WO2023223571A1

WO2023223571A1 - Tool route correction device, machine tool system, tool route correction method, and program

Info

Publication number: WO2023223571A1
Application number: PCT/JP2022/035318
Authority: WO
Inventors: 義浩細川; 泰久市川; 翔高阪
Original assignee: 三菱電機株式会社
Priority date: 2022-05-18
Filing date: 2022-09-22
Publication date: 2023-11-23

Abstract

A tool route correction device (1) comprises: an estimation unit (12) that estimates, on the basis of a tool route that is the route of a tool and a condition for machining using the tool, the shape and size of a portion to be machined when an object to be machined is machined by the tool; a calculation unit (13) for correcting the tool route on the basis of a positional deviation, from the tool route, of the portion to be machined having the shape and size estimated by the estimation unit (12) , and generating a tool correction route for bringing the portion to be machined closer to a theoretical shape and a theoretical size; and a transmission unit (14) that transmits data of the correction route to a numerical control device (50) for controlling a machine tool which holds the tool.

Description

Tool path correction device, machine tool system, tool path correction method and program

The present disclosure relates to a tool path correction device, a machine tool system, a tool path correction method, and a program.

Some machine tools correct the machining path, which is the path of the tool, in order to process the workpiece with high precision.

For example, Patent Document 1 discloses a machine tool that detects or inspects various parameters including the dimensions of a workpiece during machining, and corrects the tool path of a milling tool, that is, a milling machine tool.

JP2020-108918A

The machine tool described in Patent Document 1 detects or inspects various parameters during machining, that is, monitors during machining, which places a heavy burden on the user.

The present disclosure has been made to solve the above problems, and includes a tool path correction device that can correct the tool path to a path that allows the workpiece to be machined with high accuracy without monitoring during machining; The purpose of this invention is to provide a machine tool system, a tool path correction method, and a program.

In order to achieve the above object, a tool path correction device according to the present disclosure includes an estimation section, a calculation section, and a transmission section. The estimation unit estimates the shape and size of the workpiece when the workpiece is machined by the tool, based on a tool path that is a path of the tool and conditions for machining by the tool. The calculation unit corrects the tool path based on the positional deviation of the workpiece having the shape and size estimated by the estimation unit with respect to the tool path, thereby creating a tool correction path that brings the workpiece closer to the theoretical shape and size. seek. The transmitter transmits the correction path data to a numerical control device that controls a machine tool that holds the tool.

According to the configuration of the present disclosure, the estimation unit calculates the shape and size of the workpiece when the workpiece is machined by the tool, based on the tool path, which is the path of the tool, and the machining conditions using the tool. The calculation unit corrects the tool path based on the positional deviation of the workpiece having the estimated shape and size with respect to the tool path, thereby making the workpiece closer to the theoretical shape and size. Find a route. Therefore, the tool path can be corrected without monitoring during machining, and a more accurate path can be obtained. As a result, according to the configuration of the present disclosure, the tool path can be corrected to a path that allows the workpiece to be machined with high accuracy.

A perspective view of a machining center operating on a tool path corrected by a tool path correction device according to an embodiment of the present disclosure A diagram showing an example of the theoretical shape of the workpiece and the shape of the actual workpiece obtained by machining when the machining center moves the tool along a circular tool path to machine the workpiece. Graph showing the relationship between the total machining distance of the tool and the maximum error value Diagram showing an example of the shape of the actual machined part when the total machining distance of the tool is 0 mm A diagram showing an example of the shape of the actual workpiece when the total machining distance of the tool is 90,000 mm. A diagram showing an example of the shape of the actual workpiece when the tool feed rate is 640 mm/min. A diagram showing an example of the shape of the actual workpiece when the tool feed rate is 1270 mm/min. A diagram showing an example of the shape of the actual workpiece when the tool feed rate is 2400 mm/min. A diagram showing an example of the shape of the actual workpiece when the tool feed rate is 3590 mm/min. Diagram showing an example of the shape of the actual workpiece when the depth of cut of the tool is 0.07mm Diagram showing an example of the shape of the actual workpiece when the depth of cut of the tool is 0 mm Hardware configuration diagram of a tool path correction device according to an embodiment of the present disclosure Block diagram of a tool path correction device according to an embodiment of the present disclosure A diagram showing an example of a learning database used for learning by a learning section included in a tool path correction device according to an embodiment of the present disclosure. A diagram showing an example of tool path and machining condition data used for learning by a learning unit included in a tool path correction device according to an embodiment of the present disclosure. Flowchart of tool path correction processing performed by the tool path correction device according to the embodiment of the present disclosure Conceptual diagram of the shape of the workpiece portion estimated by the estimation unit included in the tool path correction device according to the embodiment of the present disclosure and the tool path to be corrected A conceptual diagram showing the relationship between the correction path generated by the calculation unit included in the tool path correction device according to the embodiment of the present disclosure and the shape of the workpiece portion estimated by the estimation unit A developed view when the workpiece portion estimated by the estimation unit included in the tool path correction device according to the embodiment of the present disclosure is developed in the circumferential direction of the tool path A developed view when the correction path generated by the calculation unit included in the tool path correction device according to the embodiment of the present disclosure is developed in the circumferential direction of the tool path Conceptual diagram of a correction path generated by a calculation unit included in a tool path correction device according to an embodiment of the present disclosure and a workpiece portion machined by the correction path Conceptual diagram of a first modification of the tool path corrected by the tool path correction device according to the embodiment of the present disclosure Conceptual diagram of a second modification of the tool path corrected by the tool path correction device according to the embodiment of the present disclosure Conceptual diagram of a third modification of the tool path corrected by the tool path correction device according to the embodiment of the present disclosure Conceptual diagram of a fourth modification of the tool path corrected by the tool path correction device according to the embodiment of the present disclosure

Hereinafter, a tool path correction device, a machine tool system, a tool path correction method, and a program according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In addition, in the figures, the same or equivalent parts are given the same reference numerals.

The tool path correction device according to the embodiment is a device that corrects the tool path of a machine tool according to processing conditions using the tool. The configuration of the tool path correction device will be described below, taking as an example the case where the tool path corrected by the tool path correction device is a tool path of a machining center, which is a type of machine tool. First, with reference to FIGS. 1 to 5, a machining center and problems with tool paths in the machining center will be described.

FIG. 1 is a perspective view of a machining center 10 operating on a tool path corrected by a tool path correction device according to an embodiment. Note that in FIG. 1, the tool magazine, pallet, etc. are omitted for simplicity in order to facilitate understanding.

As shown in FIG. 1, the machining center 10 includes a column 110, a table 120 that is movable relative to the column 110, a saddle 130, and a spindle head 140.

The column 110 extends upward from a base 150 fixed to the installation location in a columnar shape.

On the other hand, the table 120 is provided at the bottom of the column 110. The table 120 is movable along a guide rail 121 extending in the front-rear direction, that is, in the Y-axis direction. A workpiece 21 of the machining center 10 can be attached to the table 120 via a pallet (not shown).

Additionally, the saddle 130 is provided at the top of the column 110. The saddle 130 is movable along a guide rail 131 extending in the left-right direction, that is, in the X-axis direction.

Furthermore, the spindle head 140 is provided on the saddle 130. The spindle head 140 is movable along a guide rail 141 extending in the vertical direction, that is, in the Z-axis direction. Further, the spindle head 140 includes a spindle rotated by a servo motor (not shown). A tool 20 held by a holder 142 is attached to the lower end of the spindle head 140.

By having such a configuration, the machining center 10 can move the tool 20 attached to the spindle head 140 relative to the workpiece 21 attached to the table 120 in the XYZ directions. As a result, the machining center 10 can move the tool 20 relative to the workpiece 21 along a desired tool path to machine the workpiece 21 into a desired shape.

However, even when the machining center 10 moves the tool 20 relative to the workpiece 21 along a constant tool path, the part of the workpiece 21 machined by the tool 20 may change depending on the machining conditions of the tool 20. The shape and size, that is, the shape and size of the processed part may differ. For example, depending on the state of wear of the tool 20, the shape and size of the machined portion may differ. Next, this problem will be explained with reference to FIGS. 2 to 5.

FIG. 2 shows the theoretical shape of the workpiece 22 and the actual workpiece 23 obtained by machining when the machining center 10 moves the tool 20 along a circular tool path to machine the workpiece 21. It is a figure showing an example of the shape.

In the example shown in FIG. 2, the theoretical shape of the processed portion 22 is circular, whereas the actual shape of the processed portion 23 is a shape obtained by deforming an ellipse into a shape with a constriction. Further, the shape of the actual processed portion 23 is larger than the theoretical processed portion 22 at the major axis of the ellipse, and smaller than the theoretical processed portion 22 at the short axis of the ellipse. As described above, the shape and size of the processed portion 23 obtained by actual processing may differ from the theoretical shape and size of the processed portion 22. This phenomenon is correlated with the total machining distance, feed rate, and depth of cut of the tool 20. Experimental results using the machining center 10 are shown in FIGS. 3-5, 6A-6D, 7A, and 7B.

FIG. 3 is a graph showing the relationship between the total machining distance of the tool 20 and the maximum error value.

Here, the total machining distance of the tool 20 is the total distance that the tool 20 has moved relative to the workpiece 21 while machining the workpiece 21 from the start of use until the time of error measurement. It is about. For example, the total machining distance of the tool 20 is also called a cutting length, a usage length, or a machining length, and means the length of the tool 20 used for cutting. On the other hand, the error refers to the magnitude of the deviation of each part of the actual part to be processed 23 from each part of the theoretical part to be processed 22.

As shown in FIG. 3, when the total machining distance of the tool 20 reaches around 30,000 mm, the error increases rapidly, and after that, although the slope of the error with respect to the total machining distance decreases, as the total machining distance of the tool 20 increases. , the error is also large. In this way, there is a correlation between the total machining distance of the tool 20 and the error. Furthermore, not only the magnitude of the error but also the location where the error is greatest changes depending on the total machining distance of the tool 20. Examples are shown in FIGS. 4 and 5.

FIG. 4 is a diagram showing an example of the actual shape of the machined portion 23 when the total machining distance of the tool 20 is 0 mm. FIG. 5 is a diagram showing an example of the actual shape of the machined portion 23 when the total machining distance of the tool 20 is 90,000 mm. Note that in FIGS. 4 and 5, the theoretical shape of the processed portion 22 is also shown for ease of understanding. Furthermore, in FIGS. 4 and 5, the angle is shown assuming that the direction to the right from the theoretical center of the circle of the processed portion 22 is 0°, and the angle increases counterclockwise from 0°.

As shown in FIG. 4, when the total machining distance of the tool 20 is 0 mm, that is, when the tool 20 is new, the angle at which the error is maximum is around 135°. On the other hand, as shown in FIG. 5, when the total machining distance of the tool 20 is 90000 mm, the angle at which the error is maximum is around 210°. In this way, when the total machining distance of the tool 20 changes, the position of the point where the error is greatest also changes due to the change. That is, the shape of the actual processed portion 23 also changes.

In this way, the shape and size of the actual machined part 23 relative to the theoretical machined part 22 change depending on the total machining distance of the tool 20. The change has a correlation with the total machining distance of the tool 20.

Further, the change in shape and size of the actual machined part 23 with respect to the theoretical machined part 22 is also correlated with the feed rate of the tool 20. Furthermore, the change has a correlation with the depth of cut of the tool 20. Experimental results are shown in FIGS. 6A-6D, FIG. 7A, and FIG. 7B.

6A to 6D are diagrams showing an example of the actual shape of the workpiece portion 23 when the feed speed of the tool 20 is 640 mm/min, 1270 mm/min, 2400 mm/min, and 3590 mm/min, respectively. . 7A and 7B are diagrams showing an example of the actual shape of the processed portion 23 when the depth of cut of the tool 20 is 0.07 mm and 0 mm, respectively. Note that the depth of cut of the tool 20 in each of FIGS. 6A to 6D is the same as the depth of cut of the tool 20 in FIG. 7B. Further, the feed speed of the tool 20 in each of FIGS. 7A and 7B is the same as in FIG. 6C.

As shown in FIGS. 6A to 6D, as the feed rate of the tool 20 increases, the shape and size of the actual machined part 23 relative to the theoretical machined part 22 change significantly. That is, as the feed rate of the tool 20 increases, the error increases.

Furthermore, as shown in FIGS. 7A and 7B, as the depth of cut of the tool 20 increases, the shape and size of the actual machined part 23 with respect to the theoretical machined part 22 become smaller. That is, the error becomes smaller due to the increase in the depth of cut of the tool 20. This is considered to be due to the fact that cutting resistance is applied due to an increase in the depth of cut of the tool 20 when the feed rate of the tool 20 exceeds a certain value.

As described above, changes in shape and size of the actual workpiece 23 relative to the theoretical workpiece 22 are not only correlated with the total machining distance of the tool 20, but also with the feed rate of the tool 20 and the cutting speed. There is also a correlation with the amount of inclusion. As a result, in the machining center 10, the actual size of the machined part 23 changes depending on the total machining distance, feed rate, or depth of cut of the tool 20, and the machining accuracy of the machined part 23 decreases. There is. Further, due to a change in the total machining distance, feed rate, or depth of cut of the tool 20, the actual shape of the machined part 23 may change, resulting in a decrease in the machining accuracy of the machined part 23.

Therefore, in order to suppress such a decrease in machining accuracy, the tool path correction device corrects the tool path according to the machining conditions of the tool 20, for example, the total machining distance. Next, the configuration of the tool path correction device will be described with reference to FIGS. 8 to 11.

FIG. 8 is a hardware configuration diagram of the tool path correction device 1 according to the embodiment. FIG. 9 is a block diagram of the tool path correction device 1. FIG. 10 is a diagram showing an example of the learning database 35 used for learning by the learning section 11 included in the tool path correction device 1. FIG. 11 is a diagram showing an example of tool path and machining condition data 36 used for learning by the learning section 11.

Note that, in order to facilitate understanding, FIGS. 8 and 9 show the overall configuration of a machining center system 100 that includes the tool path correction device 1 and the machining center 10.

As shown in FIG. 8, the tool path correction device 1 includes a processor 31, a memory 32, and a network interface 33. The processor 31, memory 32, and network interface 33 are connected by a bus 34.

The network interface 33 connects the processor 31 and the memory 32 to an external device via the network 200, for example, the Internet, and enables communication with the external device. Specifically, network interface 33 connects processor 31 and memory 32 to numerical control device 50 provided in machining center 10 .

The numerical control device 50 includes a memory 51 and

microprocessors

52 and 53. The memory 51 includes a numerical data storage section 54 shown in FIG. Further, the

microprocessors

52 and 53 implement the calculation section 55 and the control section 56 shown in FIG. 9 configured as software by respectively executing programs stored in the memory 51. Then, the calculation unit 55 calculates the tool path of the tool 20 from the numerical data stored in the numerical data storage unit 54. On the other hand, the control unit 56 drives a servo motor (not shown) that drives the column 110, table 120, saddle 130, spindle head 140, etc. of the machining center 10, based on the tool path calculated by the calculation unit 55.

Returning to FIG. 8, the network interface 33 is connected to the numerical control device 50 having such a configuration, so that data can be transmitted and received between the numerical control device 50, the processor 31, and the memory 32 via the network 200. Make it.

The processor 31 and memory 32 constitute a computer. The tool path correction device 1 performs various processes for transmitting and receiving data with the numerical control device 50 by having the processor 31 read and execute various programs stored in the memory 32.

For example, the tool path correction device 1 reads out and executes a learning program stored in the memory 32, so that from the tool path, the workpiece 21 is actually machined by the machining center 10. A learning process is performed to generate an estimation model for estimating the shape and size of 23. Further, the tool path correction device 1 performs tool path correction processing for correcting the tool path based on the above-mentioned estimated model by reading out and executing the tool path correction program stored in the memory 32.

The tool path correction device 1 includes functional blocks configured as software shown in FIG. 9 in order to perform these learning processes and tool path correction processes. Specifically, the tool path correction device 1 includes a learning section 11, an estimating section 12, a calculating section 13, and a transmitting section 14.

An input device 15 composed of a keyboard, touch panel, etc. is connected to the tool path correction device 1. The learning unit 11 is a part that performs the above-described learning process when a learning command is input from the input device 15. When the learning command is input, the learning unit 11 performs learning based on the learning database 35 stored in the learning DB (Data Base) storage unit 16, and generates the above-described estimated model.

To explain in detail, as shown in FIG. 10, the learning database 35 stores in advance a learning database 35 in which data on tool paths, machining conditions, and additional machining conditions are associated with data on machining results. There is.

Here, in the case of this embodiment, the tool path refers to the path of the tool 20 with respect to the workpiece 21 when the machining center 10 processes the workpiece 21. That is, the tool path is a relative path between the tool 20 and the workpiece 21.

Note that the tool path is preferably a path obtained from an NC program, for example, a path expressed in an XYZ coordinate system. The tool path may be represented by coordinates of a starting point, an ending point, and a way point from the starting point to the ending point.

Further, the machining conditions are the conditions under which the machining center 10 performs machining with the tool 20, and the machining conditions include, for example, the material of the workpiece 21, the feed rate of the tool 20, the cutting speed, and the device number of the machining center 10. , the model number of the tool 20 is included.

Note that the machining conditions preferably include at least one of the feed rate and cutting speed of the tool 20. Further, the machining conditions may include the depth of cut of the tool 20. In addition, the machining conditions may include the cutting speed or the spindle rotation speed of the spindle head 140. Furthermore, the machining conditions may include the material of the tool 20, the hardness of the material of the tool 20, or the hardness of the material of the workpiece 21.

The additional machining conditions are conditions that are found through detection and inspection from the start of machining to the end of machining by the tool 20, and are conditions that are added after machining. For example, the additional machining conditions include the total machining distance of the tool 20 and the tool temperature during machining.

Note that in the additional machining conditions, the total machining distance of the tool 20 is one index indicating wear of the tool 20, and therefore may be replaced with wear information of the tool 20. In this case, the wear information on the tool 20 may include whether or not the tool 20 has been polished, the number of times the tool 20 has been polished, and the elapsed time since manufacture if the tool 20 deteriorates over time.

Further, the machining result data refers to data on the shape and size of the actual machined portion 23, which is formed on the workpiece 21 as a result of the tool 20 moving along the tool path described above.

The learning DB storage unit 16 shown in FIG. 9 stores tool path and machining condition data 36 shown in FIG. 11. The learning database 35 having such contents is generated by operating the machining center 10 based on the tool path and machining condition data 36.

In detail, the learning database 35 is created by the following procedure. (1) The learning unit 11 reads the tool path and machining condition data 36, transmits the read tool path and machining condition data 36 to the numerical control device 50 of the machining center 10, and causes the machining center 10 to process the workpiece 21. (2) The learning unit 11 acquires the above additional machining conditions from the machining center 10 at that time. Furthermore, (3) the user measures the processed portion 23 of the processed workpiece 21 using a contact type three-dimensional measuring machine, a scanning laser probe type, or an optical type non-contact type three-dimensional measuring machine. By doing so, data on the shape and size of the part to be machined 23 is acquired, and the acquired data on the shape and size of the part to be machined 23 is used as machining result data. (4) The tool path and machining condition data 36 used in step (1) and the additional machining conditions acquired in step (2) are associated with the machining result data acquired in step (3). By repeating these steps (1) to (4), the learning database 35 is created.

Returning to FIG. 9, the learning unit 11 reads the learning database 35 from the learning DB storage unit 16, and causes the neural network unit 18 of the learning unit 11 itself to learn each data of the read learning database 35. .

The neural network unit 18 has a plurality of nodes called neurons. These nodes are combined to form an input layer, a hidden layer, and an output layer. When each data of the tool path, machining condition, and additional machining condition of each No. of the learning database 35 is input to the input layer, the neural network section 18 inputs the data of each No. corresponding to them from the output layer. The weights of connections between nodes are adjusted so that parameters related to the processed result data are output. Thereby, the neural network unit 18 generates a learned model. In other words, the neural network unit 18 performs learning to generate the above-mentioned estimation model.

When the learning of the neural network unit 18 is completed, the learning unit 11 stores the weights of the connections between the nodes in the learned data storage unit 17. Thereby, the learning unit 11 stores the weight parameters for constructing the estimation model.

On the other hand, when a correction command to correct the tool path is input from the input device 15, the estimating unit 12 performs the above-mentioned tool path correction process to determine whether the workpiece 21 is machined by the tool 20. This is a part for estimating the shape and size of the part to be processed 23. Note that the estimating section 12 is also called a processed part estimating section.

Although detailed contents will be described later, the above-mentioned correction command includes each data of the tool path, machining conditions, and additional machining conditions described in the learning database 35. The estimating unit 12 extracts these data from the correction command, and uses the above-mentioned estimation model to estimate the shape and size of the machined portion 23 from the extracted data of the tool path, machining conditions, and additional machining conditions. The estimation unit 12 transmits data on the estimated shape and size of the processed portion 23 to the calculation unit 13.

The calculation unit 13 is a part of the tool path correction process described above that corrects the tool path. Although detailed contents will be described later, the calculation unit 13 corrects the tool path based on the positional deviation of the workpiece portion 23 having the shape and size estimated by the estimation unit 12 with respect to the tool path. Thereby, the calculation unit 13 determines a correction path for the tool 20 that brings the processed portion 23 closer to the theoretical shape and size. Note that since the calculation unit 13 generates a correction path, it is also referred to as a correction path generation unit.

On the other hand, the transmitter 14 transmits the correction path data to the numerical control device 50 of the machining center 10. Thereby, the calculation unit 13 processes the workpiece 21 using the previous tool path, thereby suppressing a decrease in the machining accuracy of the workpiece portion 23.

Next, with reference to FIGS. 12 and 13A to 13E, the processing performed by the estimation unit 12 and the calculation unit 13, that is, the tool path correction processing, will be described in detail.

In the following description of the tool path correction process, the above-mentioned learning database 35 is created and stored in the learning DB storage section 16, and the learning section 11 uses the learning database 35 to perform the neural network in advance. It is assumed that the section 18 is made to learn. That is, it is assumed that the tool path correction device 1 executes the learning process in advance. As a result, it is assumed that the learned data storage section 17 stores the weights of the connections of the nodes of the neural network section 18 .

FIG. 12 is a flowchart of the tool path correction process performed by the tool path correction device 1.

First, the user inputs a correction command to correct the tool path from the input device 15. In the tool path correction device 1, when a correction command is input, the processor 31 reads and executes the tool path correction program stored in the memory 32, and as a result, the flow of tool path correction processing is started.

When the flow of the tool path correction process is started, first, as shown in FIG. 12, the estimation unit 12 acquires the tool path, machining conditions, and additional machining conditions (step S1).

The above-mentioned correction command includes data of the tool path to be corrected, machining conditions, and additional machining conditions input by the user into the input device 15. The estimation unit 12 obtains the tool path, machining conditions, and additional machining conditions by extracting the tool path, machining conditions, and additional machining conditions from the correction command.

Note that the estimation unit 12 may obtain the tool path and machining conditions from the numerical control device 50 included in the machining center system 100 via the network 200. In this case, the additional processing conditions may be input by the user to the numerical control device 50 from the input device 15. Then, the estimation unit 12 may acquire the input additional processing conditions from the input device 15.

Next, the estimating unit 12 estimates the shape and size of the machined portion 23 when the workpiece 21 is machined by the tool 20 (step S2).

In detail, the estimating unit 12 first reads the weights of the connections of the nodes of the neural network unit 18 from the learned data storage unit 17. The estimation unit 12 includes a neural network unit 19 shown in FIG. 9, which has the same layer structure as the neural network unit 18. Then, the estimating unit 12 applies the read node connection weights to the neural network unit 19 that it owns to construct a learned model, that is, the above-described estimated model.

The constructed estimation model is formed by the neural network unit 19. The estimation unit 12 inputs data on the tool path, machining conditions, and additional machining conditions to the input layer included in the neural network unit 19, and calculates the estimated shape of the workpiece portion 23 from the output layer included in the neural network unit 19. and obtain parameters regarding size data. The estimation unit 12 estimates the shape and size of the processed portion 23 using the parameters.

Next, the calculation unit 13 generates a correction path (step S3). Generation of the correction path will be described in detail with reference to FIGS. 13A to 13E.

FIG. 13A is a conceptual diagram of the shape of the workpiece portion 23 estimated by the estimation unit 12 included in the tool path correction device 1 and the tool path 40 to be corrected. FIG. 13B is a conceptual diagram showing the relationship between the correction path 44 generated by the calculation unit 13 included in the tool path correction device 1 and the shape of the workpiece portion 23 estimated by the estimation unit 12. FIG. 13C is a developed view of the workpiece portion 23 estimated by the estimation unit 12 developed in the circumferential direction of the tool path 40. FIG. 13D is a developed view of the correction path 44 generated by the calculation unit 13 expanded in the circumferential direction of the tool path 40. FIG. 13E is a conceptual diagram of the correction path 44 generated by the calculation unit 13 and the processed portion 23 processed by the correction path 44.

In the example shown in FIG. 13A, the tool path 40 is circular, whereas the estimated shape of the processed portion 23 is an ellipse. Note that the tool path 40 is a path drawn circularly clockwise from a starting point 41. As shown in FIG. 13B, the calculation unit 13 calculates the positional deviation of each part of the estimated workpiece part 23 with respect to each part of the tool path 40, that is, the error 42. Then, the calculation unit 13 calculates the error 42 for the entire estimated processed portion 23.

Furthermore, when the calculated error is E and the proportionality coefficient less than 1 is κ, the calculation unit 13 calculates a correction path 44 in which the error 43 of each part of the tool path 40 shown in FIG. 13B becomes -κE. demand. Thereby, the calculation unit 13 generates a correction path 44 that develops as shown in FIG. 13D for the tool path 40 that develops as shown in FIG. 13C. As a result, when the calculation unit 13 corrects the tool path 40, it obtains a correction path 44 shown in FIG. 13D that can form the processed portion 23 having the same shape as the tool path 40.

In this way, the calculation unit 13 determines the error of each part of the estimated workpiece part 23 with respect to each part of the tool path 40, and corrects the tool path 40 based on the determined error, thereby adjusting the workpiece part 23. A correction path 44 for the tool 20 that approaches the theoretical shape and size is generated.

Returning to FIG. 12, when the calculation unit 13 generates the correction path 44 in step S3, the transmitting unit 14 transmits the generated correction path 44 data (step S4). Specifically, the transmitter 14 transmits the correction path 44 data to the numerical control device 50.

As a result, when the numerical control device 50 moves the tool 20 based on the correction path 44 data, the size of the workpiece part 23 machined by the machining center 10 changes or the shape of the workpiece part 23 changes. It prevents you from storing things away. This prevents the processing accuracy of the processed portion 23 from decreasing.

When the transmission of the correction path 44 data is completed, the transmitter 14 ends the flow of the tool path correction process.

Note that the machining center 10 described in the above embodiment is an example of a machine tool as referred to in the present disclosure. Furthermore, the machining conditions and additional machining conditions of the machining center 10 are examples of conditions for machining using a tool as referred to in the present disclosure. The machining center system 100 is an example of a machine tool system in the present disclosure. The estimated model is an example of a trained model as referred to in this disclosure. The tool path correction program is an example of a program referred to in the present disclosure.

As described above, in the tool path correction device 1, the estimating unit 12 estimates the workpiece to be machined when the workpiece 21 is machined by the tool 20, based on the tool path 40, the machining conditions by the tool 20, and the additional machining conditions. Estimate the shape and size of portion 23. Further, the calculation unit 13 corrects the tool path 40 based on the positional deviation of the workpiece portion 23 having the estimated shape and size with respect to the tool path 40. Specifically, the calculation unit 13 generates a correction path 44 by correcting the tool path 40 based on the estimated deviation of each part of the workpiece portion 23 with respect to each part of the tool path 40. As a result, the tool path correction device 1 can correct the tool path 40 and obtain the corrected path 44, which is a more accurate path, without monitoring during machining. Thereby, the tool path correction device 1 can correct the tool path 40 to a correction path 44 that can process the workpiece 21 with high precision.

In the tool path correction device 1, wear information, more specifically, the total machining distance of the tool 20, is used as an additional machining condition when the estimation unit 12 estimates the shape and size of the workpiece portion 23. Therefore, even when the tool 20 is worn out, the tool path correction device 1 can correct the tool path 40 to the correction path 44 to suppress a decrease in machining accuracy. Note that the wear information is information on changes in the tool 20 over time. The tool path correction device 1 can suppress a decrease in machining accuracy when the tool 20 changes over time.

Furthermore, in the tool path correction device 1, the feed rate and cutting speed of the tool 20 are used as machining conditions when the estimation unit 12 estimates the shape and size of the workpiece portion 23. For this reason, the tool path correction device 1 can be used even when the shape and size of the workpiece portion 23 change due to the feed rate and cutting speed of the tool 20 reaching a specific level and cutting resistance increasing. By correcting the path 40 to the corrected path 44, it is possible to suppress a decrease in processing accuracy.

Furthermore, in the tool path correction device 1, the learning unit 11 generates an estimation model using the learning database 35 obtained by actually machining the workpiece 21 with the machining center 10. Therefore, the tool path correction device 1 can correct the tool path 40 to a correction path 44 suitable for the actual machining center 10. Furthermore, the tool path correction device 1 obtains the correction path 44 using the estimation model generated by the learning section 11, so the configuration is simple. For example, the tool path correction device 1 can determine the correction path 44 without using a numerical simulation that models error elements of the operation of the machining center 10, which will be described later. Since numerical simulation is not used, it is naturally unnecessary to adjust the numerical simulation parameters.

The tool path correction device 1 is particularly effective for a machining center 10 with high repeatability positioning accuracy, which indicates how much error occurs when positioning is repeatedly performed at the same position from the same direction, that is, a machining center 10 with high reproducibility. .

(Modified example)
Note that in the embodiment, the numerical control device 50 is not provided with an input device, but the numerical control device 50 may be provided with an input device. In that case, the input device of the numerical control device 50 may be used instead of the input device 15 described above.

Furthermore, in the embodiment, the operation of the tool path correction device 1 is described using an example in which the machining center 10 moves the tool 20 along a circular tool path 40 to process the workpiece 21. However, the tool path correction device 1 is not limited to this. The tool path correction device 1 corrects the tool path 40, which is the path of the tool 20, to obtain a correction path 44 of the tool 20 that brings the machined portion 23 of the workpiece 21 closer to the theoretical shape and size. The data of the determined correction path 44 may be transmitted to the numerical control device 50. Therefore, the tool path correction device 1 may correct a tool path 40 other than a circular shape.

14A to 14D are conceptual diagrams of first to fourth modifications of the tool path 40 corrected by the tool path correction device 1. Note that in FIGS. 14A to 14D, the tool 20 is placed at the starting point of the tool path 40 for easy understanding. Furthermore, the moving direction of the tool 20 is shown by an arrow.

The tool path correction device 1 may correct a first modification of the rectangular tool path 40 shown in FIG. 14A or a second modification of the diamond-shaped tool path 40 shown in FIG. 14B. Further, the tool path correction device 1 may correct a third modification example of the curved tool path 40 shown in FIG. 14C or a fourth modification example of the linear tool path 40 shown in FIG. 14D. Further, the tool path correction device 1 may target the tool path 40 formed by the combination of the first to fourth modifications.

The reason why the tool path correction device 1 should correct such a tool path 40 is that if the tool path 40 is like this, the acceleration or deceleration of the tool 20 is likely to be large, and the tool path correction device 1 can easily correct the workpiece. This is because the effect of being able to process the object 21 with high precision is remarkable. Furthermore, when the machining center 10 moves the tool 20 along such a tool path 40, due to variations in static stiffness, dynamic stiffness, dynamic characteristics, etc. unique to each machining center 10, or due to variations in the machining center 10, Due to the assembly accuracy or operation accuracy of parts such as ball screws, motors, gears, etc., a difference occurs between the theoretical shape of the machined part 22 and the shape of the actual machined part 23 obtained by machining. This is because such a tool path 40 is easy to use, and the effect of the tool path correction device 1 is significant.

The tool path correction device 1, machine tool system, tool path correction method, and program according to the embodiment of the present disclosure have been described above, but the tool path correction device 1, machine tool system, tool path correction method, and program are , but not limited to.

For example, in the embodiment, the tool path correction device 1 uses the total machining distance of the tool 20 as the additional machining condition, but the tool path correction device 1 is not limited to this. In the tool path correction device 1, the estimation unit 12 may estimate the shape and size of the workpiece portion 23 based on the tool path 40 and the machining conditions of the tool 20. The additional machining conditions of the machining center 10 described in the embodiment may be the machining conditions of the tool 20. Further, the machining conditions of the machining center 10 described in the embodiment may also be conditions for machining the tool 20. Therefore, the machining conditions and additional machining conditions of the machining center 10 are arbitrary as long as they are conditions for machining the tool 20.

For example, in the embodiment, the machining conditions and additional machining conditions of the machining center 10 include the feed rate, cutting speed, and total machining distance of the tool 20; It is sufficient to include at least one of feed rate, cutting speed, and total machining distance. For example, the machining conditions and additional machining conditions of the machining center 10 may include only the feed rate, cutting speed, or total machining distance of the tool 20, or may include a combination thereof. Since these machining conditions and additional machining conditions also include parameters that are correlated with changes in shape and size of the actual workpiece 23 relative to the theoretical workpiece 22, the estimation unit 12 This is because the shape and size of the machined portion 23 when the workpiece 21 is machined by the tool 20 can be estimated based on the machining conditions and the additional machining conditions.

Furthermore, the machining conditions and additional machining conditions of the machining center 10 may further include the depth of cut of the tool 20 described using FIGS. 7A and 7B. In that case, the machining conditions and additional machining conditions of the machining center 10 may include at least one of the feed rate of the tool 20, the cutting speed, the total machining distance, and the depth of cut. These machining conditions and additional machining conditions also include parameters that are correlated with changes in shape and size of the actual machined part 23 with respect to the theoretical machined part 22, as in the case described above. This is because the section 12 can estimate the shape and size of the processed portion 23.

Furthermore, in the embodiment, the tool path correction device 1 uses the total machining distance of the tool 20 as wear information, but the tool path correction device 1 is not limited to this. In the tool path correction device 1, as described above, the estimation unit 12 may estimate the shape and size of the workpiece portion 23 based on the tool path 40 and the machining conditions of the tool 20. It is preferable that the wear information of the tool 20 is used as the machining condition of the tool 20. The wear information in that case is arbitrary as long as it satisfies the above requirements.

For example, when the total machining distance of the tool 20 is L, the hardness of the workpiece 21 is ε, the cutting speed is s, and the constant parameter is β,
α=L×β×ε×s
The wear parameter α of the tool 20 may be used as the wear information.

Additionally, the estimating unit 12 may use information on changes over time of the tool 20 as conditions for machining the tool 20. Further, the estimating unit 12 may use information on changes over time of members provided in the machining center 10 as conditions for machining the tool 20. In this case, the member may be calibrated periodically, for example, once or several times a year.

Furthermore, in the embodiment, the estimation unit 12 constructs the estimation model using a neural network unit (not shown), but the estimation unit 12 is not limited to this. As described above, the estimating unit 12 only needs to estimate the shape and size of the workpiece portion 23 based on the tool path 40 and the machining conditions of the tool 20, and as long as this is the case, the specific implementation means may be arbitrary. It is. For example, the estimation unit 12 may be constructed using a learned model learned by machine learning other than a neural network. In this case, the learning database 35 described in the embodiment is preferably used for learning.

In the embodiment, the calculation unit 13 generates a correction path 44 by correcting the tool path 40 based on the estimated deviation of each part of the workpiece portion 23 with respect to each part of the tool path 40. However, the calculation unit 13 is not limited to this. The calculation unit 13 corrects the tool path 40 based on the positional deviation of the workpiece 23 having the shape and size estimated by the estimation unit 12 with respect to the tool path 40, so that the workpiece 23 has the theoretical shape and size. Any method that generates a correction path 44 for the tool 20 that brings the tool 20 closer to . For example, the calculation unit 13 extracts a characteristic part of the workpiece part 23 having the shape and size estimated by the estimation unit 12, and calculates the tool path 40 based on the positional deviation of the extracted characteristic part with respect to the corresponding part of the tool path 40. It may be corrected. Here, the characteristic portions include, for example, the center of gravity, bent portions, and corner portions.

In the embodiment, the estimation unit 12 acquires the tool path input by the user from the input device 15. However, the estimation unit 12 is not limited to this. The estimation unit 12 may receive data on the tool path of the tool 20 from the numerical control device 50 and use the data on the tool path.

Similarly, in the embodiment, the estimation unit 12 acquires the machining conditions and additional machining conditions input by the user from the input device 15. However, the estimation unit 12 is not limited to this. The estimation unit 12 may obtain operation information of the machining center 10 from the numerical control device 50, for example, obtain a history of past tool paths, and calculate wear information. In other words, the estimation unit 12 may obtain operation information of the machining center 10 and calculate the total machining distance of the tool 20.

Furthermore, in the embodiment, the tool path correction device 1 corrects the tool path of the machining center 10. However, the tool path correction device 1 is not limited to this. The tool path correction device 1 may be any device that can send correction path data to a numerical control device that controls a machine tool. Therefore, the tool path correction device 1 may be any machine tool that is controlled by the numerical control device 50. For example, the tool path correction device 1 may correct the tool path of a milling machine. In addition, the tool path correction device 1 may correct the tool path of a lathe or an electrical discharge machine. In short, the tool path correction device 1 can be applied to machine tools such as milling machines, lathes, and electric discharge machines, for example.

Furthermore, in the embodiment, the tool path correction device 1 includes a learning section 11, a learning DB storage section 16, and a learned data storage section 17. However, the tool path correction device 1 is not limited to this. The tool path correction device 1 only needs to include at least an estimation section 12, a calculation section 13, and a transmission section 14. Therefore, the learning section 11, the learning DB storage section 16, and the learned data storage section 17 have arbitrary configurations. For example, the learning section 11, the learning DB storage section 16, and the learned data storage section 17 may be provided in a learning device connected to the tool path correction device 1 via the network 200. In that case, the learning device may be configured by a server including a microprocessor and memory. Then, the learning program described in the embodiment is stored in the memory of the server, and the server's microprocessor executes the learning program, so that the server may perform the learning process.

In the embodiment, the tool path correction program and the learning program are stored in the memory 32, but the tool path correction program and the learning program can be stored on a flexible disk, CD-ROM (Compact Disc Read-Only Memory), or DVD (Digital). The information may be stored and distributed in a computer-readable non-transitory recording medium such as a Versatile Disc or a Magneto-Optical Disc (MO). In this case, the tool path correction device 1 that executes the tool path correction process and the learning process may be configured by installing the tool path correction program and learning program stored in the recording medium into a computer.

Further, the tool path correction program or learning program is stored in a disk device included in a server device on a communication network such as the Internet, and the tool path correction program or learning program is, for example, superimposed on a carrier wave and downloaded. Good too. The tool path correction process and learning process described above may also be achieved by starting and executing the tool path correction program or the learning program while being transferred via the communication network. Furthermore, the tool path correction described above can also be performed by executing all or part of the tool path correction program or learning program on a server device, and executing the program while the computer transmits and receives information regarding these processes via a communication network. A processing or learning process may be accomplished.

In addition, when tool path correction processing or learning processing is realized by each OS (Operating System), or when it is realized through cooperation between the OS and an application, only the parts other than the OS are used as the medium. It may be stored and distributed, or it may be downloaded. Further, the means for realizing the functions of the tool path correction device 1 is not limited to software, and a part or all of it may be realized by dedicated hardware including a circuit.

The present disclosure is capable of various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Further, the embodiments described above are for explaining the present disclosure, and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is indicated by the claims rather than the embodiments. Various modifications made within the scope of the claims and the meaning of the disclosure equivalent thereto are considered to be within the scope of the present disclosure.

This application is based on Japanese Patent Application No. 2022-81458 filed on May 18, 2022. The entire specification, claims, and drawings of Japanese Patent Application No. 2022-81458 are incorporated herein by reference.

1 Tool path correction device, 10 Machining center, 11 Learning unit, 12 Estimating unit, 13 Calculating unit, 14 Transmitting unit, 15 Input device, 16 Learning DB storage unit, 17 Learned data storage unit, 18, 19 Neural network unit, 20 tool, 21 workpiece, 22, 23 workpiece part, 31 processor, 32 memory, 33 network interface, 34 bus, 35 learning database, 36 tool path and machining condition data, 40 tool path, 41 starting point, 42 , 43 error, 44 correction path, 50 numerical control device, 51 memory, 52, 53 microprocessor, 54 numerical data storage section, 55 calculation section, 56 control section, 100 machining center system, 110 column, 120 table, 121 guide rail, 130 saddle, 131 guide rail, 140 spindle head, 141 guide rail, 142 holder, 150 base, 200 network.

Claims

an estimation unit that estimates the shape and size of a machined part when the workpiece is machined by the tool, based on a tool path that is a tool path and processing conditions by the tool;
The tool corrects the tool path based on the positional deviation of the workpiece portion having the shape and size estimated by the estimation unit with respect to the tool path, thereby bringing the workpiece portion closer to a theoretical shape and size. an arithmetic unit that calculates a correction path of;
a transmitter that transmits data of the correction path to a numerical control device that controls a machine tool that holds the tool;
Equipped with
Tool path correction device.
The calculation unit calculates a deviation of each part of the workpiece part having the shape and size estimated by the estimation unit with respect to each part of the tool path, and generates the correction path based on the calculated positional deviation. do,
The tool path correction device according to claim 1.
The estimation unit uses wear information of the tool as a condition for the machining.
The tool path correction device according to claim 1 or 2.
The tool wear information is a total machining distance over which the tool was used for machining.
The tool path correction device according to claim 3.
The estimation unit uses a feed rate or a depth of cut of the tool as a condition for the machining.
The tool path correction device according to claim 1 or 2.
The estimation unit estimates the shape and size of the machined part using a trained model that has learned the shape and size of the machined part with respect to the tool path and the machining conditions.
The tool path correction device according to any one of claims 1 to 5.
A tool path correction device according to any one of claims 1 to 6,
the machine tool having a holder that holds the tool;
the numerical control device that controls the machine tool;
A machine tool system equipped with
The numerical control device transmits data on the tool path to the estimating unit, receives data on the correction path from the transmission unit, and determines a state in which the tool held in the holder operates on the correction path. controlling said machine tool to;
The machine tool system according to claim 7.
The processing conditions are wear information of the tool,
The tool path correction device obtains operation information of the machine tool from the numerical control device and calculates the wear information.
The machine tool system according to claim 7 or 8.
estimating the shape and size of the workpiece when the workpiece is machined by the tool, based on a tool path that is a path of a tool attached to a machine tool and processing conditions by the tool;
By correcting the tool path based on the positional deviation of the workpiece having the shape and size estimated in the step of estimating the shape and size of the workpiece with respect to the tool path, the workpiece is theoretically calculated. generating a correction path for the tool that approximates the shape and size above;
Equipped with
How to correct tool path.
The computer that sends and receives data to the numerical control device that controls the machine tool that holds the tool,
estimating the shape and size of the workpiece when the workpiece is machined by the tool, based on the tool path that is the path of the tool and the conditions for machining by the tool;
By correcting the tool path based on the positional deviation of the workpiece having the shape and size estimated in the step of estimating the shape and size of the workpiece with respect to the tool path, the workpiece is theoretically calculated. generating a correction path for the tool that approximates the shape and size above;
transmitting data of the correction path to the numerical control device;
A program to run.