When the additional information of the drawing data includes workpiece hardness information, the acquisition unit 211 may acquire the workpiece hardness information from the additional information of the drawing data.

[0072] The workpiece temperature is seventh information indicating the temperature of the workpiece W. As described above, the machine tool 104 is provided with a thermometer that measures the temperature of the workpiece. The machine information acquisition unit 307 acquires workpiece temperature information indicating the temperature of the workpiece from the thermometer. The machine tool control device 103 transmits the acquired workpiece temperature information to the server 101. As a result, the acquisition unit 211 of the server 101 acquires the workpiece temperature information.

[0073] The coolant temperature is eighth information indicating the temperature of the coolant liquid in the machine tool 104. As described above, the machine tool 104 is provided with a thermometer indicating the temperature of the coolant liquid. The machine information acquisition unit 307 acquires coolant temperature information indicating the temperature of the coolant liquid from the thermometer. The machine tool control device 103 transmits the acquired coolant temperature information to the server 101. As a result, the acquisition unit 211 of the server 101 acquires the coolant temperature information.

[0074] The machine tool control device 103 transmits the above-mentioned information on each physical property value to the server 101 every time the workpiece W is machined. The control unit 201 of the server 101 stores the received information on each physical property value in the physical property table every time the workpiece W is machined.

[0075] The information on each physical property value is information when the machine tool 104 processes the workpiece W. After the workpiece W has been processed, the information on each physical property value becomes unnecessary. For this reason, the conventional machine tool control device 103 did not store or use the information on each physical property value.

[0076] In this embodiment, the server 101 acquires information on each physical property value from the machine tool control device 103 each time machining is performed on the workpiece W, and stores the information in the physical property value table. As shown in the example of Fig. 6, the control unit 201 stores the physical property value information from the machining performed two times before last and the physical property value information from the machining performed previously in the physical property value table.

[0077] Then, the correction unit 217 uses the physical property value information from the machining performed before last and the physical property value information from the machining performed previously to correct the number of rotations of the tool 401. The correction unit 217 also uses the physical property value information from the machining performed before last and the physical property value information from the previous machining to correct the feed rate and the cutting depth.

[0078] In this embodiment, the correction value calculation unit 216 calculates a correction value for the rotation speed of the tool 401 using physical property information related to the machining before last and physical property information related to the previous machining. Then, the correction unit 217 corrects the rotation speed of the tool 401 with the calculated correction value. This makes it possible to set an appropriate rotation speed of the tool 401 based on the physical property information related to the current machining.

[0079] Furthermore, in this embodiment, the correction value calculation unit 216 corrects the rotation speed of the tool 401 using the physical property value information relating to the machining before last and the physical property value information relating to the previous machining, but does not use the physical property value information relating to the machining before the machining before last.

[0080] The physical property information relating to the machining before the previous machining has a low correlation with the physical property values ​​relating to the current machining. Therefore, if the above correction is performed using the physical property information relating to machining many times back from the current machining, the current physical property values ​​cannot be reflected. As a result, the accuracy of the correction of the rotation speed of the tool 401 decreases.

[0081] Therefore, in this embodiment, the physical property information related to the machining before last and the physical property information related to the previous machining are used. Therefore, the control unit 201 does not store the physical property information of the machining before the machining before last in the tool table. Since the storage unit 203 does not need to store the physical property information related to the machining before the machining before last, the amount of data stored in the storage unit 203 can be reduced.

[0082] 7 is a diagram showing an example of the additional information of the drawing data. As described above, the drawing data is data that represents the shape of a workpiece. The additional information of the drawing data is, for example, a file name. Naming rules are defined for the file name of the drawing data.

[0083] 7, "SUS" in the file name "XXX-SUS1000.STL" indicates that the material of the workpiece W indicated by the drawing data is stainless steel. For example, if the part of the file name of the drawing data corresponding to "SUS" is "AL", this indicates that the material of the workpiece W indicated by the drawing data is aluminum. The control unit 201 may recognize the material of the workpiece represented by the drawing data based on the file name of the drawing data.

[0084] Next, an example of the process flow related to the tool data of this embodiment will be described. Fig. 8 is a flowchart showing an example of the process flow related to the tool data. For example, assume that a new tool 401 is introduced into the machine tool 104. The acquisition unit 211 of the server 101 acquires an initial tool radius value of the tool 401 (step S101).

[0085] For example, assume that a new tool is introduced into the machine tool 104. The worker inputs information about the introduced new tool into the machine tool control device 103. The information about the new tool includes tool type information indicating the type of the new tool, tool diameter information (tool diameter initial value) indicating the tool diameter of the new tool, and cutting speed information indicating the cutting speed of the new tool. When the information about the new tool is input into the machine tool control device 103, the machine tool control device 103 transmits the information about the new tool to the server 101. The information about the new tool received by the server 101 is stored in the tool table. The new tool type information is stored in the tool table as a tool ID in association with the new tool diameter information and the new cutting speed information. The acquisition unit 211 acquires the tool type information, tool diameter information, and cutting speed information of the new tool from the tool table.

[0086] Furthermore, when the machine tool control device 103 recognizes that a new tool has been introduced into the machine tool 401, it may request information about the new tool from the computer of the company that manufactured the new tool. In this case, the machine tool control device 103 may transmit the information about the new tool acquired in response to the request to the server 101. Alternatively, when the server 101 detects that a new tool has been introduced into the machine tool 104, it may directly acquire information about the new tool from the computer of the company that manufactured the new tool. Information about the new tool acquired by the server 101 is stored in the tool table. The new tool type information is stored in the tool table as a tool ID in association with new tool diameter information and new cutting speed information. The acquisition unit 211 may acquire the tool type information, tool diameter information, and cutting speed information of the new tool from the tool table. Furthermore, the acquisition unit 211 may acquire information about the new tool from an external server that stores information about a plurality of tools. The acquisition unit 211 may acquire information about the new tool using another method.

[0087] The information about the new tool includes manufacturer information indicating the manufacturer that manufactured the new tool. The manufacturer information is also stored in the tool table. The acquisition unit 211 acquires the manufacturer information of the tool 401 from the information stored in the tool table (step S102). The acquisition unit 211 acquires cutting speed information of the tool 401 from the information stored in the tool table (step S103).

[0088] The rotation speed calculation unit 212 calculates the ideal rotation speed value by applying the acquired cutting speed information and the initial tool diameter value to the above-mentioned formula 1 (step S104). The feed speed calculation unit 213 calculates the ideal feed speed value by applying the acquired initial tool diameter value and the initial rotation speed value calculated in step S104 to the above-mentioned formula 2 (step S105).

[0089] The cutting depth calculation unit 214 calculates the ideal cutting depth value by applying the acquired initial tool diameter value to the above-mentioned formula 4 (step S106). The control unit 201 associates each value obtained by the processing of steps 106 to S107 with a new tool ID, and stores the tool ID and each value in the tool table (step S107).

[0090] The control unit 201 determines whether machining has been performed on the workpiece W (step S108). For example, every time the machine tool 104 performs machining on the workpiece W, the machine tool control device 103 transmits information indicating that machining has been performed (machining execution information) to the server 101. When the server 101 receives the machining execution information, the control unit 201 may determine that machining has been performed on the workpiece W.

[0091] If the workpiece W has not been machined, the control unit 201 determines No in step S108 and returns the process to step S108. In this case, the control unit 201 waits until the workpiece W is machined.

[0092] If machining has been performed on the workpiece W, the control unit 201 determines Yes in step S108 and advances the process to step S109. In this case, the acquisition unit 211 acquires an image of the tool 401 (step S109).

[0093] As described above, the camera 407 in the machine tool 104 captures an image of the machined portion of the tool 401 after machining. The machine tool control device 103 transmits the image of the machined tool 401 captured by the camera 407 to the server 101. As a result, the acquisition unit 211 acquires the image of the tool 401. The control unit 201 stores the acquired image of the tool 401 in the memory unit 203.

[0094] The wear amount calculation unit 215 performs image analysis on the acquired image of the tool 401 to acquire information on the tool diameter of the tool 401 after machining (step S110). The wear amount calculation unit 215 stores the information on the tool diameter of the tool 401 after machining in the storage unit 203 every time machining is performed on the workpiece W. Therefore, when new machining is performed on the workpiece W, the information on the tool diameter of the tool 401 before machining is stored in the storage unit 203.

[0095] The wear amount calculation unit 215 acquires information on the tool diameter of the tool 401 before machining stored in the storage unit 203. Then, the wear amount calculation unit 215 calculates the difference between the tool diameter before machining and the tool diameter after machining as the wear amount of the tool 401, taking the tool diameter acquired in step S110 as the tool diameter after machining (step S111).

[0096] The wear amount calculation unit 215 updates the wear amount information in the tool table by storing the calculated wear amount information in the previous wear amount item of the tool table (step S112). If wear amount information is stored in the previous wear amount item of the tool table, the wear amount calculation unit 215 stores the wear amount information stored in the previous wear amount item in the wear amount before last item.

[0097] As a result, every time machining is performed on the workpiece W, the information on the wear amount of the tool 401 for the past two machining operations is updated in the tool table. After step S112 is executed, the control unit 201 returns the process to step S108. The above-mentioned processes of steps S108 to S112 are repeated. As a result, every time machining is performed on the workpiece W using the tool 401, the information on the wear amount before the previous machining operation and the information on the wear amount for the previous machining operation are updated in the tool table. In other words, the processes of steps S108 to S112 in the flowchart of FIG. 8 and each process in the flowchart of FIG. 10 are repeated. As a result, the tool table is updated semi-permanently.

[0098] FIG. 9 is a diagram showing an example of a change in the tool table. For example, suppose that a new tool 401 is introduced to the machine tool 104. As described above, the machine tool control device 103 transmits the tool information, tool diameter, manufacturer, and cutting speed information of the newly introduced tool 401 to the server 101. As a result, when the new tool 401 is introduced to the machine tool 104, the acquisition unit 211 acquires each piece of information from the machine tool control device 103. For example, suppose that the tool information is "center drill", the tool diameter is "6", the manufacturer is "Company A", and the cutting speed is "20". In this case, in steps S101 to S103, the acquisition unit 211 acquires these pieces of information.

[0099] Furthermore, the ideal rotation speed, the ideal feed rate, and the ideal cutting depth are calculated by performing the processes in steps S104 to S106. It is assumed that the calculated ideal rotation speed is "2387", the calculated feed rate is "383", and the calculated cutting depth is "6". The control unit 201 generates a new tool ID (tool ID "10" in the example of FIG. 9), and stores the information acquired in steps S101 to S103 and the values ​​calculated in steps S1014 to S106 in the tool table in association with the new tool ID. As a result, as shown in the table example in FIG. 9, information is stored in each of the items of the tool diameter, manufacturer, rotation speed, feed rate, cutting depth, and cutting speed in the tool table, and the tool table is updated.

[0100] When the tool 401 with the tool ID "010" is used for the first time, the wear amount calculation unit 215 calculates the difference in the tool diameter of the tool 401 before and after machining as the wear amount of the tool 401 based on the images of the tool 401 before and after machining. It is assumed that the calculated wear amount is "0.01". The wear amount calculation unit 215 stores the calculated wear amount "0.01" in the previous wear amount item of the tool table.

[0101] When the tool 401 with the tool ID "010" is used next, the wear amount calculation unit 215 calculates the difference between the tool diameter of the tool 401 before and after machining as the wear amount of the tool 401. It is assumed that the calculated wear amount is "0.02". The wear amount calculation unit 215 stores the calculated wear amount "0.02" in the previous wear amount item of the tool table. At this time, the wear amount calculation unit 215 stores the previous wear amount "0.01" in the wear amount before previous item of the tool table. When the tool 401 with the tool ID "010" is used next, the wear amount calculation unit 215 stores the wear amount "0.02" in the wear amount before previous item of the tool table and stores the newly calculated wear amount in the previous wear amount item. Thereafter, the wear amount calculation unit 215 updates the information on the wear amount before previous and the information on the previous wear amount in the tool table every time machining of the workpiece W is performed using the tool 401.

[0102] Next, an example of a process flow related to physical property information in this embodiment will be described. FIG. 10 is a flowchart showing an example of a process flow related to physical property values. The control unit 201 judges whether processing has been performed on the workpiece W (step S201). The judgment in step S201 may be performed based on the above-mentioned processing execution information, for example. The judgment in step S201 may be the same process as the judgment in step S108 described above, or may be a different judgment process.

[0103] The acquiring unit 211 acquires the tool ID of the tool 401 used in the current machining (step S202). The tool ID may be included in the above-mentioned machining execution information, for example. In this case, the acquiring unit 211 acquires the tool ID from the machining execution information.

[0104] The acquiring unit 211 acquires a material ID that identifies the material of the workpiece W that is the target of the current machining (step S203). The material ID is included, for example, in the supplementary information of the above-mentioned drawing data. The material ID may be included as part of the file name of the drawing data. In this case, the acquiring unit 211 acquires the material ID from the file name of the drawing data.

[0105] The control unit 201 refers to the physical property table in Fig. 6 and determines whether the physical property value before the previous one corresponding to the same tool ID as the tool ID acquired in step S203 is stored (step S204). In this embodiment, the physical property values ​​are the compliance value, the spindle load factor, the tool hardness, the tool toughness, the workpiece hardness, the workpiece toughness, the workpiece temperature, and the coolant temperature.

[0106] If the second previous physical property value corresponding to the same tool ID as the tool ID acquired in step S203 is stored in the physical property table, the control unit 201 determines the process as Yes in step S204 and proceeds to step S205. On the other hand, if the second previous physical property value is not stored in the physical property table, the control unit 201 determines the process as No in step S204 and proceeds to step S206.

[0107] The control unit 201 refers to the physical property table in FIG. 6 and determines whether or not the previous physical property value corresponding to the same material ID as the material ID acquired in step S204 is stored (step S205).

[0108] If the previous physical property value corresponding to the same material ID as the material ID acquired in step S204 is stored in the physical property value table, the control unit 201 determines "Yes" in step S205 and proceeds to step S208. On the other hand, if the previous physical property value is not stored in the physical property value table, the control unit 201 determines "No" in step S205 and proceeds to step S206.

[0109] If the determination in step S204 is No, or if the determination in step S205 is No, the amount of accumulated physical property information corresponding to the acquired tool ID and material ID is small. In this case, a process of storing the physical property values ​​in the physical property table is performed until the last two pieces of physical property information corresponding to the tool ID and material ID are accumulated.

[0110] The acquisition unit 211 refers to the tool table and acquires the ideal rotation speed value, the ideal feed rate value, and the ideal cutting depth value corresponding to the tool ID acquired in step S202. Then, the control unit 201 outputs each of the acquired ideal values ​​to the machine tool control device 103 via the network NW (step S206). Each ideal value is an uncorrected value.

[0111] The machine tool control device 103 controls the machine tool 104 to machine the workpiece W based on each ideal value received from the server 101. The machine tool 104 machines the workpiece W using a tool 401 based on the control from the machine tool control device 103.

[0112] The control unit 201 performs a physical property value storage process (step S207). After the above-mentioned machining of the workpiece W is performed, the machine tool control device 103 transmits various information used in the physical property value storage process to the server 101. After the server 101 receives the various information, the control unit 201 performs a physical property value storage process to store the physical property values ​​in a physical property table.

[0113] The physical property value storage process will be described below. Changes in the physical property value table when the physical property value storage process is executed will be described later. Fig. 11 is a flowchart showing an example of the processing flow of the physical property value storage process. The control unit 201 calculates a compliance value based on the amount of displacement and the applied force (step S301).

[0114] The control unit 201 calculates the compliance value by applying the amount of displacement of the tool 401 when machining the workpiece W and the force applied when the spindle of the tool 401 comes into contact with the workpiece W to the above-mentioned formula 6. The amount of displacement is calculated based on, for example, the encoder of the machine tool 104. Also, the applied force is calculated based on, for example, the current value of a spindle ammeter of the machine tool 104.

[0115] The control unit 201 calculates the spindle load factor based on the current value (step S302). The control unit 201 can calculate the spindle load factor by dividing the spindle current value acquired from the spindle ammeter of the machine tool 104 when machining of the workpiece W is performed by the rated current value.

[0116] The control unit 201 acquires the tool hardness based on the catalog data (step S303), and the tool toughness based on the catalog data (step S304).

[0117] The control unit 201 calculates the workpiece hardness based on the workpiece hardness value (step S305). The workpiece hardness value is acquired, for example, from a hardness meter provided in the machine tool 104 that measures the hardness of the workpiece W.

[0118] The control unit 201 acquires the workpiece toughness based on the material property data (step S306). The workpiece toughness is acquired, for example, from the additional information that is associated with the drawing data that the server 101 acquires from the ordering computer 102.

[0119] The control unit 201 acquires the workpiece temperature based on the measured temperature of the workpiece (step S307). The workpiece temperature is acquired, for example, from a thermometer provided in the machine tool 104 that measures the temperature of the workpiece.

[0120] The control unit 201 acquires the coolant temperature based on the measured temperature of the coolant (step S308). The coolant temperature is acquired, for example, from a thermometer provided in the machine tool 104 that indicates the temperature of the coolant.

[0121] Through steps S301 to S308 above, control unit 201 acquires each physical property value when machine tool 104 performs machining on workpiece W. Control unit 201 stores each acquired physical property value in a physical property value table (step S309) in association with the tool ID acquired in step S202 and the material ID acquired in step S203. This completes the physical property value storage process.

[0122] Fig. 12 is a diagram showing an example of changes in the physical property table. Fig. 12 shows compliance values ​​as physical property values, but the same applies to other physical property values. For example, assume that the machine tool 104 performs machining on a workpiece W with a material ID of "003" using a tool 401 with a tool ID of "001".

[0123] Also, assume that the workpiece W with material ID "003" was machined for the second time using the tool 401 with tool ID "001". The compliance value in the first machining is "521", and this compliance value is stored in the physical property value table.

[0124] The control unit 201 executes steps S301 to S308 to obtain each physical property value during machining of the workpiece W with the material ID "003" using the tool 401 with the tool ID "001". Among the obtained physical property values, the compliance value is assumed to be "221".

[0125] The control unit 201 stores the value "521" stored in the previous compliance value item in the item before last of the same compliance value. At the same time, the control unit 201 stores the acquired compliance value "221" in the previous item. As a result, the previous physical property value and the previous physical property value corresponding to the material ID "003" and the tool ID "001" are stored in the physical property value table.

[0126] Next, the process after step S207 will be described. As shown in Fig. 10, after the physical property storage process of step S207 is completed, the control unit 201 returns the process to step S201. As described above, if the control unit 201 determines Yes in step S205, the control unit 201 advances the process to step S208. The control unit 201 performs a correction process (step S208).

[0127] 13 is a flow chart showing an example of the flow of the correction process. The acquisition unit 211 acquires each of the physical property values ​​from the physical property table, which correspond to the tool ID acquired in step S202 and the material ID acquired in step S203, from the physical property table (step S401). The physical property values ​​acquired in this embodiment are the numerical values ​​of the compliance value, the spindle load factor, the tool hardness, the tool toughness, the workpiece hardness, the workpiece toughness, the workpiece temperature, and the coolant temperature.

[0128] The correction value calculation unit 216 divides each previously acquired physical property value by the corresponding physical property value before last to obtain each divided value of each physical property value (step S402).

[0129] The correction value calculation unit 216 calculates a value (influence index) by applying a logistic function to each divided value (step S403). At this time, the correction value calculation unit 216 applies the logistic function to each divided value using the following formula 7. In the following formula 7, X1 represents the influence index, and Y1 represents the divided value. "X1=1 / (1+exp(-Y1))" (Formula 7)

[0130] The influence index X1 represents the actual influence of the physical property values ​​related to the previous machining and the physical property values ​​related to the previous machining on the rotation speed, feed speed, and cutting depth. By applying the logistic function, the influence index X1 converges to a value within the range of 0 to 1. The influence index X1 represents the likelihood of the physical property values ​​affecting the rotation speed, feed speed, and cutting depth.

[0131] The correction value calculation unit 216 calculates an influence index X1 for each physical property value. The closer the influence index X1 is to 1, the greater the influence of the actual physical property value on the rotation speed, feed speed, and cutting depth. On the other hand, the closer the influence index X1 is to 0, the smaller the influence of the actual physical property value on the rotation speed, feed speed, and cutting depth.

[0132] The influence index X1 is calculated for each of the physical property values. The correction value calculation unit 216 adds up the influence indexes X1 of the physical property values ​​to obtain a sum (step S404).

[0133] Next, the correction value calculation unit 216 refers to the tool table and acquires the wear amount before last and the previous wear amount corresponding to the tool ID acquired in step S202 (step S405). The flowchart in Fig. 13 is executed when it is determined as Yes in step S205 in Fig. 10. Therefore, the above-mentioned wear amount before last and the previous wear amount are stored in the tool table.

[0134] The correction value calculation unit 216 determines whether the wear amount before last is greater than the wear amount the previous time (step S406). If the wear amount before last is greater than the wear amount the previous time, the correction value calculation unit 216 determines Yes in step S406 and proceeds to step S407. In this case, the correction value calculation unit 216 sets the first correction coefficient to a positive value (step S407).

[0135] If the wear amount before last is equal to or less than the wear amount of the previous time, the correction value calculation unit 216 determines No in step S406 and proceeds to step S408. In this case, the correction value calculation unit 216 sets the first correction coefficient to a negative value (step S408).

[0136] The first correction coefficient will be described. The first correction coefficient is a coefficient used when correcting the rotation speed, and is stored in advance in the storage unit 203. For example, the first correction coefficient may be set as a value according to the material of the workpiece W. Each correction coefficient including the first correction coefficient is changeable.

[0137] When the first correction coefficient is a positive value, a positive rotation speed correction value is added to the ideal rotation speed value. When the wear amount before last is greater than the wear amount in the previous processing, the rotation speed of the tool 401 in the previous processing is smaller than the rotation speed of the tool 401 in the processing before last. Therefore, a correction must be made to increase the rotation speed of the tool 401. Therefore, the correction value calculation unit 216 sets the first correction coefficient to a positive value. As a result, the rotation speed of the tool 401 in the current processing is increased.

[0138] When the first correction coefficient is a negative value, the rotation speed correction value is subtracted from the ideal rotation speed value. When the wear amount before last is equal to or less than the previous wear amount, the rotation speed of the tool 401 in the previous machining is greater than the rotation speed of the tool 401 in the machining before last. For this reason, a correction must be made to reduce the rotation speed of the tool 401. Therefore, the correction value calculation unit 216 sets the first correction coefficient to a negative value. As a result, the rotation speed of the tool 401 in the current machining is reduced.

[0139] The correction value calculation unit 216 multiplies the sum of the influence indexes calculated in step S404 by the first correction coefficient to calculate the rotation speed correction value (step S409). If the first correction coefficient is a positive value, the rotation speed correction value is a positive value. If the first correction coefficient is a negative value, the rotation speed correction value is a negative value.

[0140] The correction value calculation unit 216 refers to the tool table and acquires the ideal rotation speed value corresponding to the tool ID acquired in step S202 (step S410). The correction unit 217 corrects the rotation speed by adding the rotation speed correction value to the ideal rotation speed value (step S411). The corrected rotation speed is the rotation speed control value.

[0141] 14 is a diagram showing an example of calculation of the rotation speed control value using the tool table. For example, assume that the machine tool 104 uses the tool 401 with the tool ID "001" to machine the workpiece W with the material ID "001". In this case, the control unit 201 acquires each physical property value corresponding to the tool ID "001" acquired in step S202 and the material ID "001" acquired in step S203 from the physical property value table.

[0142] In step S402, the correction value calculation unit 216 divides each of the acquired previous physical property values ​​by the corresponding physical property value from the time before last. In the example of Fig. 14, the control unit 201 acquires the compliance value from the time before last, "586", and the compliance value from the time before last, "278", which correspond to the tool ID "001" and the material ID "001". Then, the correction value calculation unit 216 calculates a value (divided value) obtained by dividing the previous compliance value "278" by the compliance value from the time before last, "586". The divided value for the compliance value is "0.4744".

[0143] Similar calculations are performed for the spindle load rate and tool hardness. The division value for the spindle load rate is "0.846", and the division value for the tool hardness is "1.01". Division values ​​are calculated in the same manner for the other physical property values. As a result, the division values ​​for each physical property value are obtained.

[0144] In step S403, the correction value calculation unit 216 applies a logistic function to each divided value to calculate each influence index. In the example of Fig. 14, the influence index of the compliance value is "0.6154", the influence index of the spindle load rate is "0.6997", and the influence index of the tool hardness is "0.733". Other influence indexes are calculated in the same manner. All influence indexes converge to values ​​within the range of 0 to 1.

[0145] In step S404, the correction value calculation unit 216 adds up the influence indexes to obtain an added value. In the example of Fig. 14, the added value is "34.372".

[0146] The correction value calculation unit 216 refers to the tool table and acquires the wear amount before last and the previous wear amount corresponding to the tool ID "001". It is assumed that the acquired wear amount before last is equal to or less than the previous wear amount. In this case, the correction value calculation unit 216 sets the first correction coefficient to a negative value in order to execute the process of step S408. It is assumed that the value of the first correction coefficient stored in the storage unit 203 is "14.8". In this case, the first correction coefficient becomes "-14.8".

[0147] In step S409, the correction value calculation unit 216 multiplies the added value "34.372" by the first correction coefficient "-14.8" to calculate the rotation speed correction value "-508.71". At this time, the correction value calculation unit 216 rounds down, rounds up, or rounds off the decimal point of the rotation speed correction value.

[0148] In step S410, the correction value calculation unit 216 refers to the tool table to obtain the ideal rotation speed value corresponding to the tool ID. It is assumed that the ideal rotation speed value is "17650". In step S411, the correction value calculation unit 216 adds the rotation speed correction value "-508" to the ideal rotation speed value "17650" to calculate the rotation speed control value "17142".

[0149] The physical properties of the tool 401 and the workpiece W, etc., related to cutting processing change over time. For this reason, a discrepancy occurs between the ideal rotation speed of the tool 401 set at an initial stage and the rotation speed of the tool 401 according to the actual physical properties.

[0150] In this embodiment, the correction value calculation unit 216 calculates a rotation speed correction value that reflects the physical property value at the time of the machining before last and the physical property value at the time of the previous machining for each physical property value such as the compliance value. The correction value calculation unit 216 corrects the ideal rotation speed value using the rotation speed correction value. This allows the rotation speed of the tool 401 to be corrected to an appropriate rotation speed according to the actual physical property value, so that the rotation speed of the tool 401 can be set in consideration of the change over time of the physical property value.

[0151] When the process of step S411 in FIG. 13 ends, the process proceeds from "A" to step S412 in FIG. 15. FIG. 15 is a flowchart continued from FIG. 13. The correction value calculation unit 216 determines whether the wear amount before last is greater than the wear amount the previous time (step S412). If the wear amount before last is greater than the wear amount the previous time, the correction value calculation unit 216 determines Yes in step S412 and proceeds to the process of step S413. In this case, the correction value calculation unit 216 sets the second correction coefficient to a negative value (step S413).

[0152] If the wear amount before last is equal to or less than the wear amount of the previous time, the correction value calculation unit 216 determines No in step S412 and proceeds to step S414. In this case, the correction value calculation unit 216 sets the second correction coefficient to a positive value (step S414).

[0153] The second correction coefficient is a coefficient used when correcting the feed speed, and is stored in advance in the storage unit 203. For example, the second correction coefficient may be set as a value according to the material of the workpiece W. The second correction coefficient may be the same as the first correction coefficient, or may be different. The second correction coefficient is changeable.

[0154] When the second correction coefficient is a positive value, the feed speed correction value is added to the ideal feed speed value. As described above, when the wear amount before the last is greater than the wear amount of the previous rotation, the correction value calculation unit 216 sets the first correction coefficient for the rotation speed as a positive value. That is, the rotation speed is corrected to be large. If the rotation speed increases, there is a risk that the workpiece W will be cut excessively. For this reason, in this embodiment, when a correction is made to increase the rotation speed, the correction value calculation unit 216 makes a correction to slow down the feed speed. For this reason, the correction value calculation unit 216 sets the second correction coefficient as a negative value.

[0155] On the other hand, if the wear amount before last is equal to or less than the wear amount of the previous machining, the correction value calculation unit 216 sets the first correction coefficient for the number of revolutions to a negative value as described above. In this case, since a correction is made to reduce the number of revolutions, it is preferable to increase the feed rate. Therefore, the correction value calculation unit 216 sets the second correction coefficient to a positive value in order to increase the feed rate of the tool 401 in the current machining.

[0156] The correction value calculation unit 216 multiplies the sum of the influence indexes calculated in step S404 by the second correction coefficient to calculate the feed speed correction value (step S415). The correction value calculation unit 216 refers to the tool table and acquires the ideal feed speed value corresponding to the tool ID acquired in step S202 (step S416).

[0157] The correction unit 217 corrects the feed speed by adding the feed speed correction value to the ideal feed speed value (step S417). The corrected feed speed is the feed speed control value. The positive / negative setting of the second correction coefficient for the feed speed has an inverse relationship to the positive / negative setting of the first correction coefficient for the rotation speed. The other calculation methods of the feed speed correction value are the same as the calculation method of the rotation speed correction value.

[0158] Next, the correction of the cutting depth will be described. The correction value calculation unit 216 judges whether the wear amount before last is greater than the wear amount the previous time (step S418). If the wear amount before last is greater than the wear amount the previous time, the correction value calculation unit 216 judges Yes in step S418 and proceeds to the process of step S419. In this case, the correction value calculation unit 216 sets the third correction coefficient to a negative value (step S419).

[0159] If the wear amount before last is equal to or less than the wear amount of the previous time, the correction value calculation unit 216 determines No in step S418 and proceeds to step S420. In this case, the correction value calculation unit 216 sets the third correction coefficient to a positive value (step S420).

[0160] The third correction coefficient is a coefficient used when correcting the cutting depth, and is stored in advance in the storage unit 203. For example, the third correction coefficient may be set as a value according to the material of the workpiece W. The third correction coefficient may be the same as the first correction coefficient and the second correction coefficient, or may be different. The third correction coefficient is changeable.

[0161] As described above, if the wear amount before the last is greater than the wear amount of the previous rotation, the rotation speed is corrected to be larger. If the rotation speed is increased, there is a risk that the workpiece W will be cut excessively, so it is preferable to perform a correction to reduce the cutting depth. For this reason, the correction value calculation unit 216 sets the third correction coefficient to a negative value.

[0162] On the other hand, if the wear amount before last is equal to or less than the wear amount of the previous machining, the rotation speed is corrected to be smaller, so it is preferable to correct the cutting amount to be larger. Therefore, the correction value calculation unit 216 sets the third correction coefficient to a positive value in order to increase the cutting amount of the tool 401 in the current machining.

[0163] The correction value calculation unit 216 multiplies the sum of the influence indexes calculated in step S404 by the third correction coefficient to calculate the cutting-in amount correction value (step S421). The correction value calculation unit 216 refers to the tool table and acquires the cutting-in amount ideal value corresponding to the tool ID acquired in step S202 (step S422).

[0164] The correction unit 217 corrects the cutting amount by adding the cutting amount correction value to the cutting amount ideal value (step S423). The corrected cutting amount is the cutting amount control value. The positive / negative setting of the third correction coefficient for the cutting amount is inverse to the positive / negative setting of the first correction coefficient for the rotation speed, similar to the second correction coefficient for the feed speed. The calculation method of the other cutting amount correction values ​​is the same as the calculation method of the rotation speed correction value.

[0165] As with the above-mentioned rotation speed correction value, in this embodiment, for each physical property value such as compliance value, a feed speed correction value and a cutting depth correction value are calculated that reflect the physical property value at the time of the previous machining and the physical property value at the time of the previous machining. The correction value calculation unit 216 corrects the ideal feed speed value and the ideal cutting depth value using the feed speed correction value and the cutting depth correction value. This allows the feed speed and cutting depth of the tool 401 to be corrected to an appropriate feed speed and cutting depth according to the actual physical property value. As a result, the feed speed and cutting depth of the tool 401 can be set in consideration of the change over time of the physical property value.

[0166] This completes the correction process in step S208 in Fig. 10. When the correction process is completed, the corrected control values ​​for the rotation speed, feed rate, and cutting depth are obtained. The control unit 201 outputs each of the corrected control values ​​to the machine tool control device 103 via the communication unit 202 (step S209). The machine tool control device 103 controls the rotation speed, feed rate, and cutting depth of the tool 401 based on each of the received control values. This makes it possible to machine the workpiece W under conditions that take into account changes in the actual physical property values.

[0167] Thereafter, the control unit 201 performs a physical property storage process (step S210). The physical property storage process in step S210 is similar to the physical property storage process in step S207, and therefore a description thereof will be omitted. When the physical property storage process in step S207 or step S210 ends, the control unit 201 returns the process to step S201.

[0168] Control unit 201 performs each of the above-mentioned processes each time machine tool 104 performs machining on workpiece W. That is, the processes of steps S108 to S112 in the flowchart of Fig. 8 and each process in the flowchart of Fig. 10 are repeatedly performed. In other words, the tool table and the physical property table are updated semi-permanently, and the correction process is also performed semi-permanently.

[0169] As described above, in this embodiment, for each physical property value such as the compliance value, a rotation speed correction value is calculated that reflects the physical property value in the previous machining and the physical property value in the previous machining. Then, the ideal rotation speed value is corrected using the rotation speed correction value, and the corrected control value is output to the machine tool control device 103. Since this process is repeated, it is possible to continue to control the rotation speed, feed rate, and cutting depth of the tool 401 to appropriate values ​​that take into account changes in the physical property values.

[0170] Each of the above-mentioned processes may be terminated midway. For example, when some kind of failure occurs in the machine tool control device 103, the machine tool 104, the tool 401, or the like, the control unit 201 may terminate each of the above-mentioned processes.

[0171] As described above, the correction value calculation unit 216 refers to the physical property table and calculates the rotation speed correction value using the physical property value information from the time before last and the previous physical property value information corresponding to the newly acquired material ID and tool ID. In this way, a rotation speed correction value reflecting the physical property values ​​from the time before last and the previous processing is calculated. Then, the correction unit 217 corrects the ideal rotation speed value using the rotation speed correction value. Therefore, the rotation speed of the tool 401 can be controlled to an appropriate value taking into account the change in the physical property value.

[0172] Similarly, the feed speed and the cutting depth of the tool 401 can be corrected to appropriate values ​​in consideration of the change in the physical property value. As a result, the feed speed and the cutting depth of the tool 401 can be controlled to appropriate values ​​in consideration of the change in the physical property value. <Modification>

[0173] In the embodiment described above, the correction unit 217 corrects three items, namely, the rotation speed, the feed speed, and the cutting depth, but it may also correct any one or two of the three items, namely, the rotation speed, the feed speed, and the cutting depth.

[0174] As described above, the physical property values ​​have been described as eight values, namely compliance value, spindle load rate, tool hardness, tool toughness, workpiece hardness, workpiece toughness, workpiece temperature and coolant temperature, but values ​​relating to other physical properties related to the machining of the workpiece W may also be used.

[0175] The storage unit 203 (storage device) storing the tool table and the physical property value table may be disposed outside the server 101. The storage device storing the tool table and the physical property value table may be stored in, for example, a database server capable of communicating with the server 101. In addition, the storage device storing the tool table and the physical property value table may be provided in the machine tool control device 103.

[0176] In the above example, each physical property value has an equal degree of influence, but the physical property value may have a different degree of influence. For example, the compliance value and the spindle load factor may have a different degree of influence. In this case, the compliance value and the spindle load factor may be weighted differently with respect to the value to which the logistic function in FIG. 14 is applied. This makes it possible to calculate a correction value that takes into account the degree of influence according to the physical property value.

[0177] Although the present embodiment has been described in detail as above, it will be easily understood by those skilled in the art that many modifications are possible without substantially departing from the novel matters and effects of the present embodiment. Therefore, all various modifications are intended to be included in the scope of the present disclosure. For example, a term described at least once in the specification or drawings together with a different term having a broader meaning or the same meaning can be replaced with that different term in any part of the specification or drawings. In addition, all combinations of the present embodiment and modifications are also included in the scope of the present disclosure. [Explanation of symbols]

[0178] 100 Machining control system, 101 Server, 102 Ordering computer, 103 Machine tool control device, 104 Machine tool, 201 Control unit, 202 Communication unit, 203 Memory unit, 204 Operation unit, 205 Display unit, 211 Acquisition unit, 212 Rotation speed calculation unit, 213 Feed rate calculation unit, 214 Cutting amount calculation unit, 215 Wear amount calculation unit, 216 Correction value calculation unit, 217 Correction unit, 301 Control unit, 302 Communication unit, 303 Memory unit, 304 Operation unit, 305 Display unit, 306 Output unit, 307 Machine information acquisition unit, 308 Image acquisition unit, 401 Tool, 402 Workpiece placement table, 403 X-axis drive mechanism, 404 Y-axis drive mechanism, 405 Z-axis drive mechanism, 406 B-axis drive mechanism

Claims

1. An information processing device that controls a machine tool that performs cutting processing on a workpiece using a tool, an acquisition unit that acquires, from a storage unit that stores physical property information indicating physical property values ​​related to the past cutting processing performed on the workpiece, the material information, the tool type information, tool diameter information indicating a tool diameter of the tool, and cutting speed information indicating a cutting speed when cutting the workpiece, in association with material information indicating a material of the workpiece and tool type information indicating a type of the tool; a rotation speed calculation unit that calculates a rotation speed of the tool based on the tool diameter information and the cutting speed information; a correction value calculation unit that refers to the storage unit, reads out the physical property value information before last and the previous physical property value information corresponding to the same material information and tool type information as the newly acquired material information and tool type information, and calculates a rotation speed correction value for the rotation speed using the read out physical property value information before last and the previous physical property value information; a correction unit that corrects a rotation speed of the tool using the rotation speed correction value; An information processing device comprising:

2. The information processing device of claim 1, wherein the physical property information is one or a combination of multiple pieces of information: first information indicating the mechanical compliance of the machine tool, second information indicating the load rate on the spindle of the machine tool, third information indicating the hardness of the tool, fourth information indicating the toughness of the tool, fifth information indicating the hardness of the workpiece, sixth information indicating the toughness of the workpiece, seventh information indicating the temperature of the workpiece, and eighth information indicating the coolant of the machine tool.

3. a feed rate calculation unit that calculates a feed rate of the tool based on the tool diameter and the rotation speed, the correction value calculation unit refers to the storage unit, reads out the second-previous physical property value information and the previous physical property value information corresponding to the same material information and tool type information as the newly acquired material information and tool type information, and calculates a feed speed correction value of the feed speed using the read out second-previous physical property value information and the previous physical property value information; The correction unit corrects the feed speed of the tool with the feed speed correction value. The information processing device according to claim 1 .

4. A cutting depth calculation unit that calculates a cutting depth of the tool based on the rotation speed, the correction value calculation unit refers to the storage unit, reads out the second-previous physical property information and the previous physical property information corresponding to the same material information and tool type information as the newly acquired material information and tool type information, and calculates a cut-in amount correction value for the cut-in amount using the read out second-previous physical property information and the previous physical property information; The correction unit corrects the cutting amount of the tool with the cutting amount correction value. The information processing device according to claim 1 .

5. a wear amount calculation unit that calculates a wear amount of the tool based on a change in the tool diameter over time, 2. The information processing device according to claim 1, wherein the correction value calculation unit calculates the rotation speed correction value as a positive value when the previous wear amount is greater than the wear amount before that, and calculates the rotation speed correction value as a negative value when the previous wear amount is equal to or less than the wear amount before that.

6. a wear amount calculation unit that calculates a wear amount of the tool based on a change in the tool diameter over time, 2. The information processing device according to claim 1, wherein the correction value calculation unit calculates the feed speed correction value as a negative value when the previous wear amount is greater than the wear amount before that, and calculates the feed speed correction value as a positive value when the previous wear amount is equal to or less than the wear amount before that.

7. a wear amount calculation unit that calculates a wear amount of the tool based on a change in the tool diameter over time, 2. The information processing device according to claim 1, wherein the correction value calculation unit calculates the feed cut-in amount correction value as a negative value when the previous wear amount is greater than the wear amount before that, and calculates the feed cut-in amount correction value as a positive value when the previous wear amount is less than or equal to the wear amount before that.

8. 2. The information processing device according to claim 1, wherein, when material information identical to the newly acquired material information is not stored in the storage unit, the newly acquired material information is stored in the storage unit in association with the physical property value information, and when tool type information identical to the newly acquired tool type information is not stored in the storage unit, the newly acquired tool type information is stored in the storage unit in association with the physical property value information.

9. 2. The information processing device according to claim 1, wherein the correction value calculation unit applies a logistic function to a value obtained by dividing a value indicated by the previous physical property information by a value indicated by the physical property information before last, and calculates the value to which the logistic function is applied as a rotation speed correction value for the rotation speed.

10. A machining control method for controlling a machine tool that performs cutting processing on a workpiece using a tool, comprising: acquires, from a storage unit that stores physical property value information indicating physical property values ​​related to the past cutting processing performed on the workpiece in association with material information indicating a material of the workpiece and tool type information indicating a type of the tool, the material information, the tool type information, tool diameter information indicating a tool diameter of the tool, and cutting speed information indicating a cutting speed when cutting the workpiece; Calculating the rotation speed of the tool based on the newly acquired tool diameter information and the cutting speed information; referring to the storage unit, reading out the second-previous physical property value information and the previous physical property value information corresponding to the same material information and tool type information as the newly acquired material information and tool type information, and calculating a rotation speed correction value of the rotation speed using the read out second-previous physical property value information and the previous physical property value information; correcting the rotation speed of the tool with the rotation speed correction value; Information processing methods.

11. A program to be executed by a computer of an information processing device that controls a machine tool that performs cutting processing on a workpiece using a tool, the program including: acquires, from a storage unit that stores physical property value information indicating physical property values ​​related to the past cutting processing performed on the workpiece in association with material information indicating a material of the workpiece and tool type information indicating a type of the tool, the material information, the tool type information, tool diameter information indicating a tool diameter of the tool, and cutting speed information indicating a cutting speed when cutting the workpiece, and Calculating the number of revolutions of the tool based on the newly acquired tool diameter information and the cutting speed information; with reference to the storage unit, reading out the second-previous physical property value information and the previous physical property value information corresponding to the same material information and tool type information as the newly acquired material information and tool type information, and calculating a rotation speed correction value of the rotation speed using the read out second-previous physical property value information and the previous physical property value information; Correcting the rotation speed of the tool with the rotation speed correction value. program.

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