Numerical control device and control method

Abstract

The machining path is shortened and the cycle time is shortened in turning. The numerical control device includes: an NC command interpretation unit that interprets the instructions of the machining program; and a tool information storage and generation unit that generates geometric information of the tool. The NC command interpretation unit includes: a cutting amount interpretation unit that interprets the cutting amount during rough machining based on the instructions; a machining shape generation unit that generates a finishing shape based on the instructions; a machining path generation unit that generates a rough machining path based on the cutting amount and the finishing shape; a tool direction temporary determination unit that temporarily determines the direction of the tool based on the geometric information and the cutting-in and cutting-out paths of the rough machining path; a path combination determination unit that determines whether to omit the cutting-out action based on the temporarily determined tool direction, cutting-in and cutting-out paths; a machining path combination unit that generates a new path that moves directly to the end point of the next cutting-out action if the cutting-out action is omitted; and a tool direction determination unit that determines the direction of the tool based on the machining shape change point of the rough machining path including the new path.

Description

Technical Field

[0001] The present invention relates to a numerical control device and a control method. Background Art

[0002] A known technique involves automatically generating a path from roughing to finishing by applying a final finished shape to a workpiece during turning from a raw material shape, and controlling axes according to the generated path and the amount of penetration specified by the machining program. For example, see Patent Document 1.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-337707 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the prior art, in order to minimize the cutting stock before finishing, a cutting-out operation is sometimes inserted after the cutting-in operation in roughing. In this case, the cutting path is increased due to the insertion of the cutting-out operation, resulting in an increase in cycle time.

[0008] Therefore, it is desirable to shorten the machining path and cycle time in turning operations.

[0009] Means for solving problems

[0010] One embodiment of the numerical control device disclosed in the present invention is a numerical control device that controls a machine tool that can freely change the relative direction of the tool tip with respect to a workpiece, and performs turning processing on the workpiece, the numerical control device comprising: an NC instruction interpretation unit that interprets the instructions of the machining program; and a tool information storage and generation unit that generates and stores geometric information related to the tool, the NC instruction interpretation unit comprising: a cutting amount interpretation unit that interprets the cutting amount during rough machining according to the instructions of the machining program; a machining shape generation unit that generates the finished machining shape of the workpiece according to the instructions; a machining path generation unit that generates a rough machining path according to the interpreted cutting amount during rough machining and the generated finished machining shape of the workpiece; and a tool information storage and generation unit that generates and stores geometric information related to the tool. A tool direction temporary determination unit, which temporarily determines the direction of the tool based on geometric information related to the tool and the cutting-in and cutting-out paths generated by the processing path generation unit; a path combination judgment unit, which determines whether to omit the cutting action based on the temporarily determined direction of the tool and the cutting-in and cutting-out paths; a processing path combination unit, which omits the cutting action when the path combination judgment unit determines that the cutting action is to be omitted, and generates a new path that moves directly to the end point of the next action of the omitted cutting action; and a tool direction determination unit, which determines the direction of the tool according to the processing shape change point where the finishing shape of the workpiece changes in the rough processing path including the new path generated by the processing path combination unit.

[0011] One aspect of the control method disclosed in the present invention is a control method for a machine tool that is implemented by a computer and can freely change the relative direction of the tool tip with respect to the workpiece, the control method for the machine tool comprising: an NC instruction interpretation step for interpreting the instructions of the machining program; and a tool information storage generation step for generating and storing geometric information related to the tool, the NC instruction interpretation step comprising: a cutting amount interpretation step for interpreting the cutting amount during rough machining according to the instructions of the machining program; a machining shape generation step for generating the finished machining shape of the workpiece according to the instructions; and a machining path generation step for generating a rough machining path according to the interpreted cutting amount during rough machining and the generated finished machining shape of the workpiece. path; a tool direction temporary determination step, temporarily determining the direction of the tool based on geometric information related to the tool and the cutting-in and cutting-out paths generated by the processing path generation step; a path combination judgment step, judging whether to omit the cutting-out action based on the temporarily determined direction of the tool and the cutting-in and cutting-out paths; a processing path combination step, omitting the cutting-out action when it is judged that the cutting-out action is to be omitted, and generating a new path that directly moves to the end point of the next action of the omitted cutting-out action; and a tool direction determination step, determining the direction of the tool according to the processing shape change point where the finishing shape of the workpiece changes in the rough processing path including the generated new path.

[0012] Effects of the Invention

[0013] According to one embodiment, a machining path can be shortened in turning processing, thereby reducing cycle time. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a functional block diagram showing a functional configuration example of a numerical controller according to one embodiment.

[0015] Figure 2 This is a diagram showing an example of tool information data.

[0016] Figure 3 This is a diagram showing an example of a multi-edge tool.

[0017] Figure 4 This is a diagram showing an example of a rough machining process path generated by the machining process path generation unit.

[0018] Figure 5 It means in Figure 4 A diagram showing an example of a case where the multi-edge tool is located at the end point of the machining path N2 in the machining path N1.

[0019] Figure 6 It means in Figure 4 An example of a case where the multi-edge tool is located at the end point of the N5 machining path in the machining path.

[0020] Figure 7 It means in Figure 4 An example of a case where the multi-edge tool is located at the end point of the N8 machining path in the machining path.

[0021] Figure 8 It means that it is determined to be omissible Figure 5 FIG. 1 is a diagram showing an example of a connection process of a machining path connection portion in the case of a cutting operation of the machining path N3.

[0022] Figure 9 It means that it is determined to be omissible Figure 6 FIG. 1 is a diagram showing an example of a connection process of a machining path connection portion in the case of a cutting operation of the machining path N6.

[0023] Figure 10 It indicates that the joint of the machining path is Figure 4 An example of the result of the combination processing of the processing paths.

[0024] Figure 11A This is a diagram showing an example of a case where the angle formed between machining paths at a machining shape change point is smaller than 180 degrees.

[0025] Figure 11B This is a diagram showing an example of a case where the angle formed between machining paths at a machining shape change point is 180 degrees or more.

[0026] Figure 12 This is a flowchart for explaining an example of NC command execution processing of a numerical controller.

[0027] Figure 13 This is a diagram showing an example of a tool in which a turning tool is attached to an oscillating mechanism.

[0028] Figure 14 This is a diagram showing an example of the joining operation of the machining path joining portion. DETAILED DESCRIPTION

[0029] <One embodiment>

[0030] First, an overview of this embodiment will be described. In this embodiment, a numerical controller interprets the instructions of a machining program, interprets the tool's cut-in amount for rough machining of a workpiece based on the interpreted machining program instructions, and generates the workpiece's finished shape. The numerical controller generates a rough machining tool path based on the rough machining cut-in amount and the finished shape of the workpiece. Based on geometric information representing the tool's shape and the cut-in and cut-out paths within the generated rough machining tool path, the numerical controller temporarily determines a tool direction in which the cut-out action can be omitted, minimizing the cutting allowance and the tool's cut-out tool length. If the cutting allowance in the temporarily determined tool direction is less than a predetermined first value and the tool's cut-out tool length is less than a predetermined second value that is different from the first predetermined value, the numerical controller determines that the cut-out action should be omitted. The numerical controller generates a new path that moves directly to the endpoint of the next cut-out action to be omitted.

[0031] Therefore, according to this embodiment, it is possible to solve the problem of “shortening the machining path and shortening the cycle time in turning machining”.

[0032] The above is an overview of this embodiment.

[0033] Next, the structure of this embodiment will be described in detail using the accompanying drawings. Here, a multi-edge tool is exemplified as a tool. In addition, as described later, the present invention can also be applied to a tool having an oscillating mechanism.

[0034] Figure 1 This is a functional block diagram showing a functional configuration example of a numerical controller according to one embodiment.

[0035] The numerical controller 10 and the machine tool 20 may be directly connected to each other via a connection interface (not shown). Alternatively, the numerical controller 10 and the machine tool 20 may be connected to each other via a network (not shown), such as a LAN (Local Area Network) or the Internet. In this case, the numerical controller 10 and the machine tool 20 include a communication unit (not shown) for communicating with each other via this connection.

[0036] The machine tool 20 is, for example, a lathe that performs lathe processing well-known to those skilled in the art, and operates according to an operation command from a numerical controller 10 described later.

[0037] The numerical controller 10 is a well-known numerical controller for those skilled in the art, and generates an operation command based on control information and sends the generated operation command to the machine tool 20 .

[0038] like Figure 1As shown, the numerical controller 10 includes a control unit 100 and a tool information memory 200. The control unit 100 also includes an NC command interpretation unit 110, an interpolation processing unit 120, a tool correction unit 130, a pulse distribution unit 140, and a tool shape storage generation unit 150. Furthermore, the NC command interpretation unit 110 includes a cutting depth interpretation unit 111, a machining shape generation unit 112, a machining path generation unit 113, a tool direction provisional determination unit 114, a path combination determination unit 115, a machining path combination unit 116, and a tool direction determination unit 117.

[0039] <Tool information memory 200>

[0040] The tool information memory 200 is a storage unit such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive) and stores tool information data 210 .

[0041] Figure 2 This is a diagram showing an example of the tool information data 210 .

[0042] like Figure 2 As shown, the tool information data 210 has, for example, a storage area that stores a tool number assigned to each multi-edge tool that can be selected and registered in the machine tool 20, an edge number assigned to each edge of each multi-edge tool, a tool position offset in the X-axis direction and the Z-axis direction pre-set according to the edge, and a tool tip R correction amount, etc.

[0043] Furthermore, the tool information data 210 may also include a storage area for storing the edge length and the like of each multi-edge tool.

[0044] As described above, the tool information data 210 may store a tool number such as “100” assigned to each registered multi-edge tool.

[0045] Furthermore, the multi-edge tool with tool number "100" is stored with edge numbers "1" to "3" assigned to it in the tool information data 210. This indicates that the multi-edge tool with tool number "100" has three edges.

[0046] Figure 3 This is a diagram showing an example of a multi-edge tool with tool number "100". The multi-edge tool with tool number "100" has an edge for roughing at edge number "1", an edge for semi-finishing at edge number "2", and an edge for finishing at edge number "3". Figure 3The multi-edge tool can continuously perform roughing, semi-finishing, and finishing by rotating the B-axis (about the Y-axis). Furthermore, the tool information data 210 pre-stores the offset amount in the X-axis direction, the offset amount in the Z-axis direction, and the tool nose R correction amount for each edge number "1" to "3."

[0047] <Control Unit 100>

[0048] The control unit 100 includes a CPU, a ROM, a RAM, a CMOS memory, and the like, and these components are configured to be able to communicate with each other via a bus, which is well known to those skilled in the art.

[0049] The CPU is a processor that controls the entire numerical control device 10. The CPU reads the system program and application program stored in the ROM via the bus, and controls the entire numerical control device 10 according to the system program and application program. Figure 1 As shown, the control unit 100 is configured to implement the functions of an NC command interpretation unit 110, an interpolation processing unit 120, a tool correction unit 130, a pulse distribution unit 140, and a tool shape storage generation unit 150. Furthermore, the NC command interpretation unit 110 is configured to implement the functions of a cutting depth interpretation unit 111, a machining shape generation unit 112, a machining path generation unit 113, a tool direction temporary determination unit 114, a path combination determination unit 115, a machining path combination unit 116, and a tool direction determination unit 117. The RAM stores various data, including temporary calculation data and display data. The CMOS memory is configured as a non-volatile memory that is backed up by a battery (not shown) and maintains its stored state even when the power to the numerical controller 10 is turned off.

[0050] <NC command interpretation unit 110>

[0051] The NC command interpretation unit 110 acquires a machining program 30 generated by an external device such as a CAD / CAM device, for example, and analyzes the acquired machining program 30 .

[0052] <Incision Amount Interpretation Section 111>

[0053] The cutting depth interpretation unit 111 pre-reads, for example, a plurality of blocks included in the machining program 30 and interprets the cutting depth during rough machining specified by the NC commands in the pre-read plurality of blocks.

[0054] <Processing Shape Generator 112>

[0055] The machining shape generating unit 112 pre-reads, for example, a plurality of blocks included in the machining program 30 , and generates the finished machined shape of the workpiece as machining shape information based on the NC commands in the pre-read plurality of blocks.

[0056] Specifically, the machining shape generation unit 112 reads the edge movement direction command (X_Z_) in the automatic edge direction determination mode (e.g., G41.9 / G42.9) and stores it as the position vector of the tool tip (machining shape information). In other words, the machining shape generation unit 112 stores all movement commands along the tool path as position vectors (machining shape information).

[0057] Furthermore, the machining shape generation unit 112 can store position vectors (machining shape information) for commands that operate in G00 / G01 / G02 / G03, such as fixed cycles, even if they are not direct G00 / G01 / G02 / G03 commands. Furthermore, the machining shape generation unit 112 can also read blocks until the edge indexing axis positioning mode cancel (G40) is read.

[0058] <Processing Path Generator 113>

[0059] The machining path generation unit 113 generates a machining path for rough machining based on the depth of cut during rough machining interpreted by the depth of cut interpretation unit 111 and the finished shape of the workpiece generated by the machining shape generation unit 112 .

[0060] In the following description, a rough machining process path is exemplified when a semicircular groove is cut as a finished shape. However, the same applies to the case where an arbitrary shape is cut as a finished shape.

[0061] Figure 4 This is a diagram showing an example of a rough machining process path generated by the machining process path generation unit 113 .

[0062] like Figure 4 As shown, the processing path generation unit 113 generates processing paths N1 to N11 as processing paths for rough processing based on the cutting amount of the edge for rough processing of the multi-edge tool 40, for example, when a semicircular groove is cut as a finishing shape for the workpiece W. In addition, N1 to N11 represent, for example, the sequence number (block) of the processing program 30. In addition, the processing paths N3, N6, and N9 are the paths for cutting out the action, and the processing path N11 shown by the dotted line is the retreat path after the rough processing is completed. In addition, as shown in FIG. Figure 4 As shown, the initial position of the edge of the multi-edge tool 40 is located at the starting point of the processing path N1, and the edge direction of the multi-edge tool 40 at the beginning of the processing is set to Figure 4 direction shown.

[0063] <Tool Direction Temporary Determination Unit 114>

[0064] The tool direction temporary determination unit 114 temporarily determines the edge direction of the multi-edge tool 40 in which the cutting action may be omitted, for example, based on the geometric information related to the multi-edge tool 40 generated by the tool shape storage generation unit 150 described later and the cutting-in and cutting-out paths generated by the processing path generation unit 113.

[0065] Figure 5 It means in Figure 4 FIG is an example of a multi-edge tool 40 at the end point of the processing path N2 in the processing path of . Figure 5 The dotted circle on the right is Figure 5 This is an enlarged view of the circular portion indicated by the dotted line on the left side.

[0066] Specifically, when the front end of the edge of the multi-edge tool 40 is located at the end point of the machining path N2, the tool direction temporary determination unit 114 temporarily determines the edge direction of the multi-edge tool 40 so that the left edge surface of the multi-edge tool 40 does not interfere with the workpiece W (i.e., the machining path N3) and the cutting operation can be omitted. Figure 5 As shown in the enlarged view on the right side of , the tool direction temporary determination unit 114 temporarily determines the edge direction of the multi-edge tool 40 so that when the front end of the edge of the multi-edge tool 40 is located at the end point of the processing path N2, the minimum margin (hereinafter also referred to as "interference avoidance margin") is obtained so that the multi-edge tool 40 does not interfere with the workpiece W.

[0067] Figure 6 It means in Figure 4 FIG. 1 is a diagram showing an example of a case where the multi-edge tool 40 is located at the end point of the machining path N5 in the machining path N5.

[0068] The tool direction temporary determination unit 114 and Figure 5 As in the case of , when the front end of the edge of the multi-edge tool 40 is at the end point of the processing path N5, the edge direction of the multi-edge tool 40 is temporarily determined so that the right edge surface of the multi-edge tool 40 does not interfere with the workpiece W (i.e., the processing paths N1 and N6), and the cutting operation can be omitted. Figure 6 As shown, the tool direction temporary determination unit 114 temporarily determines the edge direction of the multi-edge tool 40 that may omit the cutting operation so as to obtain the minimum interference avoidance margin so that the multi-edge tool 40 does not interfere with the workpiece W.

[0069] Figure 7 It means in Figure 4 FIG is an example of a multi-edge tool 40 being located at the end point of the processing path of N8 in the processing path of . Figure 7 The dotted circle on the right side of Figure 5 The same is true for Figure 7This is an enlarged view of the circular portion indicated by the dotted line on the left side.

[0070] The tool direction temporary determination unit 114 and Figure 5 As in the case of , when the front end of the edge of the multi-edge tool 40 is at the end point of the processing path N8, the edge direction of the multi-edge tool 40 is temporarily determined so that the left edge surface of the multi-edge tool 40 does not interfere with the workpiece W (i.e., the processing paths N3, N4, and N9), and the cutting operation can be omitted. Figure 7 As shown in the enlarged view on the right side of , the tool direction temporary determination unit 114 temporarily determines the edge direction of the multi-edge tool 40 so that when the front end of the edge of the multi-edge tool 40 is located at the end point of the processing path N8, the minimum interference avoidance margin is obtained so that the multi-edge tool 40 does not interfere with the workpiece W.

[0071] <Path combination determination unit 115>

[0072] The path combination determination unit 115 determines whether to omit the cutting action of each of the processing paths N3, N6, and N9 based on the edge direction of the multi-edge tool 40 that may be able to omit the cutting action, which is temporarily determined by the tool direction temporary determination unit 114, and the cutting-in and cutting-out paths generated by the processing path generation unit 113.

[0073] Specifically, the path combination determination unit 115 is as follows, for example Figure 5 As shown, the cut-out edge length and the cutting margin (the longest distance between the N3 machining path and the left edge surface of the multi-edge tool 40) are calculated when the multi-edge tool 40 is directed toward the edge direction temporarily determined at the end point of the N2 machining path (i.e., the starting point of the N3 machining path). When the calculated cutting margin is less than a predetermined threshold value α and the calculated cutting edge length is less than a predetermined threshold value β, the path combination determination unit 115 determines that the cutting action of the N3 machining path can be omitted because the cutting margin and the cutting edge length are sufficiently small. On the other hand, when the calculated cutting margin is greater than the threshold value α or the calculated cutting edge length is greater than the threshold value β, the path combination determination unit 115 may determine that the cutting action of the N3 machining path cannot be omitted because the cutting margin or the cutting edge length are sufficiently large.

[0074] Similarly, the path combination determination unit 115 is as follows, for example Figure 6As shown, the cut-out edge length and the cutting margin (the longest distance between the N6 machining path and the right edge surface of the multi-edge tool 40) are calculated when the multi-edge tool 40 is directed toward the edge direction temporarily determined at the end point of the N5 machining path (i.e., the starting point of the N6 machining path). When the calculated cutting margin is less than the threshold value α and the calculated cutting edge length is less than the threshold value β, the path combination determination unit 115 determines that the cutting action of the N6 machining path can be omitted because the cutting margin and the cutting edge length are sufficiently small. On the other hand, when the calculated cutting margin is greater than the threshold value α or the calculated cutting edge length is greater than the threshold value β, the path combination determination unit 115 may determine that the cutting action of the N6 machining path cannot be omitted because the cutting margin or the cutting edge length are sufficiently large.

[0075] In addition, the path combination determination unit 115 is as follows, for example Figure 7 As shown, the cut-out edge length and the cutting margin (the longest distance between the machining path of N9 and the left edge surface of the multi-edge tool 40) are calculated when the multi-edge tool 40 is directed toward the edge direction temporarily determined at the end point of the machining path of N8 (i.e., the starting point of the machining path of N9). When the calculated cutting margin is less than the threshold value α and the calculated cutting edge length is less than the threshold value β, the path combination determination unit 115 determines that the cutting action of the machining path of N9 can be omitted because the cutting margin and the cutting edge length are sufficiently small. On the other hand, when the calculated cutting margin is greater than the threshold value α or the calculated cutting edge length is greater than the threshold value β, the path combination determination unit 115 may determine that the cutting action of the machining path of N9 cannot be omitted because the cutting margin or the cutting edge length are sufficiently large.

[0076] <Processing path junction 116>

[0077] When the path combination determination unit 115 determines that the cutout operation is omitted, the machining path combination unit 116 omits the cutout operation and generates a new machining path that moves directly to the end point of the next operation (machining path) after the omitted cutout operation.

[0078] Figure 8 It means that it is determined to be omissible Figure 5 FIG. 1 is a diagram showing an example of the combining process performed by the machining path combining unit 116 in the case of the cutting operation of the machining path N3.

[0079] Specifically, the processing path combination portion 116 is as follows Figure 8 As shown, the machining path N3 in which the cutting operation is omitted is used, and a new machining path N4' is generated which moves directly from the end point of the machining path N2 to the end point of the machining path N4.

[0080] Figure 9 It means that it is determined to be omissible Figure 6 FIG. 1 is a diagram showing an example of the combining process performed by the machining path combining unit 116 in the case of the cutting operation of the machining path N6.

[0081] like Figure 9 As shown, the machining path junction 116 and Figure 8 As in the case of , the machining path N6 in which the cutting operation is performed is omitted, and a new machining path N7' is generated which moves directly from the end point of the machining path N5 to the end point of the machining path N7.

[0082] Figure 10 It represents the processing path combination part 116 for Figure 4 An example of the result of the combined processing of the processing paths is shown in FIG. Figure 10 In the machining path, it is shown that the multi-edge tool 40 is oriented in Figure 7 In the case of the edge direction temporarily determined at the end point of the processing path N8 shown, the cutting residue is larger than the threshold value α, or the cut-out edge length is larger than the threshold value β. Therefore, the path combination judgment unit 115 determines that the cutting action of the processing path N9 cannot be omitted, and the processing path N9 remains as it is.

[0083] <Tool Direction Determination Unit 117>

[0084] The tool direction determination unit 117 determines the edge direction of the multi-edge tool 40 according to the machining shape change point where the finishing shape of the workpiece W changes in the rough machining machining path generated by the machining path generation unit 113 or the rough machining machining path including the new machining path generated by the machining path combination unit 116.

[0085] Specifically, when the angle formed between the machining path N(i) and the machining path N(i+1) at the point Pi where the machining path N(i) switches to the machining path N(i+1) (hereinafter also referred to as a "machining shape change point") is less than 180 degrees, the tool direction determination unit 117 determines the angle at which the center line of the angle coincides with the center line of the edge tip of the multi-edge tool 40 as the edge direction (the positioning angle of the edge indexing axis). Here, i is an integer from 1 to 10.

[0086] Figure 11A This is a diagram showing an example of a case where the angle formed between machining paths at the machining shape change point Pi is smaller than 180 degrees.

[0087] like Figure 11AAs shown, the tool direction determination unit 117 determines the edge direction so that the bisector of the angle formed by the machining path of N(i) and the machining path of N(i+1) at the machining shape change point Pi coincides with the center of the edge tip angle of the multi-edge tool 40. v The angle (clockwise) between the bisector direction of the angle formed by the machining path of N(i) and the machining path of N(i+1) at the machining shape change point Pi and the X-axis direction.

[0088] In addition, the tool direction determination unit 117 can also determine the angle at which the vertical direction of the cutting surface of each of the processing paths N(i) and N(i+1) is consistent with the center line of the edge front end point of the multi-edge tool 40 as the edge direction (the positioning angle of the edge indexing axis) when the angle between the processing path of N(i) and the processing path of N(i+1) at the processing shape change point Pi is greater than 180 degrees.

[0089] Figure 11B This is a diagram showing an example of a case where the angle formed between machining paths at the machining shape change point Pi is 180 degrees or more.

[0090] like Figure 11B As shown, the tool direction determination unit 117 determines the edge direction so that the vertical direction (dashed line) of each of the cutting surface of the machining path N(i) and the machining path N(i+1) at the machining shape change point Pi coincides with the center of the edge front angle of the multi-edge tool 40. v1 ,θ v2 The angle (clockwise) between the direction perpendicular to the cutting surface (workpiece side) and the X-axis direction is shown for each of the machining paths N(i) and N(i+1) at the machining shape change point Pi.

[0091] <Interpolation Processing Unit 120>

[0092] The interpolation processing unit 120 performs interpolation processing on the machining path received from the NC command interpretation unit 110 to calculate a command position and a command speed.

[0093] <Tool Calibration Unit 130>

[0094] The tool correction unit 130 calculates the tool correction amount using the positional deviation amount and tool nose R correction amount of the selected multi-edge tool 40 and geometric information of the multi-edge tool 40 generated by the tool shape memory generation unit 150 described later.

[0095] <Pulse Distribution Unit 140>

[0096] The pulse distribution unit 140 outputs pulses corresponding to the calculated movement amounts of the respective axes for tool calibration to the respective servo motors (not shown) included in the machine tool 20 .

[0097] <Tool Shape Storage Generator 150>

[0098] The tool shape storage generating unit 150 generates geometric information of the multi-edge tool 40 based on the tool information data 210 held in the tool information memory 200 .

[0099] <NC Command Execution Processing of Numerical Control Device 10>

[0100] Next, an example of the operation related to the NC command execution process of the numerical controller 10 when rough machining is performed according to the machining program 30 for turning machining using the multi-edge tool 40 will be described.

[0101] Figure 12 This is a flowchart for explaining an example of NC command execution processing of the numerical controller 10 .

[0102] In step S11 , the NC command interpretation unit 110 reads the machining program 30 .

[0103] In step S12 , the cutting depth interpretation unit 111 pre-reads a plurality of blocks included in the machining program 30 and interprets the cutting depth during rough machining specified by the NC commands in the pre-read plurality of blocks.

[0104] In step S13 , the machining shape generating unit 112 pre-reads a plurality of blocks included in the machining program 30 , and generates the finished machined shape of the workpiece based on the NC commands in the pre-read plurality of blocks.

[0105] In step S14 , the machining path generation unit 113 generates a machining path for rough machining based on the depth of cut during rough machining interpreted in step S12 and the finished shape of the workpiece generated in step S13 .

[0106] In step S15, the tool direction temporary determination unit 114 temporarily determines the edge direction of the multi-edge tool 40 in which the cutting action may be omitted based on the geometric information related to the multi-edge tool 40 generated by the tool shape storage generation unit 150 and the cutting-in and cutting-out paths in the rough machining path generated in step S14.

[0107] In step S16, the path combination determination unit 115 determines whether to omit the cutting operation based on the edge direction of the multi-edge tool 40 temporarily determined in step S15 and the cutting-in and cutting-out paths generated in step S14. If the cutting operation is omitted, the process proceeds to step S17. On the other hand, if the cutting operation is not omitted, the process proceeds to step S18.

[0108] In step S17 , the machining path combining unit 116 generates a new machining path that moves directly to the end point of the next operation (machining path) of the cutting operation determined to be omitted in step S16 .

[0109] In step S18 , the tool direction determination unit 117 determines the edge direction of the multi-edge tool 40 at each machining shape change point in the machining path of the rough machining.

[0110] In step S19 , the interpolation processing unit 120 performs interpolation processing on the machining path received from the NC command interpretation unit 110 to calculate the command position and command speed.

[0111] In step S20 , the tool correction unit 130 calculates the tool correction amount using the positional deviation amount (eg, turning tool) and tool nose R correction amount of the selected multi-edge tool 40 , and the geometric information of the multi-edge tool 40 generated by the tool shape storage generating unit 150 .

[0112] In step S21 , the numerical controller 10 controls the rough machining process based on the generated machining path.

[0113] In step S22, the numerical controller 10 determines whether the rough machining process instructed by the machining program 30 has been completed. If the rough machining process has been completed, the process proceeds to step S23. If the rough machining process has not been completed, the process proceeds to step S15.

[0114] In step S23 , the numerical controller 10 executes rough machining (semi-finishing machining) and finishing machining.

[0115] Through the above, the numerical controller 10 temporarily determines the edge direction of the multi-edge tool 40 based on the geometric information related to the multi-edge tool 40 and the cut-in and cut-out paths in the generated rough machining path. The numerical controller 10 determines whether the cut-out operation can be omitted based on the temporarily determined edge direction of the multi-edge tool 40 and the generated cut-in and cut-out paths. If the numerical controller 10 determines that the cut-out operation can be omitted, it generates a new path that moves directly to the end point of the next operation of the omitted cut-out operation.

[0116] Thus, the numerical controller 10 can shorten the roughing path and cycle time in turning. That is, the numerical controller 10 can single the cutting to finishing operations by appropriately determining the edge direction of the multi-edge tool 40, thereby shortening the roughing cycle time.

[0117] Although one embodiment has been described above, the numerical control device 10 is not limited to the above-described embodiment, and includes modifications and improvements within a scope that can achieve the purpose.

[0118] <Variation 1>

[0119] In the above embodiment, the numerical controller 10 is provided as a separate device from the machine tool 20 , but the present invention is not limited thereto. For example, the numerical controller 10 may be included in the machine tool 20 .

[0120] <Variation 2>

[0121] In addition, for example, in the above-mentioned embodiment, the multi-edge tool 40 is used as a tool, but it is not limited to this. Figure 13 As shown, if the tool has an oscillating mechanism or the like and can freely change the relative orientation of the tool tip with respect to the workpiece, the cutting operation can be omitted.

[0122] <Variation 3>

[0123] In addition, for example, when the path combination determination unit 115 determines that the cut-out action is omitted, the machining path combination unit 116 omits the cut-out action and generates a new machining path that moves directly to the end point of the next action (machining path) of the omitted cut-out action, but the present invention is not limited to this. For example, when the next action of the omitted cut-out action and the actions after the next action are fast feed actions, the machining path combination unit 116 may also generate a new machining path that moves directly to the end point of the next action (machining path) of the omitted cut-out action. Figure 14 As shown, the starting point of the next action after the omitted cutting action is replaced, and the action of moving directly from the starting point of the omitted cutting action to the replaced starting point is used as a connecting action (rapid feed action).

[0124] Thereby, the numerical controller 10 can feed the tool quickly at once.

[0125] In addition, each function included in the numerical controller 10 in one embodiment can be realized by hardware, software, or a combination thereof. Here, realization by software means realization by having a computer read a program and execute it.

[0126] The program can be stored using various types of non-transitory computer-readable media and provided to the computer. Non-transitory computer-readable media include various types of tangible recording media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., floppy disks, magnetic tapes, hard disk drives), optical magnetic recording media (e.g., optical magnetic disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs). In addition, the program can also be provided to the computer via various types of transient computer-readable media. Examples of transient computer-readable media include electrical signals, optical signals, and electromagnetic waves. Transient computer-readable media can provide the program to the computer via wired communication paths such as electric wires and optical fibers, or wireless communication paths.

[0127] Furthermore, the steps describing the program recorded in the recording medium naturally include processing that is performed in time series in the order in which they are performed, but also include processing that is not necessarily performed in time series, and processing that is executed in parallel or individually.

[0128] In other words, the numerical control device and control method of the present disclosure can take various embodiments having the following structures.

[0129] (1) The numerical control device 10 disclosed in the present invention controls a machine tool 20 capable of freely changing the relative direction of the tool tip with respect to the workpiece W, and performs turning processing on the workpiece W. The numerical control device comprises: an NC instruction interpretation unit 110, which interprets the instructions of the machining program 30; and a tool information storage generating unit 150, which generates and stores geometric information related to the tool. The NC instruction interpretation unit 110 comprises: a cutting amount interpretation unit 111, which interprets the cutting amount during rough machining according to the instructions of the machining program 30; a machining shape generating unit 112, which generates the finishing shape of the workpiece W according to the instructions; and a machining path generating unit 113, which generates a rough machining path according to the interpreted cutting amount during rough machining and the generated finishing shape of the workpiece W. a tool direction temporary determination unit 114, which temporarily determines the direction of the tool based on the geometric information related to the tool and the cutting-in and cutting-out paths generated by the processing path generation unit 113; a path combination judgment unit 115, which determines whether to omit the cutting action based on the temporarily determined tool direction and the cutting-in and cutting-out paths; a processing path combination unit 116, which omits the cutting action when the path combination judgment unit 115 determines that the cutting action is to be omitted, and generates a new path that moves directly to the end point of the next action of the omitted cutting action; and a tool direction determination unit 117, which determines the direction of the tool according to the processing shape change point where the finishing shape of the workpiece W changes in the rough processing path including the new path generated by the processing path combination unit 116.

[0130] According to the numerical control device 10 , the machining path can be shortened in turning, thereby reducing the cycle time.

[0131] (2) In the numerical control device 10 described in (1), the tool direction temporary determination unit 114 may temporarily determine the direction of the tool so as to minimize the cutting residue and the tool cutting length of the tool, and the path combination determination unit 115 may determine that the cutting action is omitted when the cutting residue in the temporarily determined tool direction is less than a predetermined threshold value α and the tool cutting length is less than a predetermined threshold value β.

[0132] Thus, the numerical controller 10 can separate the operations from cutting in to finishing by appropriately determining the direction of the tool, thereby shortening the rough machining cycle time.

[0133] (3) In the numerical control device 10 described in (1) or (2), the processing path combining unit 116 may generate an action of replacing the starting point of the action after the next next action and moving directly from the starting point of the cut-out action to the replaced starting point as a combining action when the path combining determination unit 115 determines that the next action after the omitted cut-out action and the action after the next next action are fast feed actions.

[0134] Thereby, the numerical controller 10 can feed the tool quickly at once.

[0135] (4) In the numerical control device 10 described in any one of (1) to (3), the tool may be a multi-edge tool or a tool having an oscillating mechanism.

[0136] Thus, the numerical control device 10 can obtain the same effects as (1) to (3).

[0137] (5) The control method disclosed in the present invention is a control method for a machine tool 20 that is implemented by a computer and can freely change the relative direction of the tool tip with respect to the workpiece W, and comprises: an NC instruction interpretation step for interpreting the instructions of the machining program 30; and a tool information storage generation step for generating and storing geometric information related to the tool, wherein the NC instruction interpretation step comprises: a cutting amount interpretation step for interpreting the cutting amount during rough machining according to the instructions of the machining program 30; a machining shape generation step for generating the finishing shape of the workpiece W according to the instructions; and a machining path generation step for generating a rough machining path according to the interpreted cutting amount during rough machining and the generated finishing shape of the workpiece W. a processing path; a tool direction temporary determination step, temporarily determining the direction of the tool based on geometric information related to the tool and the cutting-in and cutting-out paths generated by the processing path generation step; a path combination judgment step, judging whether to omit the cutting-out action based on the temporarily determined tool direction and the cutting-in and cutting-out paths; a processing path combination step, omitting the cutting-out action when it is judged that the cutting-out action is to be omitted, and generating a new path that moves directly to the end point of the next action of the omitted cutting-out action; and a tool direction determination step, determining the direction of the tool according to the processing shape change point where the finishing shape of the workpiece W changes in the rough processing path including the generated new path.

[0138] According to this control method, the same effect as (1) can be obtained.

[0139] Explanation of symbols

[0140] 10 numerical control device,

[0141] 100 control devices,

[0142] 110NC instruction interpretation department,

[0143] 111 Cut-in Interpretation Department,

[0144] 112 machining shape generation unit,

[0145] 113 processing path generation unit,

[0146] 114 Tool Direction Temporary Decision Department,

[0147] 115 Path combination judgment unit,

[0148] 116 machining path junction,

[0149] 117 Tool direction determination unit,

[0150] 120 interpolation processing unit,

[0151] 130 Tool Calibration Department,

[0152] 140 pulse distribution unit,

[0153] 150 tool shape storage generation unit,

[0154] 200 tool information memory,

[0155] 210 tool information data,

[0156] 20 machine tools,

[0157] 30 processing procedures.

Claims

1. A numerical control device for controlling a machine tool capable of freely changing the relative direction of a tool tip with respect to a workpiece, for performing turning processing on the workpiece, characterized in that: The numerical control device comprises: NC instruction interpretation unit, which interprets the instructions of the machining program; and a tool information storage generating unit that generates and stores geometric information related to the tool; The NC instruction interpretation unit has: a cutting depth interpretation unit for interpreting the cutting depth during rough machining according to the instructions of the machining program; a machining shape generating unit configured to generate a finished machining shape of the workpiece according to the instruction; a machining path generating unit for generating a rough machining path based on the interpreted cutting depth during the rough machining and the generated finished shape of the workpiece; a tool direction temporary determination unit configured to temporarily determine the direction of the tool based on geometric information related to the tool and the cutting-in and cutting-out paths generated by the machining path generation unit; a path combination determination unit for determining whether to omit a cutting-out action based on the temporarily determined direction of the tool and the cutting-in and cutting-out paths; a machining path combining unit for omitting the cutting action and generating a new path for directly moving to an end point of a next action of the omitted cutting action when the path combining determining unit determines that the cutting action is omitted; as well as A tool direction determination unit determines the direction of the tool at a machining shape change point where the finished shape of the workpiece changes in the rough machining path including the new path generated by the machining path combination unit.

2. The numerical control device according to claim 1, wherein The tool direction temporary determination unit temporarily determines the direction of the tool so that the cutting residual amount and the cut-out tool length of the tool are minimized. When the temporarily determined cutting amount in the direction of the tool is less than a first predetermined value and the cutting tool length of the tool is less than a second predetermined value that is different from the first predetermined value, the path combination determination unit determines to omit the cutting action.

3. The numerical control device according to claim 1 or 2, characterized in that: When the path combination judgment unit determines that the next action of the omitted cut-out action and the action after the next action are fast feed actions, the processing path combination unit generates an action of replacing the starting point of the action after the next action, and moves directly from the starting point of the cut-out action to the replaced starting point as a combination action.

4. The numerical control device according to claim 1 or 2, characterized in that: The tool is a multi-edge tool or a tool with an oscillating mechanism.

5. A method for controlling a machine tool by computer, capable of freely changing the relative direction of a tool tip with respect to a workpiece, characterized in that: The control method has the following features: NC instruction interpretation step, interpreting the instructions of the machining program; and a tool information storage generation step, generating and storing geometric information related to the tool, The NC instruction interpretation step includes: a step of interpreting the cutting amount during rough machining according to the instructions of the machining program; a machining shape generating step, generating a finishing shape of the workpiece according to the instruction; a machining path generating step of generating a rough machining path according to the interpreted cutting depth during the rough machining and the generated finish machining shape of the workpiece; a tool direction temporary determination step of temporarily determining the direction of the tool based on geometric information related to the tool and the cutting-in and cutting-out paths generated by the machining path generation step; a path combination determination step of determining whether to omit the cutting-out action based on the temporarily determined direction of the tool and the cutting-in and cutting-out paths; a processing path combining step, in which, when it is determined that the cutting action is omitted, the cutting action is omitted and a new path is generated that moves directly to the end point of the next action of the omitted cutting action; as well as The tool direction determining step is a step of determining the direction of the tool at a machining shape changing point where the finished shape of the workpiece changes in the rough machining path including the generated new path.

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