Machining shape model comparison device and numerical control machine system

Abstract

The present invention enables the simple determination of the cause of an abnormality of a machined surface of a machined workpiece regardless of the proficiency of a user.　The present invention comprises: a machining shape model storage unit that stores at least a first, second, and third machining shape model which are generated on the basis of three machining position data items of at least three steps in series of machining an object with a machine tool; a machining shape model selection unit that selects the first and second machining shape models, and the second and third machining shape models; a machining shape model acquisition unit that acquires the first and second machining shape models and also acquires the second and third machining shape models; and a difference calculation unit that finds a set of the distances between the machined surface of the first machining shape model and the machined surface of the second machining shape model as a first difference set, and finds a set of the distances between the machined surface of the second machining shape model and the machining surface of the third machining shape model as a second difference set.

Description

[Technical field]

[0001] The present invention relates to a machining shape model comparison device and a numerically controlled machine system, and more particularly to a machining shape model comparison device that compares machining shape models of workpieces machined by a machine tool, and a numerically controlled machine system including a machining shape model comparison device. [Background technology]

[0002] Patent document 1 describes a simulation device that makes it easy to identify the causes of problems in machining a workpiece, or to confirm the effects of adjustments to machining programs, control commands such as position commands, servo control, machine operations, etc. This simulation device includes a plurality of storage units for storing a plurality of machining position data obtained from at least two of a machining program, control commands for servo control of a servo motor that drives the machine tool, and feedback information from the servo motor and the machine tool when a workpiece is machined by a machine tool, a machining surface simulation unit that simulates a plurality of machining surfaces using the plurality of stored machining position data, and a display unit that displays images of the plurality of machining surfaces obtained by simulating the plurality of machining surfaces side by side.

[0003] Patent Document 2 describes a numerical control simulation device that can estimate the processed shape of a workpiece when processing is performed from a numerical control program and drive system characteristics. This numerical control simulation device includes a program reading unit which reads in a numerical control program that commands a workpiece machining path, a pre-processing unit which corrects the read-in command path using correction parameters to obtain a corrected path, an interpolation / acceleration / deceleration unit which performs interpolation / acceleration / deceleration based on the corrected path and acceleration / deceleration parameters, a drive system model which estimates a tool tip position using servo parameters for the results of interpolation / acceleration / deceleration, a 3D solid simulation unit which performs a 3D solid simulation using the tool tip position to calculate an estimated machining shape, a shape display unit which displays the calculated estimated machining shape, and a shape error calculation unit which compares a target machining shape with the estimated machining shape and calculates a shape error. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-071951 [Patent Document 2] Patent No. 3399419 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above Patent Document 1, it is said that by using a simulation of the machined surface, it is possible to easily identify which of the elements (processes) of the machining program, the control commands for servo control of the servo motor that drives the machine tool, the servo control, and the machine operation is causing an abnormality in the machined surface of a machined workpiece (work). The above-mentioned Patent Document 2 claims that this can be useful for an operator (user) to estimate the cause of a portion having a large shape error.

[0006] However, with the technology described in Patent Document 1, it is not necessarily easy for a user to judge abnormalities in the machining surface of a machined workpiece by looking at images of multiple machining surfaces obtained by simulating multiple machining surfaces displayed on a display unit. Patent Document 2 does not mention the case where there are multiple elements of abnormality on the machined surface of a machined workpiece, as described in Patent Document 1.

[0007] Therefore, when there are multiple elements (processes) that cause abnormalities in the machined surface of a machined workpiece, it is desirable to enable the user to easily identify which element is causing the abnormality in the machined surface of the machined workpiece. It is also desirable to be able to quantitatively determine which factor is causing the abnormality in the machined surface of the machined workpiece. [Means for solving the problem]

[0008] (1) A first aspect of the present disclosure provides a machining system including: a machining shape model storage unit that stores at least a first machining shape model, a second machining shape model, and a third machining shape model that are generated based on three machining position data of at least three serial processes when machining a workpiece by a machine tool; a machining shape model selection unit that selects the first and second machining shape models, and the second and third machining shape models, stored in the machining shape model storage unit; a machining shape model acquisition unit that acquires the first and second machining shape models selected by the machining shape model selection unit, and acquires the second and third machining shape models; a difference calculation unit that obtains a set of distances between the machining surface of the first machining shape model and the machining surface of the second machining shape model acquired by the machining shape model acquisition unit as a set of first difference values, and obtains a set of distances between the machining surface of the second machining shape model and the machining surface of the third machining shape model as a set of second difference values; The machining shape model comparison device is provided with:

[0009] (2) A second aspect of the present disclosure provides a machining shape model storage unit that stores at least a first machining shape model and a second machining shape model that are generated based on two machining position data of at least two serial processes when machining a workpiece by a machine tool; a machining shape model selection unit that selects the first and second machining shape models stored in the machining shape model storage unit; a machining shape model acquisition unit that acquires the first and second machining shape models selected by the machining shape model selection unit; a difference calculation unit that calculates a set of distances between a machining surface of the first machining shape model and a machining surface of the second machining shape model, which are acquired by the machining shape model acquisition unit, as a set of difference values; The machining shape model comparison device includes a difference evaluation value calculation unit that calculates a statistical quantity of the set of difference values ​​as an evaluation value.

[0010] (3) A third aspect of the present disclosure is a numerically controlled machine system including the machining shape model comparison device described in (1) above, and a numerical control device having a simulation unit that generates at least first, second and third machining shape models based on three machining position data of at least three serial processes when machining a workpiece by a machine tool.

[0011] (4) A fourth aspect of the present disclosure provides a computer comprising: Storing at least a first machining shape model, a second machining shape model, and a third machining shape model generated based on three machining position data of at least three serial processes when machining a workpiece by a machine tool; Selecting the first and second machining shape models and the second and third machining shape models that have been saved; acquiring the selected first and second machining shape models, and acquiring the selected second and third machining shape models; determining a set of distances between the acquired machining surface of the first machining shape model and the machining surface of the second machining shape model as a set of first difference values, and determining a set of distances between the acquired machining surface of the second machining shape model and the machining surface of the third machining shape model as a set of second difference values; The present invention is a computer-readable information storage medium that stores a program for causing the computer to execute the above-mentioned steps. Effect of the Invention

[0012] According to an aspect of the present disclosure, when a workpiece is machined by a machine tool and there are at least three serial processes, a user can easily identify which process is causing an abnormality in the machined surface of the machined workpiece. Furthermore, according to the aspects of the present disclosure, it is possible to quantitatively determine which process is causing the abnormality in the machined surface of the machined workpiece. [Brief description of the drawings]

[0013] [Figure 1] 1 is a block diagram showing an example of the configuration of a numerically controlled machine system including a machining shape model comparison device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing a machining shape model of a workpiece. [Diagram 3] 1 is a block diagram showing an example of the configuration of a machining shape model comparison device according to a first embodiment of the present invention. [Figure 4] 5A to 5C are schematic explanatory diagrams showing a method for determining a distance between machining surfaces of two machining shape models as a difference value. [Diagram 5] 4 is a flowchart showing an operation of the machining shape model comparison device. [Figure 6] FIG. 11 is a block diagram showing an example of the configuration of a machining shape model comparison device according to a second embodiment of the present invention. [Figure 7] FIG. 4 is a diagram showing a display screen of a difference display section. [Figure 8] FIG. 11 is a block diagram showing an example of the configuration of a machining shape model comparison device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0015] (First embodiment) Fig. 1 is a block diagram showing an example of the configuration of a numerically controlled machine system including a machining shape model comparison device according to a first embodiment of the present invention. A numerically controlled machine system (hereinafter referred to as an NC machine system) 10 shown in Fig. 1 includes a numerical control device (hereinafter referred to as an NC device) 100, a servo control unit 200, a servo motor 300, a machine 400, and a machining shape model comparison device 500. The machine 400 is a machine tool that performs cutting and the like. The NC device 100 may be included in the machine 400. Also, the servo motor 300 may be included in the machine 400. Also, the machining shape model comparison device 500 may be included in the NC device 100. When the machine 400 has multiple axes, for example, three axes, an X-axis, a Y-axis, and a Z-axis, a servo control unit 200 and a servo motor 300 are provided for each axis.

[0016] The NC device 100 includes a storage unit 101 , a smoothing control unit 102 , an acceleration / deceleration control unit 103 , a machine coordinate conversion unit 104 , a simulation data output unit 105 , a coordinate conversion unit 106 , and a simulation unit 110 . The details of the configuration and operation of the NC machine system 10 excluding the machining shape model comparison device 500 are described in Patent Document 1, so the configuration and operation will be briefly described below. The simulation unit in Patent Document 1 differs from the simulation unit 110 described later in that it includes a machining surface simulation display unit that displays the results of the machining surface simulation and a display setting designation unit that sets the display.

[0017] In order to implement the functional blocks included in the NC device 100, the NC device 100 can be configured by a computer including an arithmetic processing unit such as a CPU (Central Processing Unit), an auxiliary storage device such as an HDD (Hard Disk Drive) storing various control programs such as application software or an OS (Operating System), and a main storage device such as a RAM (Random Access Memory) for storing data temporarily required when the arithmetic processing unit executes a program. In the NC device 100, the arithmetic processing unit reads the application software or the OS from the auxiliary storage device, expands the read application software or OS in the main storage device, and performs arithmetic processing based on these application software or OS, thereby realizing the functional blocks included in the NC device 100.

[0018] <NC device 100 and servo control unit 200> The storage unit 101 stores a machining program and tool information including a command path (arrangement of command points) indicating a machining path, which are input. Based on a machining execution instruction, the machining program and tool information are read from the storage unit 101 and input to the smoothing control unit 102 and the simulation data output unit 105. The machining program includes a command path indicating a machining path, which becomes machining position data.

[0019] The smoothing control unit 102 performs smoothing control of the movement path based on the movement command indicated by the machining program. Specifically, the smoothing control unit 102 corrects the movement command to a smooth path and then interpolates the points on the corrected movement path at an interpolation period (path correction).

[0020] The acceleration / deceleration control unit 103 generates a movement speed pattern based on the movement command interpolated by the smoothing control unit 102, the acceleration / deceleration based on the acceleration / deceleration time constant, and the maximum speed, generates a position command based on the movement speed pattern, and outputs it to the machine coordinate conversion unit 104. The position command becomes a control command for servo control of the servo motor 300 that drives the machine tool.

[0021] The machine coordinate conversion unit 104 converts the work coordinates into machine coordinates for the position command output from the acceleration / deceleration control unit 103, and outputs the position command converted into machine coordinates to the servo control unit 200 and the simulation data output unit 105.

[0022] The simulation data output unit 105 outputs to the coordinate conversion unit 106 the machining position data of the machining program output from the storage unit 101, the position command (which becomes the machining position data) output from the machine coordinate conversion unit 104, the machining position data which is the motor feedback information (illustrated as motor FB) which becomes the first feedback information output from the servo motor 300, and the machining position data which is the scale feedback information (illustrated as scale FB) which becomes the second feedback information output from the machine 400.

[0023] The coordinate conversion unit 106 converts the four pieces of processing position data output from the simulation data output unit 105 into processing position data in a common coordinate system, and outputs the converted processing position data to the storage units 111 to 114.

[0024] The servo control unit 200 obtains a position deviation, which is the difference between the input position command and at least one of the position detection values ​​of the motor feedback information and the scale feedback information, creates a speed command using the position deviation, and further generates a torque command based on the speed command and outputs it to the servo motor 300. The motor feedback information is a position detection value from a rotary encoder associated with the servo motor 300, and the scale feedback information is a position detection value from a linear scale attached to the machine 400. The servo control unit 200 does not need to perform feedback control using both the motor feedback information output from the servo motor 300 and the scale feedback information output from the machine 400; for example, the scale feedback information may not be input to the servo control unit 200 but may be output only to the coordinate conversion unit 106.

[0025] The rotational angle position of the servo motor 300 is detected by a rotary encoder that serves as a position detector associated with the servo motor 300, and the detected signal is integrated and output as motor feedback information to the servo control unit 200 and the simulation data output unit 105. The scale feedback information is a position detection value from a linear scale attached to the end of a ball screw of the machine 400. The linear scale detects the moving distance of the ball screw, and outputs the output as scale feedback information to the servo control unit 200, and also inputs it to the simulation data output unit 105 as position information of the ball screw, which is the moving part of the machine 400.

[0026] The simulation unit 110 includes a storage unit 111 , a storage unit 112 , a storage unit 113 , a storage unit 114 , a simulation start command unit 115 , a shape simulation unit 116 , a shape simulation display unit 117 , a confirmation location designation unit 118 , and a machining surface simulation unit 119 .

[0027] As described above, the storage units 111, 112, 113, and 114 respectively store the machining position data of the machining program, the machining position data output from the machine coordinate conversion unit 104, the machining position data output from the servo motor 300, and the machining position data output from the machine 400. The machining position data stored in the storage units 111, 112, 113, and 114 is machining position data in a common coordinate system. The number N of processing position data is not limited to four, and may be two, three, or five or more (N>2).

[0028] When a simulation start request is input to the NC device 100, the simulation start command unit 115 first reads out the machining position data of the machining program from the storage unit 111, and sends a simulation start command together with the machining position data of the machining program to the shape simulation unit 116. Note that the machining position data to be read out first is not limited to the machining position data stored in the storage unit 111, and any of the machining position data in the storage units 111 to 114 may be read out.

[0029] When the shape simulation unit 116 receives a simulation start command, it performs a shape simulation using the machining position data of the machining program, and sends image information indicating the shape of the workpiece (hereinafter referred to as the work) obtained by the shape simulation to the shape simulation display unit 117.

[0030] The shape simulation display unit 117 displays the shape of the work on a screen based on image information showing the shape of the work. The shape simulation display unit 117 is, for example, a liquid crystal display device with a touch panel. When a user observes a work that has actually been machined by the machine 400 and finds an abnormality in the work, the user uses the touch panel to specify a location on the work that the user wants to check in order to detect the cause of the abnormality.

[0031] The check location designation unit 118 sends coordinate information for designating the check location specified on the touch panel to the machining surface simulation unit 119. Here, the entire workpiece is designated as the check location.

[0032] The machining surface simulation unit 119 cooperates with the simulation start command unit 115 to perform a simulation of the machining surface (hereinafter referred to as machining surface simulation) as follows.

[0033] The machining surface simulation unit 119 identifies the machining position data of the confirmation location based on the coordinate information, and first executes a first machining surface simulation.

[0034] The machining surface simulation unit 119 reads out the machining position data from the storage unit 111 or receives it from the simulation start command unit 115, and uses it for a first machining surface simulation. The first machining surface simulation is performed by calculating the portion to be cut off based on the position data and tool information.

[0035] When the first machining surface simulation using the machining position data of the machining program is completed, the machining surface simulation unit 119 sends a notification of the end of the first machining surface simulation to the simulation start command unit 115. The machining surface simulation unit 119 stores coordinate information indicating the confirmation location. The machining surface simulation unit 119 stores the first machining shape model obtained by the first machining surface simulation in the machining shape model storage unit 501 described later. For example, the machining shape of the first machining shape model of the workpiece is the machining shape shown in the perspective view of FIG. 2. The shape of the three uneven parts 20-1 in FIG. 2 is an inverse uneven shape to the shape of the three uneven parts 20-2. The workpiece shown in FIG. 2 is an evaluation workpiece described in JP 2019-040586 A.

[0036] When the simulation start command unit 115 receives a notification of the end of the first machining surface simulation, it reads out the machining position data output from the machine coordinate conversion unit 104 from the storage unit 112, and sends the machining position data output from the machine coordinate conversion unit 104 to the machining surface simulation unit 119. Since the coordinate information indicating the confirmation location is stored in the machining surface simulation unit 119, it is not necessary to specify the shape simulation and the confirmation location, and the simulation start command unit 115 directly sends the machining position data output from the machine coordinate conversion unit 104 to the machining surface simulation unit 119.

[0037] The machining surface simulation unit 119 executes a second machining surface simulation using the machining position data output from the machine coordinate conversion unit 104, and when the second machining surface simulation is completed, sends a second machining surface simulation completion notification to the simulation start command unit 115. The machining surface simulation unit 119 stores the second machining shape model obtained from the second machining surface simulation in the machining shape model storage unit 501.

[0038] The operations related to the second machining surface simulation described above are similarly performed for the third and fourth machining surface simulations, and the machining surface simulation unit 119 stores the third and fourth machining shape models obtained by the third and fourth machining surface simulations in the machining shape model storage unit 501.

[0039] <Processing Shape Model Comparison Device 500> FIG. 3 is a block diagram showing an example of the configuration of a machining shape model comparison device according to the first embodiment of the present invention. As shown in FIG. 3, the machining shape model comparison device 500 includes a machining shape model storage unit 501, a machining shape model selection unit 502, a machining shape model acquisition unit 503, and a difference calculation unit 504.

[0040] The machining shape model storage unit 501 stores a first machining shape model obtained by performing a machining surface simulation using machining position data of the machining program, a second machining shape model obtained by performing a machining surface simulation using machining position data output from the machine coordinate conversion unit 104, a third machining shape model obtained by performing a machining surface simulation using machining position data output from the servo motor 300, and a fourth machining shape model obtained by performing a machining surface simulation using machining position data output from the machine 400. The number of machining shape models to be stored is not limited to four, and is the same as the number N (N>2) of machining position data described above.

[0041] The machining shape model selection unit 502 selects at least two pairs of machining shape models of two adjacent processes from the first to fourth machining shape models stored in the machining shape model storage unit 501. When selecting two pairs, the selection is made so that a common machining shape model is included between the two pairs. This is to grasp which process among a plurality of chronological processes of the workpiece is causing an abnormality in the machined surface of the workpiece.

[0042] The NC machine system 10, excluding the machining shape model comparison device 500, operates in a number of steps including four serial steps consisting of reading a machining program, generating a position command, outputting motor feedback information from the servo motor 300, and outputting scale feedback information from the machine 400 driven by the servo motor 300, and generates first to fourth machining shape models.

[0043] Therefore, the pair of machining shape models of two adjacent processes corresponds to a pair of the first machining shape model and the second machining surface shape model, a pair of the second machining shape model and the third machining surface shape model, or a pair of the third machining shape model and the second machining surface shape model. A method of selecting at least two pairs of machining shape models may be predetermined or may be specified by a user.

[0044] In the following description, the machining shape model selection unit 502 selects a pair of the first machining shape model and the second machining surface shape model, a pair of the second machining shape model and the third machining surface shape model, and 3 The machining shape model and the 4 A pair with the machining surface shape model of the above is selected.

[0045] The machining shape model acquisition unit 503 acquires the first machining shape model and the second machining shape model selected by the machining shape model selection unit 502 from the machining shape model storage unit 501 .

[0046] The difference calculation unit 504 obtains the distance between the machining surface of the first machining shape model output from the machining shape model acquisition unit 503 and the machining surface of the second machining shape model as a difference value. Fig. 4 is a schematic explanatory diagram showing a method for determining the distance between the machining surfaces of two machining shape models as a difference value. In Fig. 4, for simplification, the two machining shape models are shown as curved surfaces, one of the two machining shape models is a reference machining shape model, and the other is a machining shape model to be compared. For example, the reference machining shape model is the first machining surface shape model, and the comparison target machining shape model is the first machining surface shape model. In Fig. 4, the reference machining shape model is shown by a solid line, and the comparison target machining shape model is shown by a dashed line.

[0047] As shown in Fig. 4, the machining surface of the reference machining shape model is subdivided into meshes. A reference machining shape model is compared with a comparison machining shape model, and the distance at which the normal of each mesh on the machining surface of the reference machining shape model intersects with the machining surface of the comparison machining shape model is taken as the difference value of that mesh. The difference calculation unit 504 calculates a difference value for each mesh, and outputs a set of difference values ​​for each mesh (hereinafter, referred to as a first set of difference values).

[0048] The machining shape model acquisition unit 503 acquires the second machining shape model and the third machining shape model selected by the machining shape model selection unit 502 from the machining shape model storage unit 501. Note that since the machining shape model acquisition unit 503 has already read out the second machining shape model to obtain the set of first difference values, if the read out second machining shape model is stored in the storage unit, it is not necessary to read out the second machining shape model again. Similar to the method of determining the first set of difference values, the difference calculation unit 504 determines the distance between the machining surface of the second machining shape model and the machining surface of the third machining shape model as a difference value for each mesh, and outputs a set of difference values ​​for each mesh (hereinafter referred to as the second set of difference values).

[0049] Similarly, the machining shape model acquisition unit 503 acquires the third machining shape model and the fourth machining shape model selected by the machining shape model selection unit 502 from the machining shape model storage unit 501 . Similar to the method of determining the first set of difference values, the difference calculation unit 504 determines the distance between the machining surface of the third machining shape model and the machining surface of the fourth machining shape model as a difference value for each mesh, and outputs a set of difference values ​​for each mesh (hereinafter referred to as the third set of difference values).

[0050] The user can determine in which process an abnormality is likely to occur, based on the first set of difference values, the second set of difference values, and the third set of difference values ​​output from the difference calculation section 504. For example, if the distribution of the first set of difference values ​​is within a normal range and the distribution of the second set of difference values ​​is within a range beyond the normal range, the user can determine that the abnormality in the machined surface of the workpiece is due to the servo control of the servo control unit 200.

[0051] Furthermore, for example, if the distribution of the first and second sets of difference values ​​is within a normal range and the distribution of the third set of difference values ​​is within a range that exceeds the normal range, the user can determine that the abnormality in the machined surface of the workpiece is due to machine operation.

[0052] In this embodiment, it is sufficient to select at least two pairs of machining shape models from the first to fourth machining shape models and obtain two sets of difference values. For example, when it is known that the abnormality in the machining surface of the workpiece is not due to machine operation, it is sufficient to obtain only the first set of difference values ​​and the second set of difference values.

[0053] In order to realize the functional blocks included in the machining shape model comparison device 500 shown in Fig. 3, the machining shape model comparison device 500 can be configured by a computer equipped with an arithmetic processing device such as a CPU (Central Processing Unit). The machining shape model comparison device 500 also includes an auxiliary storage device such as an HDD (Hard Disk Drive) that stores various control programs such as application software or an OS (Operating System), and a main storage device such as a RAM (Random Access Memory) for storing data temporarily required when the arithmetic processing device executes a program.

[0054] In the machining shape model comparison device 500, the arithmetic processing device reads the application software or the OS from the auxiliary storage device, and performs arithmetic processing based on the application software or the OS while expanding the read application software or the OS in the main storage device. Also, based on the calculation results, various hardware components provided in the machining shape model comparison device 500 are controlled. In this way, the functional blocks of this embodiment are realized. In other words, this embodiment can be realized by the cooperation of hardware and software.

[0055] Next, the operation of the machining shape model comparison device 500 will be described with reference to the flowchart of FIG. In step S10, the machining shape model selection unit 502 selects at least two pairs of machining shape models for two adjacent processes from the first to fourth machining shape models stored in the machining shape model storage unit 501. When selecting two pairs, the selection is made so that a common machining shape model is included between the two pairs.

[0056] In step S11 , the machining shape model acquisition unit 503 acquires, from the machining shape model storage unit 501 , two machining shape models included in one of the machining shape model pairs selected by the machining shape model selection unit 502 .

[0057] In step S12, the difference calculation unit 504 calculates a difference value for each mesh of the two machining shape models acquired from the machining shape model acquisition unit 503, and outputs a set of difference values. Each difference value is the distance at which the normal to each mesh of one machining shape model intersects with the machining surface of the other machining shape model.

[0058] In step S13, it is determined whether or not to obtain difference values ​​for other pairs of machining shape models. If difference values ​​are to be obtained for other pairs of two machining shape models as well ("YES" in step S14), the process returns to step S11. If difference values ​​are not to be obtained for other pairs of machining shape models ("NO" in step S14), the process ends. Note that since at least two pairs of machining shape models are selected, steps S11 to S13 are repeated at least twice.

[0059] Second embodiment In this embodiment, an embodiment will be described in which a set of difference values ​​output from a difference calculation unit 504 is displayed on a machined shape model using colors. 6 is a block diagram showing an example of the configuration of a machining shape model comparison device according to a second embodiment of the present invention. The configuration of the NC machine system excluding the machining shape model comparison device is the same as that of the NC machine system 10 shown in FIG. The machining shape model comparison device 500A of this embodiment has a difference display unit 505 added to the machining shape model comparison device 500 shown in Fig. 3. Fig. 7 is a diagram showing a display screen of the difference display unit.

[0060] The difference display unit 505 displays a first image on a display screen of a display device such as a liquid crystal display device. The first image is an image in which a difference value for each mesh between the first machining shape model and the second machining shape model is drawn on the machining surface of the first machining shape model output from the machining shape model acquisition unit 503 in a color according to the difference value.

[0061] Further, the difference display unit 505 displays the second image on the display screen of a display device such as a liquid crystal display device. The second image is an image in which, on the surface of the second machining shape model output from the machining shape model acquisition unit 503, difference values ​​for each mesh between the second machining shape model and the third machining shape model are drawn in colors according to the difference values.

[0062] The difference display unit 505 displays the third image on a display screen of a display device such as a liquid crystal display device. The third image is an image in which, on the surface of the third machining shape model output from the machining shape model acquisition unit 503, difference values ​​for each mesh between the third machining shape model and the fourth machining shape model are drawn in colors according to the difference values. The first image, the second image, and the third image are arranged side by side in the horizontal direction on the display screen. Note that the direction in which the first to third images are arranged is not limited to the horizontal direction and may be, for example, the vertical direction.

[0063] 7, the difference display unit 505 displays in black the portions in the second image where the difference value for each mesh exceeds a predetermined threshold, and does not color (does not color in black) the portions in the first and third images where the difference value for each mesh is equal to or less than the predetermined threshold. Note that "display according to the difference value" also includes the case where the difference value is equal to or less than the predetermined threshold and is colorless. By looking at the display screen of Figure 7, the user can see that there are many locations in the second image where the difference values ​​for each mesh exceed a predetermined threshold value, and that the abnormality in the machined surface of the workpiece is due to the servo control of the servo control unit 200.

[0064] Two thresholds may be provided for determining the difference value, and when the difference value for each mesh is equal to or less than the first threshold value d1, it may be colored blue, when it exceeds the first threshold value d1 and is equal to or less than the second threshold value d2 (d2>d1), it may be colored green, and when it exceeds the second threshold value d2, it may be colored red. In this case, by checking the areas in one image that are drawn in blue, green, and red, it is possible to determine the variation in the difference value. Also, three or more thresholds may be provided. In the above explanation, the difference value range for each mesh is displayed using a color, but it may be displayed using a shading, a fill pattern, etc. It is also possible to place a pin at a point where the difference value exceeds a predetermined threshold value.

[0065] Third embodiment In the first and second embodiments, an example has been described in which at least two pairs of machining shape models are selected from the first to fourth machining shape models stored in the machining shape model storage unit 501, and the distance between the machining surfaces of the machining shape models is obtained as a difference value for each mesh. In the first and second embodiments, it is possible to determine in which process an abnormality occurs in the machining surface of the workpiece.

[0066] In this embodiment, at least one pair of machining shape models is selected from the first to fourth machining shape models, the distance between the machining surfaces of the machining shape models is calculated as a difference value for each mesh, and the statistics of the set of difference values ​​is calculated as an evaluation value. The statistics is a numerical value that indicates the characteristics of a set of data, such as an average value, a variance value, a standard deviation value, etc.

[0067] 8 is a block diagram showing an example of the configuration of a machining shape model comparison device according to a third embodiment of the present invention. The configuration of the NC machine system excluding the machining shape model comparison device is the same as that of the NC machine system 10 shown in FIG. The machining shape model comparison device 500B of this embodiment further includes a difference evaluation value calculation unit 506 and an abnormality determination unit 507 in addition to the machining shape model comparison device 500 shown in Fig. 3. The abnormality determination unit 507 does not need to be provided when abnormality determination is not performed.

[0068] The machining shape model selection unit 502 selects at least one pair of machining shape models for two adjacent processes from the first to fourth machining shape models stored in the machining shape model storage unit 501. A method for selecting the pair of machining shape models may be determined in advance or may be specified by the user. In the following description, it is assumed that the machining shape model selection unit 502 selects a pair of a first machining shape model and a second machining surface shape model.

[0069] The machining shape model acquisition unit 503 acquires the first machining shape model and the second machining shape model selected by the machining shape model selection unit 502 from the machining shape model storage unit 501 .

[0070] As in the first embodiment, the difference calculation unit 504 obtains, as a difference value, the distance between the machining surface of the first machining shape model and the machining surface of the second machining shape model output from the machining shape model acquisition unit 503. The difference calculation unit 504 obtains a difference value for each mesh, and outputs a set of difference values ​​for each mesh (a set of first difference values).

[0071] The difference evaluation value calculation unit 506 calculates the average value of the set of first difference values ​​by accumulating the absolute values ​​of the difference values ​​for each mesh and dividing the result by the number of meshes, and outputs the result as a first evaluation value. When the average value of the set of first difference values ​​exceeds a predetermined threshold value, the abnormality determination unit 507 can determine that an abnormality has occurred in the machined surface of the workpiece due to a control command based on the machining program.

[0072] In this embodiment, similarly to the first embodiment, the difference calculation unit 504 may calculate a second set of difference values ​​and a third set of difference values ​​in addition to the first set of difference values. In that case, as described above, the difference evaluation value calculation unit 506 calculates and outputs the average value of the first set of difference values, calculates and outputs the average value of the second set of difference values ​​by accumulating the absolute values ​​of the difference values ​​for each mesh and dividing by the number of meshes, and calculates and outputs the average value of the third set of difference values ​​by accumulating the absolute values ​​of the difference values ​​for each mesh and dividing by the number of meshes.

[0073] The abnormality determination unit 507 can determine in which process an abnormality is likely to occur based on the average value of the first set of difference values, the average value of the second set of difference values, and the average value of the third set of difference values. For example, when the average value of the standard set of difference values ​​is 1, the average value of the first set of difference values ​​is 1.01 times, the average value of the second set of difference values ​​is 3.85 times, and the average value of the third set of difference values ​​is 0.98 times. In this case, the abnormality determination unit 507 can determine that the abnormality in the machined surface of the workpiece is due to the servo control of the servo control unit 200.

[0074] Although each embodiment of the present invention has been described above, each component of the machining shape model comparison device can be realized by hardware, software, or a combination of these. Here, being realized by software means being realized by a computer reading and executing a program.

[0075] The program can be stored and provided to a computer using various types of non-transitory computer readable recording media. The non-transitory computer readable recording media include various types of tangible recording media. The non-transitory computer readable recording media include, for example, magnetic recording media (e.g., hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, and semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs (random access memories)).

[0076] The above-described embodiment is a preferred embodiment of the present invention, but the scope of the present invention is not limited to the above-described embodiment, and the present invention can be implemented in various modified forms without departing from the gist of the present invention.

[0077] The machining shape model comparison device and the numerically controlled machine system according to the present disclosure can take various embodiments having the following configurations, including the above-mentioned embodiment.

[0078] (1) A machining shape model storage unit (e.g., machining shape model storage unit 501) that stores at least a first machining shape model, a second machining shape model, and a third machining shape model that are generated based on three machining position data of at least three serial processes when machining a workpiece by a machine tool; a machining shape model selection unit (e.g., a machining shape model selection unit 502) that selects the first and second machining shape models, and the second and third machining shape models stored in the machining shape model storage unit; a machining shape model acquisition unit (e.g., a machining shape model acquisition unit 503) that acquires the first and second machining shape models selected by the machining shape model selection unit, and acquires the second and third machining shape models; a difference calculation unit (e.g., a difference calculation unit 504) that obtains a set of distances between the machining surface of the first machining shape model and the machining surface of the second machining shape model acquired by the machining shape model acquisition unit as a set of first difference values, and obtains a set of distances between the machining surface of the second machining shape model and the machining surface of the third machining shape model as a set of second difference values; A machining shape model comparison device (machining shape model comparison device 500, 500A, 500B) comprising: According to this machining shape model comparison device, when there are at least three serial processes when machining a workpiece with a machine tool, the user can easily identify which process is causing the abnormality in the machining surface of the machined workpiece.

[0079] (2) The machining shape model comparison device described in (1) above, further comprising a difference display unit (e.g., a difference display unit 505) that displays at least a part of a set of first difference values ​​on the first machining shape model or the second machining shape model according to the first difference values, and displays at least a part of a set of second difference values ​​on the second machining shape model or the third machining shape model according to the second difference values. According to this machining shape model comparison device, it is possible to visually identify the location where a difference occurs.

[0080] (3) The machining shape model comparison device according to (1) or (2) above, further comprising a difference evaluation value calculation unit (e.g., the difference evaluation value calculation unit 506) that calculates a statistical quantity of the set of the first difference values ​​as a first evaluation value and calculates a statistical quantity of the set of the second difference values ​​as a second evaluation value. According to this machining shape model comparison device, it is possible to quantitatively compare the first set of difference values ​​with the second set of difference values.

[0081] (4) The machining shape model comparison device according to (3) above, wherein the first evaluation value is a mean value, a variance value, or a standard deviation of the first set of difference values, and the second evaluation value is a mean value, a variance value, or a standard deviation of the second set of difference values.

[0082] (5) The machining shape model comparison device according to (3) or (4) above, further comprising an abnormality determination unit (e.g., the abnormality determination unit 507) that determines in which process of the at least three serial processes an abnormality has occurred, based on the first evaluation value and the second evaluation value. According to this machining shape model comparison device, it is possible to automatically determine which process among at least three serial processes is causing an abnormality in the machined product.

[0083] (6) a machining shape model storage unit that stores at least a first machining shape model and a second machining shape model that are generated based on two machining position data of at least two serial processes when machining a workpiece by a machine tool; a machining shape model selection unit that selects the first and second machining shape models stored in the machining shape model storage unit; a machining shape model acquisition unit that acquires the first and second machining shape models selected by the machining shape model selection unit; a difference calculation unit that calculates a set of distances between a machining surface of the first machining shape model and a machining surface of the second machining shape model, which are acquired by the machining shape model acquisition unit, as a set of difference values; The machining shape model comparison device includes a difference evaluation value calculation unit that calculates a statistical quantity of the set of difference values ​​as an evaluation value. According to this machining shape model comparison device, it is possible to quantitatively determine which process is causing the abnormality in the machined surface of the machined workpiece.

[0084] (7) A numerically controlled machine system comprising: a machining shape model comparison device according to any one of (1) to (5) above; and a numerical control device having a simulation unit that generates at least first, second and third machining shape models based on three machining position data of at least three serial processes when machining a workpiece using a machine tool.

[0085] (8) A computer Storing at least a first machining shape model, a second machining shape model, and a third machining shape model generated based on three machining position data of at least three serial processes when machining a workpiece by a machine tool; Selecting the first and second machining shape models and the second and third machining shape models that have been saved; acquiring the selected first and second machining shape models, and acquiring the selected second and third machining shape models; determining a set of distances between the acquired machining surface of the first machining shape model and the machining surface of the second machining shape model as a set of first difference values, and determining a set of distances between the acquired machining surface of the second machining shape model and the machining surface of the third machining shape model as a set of second difference values; A computer-readable information storage medium storing a program for executing the above. According to this computer-readable information storage medium, the stored program can enable a user to easily identify which process is causing an abnormality in the machined surface of a machined workpiece when there are at least three serial processes when machining the workpiece with a machine tool. [Explanation of symbols]

[0086] 10 NC Machine System 100 NC equipment 110 Simulation Department 200 Servo control unit 300 Servo Motor 400 machines 500, 500A, 500B Processing shape model comparison device 501 Processing shape model storage unit 502 Machining shape model selection section 503 Machining shape model acquisition unit 504 Difference calculation part 505 Difference display area 506 Difference evaluation value calculation unit 507 Abnormality determination section

Claims

1. a machining shape model storage unit that stores at least a first machining shape model, a second machining shape model, and a third machining shape model that are generated based on three machining position data of at least three serial processes when machining a workpiece by a machine tool; a machining shape model selection unit which selects the first and second machining shape models, and the second and third machining shape models stored in the machining shape model storage unit; a machining shape model acquisition unit that acquires the first and second machining shape models selected by the machining shape model selection unit, and acquires the second and third machining shape models; a difference calculation unit that obtains a set of distances between the machining surface of the first machining shape model and the machining surface of the second machining shape model acquired by the machining shape model acquisition unit as a set of first difference values, and obtains a set of distances between the machining surface of the second machining shape model and the machining surface of the third machining shape model as a set of second difference values; a difference evaluation value calculation unit that calculates a statistic of the first set of difference values ​​as a first evaluation value and calculates a statistic of the second set of difference values ​​as a second evaluation value; The machining shape model comparison device includes:

2. 2. The machining shape model comparison device according to claim 1, further comprising a difference display unit that displays at least a part of a set of first difference values ​​on the first machining shape model or the second machining shape model in accordance with the first difference values, and displays at least a part of a set of second difference values ​​on the second machining shape model or the third machining shape model in accordance with the second difference values.

3. 3. The machining shape model comparison device according to claim 1, wherein the first evaluation value is an average value, a variance value, or a standard deviation of the first set of difference values, and the second evaluation value is an average value, a variance value, or a standard deviation of the second set of difference values.

4. 4. The machining shape model comparison device according to claim 1, further comprising an abnormality determination unit that determines in which process of the at least three serial processes an abnormality occurs, based on the first evaluation value and the second evaluation value.

5. a machining shape model storage unit that stores at least a first machining shape model and a second machining shape model that are generated based on two machining position data of at least two serial processes when machining a workpiece by a machine tool; a machining shape model selection unit that selects the first and second machining shape models stored in the machining shape model storage unit; a machining shape model acquisition unit that acquires the first and second machining shape models selected by the machining shape model selection unit; a difference calculation unit that calculates a set of distances between a machining surface of the first machining shape model and a machining surface of the second machining shape model, the distances being acquired by the machining shape model acquisition unit, as a set of difference values; The machining shape model comparison device includes a difference evaluation value calculation unit that calculates a statistical quantity of the set of difference values ​​as an evaluation value.

6. 5. A numerically controlled machine system comprising: a machining shape model comparison device according to any one of claims 1 to 4; and a numerical control device having a simulation unit that generates at least first, second and third machining shape models based on three machining position data of at least three serial processes when machining a workpiece by a machine tool.

7. Computer, storing at least a first machining shape model, a second machining shape model, and a third machining shape model, which are generated based on three machining position data of at least three serial processes when machining a workpiece by a machine tool; Selecting the first and second machining shape models and the second and third machining shape models that have been stored; acquiring the selected first and second machining shape models, and acquiring the selected second and third machining shape models; A set of distances between the acquired machining surface of the first machining shape model and the machining surface of the second machining shape model is obtained as a set of first difference values, and a set of distances between the acquired machining surface of the second machining shape model and the machining surface of the third machining shape model is obtained as a set of second difference values; calculating a statistic of the first set of difference values ​​as a first evaluation value, and calculating a statistic of the second set of difference values ​​as a second evaluation value; A program that executes like this.

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