Numerical control device and control method

Abstract

While avoiding interference between the workpiece and the tool, it is easy to position the edge indexing shaft so that the selected edge always contacts the cutting surface. The numerical control device has: a tool shape information storage and generation unit that generates and stores geometric information related to the shape of a multi-edge tool for turning as tool shape information; a machining shape information generation unit that generates machining shape information related to the shape of the turning based on the relative movement direction information between the multi-edge tool and the workpiece and the position relationship information between the multi-edge tool and the workpiece indicated in the turning program; an edge direction determination unit that determines the edge direction of the multi-edge tool at the machining shape change points where the machining shape changes based on the generated tool shape information and the generated machining shape information; and a machining control unit that controls the turning while changing the edge direction of the multi-edge tool between the machining shape change points according to the edge direction of the multi-edge tool at each machining shape change point.

Description

Technical Field

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

[0002] There is a multi-edge tool having a plurality of edges, with tools for different uses mounted on each edge and the approach angle being changed, whereby it is possible to correspond to workpieces of all shapes.

[0003] In machining using a multi-edge tool, the edge number and offset information of each edge are preset in advance. By selecting the edge number through a machining program and applying the corresponding offset from the program instruction point (edge rotation center), the edge of the selected multi-edge tool is thus made to match the cutting surface of the workpiece to be machined.

[0004] Figure 11 It is a diagram showing an example of tool information data.

[0005] Figure 12 It is a diagram showing an example of a machining program for making the edge of a multi-edge tool match the cutting surface of a workpiece.

[0006] Figure 13 It is a diagram showing an example when the multi-edge tool and the workpiece are matched.

[0007] As Figure 11 shown, the numerical control device has, in a storage unit such as a memory included in the numerical control device, tool information data storing, for example, tool numbers such as "100" assigned to registered multi-edge tools, edge numbers such as "1", "2", "3", etc. assigned to each edge of each multi-edge tool, tool position offsets in the X-axis direction and Z-axis direction preset for each edge, and the tip R correction amount.

[0008] The numerical control device uses Figure 11 the tool information data shown to execute Figure 12 the machining program, thereby selecting edge 1 and applying the corresponding offset (for example, a tool position offset of 4.5 mm in the X-axis direction) from the program instruction point (edge rotation center). Thus, as Figure 13 shown, it is possible to make edge 1 match the cutting surface of the workpiece.

[0009] In addition, in Figure 12In the machining program shown, in sequence number "N1", a multi-edge tool with tool number "100" is selected, and edge 1 with edge number "1" is selected. Further, in sequence number "N2", the tool position offset and the nose radius correction amount for edge number "1" pre-corresponded in "D99" are set, and the spindle speed is set in sequence number "N3". Further, in sequence number "N4", the positioning angle of the edge indexing axis (hereinafter, also referred to as "B axis" unless otherwise specified) is set so that the selected edge contacts the workpiece, and in sequence number "N5", the machining start position is positioned absolutely. Further, a cutting machining command is output in sequence number "N6". In sequence number "N10", the tool position offset and the nose radius correction amount for edge number "2" are made effective.

[0010] Moreover, after matching edge 1 of the multi-edge tool with the cutting surface of the workpiece as described above, the numerical control device can also transform, for example, using the method described in Patent Document 1, the tool position offset registered in the tool information data corresponding to the change in the positioning angle of the tool rotation axis Figure 11 and apply it as a new tool position offset. Thus, as Figure 14 shown, even when the indexing axis (B axis) of the multi-edge tool is inclined by a certain angle, the numerical control device can transform the above offset corresponding to the inclination angle and apply it.

[0011] Or, as Figure 15 shown, the numerical control device can also use the method described in Patent Document 2, and perform tool length correction at all times in the middle of the block corresponding to the change in the positioning angle of the tool rotation axis, and perform control so that the edge moves along the indicated path.

[0012] Figure 14 is a diagram showing an example of the method described in Patent Document 1. Figure 15 is a diagram showing an example of the method described in Patent Document 2.

[0013] Prior Art Documents

[0014] Patent Documents

[0015] Patent Document 1: Japanese Patent Laid-Open No. 3-109606

[0016] Patent Document 2: Japanese Patent Laid-Open No. 5-100723 Summary of the Invention

[0017] Problems to be Solved by the Invention

[0018] However, as Figure 13As shown, when a numerical control device performs machining using a multi-edge tool for turning with multiple edges, in the case of tool change using the tool number and edge number used in the T instruction and E instruction, it is necessary to appropriately position according to the edge indexing axis (B-axis) instruction so that the selected edge matches the cutting surface of the workpiece.

[0019] In addition, there is a situation where the numerical control device needs to reposition the B-axis in a manner that the selected edge matches the cutting surface of the workpiece in correspondence with the change in the direction perpendicular to the cutting surface in the XZ plane, even if the B-axis is temporarily positioned appropriately.

[0020] Figure 16 is a diagram showing an example of machining representing the change in the direction perpendicular to the cutting surface in the XZ plane. In addition, Figure 16 the upper part shows the shape of the entire workpiece, Figure 16 the lower part shows Figure 16 the cross-section of the workpiece in the XZ plane of the rectangular dotted-line part in the upper part.

[0021] As Figure 16 shown in the upper part, the workpiece has, for example, the shape of a cylinder W1 and a cylinder W2 with a radius larger than that of the cylinder W1. When the multi-edge tool cuts the side surface of the cylinder W1 of the workpiece, the edge direction of the edge 1 of the multi-edge tool is the direction perpendicular to the cutting surface in the X-axis direction of the side surface of the cylinder W1. On the other hand, when the multi-edge tool cuts the upper surface of the cylinder W2 of the workpiece, the edge direction of the edge 1 of the multi-edge tool is the direction perpendicular to the cutting surface in the Z-axis direction of the upper surface of the cylinder W2. That is, when the tool path of the machining advances from the side surface of the cylinder W1 to the upper surface of the cylinder W2, as Figure 16 shown in the lower part, it is necessary to position the B-axis in a manner that the edge direction of the edge 1 of the multi-edge tool changes.

[0022] However, as Figure 16 shown, in the case where the machining shape of the workpiece is complex, it is difficult for the user to make a positioning instruction program for the B-axis while avoiding interference between the cutting surface and the tool in correspondence with the change in the direction perpendicular to the cutting surface. In such machining, the user needs to create a program based on CAM (Computer Aided Manufacturing).

[0023] Therefore, it is desired to easily position the edge indexing axis while avoiding interference between the workpiece and the tool so that the selected edge always contacts the cutting surface.

[0024] Means for Solving the Problem

[0025] One aspect of the numerical control device of the present disclosure is a numerical control device that controls a machine tool for turning a workpiece using a multi-edge tool for turning. The numerical control device includes: a tool shape information storage and generation unit that generates and stores geometric information related to the shape of the multi-edge tool as tool shape information; a machining shape information generation unit that generates machining shape information related to the shape of the turning based on the relative movement direction information between the multi-edge tool and the workpiece and the position relationship information between the multi-edge tool and the workpiece indicated in the turning program; an edge direction determination unit that determines the edge direction of the multi-edge tool at machining shape change points where the machining shape changes based on the generated tool shape information and the generated machining shape information; and a machining control unit that controls the turning while changing the edge direction of the multi-edge tool between the machining shape change points according to the edge direction of the multi-edge tool at each machining shape change point.

[0026] One aspect of the control method of the present disclosure is a control method for a machine tool that is implemented by a computer and turns a workpiece using a multi-edge tool for turning. Geometric information related to the shape of the multi-edge tool is generated and stored as tool shape information. Machining shape information related to the shape of the turning is generated based on the relative movement direction information between the multi-edge tool and the workpiece and the position relationship information between the multi-edge tool and the workpiece indicated in the turning program. The edge direction of the multi-edge tool is determined at machining shape change points where the machining shape changes based on the generated tool shape information and the generated machining shape information. The turning is controlled while changing the edge direction of the multi-edge tool between the machining shape change points according to the edge direction of the multi-edge tool at each machining shape change point.

[0027] Advantageous Effects of the Invention

[0028] According to one aspect, it is possible to easily position the edge indexing axis while avoiding interference between the workpiece and the tool so that the selected edge is always in contact with the cutting surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a functional block diagram showing a functional configuration example of a numerical control device according to an embodiment.

[0030] Figure 2 is a diagram showing an example of tool information data.

[0031] Figure 3A is a diagram showing an example of a multi-edge tool.

[0032] Figure 3BThis is a diagram showing an example of a multi-edge tool.

[0033] Figure 3C This is a diagram showing an example of a multi-edge tool.

[0034] Figure 4A This is a diagram showing Figure 3B In the case of a multi-edge tool, the vector V from the edge tip of edge 1 to the edge tip of another edge ENEM This is an example diagram.

[0035] Figure 4B This is a diagram showing Figure 3B In the case of a multi-edge tool, the indexing angle β for centering the front corner of edge 2 E2 This is an example diagram.

[0036] Figure 5A This is a diagram showing an example of a machining program for a tool path that indicates machining based on a multi-edge tool.

[0037] Figure 5B This is a diagram showing Figure 5A An example of the finish machining shape of a workpiece cut by the machining program

[0038] Figure 6A This is a diagram showing an example of a machining program for a tool path that does not indicate machining based on a multi-edge tool.

[0039] Figure 6B This is a diagram showing Figure 6A An example of the tool path of workpiece W cut by the machining program

[0040] Figure 7 This is a diagram showing an example of a machining shape based on machining shape information.

[0041] Figure 8A This is a diagram showing an example when the angle between tool paths is less than 180 degrees.

[0042] Figure 8B This is a diagram showing an example when the angle between tool paths is 180 degrees or more.

[0043] Figure 9A This is a diagram showing an example for explaining the operation of the interference determination unit.

[0044] Figure 9B This is a diagram showing an example for explaining the operation of the interference determination unit.

[0045] Figure 10 This is a flowchart for explaining an example of the NC instruction execution process of a numerical control device.

[0046] Figure 11This is a diagram showing an example of tool information data.

[0047] Figure 12 This is a diagram showing an example of a machining program for matching the edges of a multi-edge tool with the cutting surface of a workpiece.

[0048] Figure 13 This is a diagram showing an example of the case where a multi-edge tool is matched with a workpiece.

[0049] Figure 14 This is a diagram showing an example of the method described in Patent Document 1.

[0050] Figure 15 This is a diagram showing an example of the method described in Patent Document 2.

[0051] Figure 16 This is a diagram showing an example of a cutting process in which the direction perpendicular to the cutting surface changes in the XZ plane. Detailed Description of the Preferred Embodiment

[0052]

[0053] First, an overview of the present embodiment will be described. In the present embodiment, the numerical control device interprets the instructions of the machining program, and based on the interpreted instructions of the machining program, obtains the relative movement direction information between the multi-edge tool and the workpiece and the positional relationship information between the multi-edge tool and the workpiece. The numerical control device uses the obtained relative movement direction information and positional relationship information to generate machining shape information related to the shape of the turning process. The numerical control device determines the edge direction of the multi-edge tool at the machining shape change points according to the tool shape information related to the shape of the multi-edge tool and the generated machining shape information, and controls the turning process while changing the edge direction of the multi-edge tool in the tool path between the machining shape change points according to the edge direction of the multi-edge tool at each machining shape change point.

[0054] Thus, according to the present embodiment, it is possible to solve the problem of "while avoiding interference between the cutting surface and the tool, easily positioning the B axis so that the selected edge always contacts the cutting surface".

[0055] The above is the overview of the present embodiment.

[0056] Next, the structure of the present embodiment will be described in detail with reference to the drawings.

[0057] Figure 1 This is a functional block diagram showing an example of the functional structure of a numerical control device according to an embodiment.

[0058] The numerical control device 10 and the machine tool 20 can also be directly connected to each other via a connection interface (not shown). In addition, the numerical control device 10 and the machine tool 20 can also 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 control device 10 and the machine tool 20 have a communication unit (not shown) for communicating with each other through such a connection.

[0059] The machine tool 20 is, for example, a lathe or the like for performing lathe machining, which is well known to those skilled in the art, and operates according to an operation instruction from the numerical control device 10 described later.

[0060] The numerical control device 10 is a numerical control device well known to those skilled in the art, generates an operation instruction according to control information, and sends the generated operation instruction to the machine tool 20. Thus, the numerical control device 10 controls the operation of the machine tool 20.

[0061] As Figure 1 shown, the numerical control device 10 has a control unit 100 and a tool information storage 200. And the control unit 100 has: an NC instruction interpretation unit 110, an interpolation processing unit 120, a tool calibration unit 130, a pulse distribution unit 140, and a tool shape storage generation unit 150. And the NC instruction interpretation unit 110 has: a machining shape information generation unit 111, an edge number instruction interpretation unit 112, an edge direction determination unit 113, and a machining control unit 114. In addition, the edge direction determination unit 113 has an interference determination unit 1131 and an alarm generation unit 1132.

[0062] <Tool Information Storage 200>

[0063] The tool information storage 200 is a storage unit such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive). The tool information storage 200 stores tool information data 210.

[0064] The tool information data 210 includes, for example, tool information and edge information related to a multi-edge tool that can be selected by the machine tool 20. In addition, the tool information data 210 ensures an area for storing information for each edge by registering the edge numbers according to the number of edges of the multi-edge tool.

[0065] Figure 2 is a diagram showing an example of the tool information data 210.

[0066] As Figure 2As shown, the tool information data 210 has, for example, a storage area that stores the tool numbers assigned to the registered multi-edge tools, the edge numbers assigned to each edge of each multi-edge tool, the angle between the edges, the edge length, and the like.

[0067] In addition, the tool information data 210 may also have a storage area that stores the tool position offset and the tip R correction amount for each multi-edge tool.

[0068] As described above, the tool information data 210 may also store tool numbers such as "100", "102", "103", etc. assigned to the registered multi-edge tools.

[0069] In addition, in the tool information data 210, edge numbers "1" to "3" are assigned to the multi-edge tool with the tool number "100" and stored. Thus, it indicates that the multi-edge tool with the tool number "100" has 3 edges. On the other hand, edge numbers "1" to "4" are assigned to the multi-edge tools with the tool numbers "102" and "103" and stored. Thus, it indicates that the multi-edge tools with the tool numbers "102" and "103" have 4 edges.

[0070] Figures 3A to 3C is a diagram showing an example of a multi-edge tool.

[0071] Figure 3A Represents the multi-edge tool with the tool number "100". The multi-edge tool with the tool number "100" has a rough machining edge at edge number "1", a semi-finishing edge at edge number "2", and a finishing edge at edge number "3". Thus, Figure 3A the multi-edge tool can continuously perform rough machining, semi-finishing, and finishing by rotating the B axis (around the Y axis). And in the tool information data 210, "0", "α E2 ", "α E3 " and "L1 E1 ", "L1 E2 ", "L1 E3 " are pre-stored in the angle between the edges and the edge length of each of the edge numbers "1" to "3".

[0072] In addition, for example, when taking the straight line connecting the tip of edge 1 with edge number 1 from the rotation center (B axis) of the multi-edge tool as a reference, the angle between the edges represents the angle, for example, in the clockwise direction, with respect to the straight line connecting the tip of other edges (such as edge 2 (E2) or edge 3 (E3)) from the rotation center (B axis) of the multi-edge tool. Therefore, the angle between the edges of edge 1 (E1) is 0 degrees.

[0073] In addition, the edge length is the distance from the rotation center (B axis) of the multi-edge tool to the front ends of the respective edges 1 (E1) to 3 (E3).

[0074] Figure 3B The multi-edge tool indicating the tool number "102". The multi-edge tool with the tool number "102" has a roughing edge at the edge number "1", a semi-finishing edge at the edge number "2", and a finishing edge at the edge number "3". Thus, by rotating the B axis (about the Y axis), the multi-edge tool can continuously perform roughing, semi-finishing, and finishing. In addition, as Figure 3B shown, the edge number "4" is a recessed part, and thus, it is an edge that cannot be used for cutting.

[0075] Also, in the tool information data 210, "0", "Θ E2 ", "Θ E3 ", "Θ E4 ", and "L2 E1 ", "L2 E2 ", "L2 E3 ", "L2 E4 " are pre-stored in the respective edge angles and edge lengths of the edge numbers "1" to "4".

[0076] Figure 3C The multi-edge tool indicating the tool number "103". The multi-edge tool with the tool number "103" has a finishing edge at the edge number "1", a roughing edge at the edge number "2", a roughing edge at the edge number "3", and a semi-finishing edge at the edge number "4". Thus, by rotating the B axis (about the Y axis), the multi-edge tool can continuously perform roughing, semi-finishing, and finishing. Also, in the tool information data 210, "0", "γ E2 ", "γ E3 ", "γ E4 " and "L3 E1 ", "L3 E2 ", "L3 E3 ", "L3 E4 " are pre-stored in the respective edge angles and edge lengths of the edge numbers "1" to "4".

[0077] <Control Unit 100>

[0078] The control unit 100 includes a CPU, ROM, RAM, CMOS memory, etc., which are configured to be able to communicate with each other via a bus and are well-known to those skilled in the art.

[0079] The CPU is a processor that integrally controls the numerical control device 10. The CPU reads out 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. Thus, as Figure 1 shown, the control unit 100 is configured to implement the functions of the NC instruction interpretation unit 110, interpolation processing unit 120, tool correction unit 130, pulse distribution unit 140, and tool shape storage generation unit 150. In addition, the NC instruction interpretation unit 110 is configured to implement the functions of the machining shape information generation unit 111, edge number instruction interpretation unit 112, edge direction determination unit 113, and machining control unit 114. In addition, the edge direction determination unit 113 is configured to implement the functions of the interference determination unit 1131 and alarm generation unit 1132. Various data such as temporary calculation data and display data are stored in the RAM. The CMOS memory is configured as a non-volatile memory as follows: It is backed up by a battery (not shown) and maintains the storage state even when the power of the numerical control device 10 is turned off.

[0080] Next, an explanation of the control unit 100 will be given. First, an explanation of the tool shape storage generation unit 150 will be given.

[0081] <Tool shape storage generation unit 150>

[0082] The tool shape storage generation unit 150 stores and generates geometric information related to the shape of the multi-edge tool as tool shape information corresponding to the multi-edge tool indicated in the machining program 30 interpreted by the edge number instruction interpretation unit 112 described later, based on the tool information data 210 registered in the tool information memory 200.

[0083] Specifically, for the multi-edge tool indicated in the machining program 30, the tool shape storage generation unit 150, based on the tool information data 210, (a) calculates the vector V from the tip of each edge to the tip of other edges ENEM , (b) attaches a non-machinable flag to the non-machinable edges, (c) calculates the indexing angle (β EN ) for centering the tip angle of each edge (i.e., the bisector of the tip angle coincides with the X-axis direction), and generates it as the tool shape information of the multi-edge tool. In addition, N and M are integers greater than or equal to 1, and N ≠ M.

[0084] Figure 4A represents Figure 3B In the case of a multi-edge tool, the vector V from the tip of edge 1 to the tip of other edges ENEM is an example of a diagram. Figure 4B represents Figure 3B In the case of a multi-edge tool, the indexing angle β for centering the tip angle of edge 2 E2Diagram of an example.

[0085] As Figure 4A shown, the tool shape storage generation unit 150 calculates vectors V from the leading edge of edge 1 (E1) to the leading edges of other edges, namely edge 2 (E2), edge 3 (E3), and edge 4 (E4). E1E2 V E1E3 V E1E4 . In addition, the tool shape storage generation unit 150 can also calculate vectors V from the leading edges of edge 2 (E2), edge 3 (E3), and edge 4 (E4) to other edges in the same way as in the case of vectors V E1E2 V E1E3 V E1E4 . ENEM .

[0086] In addition, as described above, Figure 3B since edge 4 of the multi-edge tool is recessed and cannot be used for cutting, the tool shape storage generation unit 150 attaches a non-machinable flag to edge 4.

[0087] In addition, as Figure 4B shown, the tool shape storage generation unit 150 calculates, for example, the indexing angle β for centering the leading edge angle of edge 2 with respect to edge 1 (E1). E2 . In addition, the tool shape storage generation unit 150 can also calculate the indexing angle β for centering the leading edge angle of edge 3 (E3) in the same way as in the case of edge 2 (E2). E3 .

[0088] The tool shape storage generation unit 150 outputs the generated tool shape information to the NC instruction interpretation unit 110 and the tool calibration unit 130 described later.

[0089] In addition, the tool shape storage generation unit 150 can also generate tool shape information in advance according to the tool information data 210 (related to the multi-edge tool) registered in the tool information memory 200, and store the generated tool shape information of the multi-edge tool in the tool information memory 200.

[0090] <NC Instruction Interpretation Unit 110>

[0091] The NC instruction interpretation unit 110, for example, obtains a machining program 30 generated by an external device such as a CAD / CAM device, and analyzes the obtained machining program 30.

[0092] In addition, in the machining program 30, there are programs that specify the tool path for machining based on a multi-edge tool and programs that do not specify the tool path for machining based on a multi-edge tool. Hereinafter, the case of (1) the machining program 30 that specifies the tool path for machining based on a multi-edge tool and the case of (2) the machining program 30 that does not specify the tool path for machining based on a multi-edge tool will be described.

[0093] (1) The case of the machining program 30 that specifies the tool path for machining based on a multi-edge tool

[0094] Figure 5A is a diagram showing an example of the machining program 30 that specifies the tool path for machining based on a multi-edge tool. Figure 5B is a diagram showing Figure 5A an example of the finish-machined shape of the workpiece W cut by the machining program 30.

[0095] As Figure 5B shown, the NC instruction interpretation unit 110 analyzes, for example, the case of performing finish machining on the tool path in the order from sequence number "N101" to sequence number "N110". In other words, Figure 5B the tool path shown is the path according to the instruction values of the machining program 30 of Figure 5A .

[0096] Here, Figure 5A the first block of the machining program 30 of Figure 5B executes the edge direction automatic determination mode, and in the tool path of Figure 5A , the multi-edge tool passes through the right side of the moving direction. In addition, when the first block of the machining program 30 of Figure 5B is "G41.9", in the tool path of

[0097] (2) The case of the machining program 30 that does not specify the tool path for machining based on a multi-edge tool

[0098] Figure 6A is a diagram showing an example of the machining program 30 that does not specify the tool path for machining based on a multi-edge tool. Figure 6B is a diagram showing an example of the tool path of the workpiece W cut by the machining program 30 of Figure 6A . In addition, Figure 6B the dashed line shown is the same as Figure 5B and represents the finish-machined shape of the workpiece W.

[0099] As Figure 6AAs shown, the machining program 30 is a program with 15 blocks. The "Gxx" in the second block is a simplified program instruction, which is the main program for machining the workpiece W into the finish-machined shape shown by the dashed line Figure 6B as shown.

[0100] In addition, the independent variable "P101" of "Gxx" represents the sequence number of the first block that determines the finish-machined shape. In addition, the independent variable "Q110" of "Gxx" represents the sequence number of the last block that determines the finish-machined shape. In addition, Figure 6A the sequence numbers "101" to "110" of the machining program 30 shown in Figure 5A are the same as those of the machining program 30 shown in

[0101] In addition, the independent variable "U2.0" of "Gxx" represents the cutting-in amount of the tool. In addition, the independent variable "F0.1" of "Gxx" represents the feed rate of the tool. In addition, the independent variable "S1000" of "Gxx" represents the spindle speed per minute. In addition, the independent variable "T100" of "Gxx" represents the tool number. In addition, the independent variable "E1" of "Gxx" represents the edge number for the outgoing path described later. In addition, the independent variable "H2" of "Gxx" represents the edge number for the return path described later.

[0102] The NC instruction interpretation unit 110 pre-reads Figure 6A the multiple blocks included in the machining program 30, and calculates the tool path of the multi-edge tool according to the NC instructions in the pre-read multiple blocks.

[0103] Specifically, the NC instruction interpretation unit 110 calculates, for example, Figure 6A the path of the finish-machined shape shown by the dashed line in Figure 6B according to the NC instructions of each of the multiple blocks of the machining program 30 shown in Figure 6B . Among them, since there is a limit to the cutting-in amount of the multi-edge tool, it is impossible to machine from the beginning along the Figure 6A finish-machined shape shown by the dashed line. Therefore, the NC instruction interpretation unit 110 calculates, according to the NC instructions of each of the multiple blocks of the machining program 30 shown in Figure 6B the tool path shown in

[0104] that can be machined within the cutting-in amount range of the multi-edge tool. Figure 6A and Figure 6B shown, the NC instruction interpretation unit 110 calculates a tool path that reciprocates in the Z-axis direction and cuts the workpiece W in the -X axis direction with a set cutting-in amount.

[0105] In other words, Figure 6B the tool path shown in Figure 6ARather than the path of the command value of the machining program 30, it is a path generated inside the numerical control device 10.

[0106] Here, the direction in which the multi-edge tool is moved along the workpiece W (the Z-axis direction in Figure 6B is also referred to as the "reciprocating axis". In addition, the direction when observing the machining end position from the machining start position with the reciprocating axis as a reference (the -Z-axis direction in Figure 6B is also referred to as the "forward path direction". In addition, the direction when observing the machining start position from the machining end position with the reciprocating axis as a reference (the +Z-axis direction in Figure 6B is also referred to as the "return path direction".

[0107] <Machining shape information generation unit 111>

[0108] The machining shape information generation unit 111 generates machining shape information related to the shape of the turning machining based on the relative movement direction information between the multi-edge tool and the workpiece and the position relationship information between the multi-edge tool and the workpiece indicated in the machining program 30 of the turning machining.

[0109] Specifically, the machining shape information generation unit 111 reads the edge movement direction command (X_Z_) in the edge direction automatic determination mode (G41.9 / G42.9) and stores it as the position vector of the tip of the multi-edge tool.

[0110] The machining shape information generation unit 111 stores all the movement commands moving on the Figure 5B tool path (or Figure 6B the finish machining shape shown by the dotted line in

[0111] as position vectors (machining shape information). In addition, the machining shape information generation unit 111 can store position vectors (machining shape information) even for commands that act in G00 / G01 / G02 / G03 internally for fixed cycles, etc., even if they are not direct G00 / G01 / G02 / G03 commands. In addition, the machining shape information generation unit 111 can also perform block reading until the edge indexing axis positioning mode cancellation (G40) is read.

[0112] <Edge number command interpretation unit 112>

[0113] The edge number command interpretation unit 112 interprets, for example, the edge number command in the machining program 30 and outputs the indicated edge number to the edge direction determination unit 113 described later.

[0114] <Edge direction determination unit 113>

[0115] As described above, the edge direction determination unit 113 determines the edge direction of the multi-edge tool at the machining shape change points where the machining shape changes, based on the tool shape information generated by the tool shape storage generation unit 150 for the indicated edge numbers and the machining shape information generated by the machining shape information generation unit 111. In addition, in the following description, the case of the edge direction of edge 1 of the multi-edge tool 40 is illustrated, but the edge directions of other edges such as edge 2 are the same.

[0116] Figure 7 It is a diagram showing an example of the machining shape based on the machining shape information.

[0117] As Figure 7 shown, for example, the tool paths A1 to A3 are calculated by the NC command interpretation unit 110, and the tool paths A1 to A3 are the paths along which the multi-edge tool 40 sequentially cuts the workpiece W.

[0118] The edge direction determination unit 113 determines the edge direction, for example, at the point P1 where the tool path A1 switches to the tool path A2 (hereinafter also referred to as the "machining shape change point") and the machining shape change point P2 where the tool path A1 switches to the tool path A2, together with the starting point of the tool path A1 and the end point of the tool path A3.

[0119] Specifically, the edge direction determination unit 113 determines the edge direction such that, for example, the bisector of the angle (e.g., 90 degrees) formed by the tool paths A1 and A2 at the machining shape change point P1 (e.g., the direction of 45 degrees to the upper left) coincides with the center of the edge front angle of edge 1 of the multi-edge tool 40. In addition, the edge direction determination unit 113 determines the edge direction such that, for example, the bisector of the angle (e.g., 90 degrees) formed by the tool paths A2 and A3 at the machining shape change point P2 (e.g., the direction of 45 degrees to the upper right) coincides with the center of the edge front angle of edge 1 of the multi-edge tool 40.

[0120] In addition, the edge direction determination unit 113 determines the edge direction such that the vertical direction of the cutting surface of the tool path A1 (i.e., the -Z axis direction) coincides with the center of the edge front angle of edge 1 of the multi-edge tool 40 at the starting point of the tool path A1. In addition, the edge direction determination unit 113 determines the edge direction such that the vertical direction of the cutting surface of the tool path A3 (i.e., the +Z axis direction) coincides with the center of the edge front angle of edge 1 of the multi-edge tool 40 at the end point of the tool path A3.

[0121] Accordingly, the interpolation processing unit 120 described below can use the start point of the tool path A1, the end point of the tool path A3, and the edge directions at the machining shape change points P1 and P2, that is, the positioning angles of the edge indexing axis, to perform interpolation on the positioning angles of the edge indexing axis on the tool path A1 from the start point of the tool path A1 to the machining shape change point P1, the tool path A2 between the machining shape change points P1 and P2, and the tool path A3 from the machining shape change point P2 to the end point of the tool path A3 through known interpolation processing. Thus, in the machining program 30, the user does not need to indicate the positioning angle of the edge indexing axis, which can reduce the burden on the user.

[0122] In addition, the edge direction determination unit 113 can also determine, when the angle between tool paths (blocks) is less than 180 degrees, the angle at which the center line of the tool path (block) angle coincides with the center line of the edge front end points of the multi-edge tool 40 as the edge direction (the positioning angle of the edge indexing axis).

[0123] Figure 8A It is a diagram showing an example when the angle between tool paths is less than 180 degrees.

[0124] As Figure 8A shown, the edge direction determination unit 113, in the same way as the Figure 7 case, determines the edge direction in such a way that the bisector of the angle formed by the tool path C(i) and the tool path C(i + 1) at the machining shape change point Pi coincides with the center of the edge front end angle of the multi-edge tool 40. Here, i is an integer of 1 or more, and θ v represents the angle difference (clockwise direction) between the bisector direction (center line workpiece direction) of the angle formed by the tool path C(i) and the tool path C(i + 1) at the machining shape change point Pi and the X-axis direction.

[0125] In addition, the edge direction determination unit 113 can also determine, when the angle between tool paths (blocks) is 180 degrees or more, the angle at which the vertical direction of the cutting surface of each tool path (block) coincides with the center line of the edge front end points of the multi-edge tool 40 as the edge direction (the positioning angle of the edge indexing axis).

[0126] Figure 8B It is a diagram showing an example when the angle between tool paths is 180 degrees or more.

[0127] As Figure 8B shown, the edge direction determination unit 113 determines the edge direction in such a way that the vertical directions (dashed lines) of the cutting surfaces of the tool paths C(i) and C(i + 1) at the machining shape change point Pi coincide with the center of the edge front end angle of the multi-edge tool 40. Here, θ v1 、θ v2Indicates the angular difference (clockwise) between the vertical direction (workpiece side) of the cutting surface of each of the tool paths C(i) and C(i+1) at the machining shape change point Pi and the X-axis direction.

[0128] The method for determining the edge direction described so far is an example. In addition, methods such as specifying the angle of the center line of the edge front end point with respect to the vertical direction of the machining surface, and maintaining the determined edge direction as long as it is not determined to cause interference in the interference determination unit described later are also considered.

[0129] <Interference determination unit 1131>

[0130] The interference determination unit 1131 determines whether interference occurs between the machining shape and the multi-edge tool 40 based on, for example, the tool shape information, the machining shape information, and the edge direction (positioning angle of the edge indexing axis) of each machining shape change point determined by the edge direction determination unit 113. When the interference determination unit 1131 determines that interference has occurred, it changes the edge direction (positioning angle of the edge indexing axis) of the machining shape change point where the interference occurred in order to avoid the interference.

[0131] Figure 9A And Figure 9B is a diagram showing an example for explaining the operation of the interference determination unit 1131.

[0132] Specifically, as Figure 9A shown, the interference determination unit 1131 matches the multi-edge tool 40 with the cutting surface of the workpiece W at the edge direction (positioning angle of the edge indexing axis) determined at each machining shape change point, for example. The interference determination unit 1131 determines the vectors V E1E2 、V E1E3 、V E1E4 from the edge front end of the edge 1 (E1) of the tool shape information to the front ends of the edges 2 (E2), 3 (E3), and 4 (E4). It determines whether at least one of E1E2 、V E1E3 、V E1E4 intersects any of the tool paths D(i) to D(i+3) of the machining shape information. When at least one of the vectors V Figure 9B intersects any of the tool paths D(i) to D(i+3), the interference determination unit 1131 determines that interference occurs between the machining shape and the multi-edge tool 40. In this case, as

[0133] The method of interference determination described so far is an example. In addition, methods such as using detailed tool shape information and machining shape information created by CAD (Computer Aided Design) to determine interference are also considered.

[0134] <Alarm generation unit 1132>

[0135] For example, when the interference between the machining shape and the multi-edge tool 40 cannot be avoided by the interference determination unit 1131, the alarm generation unit 1132 generates an alarm to stop the interpretation and execution of the machining program 30. In this case, the generated alarm can be displayed on a display device (not shown) such as a liquid crystal display included in the numerical control device 10, or can be output in the form of sound via a speaker (not shown) included in the numerical control device 10.

[0136] In addition, for example, the alarm generation unit 1132 can also generate an alarm to stop the interpretation and execution of the machining program when the edge 4 with the non-machinable flag of the multi-edge tool shown in the tool shape information is to be used for machining. Figure 3B

[0137] <Machining control unit 114>

[0138] The machining control unit 114 controls the turning machining of the machine tool 20 while changing the edge direction of the multi-edge tool between the machining shape change points corresponding to the interpolation process of the interpolation processing unit 120 according to the edge direction of the multi-edge tool 40 at each machining shape change point.

[0139] <Interpolation processing unit 120>

[0140] The interpolation processing unit 120 performs interpolation processing on the tool path received from the NC instruction interpretation unit 110 and calculates the command position and command speed. In addition, the interpolation processing unit 120 interpolates the edge direction (positioning angle of the edge indexing axis) between each machining shape change point according to the edge direction (positioning angle of the edge indexing axis) of each machining shape change point determined by the edge direction determination unit 113.

[0141] <Tool calibration unit 130>

[0142] The tool calibration unit 130 calculates the tool calibration amount using the position offset amount and the tip R calibration amount of the selected multi-edge tool 40, and the tool shape information of the multi-edge tool 40 generated by the tool shape storage generation unit 150.

[0143] <Pulse distribution unit 140>

[0144] ​The pulse distribution unit 140 outputs the pulses of the axis movement amounts for tool calibration calculated to each servo motor (not shown) included in the machine tool 20.

[0145] <NC instruction execution process of numerical control device 10>

[0146] Next, an example of the operation of the NC instruction execution process of the numerical control device 10 in the case of performing cutting processing of the machining program 30 for machining the edge using the multi-edge tool 40 will be described.

[0147] Figure 10 It is a flowchart for explaining an example of the NC instruction execution process of the numerical control device 10.

[0148] In step S11, the NC instruction interpretation unit 110 reads in the machining program 30.

[0149] In step S12, the NC instruction interpretation unit 110 pre-reads a plurality of blocks included in the machining program 30 read in step S11, and calculates, based on the NC instructions in the pre-read plurality of blocks, for example Figure 5B or Figure 6B the tool path of the multi-edge tool 40 shown.

[0150] In step S13, the tool shape storage generation unit 150 generates geometric information related to the shape of the multi-edge tool 40 indicated in the machining program 30 as tool shape information based on the tool information data 210 registered in the tool information memory 200, and stores it.

[0151] In step S14, the machining shape information generation unit 111 generates machining shape information related to the shape of this turning machining based on the relative movement direction information of the multi-edge tool 40 and the workpiece W and the position relationship information between the multi-edge tool 40 and the workpiece W indicated in the machining program 30.

[0152] In step S15, the edge direction determination unit 113 determines the edge direction of the multi-edge tool 40 at the machining shape change points where the machining shape changes based on the tool shape information generated in step S13 and the machining shape information generated in step S14.

[0153] In step S16, the interference determination unit 1131 determines whether interference occurs between the machining shape and the multi-edge tool 40 based on the tool shape information generated in step S13, the machining shape information generated in step S14, and the edge direction (the positioning angle of the edge indexing axis) determined at the machining shape change points in step S15. In the case where interference occurs, the process proceeds to step S17. On the other hand, in the case where no interference occurs, the process proceeds to step S19.

[0154] In step S17, the edge direction determination unit 113 changes the edge direction (the positioning angle of the edge indexing axis) at the machining shape change point determined to cause interference in step S16.

[0155] In step S18, the alarm generation unit 1132 determines whether interference is avoided at the machining shape change point. If interference is avoided at the machining shape change point, the process proceeds to step S19. On the other hand, if interference cannot be avoided at the machining shape change point, the process proceeds to step S23.

[0156] In step S19, the interpolation processing unit 120 performs interpolation processing on the tool path received from the NC command interpretation unit 110, calculates the command position and command speed, and interpolates the edge direction (the positioning angle of the edge indexing axis) between the machining shape change points according to the edge direction (the positioning angle of the edge indexing axis) of the machining shape change point determined in step S15.

[0157] In step S20, the tool correction unit 130 calculates the tool correction amount using the position offset amount of the selected multi-edge tool 40 (such as a turning tool), the tip R correction amount, and the tool shape information generated in step S13.

[0158] In step S21, the machining control unit 114 controls the machining process according to the tool path calculated by the interpolation processing unit 120.

[0159] In step S22, the machining control unit 114 determines whether all the machining processes indicated by the machining program have ended. If all the machining processes have ended, the NC command execution process ends. If all the machining processes have not ended, the process transfers to step S15.

[0160] In step S23, the alarm generation unit 1132 generates an alarm and stops the interpretation and execution of the machining program 30. After that, the NC command execution process ends.

[0161] Through the above, the numerical control device 10 can easily position the edge indexing axis while avoiding interference between the workpiece and the tool by determining the edge direction (the positioning angle of the edge indexing axis) of the multi-edge tool 40 at the machining shape change point, so that the selected edge is always in contact with the cutting surface.

[0162] In addition, the numerical control device 10 checks for interference between the cutting surface and the multi-edge tool 40, automatically avoids it, or generates an alarm and stops the operation when interference cannot be avoided, so that complex shape machining can also be performed safely.

[0163] In addition, when the numerical control device 10 performs machining using a multi-edge tool 40 for turning with multiple edges in one tool, it controls the edge indexing axis (B axis) so that the selected edge always contacts the cutting surface corresponding to the change in the direction perpendicular to the cutting surface. Thus, even when machining a complex shape, a machining program 30 can be created without being aware of the direction perpendicular to the cutting surface, and the machining program 30 can be easily created without using CAM.

[0164] In addition, the numerical control device 10 does not need to determine the edge direction (the positioning angle of the edge indexing axis) of the multi-edge tool 40 in the machining program 30. Therefore, the machining shape instruction part of the existing machining program can be reused.

[0165] As described above, one embodiment has been explained, but the numerical control device 10 is not limited to the above embodiment and includes variations, improvements, etc. within the range that can achieve the purpose.

[0166] <Variation Example>

[0167] In the above embodiment, the numerical control device 10 is provided as a device different from the machine tool 20, but it is not limited thereto. For example, the numerical control device 10 may also be included in the machine tool 20.

[0168] Furthermore, each function included in the numerical control device 10 in one embodiment can be separately implemented by hardware, software, or a combination thereof. Here, implementing by software means implementing by a computer reading and executing a program.

[0169] The program can be stored using various types of non-transitory computer-readable media and provided to a computer. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (such as floppy disks, magnetic tapes, hard disk drives), magneto-optical recording media (such as magneto-optical disks), CD-ROM (Read Only Memory), CD-R, CD-R / W, semiconductor memories (such as mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM). Additionally, the program can also be provided to the computer via various types of transitory computer-readable media. Examples of transitory 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.

[0170] Furthermore, the steps of describing a program recorded in a recording medium, of course, include processes that proceed in time series in their order, and also include processes that do not necessarily proceed in time series, as well as processes that are executed in parallel or individually.

[0171] In other words, the numerical control device and control method of the present disclosure can adopt various embodiments having the following structures.

[0172] (1) The numerical control device 10 of the present disclosure is a numerical control device that controls a machine tool 20 for turning a workpiece W using a multi-edge tool 40 for turning, and has: a tool shape information storage generation unit 150 that generates and stores geometric information related to the shape of the multi-edge tool 40 as tool shape information; a machining shape information generation unit 111 that generates machining shape information related to the shape of the turning based on the relative movement direction information of the multi-edge tool 40 and the workpiece W and the position relationship information of the multi-edge tool 40 and the workpiece W indicated in the machining program 30 for turning; an edge direction determination unit 113 that determines the edge direction of the multi-edge tool 40 at machining shape change points where the machining shape changes based on the generated tool shape information and the generated machining shape information; and a machining control unit 114 that controls the turning while changing the edge direction of the multi-edge tool 40 between the machining shape change points according to the edge direction of the multi-edge tool 40 at each machining shape change point.

[0173] According to the numerical control device 10, it is possible to easily position the edge indexing axis while avoiding interference between the workpiece and the tool, so that the selected edge is always in contact with the cutting surface.

[0174] (2) In the numerical control device 10 described in (1), it may also be that the geometric information at least includes the angle formed between the edges included in the multi-edge tool and the distance from the rotation center to the edge tip, and is stored in the tool information storage 200 included in the numerical control device 10 in association with the edge numbers.

[0175] Thereby, the numerical control device 10 can determine whether interference occurs between the machining shape and the multi-edge tool 40.

[0176] (3) In the numerical control device 10 described in (1) or (2), it may also be that the tool shape information storage and generation unit 150 determines the edges of the multi-edge tool that cannot be used for machining based on the tool shape information, attaches a non-machinable flag to the edges that cannot be used for machining, and the edge direction determination unit 113 generates an alarm and stops the interpretation and execution of the machining program 30 when an edge with a non-machinable flag attached is to be used for machining.

[0177] Thereby, the numerical control device 10 can also perform complex shape machining safely.

[0178] (4) In the numerical control device 10 described in any one of (1) to (3), it may also be that the position relationship information between the multi-edge tool 40 and the workpiece W specifies whether the moving direction of the workpiece W relative to the multi-edge tool 40 is on the right side or the left side.

[0179] Thereby, the numerical control device 10 can also perform complex shape machining safely.

[0180] (5) In the numerical control device 10 described in any one of (1) to (4), it may also be that the edge direction determination unit 113 determines the edge direction so that there is no interference between the multi-edge tool 40 and the workpiece W, and generates an alarm and stops the interpretation and execution of the machining program when interference cannot be avoided.

[0181] Thereby, the numerical control device 10 can also perform complex shape machining safely.

[0182] (6) The control method of the present disclosure is a control method for a machine tool 20 that performs turning machining on a workpiece W using a multi-edge tool 40 for turning machining, generates geometric information related to the shape of the multi-edge tool 40 as tool shape information and stores it, generates machining shape information related to the shape of the turning machining according to the relative movement direction information of the multi-edge tool 40 and the workpiece W and the position relationship information of the multi-edge tool 40 and the workpiece W indicated in the machining program 30 for turning machining, determines the edge direction of the multi-edge tool 40 at the machining shape change points where the machining shape changes according to the generated tool shape information and the generated machining shape information, and controls the turning machining while changing the edge direction of the multi-edge tool between the machining shape change points according to the edge direction of the multi-edge tool 40 at each machining shape change point.

[0183] According to this control method, the same effect as (1) can be obtained.

[0184] Symbol Explanation

[0185] 10 Numerical control device,

[0186] 100 Control unit,

[0187] 110 NC instruction interpretation unit,

[0188] 111 Machining shape information generation unit,

[0189] 112 Edge number instruction interpretation unit,

[0190] 113 Edge direction determination unit,

[0191] 1131 Interference determination unit,

[0192] 1132 Alarm generation unit,

[0193] 114 Machining control unit,

[0194] 120 Interpolation processing unit,

[0195] 130 Tool calibration unit,

[0196] 140 Pulse distribution unit,

[0197] 150 Tool shape storage generation unit,

[0198] 200 Tool information memory,

[0199] 210 Tool information data.

Claims

1. A numerical control device controls a machine tool for turning a workpiece using a multi-edge tool for turning. The numerical control device is characterized in that: The numerical control device has: A tool shape information storage and generation unit that generates geometric information related to the shape of the multi-edge tool as tool shape information and stores it; A machining shape information generation unit that generates machining shape information related to the shape of the turning based on the relative movement direction information of the multi-edge tool and the workpiece indicated in the turning program and the positional relationship information between the multi-edge tool and the workpiece; An edge direction determination unit that determines the edge direction of the multi-edge tool at machining shape change points where the machining shape changes based on the generated tool shape information and the generated machining shape information; and A machining control unit that controls the turning while changing the edge direction of the multi-edge tool between the machining shape change points according to the edge direction of the multi-edge tool at each machining shape change point.

2. The numerical control device according to claim 1, characterized in that: The geometric information at least includes the angle formed between the edges included in the multi-edge tool and the distance from the rotation center to the edge tip, and is stored in the storage unit included in the numerical control device in association with the edge numbers.

3. The numerical control device according to claim 1 or 2, characterized in that: The tool shape information storage and generation unit determines the edges of the multi-edge tool that cannot be used for machining based on the tool shape information, and attaches a non-machinable flag to the edges that cannot be used for machining. The edge direction determination unit generates an alarm and stops the interpretation and execution of the machining program when attempting to use the edge with the non-machinable flag attached for machining.

4. The numerical control device according to any one of claims 1 to 3, characterized in that: The positional relationship information between the multi-edge tool and the workpiece specifies whether the movement direction of the workpiece relative to the multi-edge tool is on the right or left side.

5. The numerical control device according to any one of claims 1 to 4, characterized in that: The edge direction determination unit determines the edge direction so that the multi-edge tool does not interfere with the workpiece, and generates an alarm and stops the interpretation and execution of the machining program when the interference cannot be avoided.

6. A control method for a machine tool for turning a workpiece using a multi-edge tool for turning, implemented by a computer, characterized in that: Generating geometric information related to the shape of the multi-edge tool as tool shape information and storing it; Generating machining shape information related to the shape of the turning based on the relative movement direction information of the multi-edge tool and the workpiece indicated in the turning program and the positional relationship information between the multi-edge tool and the workpiece; Determining the edge direction of the multi-edge tool at machining shape change points where the machining shape changes based on the generated tool shape information and the generated machining shape information; According to the edge direction of the multi-edge tool at each of the machining shape change points, while changing the edge direction of the multi-edge tool between the machining shape change points, the turning machining is controlled.

Images