Numerical control device and control method

Abstract

The present invention automatically switches edges of a multi-edge tool. A numerical control device controls a machine tool that uses a multi-edge tool for turning a workpiece. The numerical control device includes: an NC command interpreter that interprets the instructions of a machining program; a storage unit that stores tool information and edge information of the multi-edge tool; a tool information generator that generates geometric information of the multi-edge tool based on the tool information and edge information. The NC command interpreter includes: a toolpath generator that calculates a toolpath based on the instructions of the machining program; an edge switching determination unit that determines whether the edges of the multi-edge tool need to be switched; an edge switching path generator that calculates an edge switching path if it is determined that edge switching is necessary. The edge switching path includes a retraction path for switching edges, a rotation direction and amount of the multi-edge tool, and a return path; and a toolpath regeneration unit that combines the edge switching path with the toolpath.

Description

Technical Field

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

[0002] A multi-edge tool has multiple edges, each with a tool for a different purpose attached to it, and can handle workpieces of various shapes by varying the approach angle. A known technique calculates the remaining life of each edge based on life data and accumulated usage time data for each edge of the multi-edge tool when a machining operation instruction is output. If at least one edge exceeds the remaining life, the multi-edge tool is determined to have reached the end of its life. For example, see Patent Document 1.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 7-314290 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, taking advantage of the characteristics of multi-edge tools, when performing a series of machining operations using different edges of a single tool without changing the tool, it is necessary to switch from one edge of the multi-edge tool to another edge to improve the workpiece shape and extend tool life. This increases cycle time due to edge switching. Furthermore, additional programming is required for edge switching, which is labor-intensive for the operator.

[0008] Therefore, it is desirable to automate edge switching of multi-edge tools.

[0009] Means for solving problems

[0010] One embodiment of a numerical control device disclosed herein is a numerical control device for controlling a machine tool that performs turning processing on a workpiece using a multi-edge tool for turning processing. The numerical control device includes: an NC command interpreter that interprets commands of a machining program; a storage unit that stores tool information and edge information of the multi-edge tool; and a tool information generator that generates geometric information of the multi-edge tool based on the tool information and edge information stored in the storage unit. The NC command interpreter includes: a toolpath generator that calculates a toolpath of the multi-edge tool based on commands of the machining program; an edge switching determination unit that determines whether an edge of the multi-edge tool needs to be switched; an edge switching path generator that, when the edge switching determination unit determines that the edge needs to be switched, calculates an edge switching path that includes a retraction path for switching the edge, a rotation direction and amount of rotation of the multi-edge tool, and a return path from the retraction path to the tool path; and a toolpath regeneration unit that combines the edge switching path with the tool path.

[0011] One embodiment of the control method disclosed herein is a control method for a machine tool implemented by a computer, wherein the machine tool performs turning processing on a workpiece using a multi-edge tool for turning processing, the control method comprising: an NC instruction interpretation step for interpreting instructions of a processing program; a tool information generation step for generating geometric information of the multi-edge tool based on tool information and edge information of the multi-edge tool maintained in a storage unit, the NC instruction interpretation step comprising: a tool path generation step for calculating a tool path of the multi-edge tool according to instructions of the processing program; an edge switching determination step for determining whether it is necessary to switch the edge of the multi-edge tool; an edge switching path generation step for calculating an edge switching path when it is determined that it is necessary to switch the edge, the edge switching path comprising a retraction path for switching the edge, a rotation direction and rotation amount of the multi-edge tool, and a return path from the retraction path to the tool path; and a tool path regeneration step for combining the edge switching path with the tool path.

[0012] Effects of the Invention

[0013] According to one embodiment, edge switching of a multi-edge tool can be performed automatically. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0017] Figure 3B This is a diagram showing an example of a multi-edge tool.

[0018] Figure 4 This is a diagram showing an example of a machining program.

[0019] Figure 5 This is a diagram showing an example of the finished shape of a workpiece cut using a machining program.

[0020] Figure 6A This is a diagram showing an example of a toolpath calculated by the toolpath generation unit.

[0021] Figure 6B Yes Figure 6A Figure 1 shows an example of a tool path labeled with numbers.

[0022] Figure 6C This is a diagram showing an example of determining edge switching based on an input signal and a physical quantity of a drive shaft.

[0023] Figure 7 Yes Figure 6A An example of a machining program for a tool path is shown.

[0024] Figure 8A This is a diagram showing an example of a retraction path, a rotation direction and amount of a multi-edge tool, and a return path.

[0025] Figure 8B This is a diagram showing an example of a retraction path, a rotation direction and amount of a multi-edge tool, and a return path.

[0026] Figure 8C This is a diagram showing an example of a retraction path, a rotation direction and amount of a multi-edge tool, and a return path.

[0027] Figure 8D This is a diagram showing an example of a retraction path, a rotation direction and amount of a multi-edge tool, and a return path.

[0028] Figure 8E This shows an example of a case where the retreat amount (avoidance amount) is different between a case of taking a long route and a case of taking a short route.

[0029] Figure 9 This is a diagram showing an example of a machining program in which an edge switching path is specified in advance.

[0030] Figure 10A FIG. 1 is a diagram showing an example of the operation of the toolpath regeneration unit.

[0031] Figure 10BAn example of the operation of the tool path regeneration unit when the next operation after the return operation of the multi-edge tool is not accompanied by cutting will be described.

[0032] Figure 11 This is a flowchart illustrating an example of NC command execution processing of a numerical controller. DETAILED DESCRIPTION

[0033] <One embodiment>

[0034] First, a brief description of this embodiment will be provided. In this embodiment, a numerical control device interprets the instructions of a machining program and calculates a toolpath for a multi-edge tool based on the interpreted machining program instructions. Based on the calculated toolpath, the numerical control device determines whether the edge of the multi-edge tool needs to be switched. If switching edges is necessary, the numerical control device calculates an edge switching path. This edge switching path includes a retraction path for switching edges, the rotation direction and amount of the multi-edge tool, and a return path from the retraction path to the toolpath. The numerical control device combines the calculated edge switching path with the toolpath and uses this combined toolpath to cause the machine tool to process the workpiece.

[0035] Therefore, according to this embodiment, the problem of “automatically switching edges of a multi-edge tool” can be solved.

[0036] The above is an overview of this embodiment.

[0037] Next, the configuration of this embodiment will be described in detail using the drawings.

[0038] Figure 1 This is a functional block diagram showing an example of the functional configuration of a numerical controller according to one embodiment.

[0039] The numerical controller 10 and the machine tool 20 can be directly connected to each other via a connection interface (not shown). Alternatively, the numerical controller 10 and the machine tool 20 can 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.

[0040] 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.

[0041] Numerical controller 10 is a numerical controller well known to those skilled in the art, and generates motion commands based on control information and sends the generated motion commands to machine tool 20 . Numerical controller 10 thus controls the motion of machine tool 20 .

[0042] like Figure 1 As shown, the numerical controller 10 includes a control unit 100 and a tool information memory 200. Furthermore, the control unit 100 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 tool path generation unit 111, an edge direction determination unit 112, an edge switching determination unit 113, an edge switching path generation unit 114, and a tool path regeneration unit 115.

[0043] <Tool information memory 200>

[0044] 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 .

[0045] The tool information data 210 includes, for example, tool information and edge information related to the multi-edge tools selectable in the machine tool 20. Furthermore, the tool information data 210 registers edge numbers corresponding to the number of edges for each multi-edge tool, thereby ensuring an area for storing information on each edge. Furthermore, the tool information data 210 assigns the same edge type number to edges with identical edge attributes (such as machining application, material, and tool nose R correction amount), and registers these edges individually.

[0046] Figure 2 This is a diagram showing an example of the tool information data 210 .

[0047] like Figure 2 As shown, the tool information data 210 has, for example, a storage area that stores a tool number assigned to each registered multi-edge tool, an edge number assigned to each edge of each multi-edge tool, an edge type number indicating the type of each edge, and a remaining life (number of uses), etc.

[0048] Furthermore, the tool information data 210 may include a storage area for storing a tool position compensation amount (for example, a turning tool) and a tool nose R correction amount for each multi-edge tool.

[0049] As described above, the tool information data 210 may store a tool number such as “0101” or “0102” assigned to each registered multi-edge tool.

[0050] Furthermore, in the tool information data 210, edge numbers "1" to "3" are assigned and stored to the multi-edge tool with tool number "0101." Thus, it is indicated that the multi-edge tool with tool number "0101" has three edges. On the other hand, edge numbers "1" to "4" are assigned and stored to the multi-edge tool with tool number "0102." Thus, it is indicated that the multi-edge tool with tool number "0102" has four edges.

[0051] Figure 3A as well as Figure 3B Represents an example of a multi-edge tool.

[0052] Figure 3A This shows a multi-edge tool with tool number "0101." The multi-edge tool with tool number "0101" has an edge for roughing at edge number "1," an edge for finishing at edge number "2," and an edge for roughing at edge number "3." Thus, by rotating the multi-edge tool about the B-axis (Y-axis), it is possible to continuously perform roughing to finishing. Furthermore, in the tool information data 210, the edge type numbers "11," "13," and "11" are pre-stored for edge numbers "1" to "3," respectively.

[0053] Figure 3B This represents a multi-edge tool with tool number "0102." The multi-edge tool with tool number "0102" has an edge for roughing at edge number "1," an edge for semi-finishing at edge number "2," an edge for roughing at edge number "3," and an edge for finishing at edge number "4." Thus, by rotating the multi-edge tool about the B-axis (Y-axis), roughing, semi-finishing, and finishing can be performed continuously. Furthermore, in the tool information data 210, "11," "12," "11," and "13" are pre-stored as edge type numbers for edge numbers "1" to "4," respectively.

[0054] In addition, the tool information data 210 stores the remaining life (number of uses) for each edge of the multi-edge tool. For example, when replacing a new tool, etc., the maximum number of uses is set as the initial value for the remaining life (number of uses) of the tool information data 210 for each edge or each tool, and the count is decremented by one each time the tool is used.

[0055] Alternatively, the lifespan (number of uses) may be counted up by 1 each time it starts at 0. In this case, the numerical controller 10 can determine whether the lifespan has been exhausted by determining whether the lifespan (number of uses) has reached a maximum number of uses. Alternatively, the lifespan (number of uses) may be the cumulative usage time or cutting distance of each edge of the multi-edge tool. In this case, the numerical controller 10 can determine whether the lifespan has been exhausted by determining whether the cumulative usage time of each edge of the multi-edge tool has reached a predetermined time, or whether the cutting distance has reached a predetermined distance.

[0056] <Control Unit 100>

[0057] 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.

[0058] 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 calibration unit 130, a pulse distribution unit 140, a tool shape storage and generation unit 150, a tool path generation unit 111, an edge direction determination unit 112, an edge switching determination unit 113, an edge switching path generation unit 114, and a tool path regeneration unit 115. The RAM stores various data, including temporary calculation data and display data. The CMOS memory is backed up by a battery (not shown) and is a non-volatile memory that maintains stored data even when the power to the control device 10 is disconnected.

[0059] <NC command interpretation unit 110>

[0060] 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 .

[0061] Figure 4 It is a diagram showing an example of the machining program 30 .

[0062] Figure 5 1 is a diagram showing an example of the finished shape of the workpiece W cut according to the machining program 30 . Figure 5 The solid line represents the finished shape of the workpiece W cut by the machining program, and the portion of the workpiece W on the right side of the solid line is cut. In addition, "N101" to "N110" represent Figure 4The numbers of the eighth to fourteenth blocks in the machining program 30 indicate corresponding parts of the finished shape shown by the solid line.

[0063] like Figure 4 As shown, the machining program 30 is a program with 14 blocks. The first block "Gxx" is a simplified program instruction, which is to cut the workpiece W into Figure 5 The solid line shows the main program for finishing the shape.

[0064] In addition, the independent variable "P101" of "Gxx" indicates the number of the initial program block for determining the finished shape. In addition, the independent variable "Q110" of "Gxx" indicates the number of the final program block for determining the finished shape. In addition, the independent variable "U2.0" of "Gxx" indicates the amount of tool cut-in. In addition, the independent variable "F0.1" of "Gxx" indicates the feed rate of the tool. In addition, the independent variable "S1000" of "Gxx" indicates the number of spindle rotations per minute. In addition, the independent variable "T1010" of "Gxx" indicates the tool number. In addition, the independent variable "E1" of "Gxx" indicates the edge number for the outward stroke described later. In addition, the independent variable "H2" of "Gxx" indicates the edge number for the return stroke described later.

[0065] <Toolpath Generation Unit 111>

[0066] The tool path generation unit 111 pre-reads a plurality of program blocks included in the machining program 30 and calculates a tool path for the multi-edge tool based on NC commands in the pre-read plurality of program blocks.

[0067] Specifically, the tool path generation unit 111 calculates the tool path based on the NC commands of each of the plurality of program blocks of the machining program 30. Figure 5 However, due to the limitation of the cutting depth of the multi-edge tool, it is not possible to follow the path of the final shape from the beginning. Figure 5 Therefore, the tool path generation unit 111 calculates a tool path that can cut within the range of the cutting depth of the multi-edge tool based on the NC commands of each of the plurality of program blocks of the machining program 30 .

[0068] Figure 6A An example of a toolpath calculated by the toolpath generation unit 111 is shown. Figure 6B Express Figure 6A An example of a tool path being numbered.

[0069] like Figure 6A as well as Figure 6BAs shown, the tool path generation unit 111 calculates a tool path for cutting the workpiece W in the −X axis direction with a set cutting depth while reciprocating in the Z axis direction in the order of numbers ( 1 ) to ( 14 ).

[0070] Figure 7 Yes Figure 6A FIG. 1 is an example of a machining program for a tool path shown in FIG. Figure 4 The processing program 30 shown is for Figure 7 The machining procedure shown is a simplified procedure.

[0071] exist Figure 7 In the machining program, in the program block (A), the multi-edge tool is Figure 6B The tool paths shown in (1) to (14) cut the workpiece W. Then, in the program block included in (B), the multi-edge tool is returned to the machining start position for finishing. And, in the program block included in (C), the multi-edge tool is moved to the machining start position. Figure 5 The tool path shown by the solid line is used for finishing.

[0072] In addition, the cutting process performed by the tool paths numbered (1) to (14) in the program block (A) is not limited to one time, and multiple cutting processes of two or more times may be performed.

[0073] In the following description, the multi-edge tool is also referred to as the direction in which the workpiece W moves (in the direction in which the multi-edge tool moves). Figure 6A The Z-axis direction in the figure is called the "reciprocating axis". In addition, the direction when the machining end position is viewed from the machining start position based on the reciprocating axis (in the figure) is called the "reciprocating axis". Figure 6A and Figure 6B The direction of the machining start position is also called the "outward direction". Figure 6A and Figure 6B The +Z axis direction is called the "return direction".

[0074] <Edge Direction Determination Unit 112>

[0075] The edge direction determination unit 112 calculates an edge indexing angle at which the multi-edge tool does not interfere with the workpiece W based on the tool path calculated by the tool path generation unit 111 and geometric information of the multi-edge tool acquired from the tool shape storage generation unit 150 described later.

[0076] <Edge Switching Determination Unit 113>

[0077] The edge switching determination unit 113 determines whether it is necessary to switch the edges of the multi-edge tool based on a specified condition.

[0078] Specifically, for example, Figure 4 As shown in the machining program, when the edge for the outward stroke and the edge for the return stroke are respectively specified by the edge number, the edge switching determination unit 113 calculates the edge number of the tool path generation unit 111 based on the edge number. Figure 6B The tool path determines whether the edge of the multi-edge tool needs to be switched.

[0079] Specifically, the edge switching determination unit 113 is based on Figure 6B The tool path is used to determine whether the following three conditions are met: Condition (a): In the tool path numbered (N), the coordinate value of the reciprocating axis moves in the forward or return direction; Condition (b): In the tool paths numbered (N+1) to (N+M), the coordinate value of the reciprocating axis moves in the direction in which the coordinate value of the reciprocating axis does not change; Condition (c): In the tool path numbered (N+M+1), the tool moves from the forward direction to the return direction or from the return direction to the forward direction. In addition, N is a natural number greater than 1, and M is a natural number greater than 0. In addition, when M is "0", condition (b) is not considered.

[0080] For example, when the edge switching determination unit 113 specifies the edge for the outward journey and the edge for the return journey respectively by edge numbers, when three conditions (a) to (c) are met, that is, when it is determined to be moving from the outward direction to the return direction or from the return direction to the outward direction, it can be determined that the edge of the multi-edge tool needs to be switched.

[0081] Reference Figure 6B ,exist Figure 6B In the case of the tool paths numbered (1) to (14) shown, the edge switching determination unit 113 determines that it is necessary to switch the edge of the multi-edge tool when switching from the tool path numbered (2) to the tool path numbered (3), from the tool path numbered (6) to the tool path numbered (7), from the tool path numbered (8) to the tool path numbered (9), and from the tool path numbered (12) to the tool path numbered (13) as indicated by the dotted circle mark. In addition, in the tool path numbered (2) to the tool path numbered (3), and the tool path numbered (8) to the tool path numbered (9), the outward direction is switched to the return direction. In addition, in the tool path numbered (6) to the tool path numbered (7), and the tool path numbered (12) to the tool path numbered (13), the return direction is switched to the forward direction.

[0082] This makes it possible, for example, to make the cutting load constant on each edge of the multi-edge tool during the forward stroke and the return stroke, or to make the cutting distance uniform between the edges of the multi-edge tool.

[0083] In addition, the edge switching determination unit 113 determines whether edge switching of the multi-edge tool is required based on the tool path and conditions (a) to (c), for example, when the edges for the outbound trip and the return trip are respectively specified by edge numbers, but the specified conditions are not limited to these.

[0084] As the specified condition, for example, an input signal or a physical quantity of a drive shaft (such as speed, torque, etc.) may be specified. In this case, the edge switching determination unit 113 may determine whether the edge of the multi-edge tool needs to be switched based on the specified condition (the input signal or the physical quantity of the drive shaft).

[0085] Figure 6C This shows an example of determining edge switching based on the input signal or the physical quantity of the drive axis. Figure 6C As shown, for example, when the multi-edge tool 40 reaches the end point of the tool path numbered (6), it can be determined that edge switching is possible by detecting that the load in the Z-axis direction is less than a specified threshold. In addition, it can be determined that edge switching is possible by detecting that the X-axis and Z-axis reach predetermined positions and inputting signals.

[0086] For example, a specified condition may include a situation where the load in the Z-axis direction is less than a predetermined value. In this case, the edge switching determination unit 113 may determine that edge switching is possible when the load in the Z-axis direction is less than the predetermined value. Alternatively, a specified condition may include a situation where the X-axis and / or Z-axis positions of the multi-edge tool 40 have reached predetermined positions. In this case, the edge switching determination unit 113 may determine that edge switching is possible based on an input signal indicating that the X-axis and / or Z-axis positions of the multi-edge tool 40 have reached predetermined positions.

[0087] In addition, as the specified condition, an intermediate point in the entire tool path may be specified. In this case, the edge switching determination unit 113 may, for example, determine the position of the intermediate point in the entire tool path. Figure 6B In the case of the numbers (1) to (14) shown, it is determined that the position is an intermediate point in the entire tool path, and thus it is determined that an edge switch is to be performed.

[0088] This allows the user to switch edges at any timing of cutting that the user deems appropriate for cutting.

[0089] When the edge switching determination unit 113 determines that the edge of the multi-edge tool does not need to be switched, the control unit 100 controls cutting along a path obtained by interpolating the tool path calculated by the tool path generation unit 111 by the interpolation processing unit 120 .

[0090] <Edge Switching Path Generator 114>

[0091] When the edge switching determination unit 113 determines that edge switching is necessary based on specified conditions, the edge switching path generation unit 114 calculates an edge switching path including a retreat path for switching edges, a rotation direction and amount of the multi-edge tool, and a return path from the retreat path to the tool path.

[0092] Figures 8A to 8D An example of the retraction path, the rotation direction and amount of the multi-edge tool, and the return path is shown.

[0093] Specifically, if Figure 8A As shown, for example, when the edge switching determination unit 113 determines that the edge needs to be switched at the point P where the tool path A1 of the multi-edge tool 40 generated by the tool path generation unit 111 switches to the tool path A2, the edge switching path generation unit 114 performs the following operation: Figure 8B As shown, based on the tool path A1 and the tool path A2, the direction shown by the dotted line (for example, the normal direction of the tool path or the direction of the bisector between the tool paths, etc.) is determined as the retraction direction (retraction direction). For example, when the multi-edge tool 40 is Figure 3A When the roughing edge 1 of the tool number "0101" shown is switched to the roughing edge 3, a method known to those skilled in the art is used to set the retraction amount (avoidance amount) so that the workpiece W does not interfere with the edge when the multi-edge tool 40 is rotated.

[0094] Then, if Figure 8C As shown, the edge switching path generation unit 114 uses a method known to those skilled in the art to set the rotation direction and amount from edge 1 to edge 3 of the multi-edge tool 40. Specifically, the edge switching path generation unit 114 sets the rotation direction to clockwise so that the amount of rotation from edge 1 to edge 3 of the multi-edge tool 40 is minimized (hereinafter also referred to as "shortcut"). Then, as shown in FIG. Figure 8D As shown, the edge switching path generation unit 114 sets the return path as the reverse operation of the retreat path (the retreat operation).

[0095] Furthermore, the edge switching path generation unit 114 sets the rotation direction and the rotation amount of the multi-edge tool 40 from the edge 1 to the edge 3 as a shortcut, but the present invention is not limited thereto.

[0096] For example, in the case of a multi-edge tool 40 Figure 3B In the case of tool number "0102" shown in FIG. 1, when the roughing edge 3 is switched to the roughing edge 1, Figure 8EAs shown, the distance between edge 4 and the B axis (e.g., 12 mm) is longer than the distance between edge 2 and the B axis (e.g., 5 mm). In this case, the edge switching path generation unit 114 can set a detour with a larger rotation amount (e.g., 210 degrees) from edge 3 to edge 1 via edge 2, rather than a detour with a smaller rotation amount (e.g., 150 degrees) from edge 3 to edge 1. This is because Figure 3B In the case of a multi-edge tool 40, the setback (allowance) equal to the distance between the edge 4 and the B-axis (e.g., 12 mm + α) must be set longer for a shorter route than for a longer route (e.g., 5 mm + α), which increases the time required for edge switching. Therefore, the edge switching path generator 114 selects a longer route with a shorter setback (allowance). Note that α is a length greater than 0 mm.

[0097] The edge switching path generating unit 114 calculates the edge switching path based on the tool path, but the present invention is not limited thereto. For example, the edge switching path may be specified in advance by the machining program 30 .

[0098] Figure 9 An example of a machining program 30 in which an edge switching path is specified in advance is shown.

[0099] like Figure 9 As shown, the second to fourth program blocks represent the edge switching action from the forward direction to the return direction, and the fifth to seventh program blocks represent the edge switching action from the return direction to the forward direction.

[0100] <Toolpath Regeneration Unit 115>

[0101] The toolpath regeneration unit 115 combines the edge switching path calculated by the edge switching path generation unit 114 with the toolpath calculated by the toolpath generation unit 111 .

[0102] Specifically, for example, Figures 8A to 8D In the case of the switchover point P from toolpath A1 to toolpath A2, the toolpath regeneration unit 115 combines the edge switching path including the retraction direction, retraction amount, rotation direction, rotation amount, and return path of the multi-edge tool 40 calculated by the edge switching path generation unit 114. The toolpath regeneration unit 115 then outputs the toolpath combined with the edge switching path to the interpolation processing unit 120.

[0103] Figure 10A An example of explaining the operation of the toolpath regeneration unit 115 is shown below.

[0104] like Figure 10AAs shown, for example, the toolpath generation unit 111 calculates toolpaths B1 to B3 , which are paths along which the multi-edge tool 40 sequentially cuts the workpiece W.

[0105] In this case, as described above, for example, when the edge switching determination unit 113 determines that edge switching is necessary at the point P where the tool path B1 switches to the tool path B2, the edge switching path generation unit 114 and the tool path generation unit 115 generate the edge switching path. Figures 8A to 8D Similarly to the case of , the edge switching path is calculated, which includes the retraction direction, retraction amount, rotation direction, rotation amount, and return path of the multi-edge tool 40 from the end point (point P) of the tool path B1.

[0106] Then, if Figure 10A As shown, the toolpath regeneration unit 115 connects the edge switching paths of (a) the retracting operation (retracting operation), (b) the rotating operation, and (c) the returning operation between the toolpath B1 and the toolpath B2.

[0107] In addition, when the next action of the return action of the multi-edge tool 40 is an action not accompanied by cutting (for example, fast forward), the tool path regeneration unit 115 can make the end point of the retraction action (retraction action) or the return action overlap with the end point of the next action.

[0108] Figure 10B An example of explaining the operation of the toolpath regeneration unit 115 when the next operation after the return operation of the multi-edge tool is not accompanied by cutting will be shown.

[0109] like Figure 10B As shown, for example, toolpaths C1 to C4 are calculated by the toolpath generation unit 111. Toolpaths C1 to C4 are paths that the multi-edge tool 40 sequentially passes through. Furthermore, toolpaths C1 and C4 are paths that the multi-edge tool 40 uses to cut the workpiece W, and toolpaths C2 and C3 are paths that the multi-edge tool 40 uses to rapidly advance from the end point (point P) of toolpath C1 to the starting point of toolpath B4.

[0110] For example, when the edge switching determination unit 113 determines that the edge needs to be switched at the point P where the toolpath C1 switches to the toolpath C2, the edge switching path generation unit 114 and the edge switching path generation unit 114 generate the edge switching path. Figures 8A to 8D Similarly to the case of , the edge switching path including the retraction direction, retraction amount, rotation direction, rotation amount, and return path of the multi-edge tool 40 is calculated.

[0111] The tool path regeneration unit 115 and Figure 10ASimilarly, at the end of tool path C1, (a) the retracting action (retracting action) and (b) the rotating action are connected. However, since tool path C2 is the next path of tool path C1 and is not accompanied by cutting, the tool path regeneration unit 115 may not connect (c) the return action as the reverse action of (a) the retracting action (retracting action), but may combine the end point of (c) the return action and the end point of tool path C2 in such a way that they overlap. In addition, Figure 10B In the case of , tool path C3 is the next path of the next path of tool path C1, and is not accompanied by cutting together with tool path C2, so the tool path regeneration unit 115 can combine the end point of the (c) return action with the end point of tool path C3 in a manner that overlaps.

[0112] Thus, the numerical controller 10 can increase the speed of the edge switching operation and shorten the cycle time.

[0113] Furthermore, the toolpath regeneration unit 115 may overlap the edge rotation operation with the retraction operation (retreat operation) or the return operation for replacing the end points of the toolpaths C2 and C3.

[0114] The interpolation processing unit 120 performs interpolation processing on the tool path received from the NC command interpretation unit 110 to calculate a command position or a command speed.

[0115] The tool correction unit 130 calculates the tool correction amount using the position compensation 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 storage generation unit 150 described later.

[0116] 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 .

[0117] The tool shape storage generating unit 150 , serving as a tool information generating unit, generates geometric information of the multi-edge tool 40 based on the tool information data 210 stored in the tool information memory 200 .

[0118] <NC Command Execution Processing of Numerical Control Device 10>

[0119] Next, an example of the operation of the NC command execution process of the numerical controller 10 when switching the edges of a multi-edge tool based on a specified condition in a machining program that performs machining using the edges of a multi-edge tool will be described.

[0120] Figure 11This is a flowchart illustrating an example of NC command execution processing by the numerical controller 10. The flow shown here is a flow of NC command execution processing for edge switching of a multi-edge tool when the outward and return edges are designated by edge numbers.

[0121] In step S11 , the NC command interpretation unit 110 reads a program block of the machining program 30 .

[0122] In step S12, the tool path generation unit 111 pre-reads a plurality of program blocks included in the machining program 30 read in step S11, and calculates, for example, Figure 6A as well as Figure 6B The tool paths of the multi-edge tool 40 are shown as numbered (1) to (14).

[0123] In step S13 , the edge direction determination unit 112 calculates an edge indexing angle at which the multi-edge tool 40 does not interfere with the workpiece W based on the tool path calculated in step S12 and the geometric information of the multi-edge tool 40 acquired from the tool shape storage creation unit 150 .

[0124] In step S14, the edge switching determination unit 113 determines whether it is necessary to switch the edges of the multi-edge tool 40 based on the toolpath calculated by the toolpath generation unit 111. If it is determined that it is necessary to switch the edges of the multi-edge tool 40, the process proceeds to step S15. On the other hand, if it is determined that it is not necessary to switch the edges of the multi-edge tool 40, the process proceeds to step S17.

[0125] In step S15 , the edge switching path generator 114 calculates an edge switching path including a retraction path for switching the edge of the multi-edge tool 40 , a rotation direction and amount of the multi-edge tool, and a return path from the retraction path to the tool path.

[0126] In step S16 , the toolpath regeneration unit 115 combines the edge switching path calculated in step S15 with the toolpath calculated in step S12 .

[0127] In step S17 , the interpolation processing unit 120 performs interpolation processing on the tool path received from the NC command interpretation unit 110 to calculate a command position or a command speed.

[0128] In step S18 , the tool correction unit 130 calculates the tool correction amount using the position compensation amount (for example, 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 acquired from the tool shape storage generator 150 .

[0129] In step S19 , the numerical controller 10 controls the machining process based on the calculated tool path (including the edge switching operation command when the edge switching operation command is calculated).

[0130] In step S20 , it is determined whether the control of the machining process based on all the tool paths has been completed. If the control of the machining process based on all the tool paths has not been completed, the process proceeds to step S14 .

[0131] As described above, when the edges for the forward stroke and the edges for the return stroke are respectively designated by edge numbers, the numerical controller 10 can automatically switch the edges of the multi-edge tool 40 .

[0132] Furthermore, by using program commands simplified to "Gxx," the burden on the user can be reduced, and interference between the multi-edge tool 40 and the workpiece W due to errors in edge switching operation commands can be avoided.

[0133] Furthermore, the numerical controller 10 switches the edge of the multi-edge tool 40 between the forward and return directions, thereby maintaining a constant cutting load during the forward and return strokes and making the cutting distance uniform between the edges. Furthermore, the numerical controller 10 can shorten the cycle time by increasing the speed of the edge switching operation.

[0134] 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 range that can achieve the purpose.

[0135] Modifications

[0136] In the above embodiment, the numerical controller 10 is a device separate 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 .

[0137] In addition, each function included in the numerical controller 10 of one embodiment can be realized by hardware, software, or a combination thereof. Here, realization by software means realization by a computer reading and executing a program.

[0138] 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 (such as floppy disks, magnetic tapes, and hard disk drives), optical magnetic recording media (such as optical magnetic disks), CD-ROMs (read-only memories), CD-Rs, CD-R / Ws, and semiconductor memories (such as 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 (transitory computer readable media). Examples of transient computer-readable media include electrical signals, optical signals, and electromagnetic waves. Transitory computer-readable media can provide the program to the computer via wired communication paths such as wires and optical fibers, or wireless communication paths.

[0139] Furthermore, the steps describing the program stored in the recording medium naturally include processing executed in time series in the order thereof, but are not necessarily processed in time series and also include processing executed in parallel or independently.

[0140] In other words, the numerical control device and control method of the present disclosure can take various embodiments having the following structures.

[0141] (1) The numerical control device 10 of the present disclosure is a numerical control device for controlling a machine tool 20 for turning a workpiece W using a multi-edge tool 40 for turning, and comprises: an NC instruction interpretation unit 110 for interpreting instructions of a machining program 30; a tool information memory 200 for storing tool information and edge information of the multi-edge tool 40; a tool shape storage generating unit 150 for generating geometric information of the multi-edge tool 40 based on the tool information and edge information stored in the tool information memory 200, and the NC instruction interpretation unit 110 comprises: a tool path generating unit 111, which calculates the tool path of the multi-edge tool 40 according to the instructions of the processing program 30; an edge switching determination unit 113, which determines whether it is necessary to switch the edge of the multi-edge tool 40; an edge switching path generation unit 114, which calculates the edge switching path when the edge switching determination unit 113 determines that it is necessary to switch the edge, and the edge switching path includes a retreat path for switching the edge, the rotation direction and rotation amount of the multi-edge tool 40, and a return path from the retreat path to the tool path; a tool path regeneration unit 115, which combines the edge switching path with the tool path.

[0142] According to the numerical controller 10 , the edges of the multi-edge tool 40 can be automatically switched.

[0143] (2) In the numerical control device 10 described in (1), the edge switching determination unit 113 can determine whether the edge needs to be switched based on a signal input from outside the numerical control device, a physical quantity applied to a drive axis included in the machine tool 20, and at least one of a tool path.

[0144] Thereby, the numerical control device 10 can perform edge switching at a timing suitable for cutting in cutting processing.

[0145] (3) In the numerical control device 10 described in (1) or (2), the edge switching path generation unit 114 may calculate the edge switching path based on at least one of the command of the machining program 30 and the tool path.

[0146] In this way, the numerical controller 10 can calculate the optimal edge switching path.

[0147] (4) In the numerical control device 10 described in any one of (1) to (3), the edge switching path calculated by the edge switching path generation unit 114 can be made so that no interference occurs between the multi-edge tool 40 and the workpiece W during the edge switching path.

[0148] Thus, the numerical controller 10 can prioritize safety when switching edges.

[0149] (5) In the numerical control device 10 described in any one of (1) to (4), the edge switching path generation unit 114 can calculate the retreat path, the rotation direction and rotation amount of the multi-edge tool 40, and the return path in a manner that shortens the time required for edge switching and at least one of the paths required for edge switching.

[0150] As a result, the numerical controller 10 can realize a high-speed edge switching operation and shorten the cycle time.

[0151] (6) The control method disclosed in the present invention is a control method for a machine tool 20 implemented by a computer, wherein the machine tool 20 uses a multi-edge tool 40 for turning to perform turning on a workpiece W, wherein the control method comprises: an NC instruction interpretation step for interpreting the instructions of the processing program 30; a tool information generation step for generating geometric information of the multi-edge tool 40 based on the tool information and edge information of the multi-edge tool maintained in the tool information memory 200, the NC instruction interpretation step comprises: a tool path generation step for calculating the tool path of the multi-edge tool 40 according to the instructions of the processing program 30; an edge switching determination step for determining whether it is necessary to switch the edge of the multi-edge tool 40; an edge switching path generation step for calculating the edge switching path when it is determined that it is necessary to switch the edge, the edge switching path including a retreat path for switching the edge, the rotation direction and rotation amount of the multi-edge tool, and a return path from the retreat path to the tool path; and a tool path regeneration step for combining the tool path with the edge switching path.

[0152] According to this control method, the same effect as (1) can be achieved.

[0153] Description of Reference Numerals

[0154] 10 Numerical control device

[0155] 100 Control Department

[0156] 110NC Instruction Interpretation Department

[0157] 111 Tool Path Generation Department

[0158] 112 edge direction determination unit

[0159] 113 Edge switching determination unit

[0160] 114 edge switching path generation unit

[0161] 115 Tool Path Regeneration Unit

[0162] 120 interpolation processing unit

[0163] 130 Tool Calibration Department

[0164] 140 Pulse Distribution Unit

[0165] 150 Tool shape storage generation unit

[0166] 200 tool information memory

[0167] 210 tool information data

[0168] 20 machine tools

[0169] 30 processing procedures

[0170] More than 40 edge tools.

Claims

1. A numerical control device for controlling a machine tool for turning a workpiece using a multi-edge tool for turning, It is characterized in that The numerical control device comprises: NC instruction interpretation unit, which interprets the instructions of the machining program; a storage unit that stores tool information and edge information of the multi-edge tool; and a tool information generating unit for generating geometric information of the multi-edge tool based on the tool information and edge information stored in the storage unit; The NC instruction interpretation unit includes: a tool path generating unit for calculating a tool path of the multi-edge tool according to instructions of the machining program; an edge switching determination unit configured to determine whether it is necessary to switch the edges of the multi-edge tool; an edge switching path generating unit that, when the edge switching determining unit determines that the edge needs to be switched, calculates an edge switching path, the edge switching path including a retraction path for switching the edge, a rotation direction and amount of the multi-edge tool, and a return path from the retraction path back to the tool path; as well as A tool path regeneration unit combines the edge switching path with the tool path.

2. The numerical control device according to claim 1, wherein The edge switching determination unit determines whether the edge needs to be switched based on at least one of a signal input from outside the numerical controller, a physical quantity applied to a drive axis included in the machine tool, and the tool path.

3. The numerical control device according to claim 1 or 2, characterized in that: The edge switching path generating unit calculates the edge switching path based on at least one of a command of the machining program and the tool path.

4. The numerical control device according to any one of claims 1 to 3, characterized in that: The edge switching path calculated by the edge switching path generating unit does not cause interference between the multi-edge tool and the workpiece in the middle of the edge switching path.

5. The numerical control device according to any one of claims 1 to 4, characterized in that: The edge switching path generating unit calculates the retraction path, the rotation direction and amount of the multi-edge tool, and the return path so as to shorten at least one of a time required to switch the edge and a path required to switch the edge.

6. A computer-implemented method for controlling a machine tool for turning a workpiece using a multi-edge turning tool, It is characterized in that The control method comprises: NC instruction interpretation steps, interpreting the instructions of the machining program; a tool information generating step of generating geometric information of the multi-edge tool based on the tool information and edge information of the multi-edge tool held in a storage unit, The NC instruction interpretation steps include: a tool path generating step of calculating a tool path of the multi-edge tool according to instructions of the machining program; an edge switching determination step, determining whether it is necessary to switch the edge of the multi-edge tool; an edge switching path generating step of calculating an edge switching path when it is determined that the edge needs to be switched, the edge switching path including a retraction path for switching the edge, a rotation direction and amount of the multi-edge tool, and a return path from the retraction path back to the tool path; as well as The tool path regeneration step combines the edge switching path with the tool path.

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