Numerical control device and control method

Abstract

The present application provides a numerical control device and a control method capable of easily performing true circle machining. The numerical control device includes a true circle machining unit that uses a command capable of action to perform true circle machining on a workpiece by a cutting tool with a start point as a center, and a machining program operation unit that operates a machining action position as a command capable of action of a machine tool according to one line of machining program in order to command the machine tool.

Description

Technical Field

[0001] This invention relates to a numerical control device and a control method. Background Technology

[0002] Conventionally, numerical control devices for controlling machine tools and the like execute workpiece machining through machining programs (for example, see Patent Document 1). The machining program processing device described in Patent Document 1 calculates a correction reference point based on the command position of the tool tip point indicated by the machining program, the command angle of the tool posture, and the tool size, and rewrites the command position of the tool tip point as the position of the correction reference point.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-70953 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Furthermore, numerical control devices also use machining (control) programs to machine workpieces into perfect circles. However, to machine a perfect circle, the coordinate values ​​of the start and end positions need to be calculated. Although this is based on simple SIN / COS trigonometric functions, a calculator is required, and the program becomes lengthy, making it difficult to manage and correct. In contrast, a method that automatically calculates coordinate values ​​through CAD / CAM machining program generation simplifies the process of generating machining programs.

[0008] However, in order to generate machining programs using CAD / CAM, skilled operators are required. In the process of correcting machining programs by changing coordinate values, such as changing the starting position of machining, CAD / CAM operations are needed every time.

[0009] Furthermore, in recent years, in machining processes such as thread cutting, unlike the previous synchronous machining of the spindle and moving axis, cutting tools with threaded tooth shapes on the cutting edge have been used to increase helical thread cutting. In these processes, helical machining is required at the thread tooth pitch, with continuous commands to a specified position. Cutting tool manufacturers and others prepare tools that provide programs for continuous commands. However, similar to CAD / CAM, tool operations are still required each time the machining program is modified due to changes in coordinate values. Additionally, like CAD / CAM, program redundancy remains unchanged.

[0010] Therefore, in order to automatically generate and execute a program for easily performing perfect circle machining on the machine, a unit that generates macro programs using variables is adopted. However, generating macro programs requires skilled operators who are familiar with the instruction rules of the numerical control device and proficient in programming. Therefore, the requirement is for easy perfect circle machining.

[0011] Methods for solving problems

[0012] The numerical control device according to the present invention includes: a machining program calculation unit, which calculates the machining action position based on a machining program of one line as an instruction for the machine tool to perform the action; and a circular machining unit, which uses the instruction to perform the action to perform circular machining on the workpiece with a cutting tool centered on a starting point.

[0013] The control method of the numerical control device disclosed herein includes the following steps: in order to give instructions to a machine tool, calculating the machining action position according to a machining program of one line as an instruction that the machine tool can perform an action; and using the instruction that can perform the action, performing a circular machining operation on a workpiece in the machine tool with a starting point as the center and a cutting tool.

[0014] Invention Effects

[0015] According to the present invention, perfect circle machining can be performed easily. Attached Figure Description

[0016] Figure 1 It is a diagram showing the structure of the machining system.

[0017] Figure 2 It is a diagram showing the outline of the machining of a perfect circle on a machine tool.

[0018] Figure 3 It is a diagram that shows a specific example of a processing procedure.

[0019] Figure 4 This is a flowchart representing the processing of a numerical control device.

[0020] Figure 5 This is a flowchart representing the processing of a numerical control device. Detailed Implementation

[0021] Figure 1 This is a diagram showing the structure of machining system 1. (For example...) Figure 1 As shown, the machining system 1 includes a numerical control device 2 and a machine tool 3.

[0022] The numerical control device 2 is a device used to control the machine tool 3 to perform predetermined machining operations. The numerical control device 2 includes a control unit 21. The control unit 21 is a processor such as a CPU (Central Processing Unit), which functions as a circular machining unit 211 and a machining program calculation unit 212 by executing programs stored in a storage unit (not shown).

[0023] Machine tool 3 is a device that performs predetermined machining operations such as cutting and measuring cutting tools based on the control of numerical control device 2.

[0024] The machine tool 3 includes an electric motor for machining the workpiece 32, a spindle and feed axis mounted on the electric motor, fixtures and cutting tools corresponding to these axes, and a worktable T for fixing the workpiece 32. Furthermore, the machine tool 3 drives the electric motor according to motion commands output from the numerical control device 2, thereby performing predetermined machining operations. Specifically, the machine tool 3 includes a cutting tool 31.

[0025] The circular machining section 211 performs circular machining on the workpiece with the starting point as the center in the machine tool 3.

[0026] In order to instruct the machine tool 3 on the operation of the circular machining unit 211, the machining program calculation unit 212 calculates the machining operation position based on the machining program of one line as an instruction for the machine tool to operate.

[0027] Figure 2 This is a diagram showing the outline of the circular machining process of machine tool 3.

[0028] The machine tool 3 uses the following processes (1) to (4) to perform circular machining on the workpiece 32 by cutting tool 31.

[0029] (1) Move the cutting tool 31 toward (close to) the workpiece 32.

[0030] (2) Make the cutting tool 31 enter the workpiece 32.

[0031] (3) The workpiece 32 is cut by the cutting tool 31.

[0032] (4) Make the cutting tool 31 retract from the workpiece 32.

[0033] (5) Move the cutting tool 31 from (approach) the workpiece 32.

[0034] Here, in Figure 2 In the figure, reference numeral O represents the starting point, reference numeral (independent variable) I represents the radius of the machined circle, reference numeral (independent variable) A represents the approach angle of the cutting tool 31, and reference numeral (independent variable) C represents the angle of the starting point from the baseline.

[0035] in addition, Figure 2 Reference numeral 33 in the attached figure represents the machining trajectory of the cutting tool 31. Reference numerals (independent variables) X, Y, and Z represent the helical movement of the cutting tool 31 in the X, Y, and Z directions, respectively, indicating the starting point on the specified plane. Reference numeral (independent variable) Q represents the spacing of the cutting tool 31 in the X, Y, and Z axis directions.

[0036] Figure 3 It is a diagram that shows a specific example of a processing procedure.

[0037] In the machining program, G102 represents the G-code for a clockwise circular cutting cycle, and G103 represents the G-code for a counterclockwise circular cutting cycle. G41 indicates that the tool diameter of the cutting tool 31 is corrected to the left relative to the cutting direction, and G42 indicates that the tool diameter is corrected to the right relative to the cutting direction.

[0038] In the machining program, G17 indicates that the XY plane is selected as the cutting plane by the cutting tool 31, G18 indicates that the ZX plane is selected as the cutting plane by the cutting tool 31, and G19 indicates that the YZ plane is selected as the cutting plane by the cutting tool 31.

[0039] Here, G102 and G103 can be selected either way when generating the machining program. Additionally, G41 and G42 can be either not selected or selected either way when generating the machining program. Furthermore, G17, G18, and G19 can be selected any one way when generating the machining program.

[0040] Furthermore, in the machining program, the independent variable I represents the radius of the machining circle processed by the cutting tool 31, and the independent variable F represents the feed rate of the cutting tool 31 for cutting. Here, the independent variable I is a required parameter; if the independent variable F is not specified, the previously specified feed rate is used as the independent variable F.

[0041] In addition, in the machining program, the independent variable G1 represents the tool diameter correction, and the independent variable G2 represents the selection of the cutting plane by the cutting tool 31. The independent variable C represents the starting position by angle. The independent variable R represents the radius of the path of the cutting tool 31 entering and retracting from the workpiece 32. The independent variable A represents the approach angle of the cutting tool 31, and the independent variables X, Y, and Z represent the helical movement of the cutting tool 31 in the X, Y, and Z directions, respectively, referring to the starting point on the specified plane. The independent variables X, Y, and Z are set according to G17 (specifying the XY plane), G18 (specifying the XZ plane), and G19 (specifying the YZ plane) mentioned above.

[0042] Additionally, the independent variable Q represents the spacing of the cutting tool 31 in the X, Y, and Z axes, indicating that continuous helical machining is performed in the axis direction perpendicular to the specified plane, calculated by dividing the difference between the indicated axial direction value and the position where the command was executed by the spacing. The independent variable D represents the tool diameter correction (number) of the cutting tool 31, and the independent variable E represents the approach speed of the cutting tool 31, which, in the absence of a command, indicates rapid feed.

[0043] Furthermore, the independent variables other than I mentioned above are arbitrarily set parameters. For example, without any instruction, independent variable A is 90°, and without any instruction, independent variable C is 0°.

[0044] As described above, according to this embodiment, the numerical control device 2 includes: a circular machining unit 211, which performs circular machining on the workpiece 32 with the starting point as the center using a cutting tool 31 in the machine tool 3; and a machining program calculation unit 212, which calculates the machining action position based on a machining program of 1 line as an instruction for the machine tool 3 to perform the action in order to instruct the operation of the circular machining unit 211 to the machine tool 3.

[0045] Previously, operators needed to generate macro programs with branches conforming to various machining specifications, requiring proficiency in programming. Furthermore, conventional programs for circular machining required calculating the coordinates of various points, the start and end points of the arc, making the programs lengthy and time-consuming to generate. The numerical control device 2 of this embodiment, in order to instruct the machine tool 3 on the actions of the circular machining unit 211, calculates the machining action positions based on a single line of machining program, providing instructions for the machine tool 3 to perform the actions. Therefore, the numerical control device 2 can easily generate circular cutting cycles based on the start point, preventing lengthy machining programs and shortening the generation time.

[0046] In addition, the machining program includes G-code, the radius of the circle to be machined, the starting position, the radius of the path for the cutting tool to enter and exit the workpiece, the approach angle of the cutting tool 31, the helical movement of each linear axis during helical machining of the cutting tool 31, the spacing between each linear axis during helical machining, the tool diameter correction number of the cutting tool, the feed rate of the cutting tool 31 for cutting, and the approach speed of the cutting tool 31. Thus, the numerical control device 2 can appropriately generate a machining program for machining a circle.

[0047] Furthermore, the machining program calculation unit 212 can change the tool diameter correction, the selection of the cutting plane by the cutting tool 31, the starting position, the radius of the path of the cutting tool 31 entering and retracting from the workpiece 32, the helical movement amount, the spacing, the tool diameter correction number, the feed rate, and the approach speed in the machining program. As a result, the numerical control device 2 can set each parameter of the machining program to appropriate values.

[0048] Based on the above, for example, in the case of generating a simple one-line machining program for circular machining, when the action is generated using only the independent variable I, the independent variable F is the previously indicated feed rate, the independent variable R is half the value of I, the independent variable A is 90°, the independent variable C is 0°, the independent variables X, Y and Z have no instructions and therefore no helical motion, the starting point is executed at the location of the machining program instruction, the independent variable Q has no instructions and therefore no continuous helical motion processing, and the circular machining is performed with the independent variable E as the rapid feed motion and the X-axis direction as the starting position.

[0049] In addition, when generating a concise one-line machining program, it is also possible to use the panel operation or dialogue of the numerical control device, or program generation in CAD / CAM.

[0050] Furthermore, the machining program can also perform machining at any position on the indicated plane under specified conditions, before the cancellation code is read after the G-code instruction, similar to a fixed-cycle drilling operation. For example, if there is no cancellation code after a machining program instruction on a single line, and any position (X-axis, Y-axis, or Z-axis) on the indicated plane is specified, then that specified position is taken as the starting point, and the workpiece is machined in a circle using the cutting tool with the starting point as the center, while maintaining the same conditions. Thus, multiple circle machining instructions can be performed without repeating the independent variable instructions.

[0051] Figure 4 as well as Figure 5 This is a flowchart illustrating the processing of the numerical control device 2.

[0052] In step S1, the machining program calculation unit 212 reads the machining program from the storage unit (not shown).

[0053] In step S2, the machining program calculation unit 212 selects the plane to be machined by any one of the independent variables G17, G18 or G19 in the machining program.

[0054] In step S3, the machining program calculation unit 212 determines whether the positioning of the start point is indicated in the machining program. If the positioning of the start point is indicated (yes), the process proceeds to step S5. If the positioning of the start point is not indicated (no), the process proceeds to step S4.

[0055] In step S4, the machining program calculation unit 212 uses any position on the plane selected in step S2 as the starting point for positioning.

[0056] In step S5, the machining program calculation unit 212 determines whether the independent variable E (approach speed) is indicated in the machining program. If the independent variable E is indicated (yes), the process proceeds to step S6. If the independent variable E is not indicated (no), the process proceeds to step S7.

[0057] In step S6, the circular machining unit 211 moves the cutting tool 31 toward the workpiece 32 according to the instruction of the independent variable E.

[0058] In step S7, the circular machining section 211 uses rapid feed to bring the cutting tool 31 closer to the workpiece 32.

[0059] In step S8, the machining program calculation unit 212 determines whether the independent variables A (approach angle), R (entry radius), and C (starting position) are indicated in the machining program. If the independent variables A, R, and C are indicated (yes), the process proceeds to step S9. If the independent variables A, R, and C are not indicated (no), the process proceeds to step S10.

[0060] In step S9, the circular machining unit 211 causes the cutting tool 31 to enter the workpiece 32 according to the instructions of the independent variables A, R and C.

[0061] In step S10, the circular machining unit 211, for example, causes the cutting tool 31 to enter the workpiece 32 according to the standard values ​​of taking the independent variable A as 90°, taking the independent variable R as 1 / 2I, and taking C as 0°.

[0062] In step S11, the machining program calculation unit 212 determines whether independent variables X, Y, Z (spiral movement amount) and independent variable Q (pitch) are indicated in the machining program. If independent variables X, Y, Z, and Q are indicated (yes), the process proceeds to step S13. If independent variables X, Y, Z, and Q are not indicated (no), the process proceeds to step S12.

[0063] In step S12, the circular machining unit 211 performs circular machining on the workpiece 32 using the cutting tool 31 according to the machining program.

[0064] In step S13, the circular machining unit 211 performs spiral machining on the workpiece 32 using the cutting tool 31 according to the machining program.

[0065] In step S14, the machining program calculation unit 212 determines whether the independent variables A (approach angle), R (entry radius), and C (starting position) are indicated in the machining program. If the independent variables A, R, and C are indicated (yes), the process proceeds to step S15. If the independent variables A, R, and C are not indicated (no), the process proceeds to step S16.

[0066] In step S15, the circular machining unit 211 causes the cutting tool 31 to retract toward the workpiece 32 according to the instructions of the independent variables A, R and C.

[0067] In step S16, the circular machining unit 211, for example, retracts the cutting tool 31 toward the workpiece 32 based on standard values ​​that regard independent variable A as 90°, independent variable R as 1 / 2I, and C as 0°.

[0068] In step S17, the machining program calculation unit 212 determines whether the independent variable E (approach speed) is indicated in the machining program. If the independent variable E is indicated (yes), the process proceeds to step S18. If the independent variable E is not indicated (no), the process proceeds to step S19.

[0069] In step S18, the circular machining unit 211 moves the cutting tool 31 closer to the workpiece 32 according to the instruction of the independent variable E.

[0070] In step S19, the circular machining section 211 uses rapid feed to bring the cutting tool 31 closer to the workpiece 32.

[0071] The embodiments of the present invention have been described above, but the present invention is not limited to the described embodiments. Furthermore, the effects described in these embodiments are merely examples of the most preferred effects produced by the present invention, and the effects of the present invention are not limited to the effects described in these embodiments.

[0072] Explanation of reference numerals in the attached figures

[0073] 1. Machining System

[0074] 2 Numerical control device

[0075] 3 machine tools

[0076] 21 Control Department

[0077] 211 Round Machining Department

[0078] 212 Machining Program Calculation Department.

Claims

1. A numerical control device, characterized in that, The numerical control device includes: The machining program calculation unit, in order to issue instructions to the machine tool, calculates the machining motion positions based on one line of machining program as instructions for the machine tool to perform actions; and The circular machining unit, using the aforementioned operational instructions, performs circular machining on the workpiece using a cutting tool, centered on a starting point. If the machining program does not indicate a cancellation code after the machining program instruction on line 1, and indicates any position on the indicated plane, then the indicated position is regarded as the starting point, and the workpiece is machined in a perfect circle in the machine tool with the cutting tool centered on the starting point.

2. The numerical control device according to claim 1, characterized in that, The machining program includes G-code, the radius of the circle to be machined, the starting position, the radius of the path of the cutting tool entering and exiting the workpiece, the approach angle of the cutting tool, the helical movement of each linear axis during helical machining, the spacing between each linear axis during helical machining, the tool diameter correction number of the cutting tool, the feed rate of the cutting tool for cutting, and the approach speed of the cutting tool.

3. The numerical control device according to claim 2, characterized in that, The machining program calculation unit can change the tool diameter correction, the selection of the cutting plane by the cutting tool, the starting position, the radius of the path of the cutting tool entering and retracting from the workpiece, the helical movement amount, the spacing, the tool diameter correction number, the feed rate, and the approach speed in the machining program.

4. A control method for a numerical control device, characterized in that, The control method comprises: In order to instruct the machine tool, the steps of calculating the machining motion positions based on a single line of machining program are used as instructions for the machine tool to perform actions; and Using the aforementioned instructions capable of performing actions, the step involves machining a workpiece in a perfect circle using a cutting tool, centered on a starting point, on the machine tool. If the machining program does not indicate a cancellation code after the machining program instruction on line 1, and indicates any position on the indicated plane, then the indicated position is regarded as the starting point, and the workpiece is machined in a perfect circle in the machine tool with the cutting tool centered on the starting point.

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