Numerical control devices and machine tools

Abstract

The numerical control device includes: an information storage unit, which associates coordinate transformation information used to transform coordinate values ​​in a rotating coordinate system into coordinate values ​​in a reference coordinate system with identification information assigned to a tool for storage; an information acquisition unit, which acquires coordinate values ​​representing a moving path of a tool assigned identification information from a machining program; and a coordinate transformation unit, which performs coordinate transformation of the coordinate values ​​representing the moving path acquired by the information acquisition unit based on the coordinate transformation information stored in the information storage unit.

Description

Technical Field

[0001] The present disclosure relates to a numerical control device and a machine tool. Background Art

[0002] Conventionally, numerical controllers with coordinate transformation functions are known. In such numerical controllers, for example, a tool's movement path is commanded using coordinate values ​​in a coordinate system obtained by rotating a reference coordinate system by a predetermined angle around a predetermined axis. In this case, the coordinate values ​​indicating the movement path are transformed into coordinate values ​​in the reference coordinate system, and the tool's movement is controlled based on the transformed coordinate values.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 3-269604 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, when commanding coordinate transformation in conventional numerical controllers, information such as the coordinate system's rotation center, direction, and amount of rotation must be written into the machining program. This complicates the machining program and can reduce its readability. Furthermore, reduced program readability can lead to workpiece machining errors.

[0008] The purpose of the present disclosure is to provide a numerical control device and a machine tool that can improve the readability of a machining program and reduce machining errors.

[0009] Means for solving problems

[0010] The numerical control device includes: an information storage unit, which associates coordinate transformation information used to transform coordinate values ​​in a rotating coordinate system into coordinate values ​​in a reference coordinate system with identification information assigned to a tool for storage; an information acquisition unit, which acquires coordinate values ​​representing a moving path of a tool assigned identification information from a machining program; and a coordinate transformation unit, which performs coordinate transformation of the coordinate values ​​representing the moving path acquired by the information acquisition unit based on the coordinate transformation information stored in the information storage unit.

[0011] Effects of the Invention

[0012] According to the present disclosure, the readability of the machining program can be improved and machining errors can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 An example of the hardware configuration of a machine tool is shown.

[0014] Figure 2 This is a block diagram showing an example of the functions of a numerical controller.

[0015] Figure 3 Explain the relationship between the base coordinate system and the rotation coordinate system.

[0016] Figure 4 An example of information stored in the information storage unit in the first embodiment is shown.

[0017] Figure 5 This shows an example of a machining program.

[0018] Figure 6 This is a flowchart showing an example of processing executed when machining a workpiece.

[0019] Figure 7 Indicates the machining direction and cutting direction as a reference.

[0020] Figure 8 An example of information stored in the information storage unit in the second embodiment is shown.

[0021] Figure 9 This shows another example of a machining program.

[0022] Figure 10 An example of information stored in the information storage unit in the third embodiment is shown.

[0023] Figure 11 This shows another example of a machining program.

[0024] Figure 12 This is a flowchart showing another example of processing executed when machining a workpiece. DETAILED DESCRIPTION

[0025] [First embodiment]

[0026] Hereinafter, the first embodiment will be described using the drawings.

[0027] Figure 1 This figure shows an example of the hardware configuration of a machine tool. Machine tool 1 is a machine that uses tools to process a workpiece. Machine tool 1 uses tools such as end mills, cutting tools, and drills to cut a workpiece. Machine tool 1 is, for example, a machining center, a lathe, a drilling machine, or a multi-tasking machine.

[0028] The machine tool 1 includes a numerical controller 2 , a display device 3 , an input device 4 , a servo amplifier 5 and a servo motor 6 , a spindle amplifier 7 and a spindle motor 8 , and peripheral equipment 9 .

[0029] The numerical controller 2 controls the entire machine tool 1 and includes a CPU (Central Processing Unit) 11 , a bus 12 , a ROM (Read Only Memory) 13 , a RAM (Random Access Memory) 14 , and a nonvolatile memory 15 .

[0030] The CPU 11 is a processor that controls the entire numerical controller 2 according to a system program. The CPU 11 reads the system program and the like stored in the ROM 13 via the bus 12. The CPU 11 also controls the servo motor 6 and the spindle motor 8 according to a machining program to perform machining of a workpiece.

[0031] The bus 12 is a communication path that mutually connects the hardware components in the numerical controller 2 . The hardware components in the numerical controller 2 exchange data via the bus 12 .

[0032] The ROM 13 is a storage device that stores a system program and the like for controlling the entire numerical controller 2 .

[0033] The RAM 14 is a storage device that temporarily stores various data. The RAM 14 temporarily stores command information indicating the tool's movement path, display data, data input from the outside, etc. The RAM 14 functions as a work area for the CPU 11 to process various data.

[0034] The nonvolatile memory 15 is a storage device that retains data even when the power to the machine tool 1 is turned off and the numerical controller 2 is not receiving power. The nonvolatile memory 15 is comprised of, for example, an SSD (Solid State Drive). The nonvolatile memory 15 stores, for example, information related to tool specifications such as tool diameter input from the input device 4, information related to tool calibration, information related to tool life, and machining programs.

[0035] The numerical controller 2 further includes a first interface 16 , a second interface 17 , an axis control circuit 18 , a spindle control circuit 19 , a PLC (Programmable Logic Controller) 20 , and an I / O unit 21 .

[0036] The first interface 16 connects the bus 12 to the display device 3. The first interface 16 transmits various data processed by the CPU 11 to the display device 3, for example.

[0037] The display device 3 receives and displays various data via the first interface 16. The display device 3 displays, for example, machining programs stored in the nonvolatile memory 15 and information related to tool calibration. The display device 3 is a display such as an LCD (Liquid Crystal Display).

[0038] The second interface 17 connects the bus 12 and the input device 4. The second interface 17 transmits data input from the input device 4 to the CPU 11 via the bus 12, for example.

[0039] The input device 4 is a device for inputting various data. For example, the input device 4 receives input related to tool calibration and tool specifications, and transmits the input data to the non-volatile memory 15 via the second interface 17. Examples of the input device 4 include a keyboard and a mouse. Alternatively, the input device 4 and the display device 3 may be configured as a single device, such as a touch panel.

[0040] The axis control circuit 18 is a circuit that controls the servo motor 6. The axis control circuit 18 receives control instructions from the CPU 11 and outputs instructions for driving the servo motor 6 to the servo amplifier 5. For example, the axis control circuit 18 transmits a torque command for controlling the torque of the servo motor 6 to the servo amplifier 5. Furthermore, the axis control circuit 18 may transmit a rotational speed command for controlling the rotational speed of the servo motor 6 to the servo amplifier 5.

[0041] The servo amplifier 5 receives a command from the axis control circuit 18 and supplies power to the servo motor 6 .

[0042] The servo motor 6 is driven by receiving power from the servo amplifier 5. The servo motor 6 is connected to, for example, a ball screw that drives the tool post, spindle head, and table. The servo motor 6 drives the tool post, spindle head, table, and other components of the machine tool 1, such as the tool post, spindle head, and table, in the X-axis, Y-axis, or Z-axis directions.

[0043] The spindle control circuit 19 is a circuit for controlling the spindle motor 8. The spindle control circuit 19 receives control commands from the CPU 11 and outputs commands for driving the spindle motor 8 to the spindle amplifier 7. For example, the spindle control circuit 19 transmits a torque command for controlling the torque of the spindle motor 8 to the spindle amplifier 7. Furthermore, the spindle control circuit 19 may also transmit a rotational speed command for controlling the rotational speed of the spindle motor 8 to the spindle amplifier 7.

[0044] The spindle amplifier 7 receives a command from the spindle control circuit 19 and supplies power to the spindle motor 8 .

[0045] The spindle motor 8 is driven by receiving power from the spindle amplifier 7. The spindle motor 8 is coupled to the spindle to rotate the spindle.

[0046] The PLC 20 is a control device that executes a ladder program to control the peripheral devices 9 . The PLC 20 controls the peripheral devices 9 via the I / O unit 21 .

[0047] The I / O unit 21 is an interface that connects the PLC 20 and the peripheral device 9 . The I / O unit 21 transmits a command received from the PLC 20 to the peripheral device 9 .

[0048] Peripheral device 9 is provided on machine tool 1 and is a device that performs auxiliary operations when machine tool 1 processes a workpiece. Peripheral device 9 may also be a device provided around machine tool 1. Peripheral device 9 is, for example, a tool changer and a robot such as a manipulator.

[0049] Next, the function of each unit of the numerical controller 2 will be described.

[0050] Figure 2 2 is a block diagram showing an example of the functions of the numerical controller 2. The numerical controller 2 includes, for example, an information storage unit 31, an information acquisition unit 32, a coordinate conversion unit 33, and a control unit 34.

[0051] The information storage unit 31 is implemented by storing data input from the input device 4 or the like or calculation results of the CPU 11 in the RAM 14 or the nonvolatile memory 15. Furthermore, the information acquisition unit 32, the coordinate conversion unit 33, and the control unit 34 are implemented by the CPU 11 performing calculations using, for example, a system program and various data stored in the ROM 13. The CPU 11 performs calculations using the RAM 14 as a work area.

[0052] The information storage unit 31 stores coordinate conversion information for converting coordinate values ​​in the rotation coordinate system into coordinate values ​​in the reference coordinate system.

[0053] The coordinate system is a general term for an origin, coordinate axes, and the like that serve as a reference for indicating a position on the machine tool 1. The coordinate system is, for example, a three-axis orthogonal coordinate system consisting of an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other.

[0054] Machine tool 1 processes a workpiece based on coordinate values ​​in a reference coordinate system. If machine tool 1 is a machining center, for example, the reference coordinate system is set so that the Z axis is parallel to the main spindle, and the X and Y axes are parallel to the direction of movement of the worktable. Alternatively, if machine tool 1 is a lathe, for example, the reference coordinate system is set so that the Z axis is parallel to the main spindle, and the X and Y axes are parallel to the direction of movement of the tool post.

[0055] A rotated coordinate system is a coordinate system set according to the tool's orientation or cutting direction. It is a coordinate system obtained by rotating a base coordinate system around a predetermined axis by a predetermined angle. A rotated coordinate system can also be a coordinate system obtained by parallel translation in a predetermined axial direction as needed.

[0056] Figure 3 The relationship between the reference coordinate system and the rotation coordinate system is explained. The Z axis of the reference coordinate system Cc is parallel to the longitudinal direction of the spindle S, and the X axis and Y axis are parallel to the movement direction of the worktable TB. The Z axis of the rotation coordinate system Cr is parallel to the longitudinal direction of the tool T. The rotation coordinate system Cr is a coordinate system obtained by rotating the reference coordinate system Cc around the X axis by an angle θ. The origin of the reference coordinate system Cc and the origin of the rotation coordinate system Cr do not necessarily have to coincide. The origin of the rotation coordinate system Cr can be a point obtained by parallel translation of the origin of the reference coordinate system Cc by ΔX, ΔY, and ΔZ in the X, Y, and Z axis directions, respectively.

[0057] Coordinate transformation information is information used to transform coordinate values ​​in the rotated coordinate system Cr into coordinate values ​​in the reference coordinate system Cc. For example, the coordinate transformation information is coordinate difference information indicating the difference between the reference coordinate system Cc and the rotated coordinate system Cr. The coordinate difference information includes information indicating the rotation center of the rotated coordinate system Cr and information indicating the rotation angle. However, the coordinate difference information does not include the parallel translation amounts ΔX, ΔY, and ΔZ from the origin of the reference coordinate system Cc to the origin of the rotated coordinate system Cr.

[0058] The coordinate transformation information is set according to the installation direction of the tool T relative to the spindle S. Figure 3 In the example shown, the tool T is mounted on an elbow AH that is tilted at an angle θ about the X axis relative to the spindle S. In this case, the coordinate transformation information includes information indicating the X axis as the rotation center of the rotating coordinate system Cr and the angle θ.

[0059] The information storage unit 31 also stores the coordinate transformation information in association with unique identification information assigned to each tool T. The unique identification information assigned to the tool T is, for example, the tool number of each tool T. The information storage unit 31 may also store information indicating the type of tool in association with the unique identification information of each tool T.

[0060] Figure 4 An example of information stored in the information storage unit 31 is shown. The information storage unit 31 stores information indicating the type of tool and coordinate conversion information in association with the tool number.

[0061] Specifically, "Drill" as the tool type and "X:45" as the coordinate transformation information are stored in association with tool number 11. "X:45" indicates that the rotated coordinate system Cr is a coordinate system rotated 45° about the X-axis of the reference coordinate system Cc. In other words, this indicates that the tool T is mounted in an orientation rotated 45° about the X-axis relative to the longitudinal direction of the spindle S.

[0062] Tool number 12 is associated with "Tap" as the tool type and "X:45" as the coordinate transformation information. Furthermore, tool number 13 is associated with "End Mill" as the tool type and "Null" as the coordinate transformation information. "Null" indicates that there is no difference between the rotating coordinate system Cr and the reference coordinate system Cc, and that the tool T is mounted with its longitudinal direction parallel to the longitudinal direction of the spindle S.

[0063] The coordinate conversion information is input by the user through the input device 4 , for example, and is stored in the information storage unit 31 .

[0064] Here, return Figure 2 Description.

[0065] The information acquisition unit 32 reads and interprets the machining program. Furthermore, the information acquisition unit 32 obtains machining command information from the interpreted machining program. The machining command information includes tool change commands and coordinate transformation commands. Furthermore, the machining command information includes command information indicating the movement path of the tool T, such as positioning commands and linear interpolation commands.

[0066] Figure 5 An example of a machining program used for machining a workpiece is shown.

[0067] The command “M6 T11” on the first line is a tool change command for the tool T having the tool number 11.

[0068] The commands "G90" and "G00 X0.0 Y0.0 Z10.0" on the second line are absolute and positioning commands, respectively. These commands position the tool T at the position (0.0, 0.0, 10.0) in the reference coordinate system Cc.

[0069] The instructions "G68.1" and "X0.0 Y-20.0Z-20.0" on the third line represent the coordinate transformation instruction and the parallel movement amount from the origin of the reference coordinate system Cc to the origin of the rotating coordinate system Cr, respectively. The parallel movement amount is specified by the coordinate value in the reference coordinate system Cc. In addition, when only "G68.1" is instructed, it is deemed that there is no parallel movement amount. That is, the origin of the reference coordinate system Cc coincides with the origin of the rotating coordinate system Cr. The coordinate transformation instruction is an instruction to transform the coordinate value until the coordinate transformation is canceled into the coordinate value in the reference coordinate system Cc. That is, the coordinate value written between the coordinate transformation instruction and the coordinate transformation cancellation instruction is the coordinate value in the rotating coordinate system Cr, and is transformed into the coordinate value in the reference coordinate system Cc by the coordinate transformation unit 33 described later.

[0070] The command "G00 X10.0 Y-20.0Z5.0" on the fourth line is a positioning command. The coordinate values ​​in this positioning command are the coordinate values ​​in the rotating coordinate system Cr.

[0071] The fifth line command "M3 S1000" is a spindle forward rotation command. The spindle forward rotation command causes the spindle S to rotate forward at 1000 rpm.

[0072] The command "G01 Z-20.0F0.1" on the sixth line is a linear interpolation command. This linear interpolation command moves the tool T to the Z:-20 position at a feed rate of 0.1 [mm / rev].

[0073] The command "G69" on the ninth line is a coordinate transformation cancel command. This command cancels the coordinate transformation.

[0074] The information acquisition unit 32 acquires these processing instruction information from the processing program.

[0075] Here, return again Figure 2 Description.

[0076] When the information acquisition unit 32 receives a coordinate conversion command, the coordinate conversion unit 33 performs coordinate conversion on the coordinate values ​​representing the movement path of the tool T obtained by the information acquisition unit 32 based on the coordinate conversion information. The coordinate conversion unit 33 performs coordinate conversion on the coordinate values ​​representing the movement path of the tool T from the time the coordinate conversion command is executed until the time the coordinate conversion cancel command is executed.

[0077] For example, the information storage unit 31 stores Figure 4 The information shown and executed Figure 5In the case of the machining program shown, the coordinate conversion unit 33 performs coordinate conversion on the coordinate values ​​(10.0, -20.0, 5.0) in the positioning command for tool T and the coordinate values ​​(10.0, -20.0, -20.0) in the linear interpolation command based on the coordinate conversion information "X:45" associated with tool T with tool number 11 and the parallel translation amount "X0.0 Y-20.0 Z-20.0" from the origin of the reference coordinate system Cc. Specifically, the coordinate conversion unit 33 performs coordinate conversion by rotating these coordinate values ​​45° around the X axis and parallel translation by 0.0, -20.0, and -20.0 in the X, Y, and Z axes, respectively.

[0078] The coordinate conversion unit 33 generates a coordinate conversion matrix for converting the coordinate values ​​in the rotation coordinate system Cr into the coordinate values ​​in the reference coordinate system Cc based on the coordinate conversion information. When the rotation coordinate system Cr is a coordinate system rotated by an angle θ about the X axis relative to the reference coordinate system Cc, the coordinate conversion unit 33 generates a coordinate conversion matrix R represented by the following equation 1: x The coordinate values ​​obtained from the machining program are multiplied by (θ) to obtain the coordinate values ​​in the reference coordinate system Cc. This allows the coordinate values ​​in the rotation coordinate system Cr obtained from the machining program to be converted into coordinate values ​​in the reference coordinate system Cc.

[0079] Mathematical formula 1

[0080]

[0081] Here, return Figure 2 Description.

[0082] The control unit 34 controls each axis according to the machining program interpreted by the information acquisition unit 32, thereby machining the workpiece. The control unit 34 controls each axis based on the coordinate values ​​in the reference coordinate system Cc. If a coordinate transformation command is specified in the machining program, the control unit 34 controls the movement of the tool T based on the coordinate values ​​transformed by the coordinate transformation unit 33.

[0083] Next, the processing executed by the numerical controller 2 when machining a workpiece will be described.

[0084] Figure 6 1 is a flowchart showing processing executed by the numerical controller 2 when machining a workpiece.

[0085] First, the information acquisition unit 32 reads a machining program (step SA01 ).

[0086] Next, the information acquisition unit 32 interprets the read processing program (step SA02 ).

[0087] Next, the information acquisition unit 32 acquires processing instruction information from the decoded processing program (step SA03 ).

[0088] Next, when the machining instruction information includes a coordinate conversion instruction, the information acquisition unit 32 acquires the coordinate conversion information stored in the information storage unit 31 (step SA04 ).

[0089] Next, the coordinate conversion unit 33 performs coordinate conversion on the coordinate values ​​indicating the movement path of the tool T written between the coordinate conversion command and the coordinate conversion cancel command based on the coordinate conversion information (step SA05 ).

[0090] Finally, the control unit 34 controls each axis based on the machining command information and the coordinate values ​​after coordinate conversion (step SA06 ).

[0091] As described above, the numerical control device 2 of the first embodiment is provided with: an information storage unit 31, which stores coordinate transformation information for transforming coordinate values ​​in the rotating coordinate system Cr into coordinate values ​​in the reference coordinate system Cc in association with identification information assigned to the tool T; an information acquisition unit 32, which acquires coordinate values ​​representing the moving path of the tool T to which the identification information is assigned from the machining program; and a coordinate transformation unit 33, which performs coordinate transformation of the coordinate values ​​acquired by the information acquisition unit 32 based on the coordinate transformation information stored in the information storage unit 31.

[0092] Therefore, it is not necessary to write information such as the rotation center, rotation direction, and rotation amount of the coordinate system used for coordinate transformation into the machining program. As a result, the readability of the machining program can be improved and machining errors can be reduced.

[0093] In the numerical controller 2 of the first embodiment, the coordinate transformation information includes coordinate difference information indicating the difference between the rotation coordinate system Cr and the reference coordinate system Cc, and the coordinate transformation unit 33 performs coordinate transformation based on the coordinate difference information.

[0094] Therefore, the information stored in the information storage unit 31 can be simplified.

[0095] [Second embodiment]

[0096] Next, the second embodiment will be described using the drawings. Description of the same configurations as those of the first embodiment will be omitted.

[0097] like Figure 2 As shown, the numerical controller 2 includes, for example, an information storage unit 31 , an information acquisition unit 32 , a coordinate conversion unit 33 , and a control unit 34 .

[0098] The information storage unit 31 stores coordinate transformation information for converting coordinate values ​​in the rotation coordinate system Cr into coordinate values ​​in the reference coordinate system Cc. The coordinate transformation information includes reference direction information and cutting direction information.

[0099] The reference direction information indicates a reference machining direction determined according to the type of tool. For example, when the tool T is a turning tool such as a cutter, the reference machining direction is the -X direction in the reference coordinate system Cc.

[0100] Cutting direction information indicates the cutting direction of the tool T. For example, if the turning tool is mounted approximately parallel to the X-Z plane in the reference coordinate system Cc and cuts in the -X direction, the cutting direction of the turning tool is the -X direction. In this case, the reference machining direction coincides with the cutting direction of the tool T.

[0101] On the other hand, if the turning tool is mounted approximately parallel to the Y-Z plane in the reference coordinate system Cc and cuts in the -Y direction, the cutting direction of the turning tool is the -Y direction. In this case, the cutting direction of the tool is the direction rotated 90° around the Z axis relative to the reference machining direction.

[0102] Figure 7 Indicates the machining direction and cutting direction that serve as the reference. Figure 7 In the example, a turning tool Tt is mounted on the tool holder TH. In this case, the reference machining direction is the -X direction in the reference coordinate system Cc. Furthermore, the turning tool Tt is mounted approximately parallel to the Y-Z plane in the reference coordinate system Cc. When turning the workpiece, the turning tool Tt cuts in the -Y direction. In this case, the cutting direction of the turning tool Tt is the -Y direction. In other words, the cutting direction of the turning tool Tt is the reference machining direction rotated 90° about the Z axis.

[0103] Figure 8 An example of information stored in the information storage unit 31 is shown. In the information storage unit 31, information indicating the type of tool, reference direction information, and cutting direction information are stored in association with the tool number.

[0104] Specifically, "turning" as the tool type, "-X" as the reference direction information, and "blank" as the cutting direction information are stored in association with the tool number 121. In this case, the cutting direction of the tool T coincides with the reference machining direction.

[0105] The tool type "Turning," the reference direction information "-X," and the cutting direction information "-Y" are stored in association with the tool number 122. In this case, the tool T is mounted approximately parallel to the Y-Z plane in the reference coordinate system Cc, and cuts in the -Y direction.

[0106] The tool type "thread cutting", the reference direction information "-X", and the cutting direction information "blank" are stored in association with the tool number 123. In this case, the cutting direction of the thread cutting tool matches the reference machining direction.

[0107] Information acquisition unit 32 (see Figure 2 ) reads and interprets the machining program. The information acquisition unit 32 obtains machining instruction information from the interpreted machining program. The machining instruction information includes tool change instructions and coordinate transformation instructions. Furthermore, the machining instruction information includes positioning instructions, linear interpolation instructions, and other instruction information indicating the movement path of the tool T.

[0108] Coordinate conversion unit 33 (see Figure 2 ) When the information acquisition unit 32 acquires a coordinate transformation command, the coordinate values ​​representing the movement path of the tool T acquired by the information acquisition unit 32 are transformed based on the coordinate transformation information. The coordinate transformation unit 33 performs coordinate transformation on the coordinate values ​​representing the movement path of the tool T from the time the coordinate transformation command is executed until the time the coordinate transformation cancel command is executed.

[0109] The coordinate conversion unit 33 performs coordinate conversion based on the reference direction information and the cutting direction information. The coordinate conversion unit 33 performs coordinate conversion based on the reference machining direction indicated by the reference direction information and the cutting direction indicated by the cutting direction information.

[0110] For example, the information storage unit 31 stores Figure 8 The information shown and executed Figure 9 In the case of the machining program shown, the coordinate conversion unit 33 performs coordinate conversion on the coordinate values ​​commanded between the coordinate conversion command “G68.1” and the coordinate conversion cancel command “G69” based on the reference direction information “−X” and the cutting direction information “−Y” associated with the tool number 122 .

[0111] Here, the difference between the cutting direction of the turning tool Tt with tool number 122 and the reference machining direction is 90° around the Z axis. In this case, the rotated coordinate system Cr is a coordinate system obtained by rotating the reference coordinate system Cc 90° around the Z axis. Therefore, the coordinate conversion unit 33 performs coordinate conversion by calculating the coordinate values ​​obtained by rotating the coordinate values ​​commanded between the coordinate conversion command and the coordinate conversion cancel command by 90° around the Z axis.

[0112] The coordinate conversion unit 33 generates a coordinate conversion matrix for converting the coordinate values ​​in the rotated coordinate system Cr into the coordinate values ​​in the reference coordinate system Cc based on the coordinate conversion information. The coordinate conversion unit 33 multiplies the generated coordinate conversion matrix by the coordinate values ​​in the rotated coordinate system Cr to obtain the coordinate values ​​in the reference coordinate system Cc.

[0113] The control unit 34 controls each axis according to the machining program interpreted by the information acquisition unit 32, thereby machining the workpiece. The control unit 34 controls each axis based on the coordinate values ​​in the reference coordinate system Cc. If a coordinate transformation command is specified in the machining program, the control unit 34 controls the movement of the tool T based on the coordinate values ​​in the reference coordinate system Cc after coordinate transformation by the coordinate transformation unit 33.

[0114] As described above, in the numerical control device 2 of the second embodiment, the coordinate transformation information includes reference direction information representing the machining direction set for each tool T and the cutting direction information representing the cutting direction of the tool T, and the coordinate transformation unit 33 performs coordinate transformation based on the difference between the direction represented by the reference direction information and the direction represented by the cutting direction information.

[0115] Therefore, it is not necessary to write information such as the rotation center, rotation direction, and rotation amount of the coordinate system used for coordinate transformation into the machining program. As a result, the readability of the machining program can be improved and machining errors can be reduced.

[0116] [Third embodiment]

[0117] Next, a third embodiment will be described using the drawings. Description of the same configurations as those of the first embodiment will be omitted.

[0118] like Figure 2 As shown, the numerical controller 2 includes, for example, an information storage unit 31 , an information acquisition unit 32 , a coordinate conversion unit 33 , and a control unit 34 .

[0119] The information storage unit 31 stores coordinate conversion information for converting coordinate values ​​in the rotation coordinate system Cr into coordinate values ​​in the reference coordinate system Cc. The coordinate conversion information includes reference direction information.

[0120] The reference direction information indicates a reference machining direction determined according to the type of tool. For example, when the tool T is a turning tool Tt such as a cutter, the reference machining direction of the tool T is the -X direction in the reference coordinate system Cc.

[0121] Figure 10This shows an example of information stored in the information storage unit 31. The information storage unit 31 stores information indicating the tool type and reference direction information in association with the tool number. Specifically, "turning" as the tool type and "-X" as the reference direction information are stored in association with the tool number 131.

[0122] In association with the tool number 132 , “turning” as the tool type and “−X” as the reference direction information are stored.

[0123] In association with the tool number 133 , “thread cutting” as the tool type and “−X” as the reference direction information are stored.

[0124] Information acquisition unit 32 (see Figure 2 ) reads and interprets the machining program. The information acquisition unit 32 obtains machining instruction information from the interpreted machining program. The machining instruction information includes tool change instructions and coordinate transformation instructions. Furthermore, the machining instruction information includes positioning instructions, linear interpolation instructions, and other instruction information indicating the movement path of the tool T.

[0125] When the information acquisition unit 32 receives a coordinate conversion command, the coordinate conversion unit 33 obtains position information indicating the position of the tool T. Based on the coordinate conversion information and the position information indicating the position of the tool T, the coordinate conversion unit 33 performs coordinate conversion on the coordinate values ​​indicating the movement path of the tool T obtained by the information acquisition unit 32. The coordinate conversion unit 33 performs coordinate conversion on the coordinate values ​​indicating the movement path of the tool T from the time the coordinate conversion command is executed until the time the coordinate conversion cancel command is executed.

[0126] For example, the information storage unit 31 stores Figure 10 The information shown in the Figure 11 In the machining program shown, the positional information of tool T is acquired from the positioning command "G90 G00 X0.0 Y50.0 Z50.0" for tool T with tool number 132. In other words, the positional information indicating the position of the tool during coordinate transformation is acquired. Furthermore, the cutting direction of tool T is determined based on this acquired positional information. For example, if the positioning command positions tool T on the +Y side of the YZ plane, the cutting direction of tool T is determined to be in the -Y direction.

[0127] On the other hand, the reference machining direction for tool T, tool number 132, is the "-X" direction. That is, the cutting direction of tool T is the direction obtained by rotating the reference machining direction 90° around the Z axis. In other words, the difference between the reference machining direction and the cutting direction for tool T is 90° around the Z axis. In this case, the rotational coordinate system Cr that commands the tool's movement path is a coordinate system obtained by rotating the reference coordinate system Cc 90° around the Z axis. Therefore, the coordinate transformation unit 33 performs coordinate transformation by calculating the coordinate values ​​obtained by rotating the coordinate values ​​commanded between the coordinate transformation command and the coordinate transformation cancel command 90° around the Z axis.

[0128] The control unit 34 controls each axis to perform workpiece machining based on the machining program interpreted by the information acquisition unit 32. If a coordinate transformation command is specified in the machining program, the control unit 34 controls the movement of the tool T based on the coordinate values ​​in the reference coordinate system Cc after the coordinate transformation by the coordinate transformation unit 33.

[0129] Figure 12 This is a flowchart showing an example of processing executed in the numerical controller 2 when machining a workpiece.

[0130] First, the information acquisition unit 32 reads the machining program (step SB01 ).

[0131] Next, the information acquisition unit 32 interprets the read processing program (step SB02 ).

[0132] Next, the information acquisition unit 32 acquires the processing instruction information from the decoded processing program (step SB03).

[0133] Next, when the machining instruction information includes a coordinate conversion instruction, the information acquisition unit 32 acquires the coordinate conversion information stored in the information storage unit 31 (step SB04 ).

[0134] Next, the coordinate conversion unit 33 obtains position information indicating the position of the tool T (step SB05 ).

[0135] Next, the coordinate transformation unit 33 transforms the coordinate values ​​representing the movement path of the tool T written between the coordinate transformation instruction and the coordinate transformation cancel instruction into coordinate values ​​in the reference coordinate system Cc based on the coordinate transformation information and the position information representing the position of the tool T (step SB06).

[0136] Finally, the control unit 34 controls each axis based on the machining command information and the coordinate values ​​after coordinate conversion (step SB07 ).

[0137] As described above, in the numerical controller 2 of the third embodiment, the coordinate transformation information includes the reference machining direction information indicating the reference machining direction set for each tool T, and the coordinate transformation unit 33 performs coordinate transformation based on the reference machining direction information and the position information of the tool T.

[0138] Therefore, it is not necessary to write information related to the coordinate system for coordinate transformation into the machining program. As a result, the readability of the machining program can be improved and machining errors can be reduced.

[0139] In addition, the respective structures in the above-mentioned first embodiment, second embodiment, and third embodiment can be combined as appropriate.

[0140] Description of Reference Signs

[0141] 1Machine Tools

[0142] 2 Numerical control device

[0143] 3 Display device

[0144] 4 input devices

[0145] 5 Servo amplifier

[0146] 6 servo motors

[0147] 7-spindle amplifier

[0148] 8 spindle motors

[0149] 9 Peripheral equipment

[0150] 11CPU

[0151] 12 buses

[0152] 13ROM

[0153] 14 RAM

[0154] 15 Non-volatile memory

[0155] 16 First interface

[0156] 17 Second interface

[0157] 18-axis control circuit

[0158] 19 Spindle control circuit

[0159] 20PLC

[0160] 21 I / O units

[0161] 31 Information Storage Department

[0162] 32 Information Acquisition Department

[0163] 33 Coordinate transformation unit

[0164] 34 Control Department

[0165] AH elbow

[0166] Cc reference coordinate system

[0167] Cr rotation coordinate system

[0168] S-spindle

[0169] TB workbench

[0170] T Tools

[0171] Tt turning tools

[0172] TH tool holder.

Claims

1. A numerical control device, characterized in that: have: an information storage unit that stores coordinate transformation information for transforming coordinate values ​​in the rotation coordinate system into coordinate values ​​in the reference coordinate system in association with identification information assigned to the tool; an information acquisition unit that acquires coordinate values ​​indicating a movement path of the tool to which the identification information is assigned from a machining program; and a coordinate conversion unit that performs coordinate conversion of the coordinate values ​​representing the movement path acquired by the information acquisition unit based on the coordinate conversion information stored in the information storage unit; The coordinate transformation information includes reference processing direction information indicating a processing direction set for each of the tools and serving as a reference for the tool. The coordinate conversion section performs the coordinate conversion based on the reference machining direction information and the position information of the tool.

2. The numerical control device according to claim 1, wherein The coordinate transformation information includes coordinate difference information indicating a difference between the rotation coordinate system and the reference coordinate system. The coordinate conversion section performs the coordinate conversion based on the coordinate difference information.

3. The numerical control device according to claim 1, wherein The coordinate transformation information includes reference direction information and cutting direction information, wherein the reference direction information indicates a machining direction set for each tool and serving as a reference for the tool, and the cutting direction information indicates a cutting direction of the tool. The coordinate conversion unit performs the coordinate conversion based on a difference between a direction indicated by the reference direction information and a direction indicated by the penetration direction information.

4. A machine tool, characterized in that: A numerical controller according to any one of claims 1 to 3 is provided.

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