Vibration cutting condition setting device for machine tool

Abstract

This invention provides a vibration cutting condition setting device that facilitates the selection of tools or the setting of parameters for vibration cutting. The vibration cutting condition setting device 3 for a machine tool 1 includes a display unit U3 and a control unit U4. The control unit U4 receives the feed rate (F) of the driven object when it is not vibrating, a first parameter (A) related to the period of vibration, and a second parameter (E) related to the amplitude of vibration, as settings for controlling the feed movement of the driven object in a manner that accompanies vibration. Based on the feed rate (F) of the driven object when it is not vibrating, the first parameter (A), and the second parameter (E), the control unit U4 calculates the maximum feed rate (Fmax) of the driven object and displays the calculated maximum feed rate (Fmax) on the display unit U3.

Description

Technical Field

[0001] The present invention relates to a vibration cutting condition setting device for a machine tool for cutting a workpiece held on a spindle. Background Technology

[0002] As a machine tool, there is a known NC (Numerical Control) automatic lathe with a spindle that holds the workpiece. If the chips generated from the workpiece rotating with the spindle become long, they may become entangled in the cutting tool, affecting continuous machining of the workpiece. Therefore, vibratory cutting is performed by alternately feeding the tool forward (moving the tool towards the workpiece) and backward (moving the tool away from the workpiece) to break up the chips. The chips are also called chips. The chip breaking condition varies depending on the spindle phase, the vibration amplitude, the feed rate during the forward movement, and the feed rate during the backward movement. The operator sets these parameters on the NC automatic lathe to enable it to perform vibratory cutting.

[0003] The machining system disclosed in Patent Document 1 generates first waveform data representing the time change of the position information from the position information of the feed axis at fixed time intervals, and divides the first waveform data into partial waveform data according to the time of each rotation of the spindle, and shifts each partial waveform data sequentially in the time axis direction in a manner matching the starting point of the first waveform data, thereby generating and representing multiple second waveform data.

[0004] [Background Technical Documents]

[0005] [Patent Literature]

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-195002 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] In cutting tools, upper limits are set for feed rates and other parameters as recommended cutting conditions to prevent chipping or welding. Here, for feed control during vibratory cutting, the feed movement of the tool is controlled in a manner that accompanies the vibration, considering the feed rate when the tool is not vibrating, the period parameter related to the vibration period, and the amplitude parameter related to the vibration amplitude. In this case, since the operator does not know the maximum feed rate during the forward movement, it is impossible to properly select the tool or set the parameters for vibratory cutting.

[0009] Furthermore, problems like those described above are not limited to lathes, but also exist in various machine tools such as machining centers.

[0010] This invention discloses a vibration cutting condition setting device that facilitates the selection of tools or the setting of parameters for vibration cutting.

[0011] [Technical means to solve the problem]

[0012] The vibration cutting condition setting device for a machine tool of the present invention has the following aspects: the machine tool includes a rotary drive unit for rotating a spindle holding a workpiece, and a feed drive unit for moving a drive object that moves at least one of a tool for cutting the workpiece and the spindle; when cutting the workpiece, the feed movement of the drive object is controlled by vibration in a manner that includes a forward movement including the tool moving towards the workpiece in the cutting direction and a backward movement in the opposite direction to the forward movement; and the vibration cutting condition setting device for the machine tool includes:

[0013] Display unit; and

[0014] The control unit receives the feed speed (F) of the driven object when it is not vibrating, a first parameter (A) related to the period of the vibration, and a second parameter (E) related to the amplitude of the vibration, as settings for controlling the feed movement of the driven object in a manner that accompanies the vibration; and

[0015] The control unit

[0016] Based on the non-vibration feed rate (F) of the driven object, the first parameter (A), and the second parameter (E), the maximum feed rate (Fmax) of the driven object is calculated; and

[0017] The calculated maximum feed rate (Fmax) is displayed on the display unit.

[0018] [The effects of the invention]

[0019] According to the present invention, the selection of tools or the setting of parameters that can be used for vibration cutting is facilitated. Attached Figure Description

[0020] Figure 1 This is a schematic diagram illustrating an example of the structure of a machine tool.

[0021] Figure 2 This is a block diagram that schematically illustrates an example of the circuit configuration of a machine tool.

[0022] Figure 3 This is a diagram illustrating an example of the tool position relative to the spindle rotation angle when the chip length coefficient A1 is 2.

[0023] Figure 4 This is a diagram that schematically illustrates an example of the tool position relative to the spindle phase when the chip length factor A1 is 2.

[0024] Figure 5 This is a diagram illustrating an example of the tool position relative to the spindle rotation angle when the chip length coefficient A1 is 3.

[0025] Figure 6 This is a diagram illustrating an example of the position of a feed movement controlled by a vibration-based feed command tool.

[0026] Figure 7 This is a diagram that schematically illustrates an example of the tool position relative to the spindle rotation angle when the chip length coefficient A1 is 2 / 3.

[0027] Figure 8 This is a diagram that schematically illustrates an example of the tool position relative to the spindle phase when the chip length factor A1 is 2 / 3.

[0028] Figure 9 This is an example diagram illustrating the settings screen for the vibration feed command CM1.

[0029] Figure 10 This is a diagram illustrating an example of the construction of an information table.

[0030] Figure 11 This is a diagram illustrating an example of accepting changes to the maximum feed rate Fmax.

[0031] Figure 12 This is an example diagram illustrating the settings screen for the vibration feed command CM2.

[0032] Figure 13 This is another example of a diagram schematically representing the position of a tool relative to the rotation angle of the spindle. Detailed Implementation

[0033] The following describes embodiments of the present invention. Of course, the following embodiments are merely illustrative of the present invention, and not all features shown in the embodiments are necessarily essential to the solutions provided by the invention.

[0034] (1) Summary of the technology included in this invention:

[0035] First, refer to Figures 1-13 The examples shown illustrate the general outline of the technology encompassed in this invention. Furthermore, the figures in this application are schematic representations of examples, and the magnification in different directions may vary, and the figures may sometimes differ. Of course, the elements of this technology are not limited to the specific examples represented by symbols.

[0036] [Aspect 1]

[0037] like Figure 1 , 2As illustrated, a machine tool 1 of one aspect of the present technology includes: a rotary drive unit U1 that rotates a spindle 11 holding a workpiece W1; and a feed drive unit U2 that moves a drive object (e.g., tool TO1) of at least one of the cutting tool TO1 and the spindle 11. When cutting the workpiece W1, the machine tool 1 controls the feed movement of the drive object in a manner accompanied by vibrations including a forward movement M1 in which the tool TO1 moves towards the workpiece W1 along the cutting direction (e.g., feed axis F1) and a backward movement M2 in the opposite direction to the forward movement M1.

[0038] The vibration cutting condition setting device 3 for the machine tool 1 includes a display unit U3 and a control unit U4. The control unit U4 receives the feed rate (F) of the driven object when it is not vibrating, a first parameter (A) related to the period of the vibration, and a second parameter (E) related to the amplitude of the vibration, as settings for controlling the feed movement of the driven object in a manner that accompanies the vibration. Based on the feed rate (F) of the driven object when it is not vibrating, the first parameter (A), and the second parameter (E), the control unit U4 calculates the maximum feed rate (Fmax) of the driven object and displays the value of the calculated maximum feed rate (Fmax) on the display unit U3.

[0039] As described above, since the value of the maximum feed rate (Fmax) is unknown in the display settings, the operator can easily select the tool TO1 for vibratory cutting by browsing the value of the maximum feed rate (Fmax), and can easily set the parameters for vibratory cutting. Therefore, aspect 1 provides a vibratory cutting condition setting device that facilitates the selection of tools for vibratory cutting or the setting of parameters.

[0040] Here, machine tools include lathes, machining centers, etc.

[0041] The feed drive unit can move the tool along the cutting direction without moving the workpiece, or move the workpiece along the cutting direction without moving the tool, or move both the tool and the workpiece along the cutting direction.

[0042] The first parameter (A) related to the period of vibration can be any parameter related to the period, and is not limited to the period itself. The first parameter (A) includes the chip length coefficient A1, the period A2, etc.

[0043] The second parameter (E) related to the amplitude of the vibration can be any parameter related to the amplitude, and is not limited to the amplitude itself. The second parameter (E) includes the recoil amount E1, the amplitude E2, etc.

[0044] The value representing the maximum feed rate is not limited to a value in mm / rev units. It can also be a conversion value such as the ratio of the maximum feed rate to the normal cutting feed rate, or the difference between the normal cutting feed rate and the maximum feed rate.

[0045] The remarks also apply to the following:

[0046] [Aspect 2]

[0047] like Figure 11 As illustrated, the control unit U4 can handle operations to change the maximum feed rate (Fmax) displayed on the display unit U3. The control unit U4 can change the non-vibrating feed rate (F) of the driven object based on the changed maximum feed rate (Fmax), the first parameter (A), and the second parameter (E), and can display the value representing the changed non-vibrating feed rate (F) of the driven object on the display unit U3. Since this aspect allows for changing the maximum feed rate (Fmax) in conjunction with cutting tools, and can confirm the changed non-vibrating feed rate (F) of the driven object, setting the non-vibrating feed rate (F) of the driven object becomes easier.

[0048] Here, the value representing the feed rate when the driven object is not vibrating is not limited to a value in mm / rev units. It can also be a converted value such as the ratio of the feed rate when the driven object is not vibrating after the change to the feed rate when the driven object is not vibrating before the change, or the difference between the feed rate when the driven object is not vibrating before the change and the feed rate when the driven object is not vibrating after the change. The appendix also applies to the following aspects.

[0049] [Aspect 3]

[0050] like Figure 11 As illustrated, the control unit U4 can calculate the cutting time (CT) required for the feed movement of the driven object accompanied by the vibration at the modified maximum feed rate (Fmax), based on the modified maximum feed rate (Fmax), the first parameter (A), and the second parameter (E), and can display the calculated cutting time (CT) value on the display unit U3. This aspect allows for changes in the maximum feed rate (Fmax) in conjunction with the cutting tool, etc., and enables confirmation of the cutting time (CT) at the modified maximum feed rate (Fmax).

[0051] Here, the value of cutting time is not limited to a value in min units; it can also be a converted value such as the ratio of the changed cutting time to the original cutting time, or the difference between the original and changed cutting times. The appendix also applies to the following aspects.

[0052] [Aspect 4]

[0053] The control unit U4 can handle operations to change the cutting time (CT) required for the feed movement of the driven object accompanying the vibration. Based on the changed cutting time (CT), the control unit U4 can change at least one of the non-vibrating feed rate (F) of the driven object and the maximum feed rate (Fmax), and can display the value of the changed feed rate parameter on the display unit U3. Since this aspect can confirm the feed rate parameter that changes due to the change in cutting time (CT), setting parameters for vibration cutting becomes easier.

[0054] (2) Specific examples of the structure of machine tools:

[0055] Figure 1 The configuration of a lathe, as an example of machine tool 1, is illustrated schematically together with the configuration of an external computer 100. Figure 1 The machine tool 1 shown is an NC automatic lathe equipped with an NC (numerical control) device 70 for numerical control of machining workpiece W1. Since a computer 100 is not a necessary component in machine tool 1, it is sometimes not connected to the machine tool 1. In this specific example, machine tool 1 includes a vibration cutting condition setting device 3.

[0056] Machine tool 1 is an NC machine tool in which a spindle table 10, a spindle table drive unit 14, a tool table 20, a feed drive unit U2 of the tool table 20, an NC device 70, etc., are assembled. Here, spindle table 10 is a general term for the front spindle table 10A and the back spindle table 10B, which is also called the opposing spindle table. A front spindle 11A with a chuck and other holding parts 12A is assembled into the front spindle table 10A. A back spindle 11B with a chuck and other holding parts 12B is assembled into the back spindle table 10B. Spindle 11 is a general term for the front spindle 11A and the back spindle 11B, which is also called the opposing spindle. Holding parts 12 are a general term for holding parts 12A and holding parts 12B. The spindle drive unit 14 is a collective term for the front spindle drive unit 14A, which moves the front spindle stage 10A, and the rear spindle drive unit 14B, which moves the rear spindle stage 10B. The rotation drive unit U1 of the spindle 11 includes a motor 13A that rotates the front spindle 11A around the spindle centerline AX1, and a motor 13B that rotates the rear spindle 11B around the spindle centerline AX1. Built-in motors integrated into the spindle can be used for motors 13A and 13B. Alternatively, motors 13A and 13B can be configured outside the spindle 11.

[0057] Figure 1The control axes of the machine tool 1 shown include the X-axis (denoted by "X"), the Y-axis (denoted by "Y"), and the Z-axis (denoted by "Z"). The Z-axis direction is horizontal along the spindle centerline AX1, which serves as the rotation center of the workpiece W1. The X-axis direction is horizontal and orthogonal to the Z-axis. The Y-axis direction is vertical and orthogonal to the Z-axis. Furthermore, the Z-axis may not be orthogonal to the X-axis if it intersects with the X-axis, nor may it be orthogonal to the Y-axis if it intersects with the X-axis. The accompanying drawings referenced in this specification are merely illustrative examples and not intended to limit the scope of the technology. The descriptions of the positional relationships of the various parts are also illustrative. Therefore, reversals of left and right orientations or rotation directions are also included in this technology. Furthermore, identical orientations or positions are not limited to strict uniformity and may deviate from strict uniformity due to errors.

[0058] Figure 1 The machine tool 1 shown is a spindle-moving lathe. The front spindle head drive unit 14A moves the front spindle head 10A in the Z-axis direction, and the rear spindle head drive unit 14B moves the rear spindle head 10B in the Z-axis direction. Of course, the machine tool 1 can be a spindle-fixed lathe where the front spindle head 10A does not move, or it can be a lathe where the rear spindle head 10B does not move while the front spindle head 10A moves in the Z-axis direction.

[0059] The front spindle 11A can releasably hold the workpiece W1 via the holding part 12A, and can rotate together with the workpiece W1 about the spindle centerline AX1. If the workpiece W1 before processing is, for example, a cylindrical (rod-shaped) strip material, it can be held from the rear end of the front spindle 11A (at... Figure 1 The workpiece W1 is supplied to the holding part 12A from the left end (in the middle). In this case, the workpiece W1 can be supplied to the holding part 12A from the front side of the main spindle 11A (at the left end). Figure 1 (Right side in the middle) A guide sleeve is configured to support the workpiece W1, allowing it to slide in the Z-axis direction. When the workpiece W1 is a relatively short piece of material before processing, it can be fed from the front end of the front spindle 11A to the holding part 12A. The motor 13A causes the front spindle 11A to rotate together with the workpiece W1 around the spindle centerline AX1. The workpiece W1, processed on the front side, is transferred from the front spindle 11A to the back spindle 11B. The back spindle 11B can be releasably held by the holding part 12B and can rotate together with the workpiece W1 around the spindle centerline AX1. The motor 13B causes the back spindle 11B to rotate together with the workpiece W1 around the spindle centerline AX1. The workpiece W1, processed on the front side, is then processed on the back side to become a finished product.

[0060] The tool holder 20 is used to mount multiple tools TO1 for machining workpiece W1 and is movable in the X-axis and Y-axis directions. The X-axis and Y-axis directions are examples of the feed axis F1. Of course, the tool holder 20 can also move in the Z-axis direction. The tool holder 20 can be a turret tool holder, a comb tool holder, etc. Among the multiple tools TO1 are turning tools with parting cutters, and rotary tools such as rotary drills or end mills. The feed drive unit U2 moves the tool holder 20, on which the multiple tools TO1 are mounted, along the feed axis F1. In this specific example, the feed drive unit U2 drives the tools TO1, and the feed drive unit U2 moves the tools TO1 along the feed axis F1.

[0061] Alternatively, feed axis F1 can be a hypothetical axis that interpolates the X and Y axes. When the tool holder 20, on which tool TO1 is mounted, can also move in the Z-axis direction, feed axis F1 can be the Z-axis, or it can be a hypothetical axis that interpolates the X, Y, and Z axes. Even when the tool holder 20 does not move in the Z-axis direction, feed axis F1, which interpolates the three axes with tool TO1 and spindle 11 as the driving objects, can be set by moving the spindle head 10, which is equipped with spindle 11, in the Z-axis direction. In any case, the direction along feed axis F1 is the cutting direction.

[0062] The computer 100, connected externally to the NC device 70, includes a processor (CPU, Central Processing Unit) 101, a semiconductor memory (ROM, Read Only Memory) 102, a semiconductor memory (RAM, Random Access Memory) 103, a storage device 104, an input device 105, a display device 106, a sound output device 107, an I / F (Interface) 108, and a clock circuit 109. The control program of the computer 100 is stored in the storage device 104, read from the CPU 101 into the RAM 103, and executed by the CPU 101. The storage device 104 can use semiconductor memory such as flash memory, magnetic recording media such as a hard disk, etc. The input device 105 can use pointing devices, a keyboard, and a touch panel attached to the surface of the display device 106. The I / F 108 is connected to the NC device 70 via wired or wireless connection to receive data from or send data to the NC device 70. The connection between computer 100 and machine tool 1 can be a network connection such as the Internet or an intranet. Computer 100 may include personal computers with tablet terminals, mobile phones such as smartphones, etc.

[0063] Figure 2 The circuit configuration of machine tool 1 is illustrated schematically. Figure 2In the machine tool 1 shown, the NC device 70 is connected to an operating unit 80, a rotary drive unit U1 for the spindle 11, a spindle head drive unit 14, and a feed drive unit U2 for the tool table 20. The rotary drive unit U1 includes a motor 13A and a servo amplifier (not shown) to rotate the front spindle 11A, and a motor 13B and a servo amplifier (not shown) to rotate the rear spindle 11B. The spindle head drive unit 14 includes a front spindle head drive unit 14A and a rear spindle head drive unit 14B. The feed drive unit U2 includes servo amplifiers 31 and 32 and servo motors 33 and 34. The NC device 70 includes a processor (CPU) 71, a ROM 72, a RAM 73, a clock circuit 74, and an I / F 75. Therefore, the NC device 70 is a type of computer. Figure 2 In this diagram, the I / F components, including the operation unit 80, rotary drive unit U1, spindle drive unit 14, feed drive unit U2, and external computer 100, are collectively represented as I / F 75. The ROM 72 contains the control program PR1, which interprets and executes the machining program PR2, and the support program PR3, which supports the creation of the machining program PR2. The ROM 72 can be a rewritable semiconductor memory. The RAM 73 stores the machining program PR2 created by the operator in a rewritable manner. The machining program is also called the NC program. The CPU 71 uses the RAM 73 as its working area to execute the control program PR1 recorded in the ROM 72, thereby realizing the function of the NC device 70. Of course, some or all of the functions implemented by the control program PR1 can also be implemented using other methods such as ASIC (Application Specific Integrated Circuit).

[0064] The operation unit 80 includes an input unit 81 and a display unit 82, serving as a user interface for the NC device 70. In this specific example, the display unit 82 is an example of the display unit U3, and the NC device 70 and the input unit 81 are examples of the control unit U4. The input unit 81 is, for example, composed of buttons or a touch panel for receiving operation input from the operator. The display unit 82 is, for example, composed of a display showing various settings received from the operator or various information related to the machine tool 1. The operator can use the operation unit 80 or the computer 100 to store the machining program PR2 in the RAM 73.

[0065] The feed drive unit U2 is equipped with a servo amplifier 31 connected to the NC device 70 and a servo motor 33 connected to the servo amplifier 31 for moving the tool stage 20 along the X-axis. In addition, the feed drive unit U2 is equipped with a servo amplifier 32 connected to the NC device 70 and a servo motor 34 connected to the servo amplifier 32 for moving the tool stage 20 along the Y-axis.

[0066] Servo amplifier 31 controls the position and speed of the tool holder 20 in the X-axis direction according to instructions from NC device 70. Servo amplifier 32 controls the position and speed of the tool holder 20 in the Y-axis direction according to instructions from NC device 70. Servo motor 33, equipped with encoder 35, rotates according to instructions from servo amplifier 31, moving the tool holder 20 in the X-axis direction via a feed mechanism (not shown) and a guide. Servo motor 34, equipped with encoder 36, rotates according to instructions from servo amplifier 32, moving the tool holder 20 in the Y-axis direction via a feed mechanism (not shown) and a guide. A ball screw mechanism or similar mechanism can be used for the feed mechanism. A combination of wedges and wedge grooves, or a sliding guide, can be used for the guide.

[0067] The NC device 70 outputs position commands for the feed movement of the tool holder 20, on which tool TO1 is mounted, to servo amplifiers 31 and 32. Servo amplifier 31 receives X-axis position commands from the NC device 70, corrects the position commands based on position feedback from the encoder 35 of the servo motor 33, and outputs torque commands to the servo motor 33. Thus, the NC device 70 controls the position of the tool holder 20 during feed movement along the X-axis. The NC device 70 can also be said to control the position of the tool TO1 during feed movement along the X-axis. Furthermore, the servo amplifier 32 receives Y-axis position commands from the NC device 70, corrects the position commands based on position feedback from the encoder 36 of the servo motor 34, and outputs torque commands to the servo motor 34. Thus, the NC device 70 controls the position of the tool holder 20 during feed movement along the Y-axis. The NC device 70 can also be said to control the position of the tool TO1 during feed movement along the Y-axis.

[0068] Although not shown, the spindle drive unit 14 also includes a servo amplifier and a servo motor. The front spindle drive unit 14A moves the front spindle 10A in the Z-axis direction via a feed mechanism and guide (not shown), and the rear spindle drive unit 14B moves the rear spindle 10B in the Z-axis direction via a feed mechanism and guide (not shown).

[0069] If the tool TO1 mounted on the tool holder 20 cuts the workpiece W1, chips, also known as shredded chips, will be generated. If the feed drive unit U2 prevents the tool TO1 from vibrating along the feed axis F1 and cuts into the workpiece W1, which is rotating around the spindle centerline AX1, continuous long chips will be generated. These continuous long chips may affect the machining of the workpiece W1 by wrapping around the tool TO1, etc. Therefore, if... Figure 3As illustrated, when cutting workpiece W1, chips are broken by vibratory cutting that repeatedly feeds the tool TO1 forward or backward along the feed axis F1. The chip breaking condition varies depending on the phase of the spindle 11, the amplitude of the vibration, the feed rate during the forward movement, and the feed rate during the backward movement.

[0070] Figure 3 The schematic example illustrates the tool position relative to the spindle rotation angle when the chip length coefficient A1 is 2, which is related to the first parameter of the vibration period. The chip length coefficient A1 refers to the rotational speed of the spindle 11 (front spindle 11A or back spindle 11B) required for one vibration cycle, also known as the number of spindle rotations required for one tool idle vibration. Tool idle vibration refers to cutting the workpiece W1 without the vibration of the tool TO1. Hereinafter, tool idle vibration will be simply referred to as idle vibration. The spindle rotation angle is the rotation angle of the spindle 11 with the rotation angle of the tool TO1 set to 0° when it is in the current position P1. The tool position is the control position of the tool TO1 with its position set to 0 when it is in the current position P1 in the cutting direction (feed axis F1). The straight line drawn from the current position P1 to the endpoint P2 represents the tool position 201 during normal cutting without vibration. The solid curve drawn from the current position P1 to the endpoint P2 represents the tool position 202 during vibration cutting. Figure 3 The lower part is an enlarged view showing the amount of one vibration cycle of the tool position relative to the spindle rotation angle.

[0071] because Figure 3 The tool position shown is the control position of the NC device 70. Therefore, the actual tool position will be offset from the position shown due to the response delay of the servo system, etc. Figures 4-8 The tool locations shown are also the same. Additionally, Figure 3 The specific values ​​shown are just examples.

[0072] Figure 3 The vibrations shown refer to the alternating forward movement M1 of tool TO1 moving towards workpiece W1 in the cutting direction, and the reverse movement M2, which is in the opposite direction to the forward movement M1. When cutting workpiece W1, the NC device 70 controls the feed movement of tool TO1 with vibrations accompanying the forward movement M1 and the reverse movement M2. The curve of the tool position relative to the spindle rotation angle includes a first change point C1 from the forward movement M1 to the reverse movement M2, and a second change point C2 from the reverse movement M2 to the forward movement M1. Figure 3 The example shown illustrates the waveform of the overlapping triangular wave vibration during normal cutting feed, as a waveform of the tool position relative to the spindle rotation angle.

[0073] exist Figure 3In this diagram, the normal cutting feed rate F is the feed rate of tool TO1 during normal cutting, not vibratory cutting; that is, the feed rate of tool TO1 when it is not vibrating. The unit of the normal cutting feed rate F is, for example, mm / rev, which represents millimeters per spindle rotation. The chip length coefficient A1 is the spindle speed required for one cycle of vibration of tool TO1, also known as the vibration cycle represented by the spindle speed of spindle 11. The unit of the chip length coefficient A1 is, for example, rev. The chip length coefficient A1 is a positive value except for 1 rev. The advance distance D is the distance the tool TO1 changes position in each cycle of vibration, representing the relative endpoint position of each advance action M1 (the position of the first change point C1). The unit of the advance distance D is, for example, mm. The retraction distance E1 is the distance of the retraction action M2 in one cycle of vibration of tool TO1, representing the relative endpoint position of each retraction action M2 (the position of the second change point C2). The unit of the retraction distance E1 is, for example, mm. During one cycle of the vibration of tool TO1, the distance traveled by tool TO1 during the forward motion is D+E1. In this specific example, when A1>1, during one cycle of vibration, tool TO1 is first controlled by a forward motion M1 with a distance of (D+E1) / 2, then controlled by a backward motion M2 with a backward amount of E1, and finally controlled by a forward motion M1 with a distance of (D+E1) / 2.

[0074] To control the position of tool TO1 during vibratory cutting, the speed of tool TO1 during its forward movement (denoted as the feed rate Fd) and the speed of tool TO1 during its backward movement (denoted as the feed rate B) are required. Therefore, a vibratory feed command specifying speeds Fd and B can be considered, for example, Figure 12 The illustrated vibration feed command CM2 serves as the command for machining program PR2. Here, it is assumed that the vibration feed command has the format "G***X(U)_Y(V)_Z(W)_D**_F**_E**_B**_J**". The "***" after G indicates the sequence number of the vibration feed command, "X(U)_Y(V)_Z(W)" indicates the position of the endpoint P2, the "**" after D indicates the value of the forward movement D, the "**" after F indicates the value of the feed rate Fd for the forward movement, the "**" after E indicates the value of the backward movement E1, the "**" after B indicates the value of the feed rate B for the backward movement, and the "**" after J indicates the idle time at the backward position (in...). Figure 12 (The middle is the stop).

[0075] In the above vibration feed command, at least several parameters such as the forward amount D, the feed speed Fd of the forward movement, the backward amount E1, and the feed speed B of the backward movement need to be adjusted through trial and error to set the vibration conditions.

[0076] In this specific example, the control of vibration cutting is achieved through trial and error by setting parameters such as "normal cutting feed rate F", "chip length coefficient A1", and "retraction amount E1" without the need for forward movement feed rate Fd or backward movement feed rate B. The control of vibration cutting in this specific example will be explained in detail below.

[0077] Figure 3 This refers to an example where, if A1 > 1, specifically A1 = 2, the first change point C1 and the second change point C2 are set within one cycle of the oscillation. Figure 4 This illustrative example illustrates the tool position relative to the spindle phase when A1 = 2. For ease of understanding, in... Figure 4 The position of the tool in the even-numbered cycle is indicated by a dashed line.

[0078] To reduce the load applied to the feed mechanism or guide, it is preferable to minimize the speed Fd, B, forward distance D, or backward distance E1. The most effective air vibration is achieved when the peak value (first change point C1) and valley value (second change point C2) of the tool TO1's movement path coincide on the phase of the spindle 11. To make the peak and valley values ​​coincide, for example, the peak value can be set at a spindle rotation angle of -180° and the valley value at a spindle rotation angle of +180°, starting from the middle of one vibration cycle (A1 / 2). When A1 = 2, if the peak value is set at a spindle rotation angle of (2 / 2) × 360 - 180 = 180° and the valley value is set at a spindle rotation angle of (2 / 2) × 360 + 180 = 540°, then... Figure 4 As shown, the principal axis phases of the peak and trough values ​​are aligned. Since the difference in principal axis rotation angles between the peak and trough values ​​is 360°, and the backward movement E1 is greater than 0, the trough value (second change point C2) in the next even-numbered cycle is positioned slightly backward from the peak value (first change point C1) in the odd-numbered cycle. This breaks the chip. Furthermore, because the tool position change during the forward motion is fixed, the chip is effectively broken.

[0079] Figure 5 The illustration shows the tool position relative to the spindle rotation angle when A1 = 3. With A1 = 3, if a peak value (first change point C1) is set at a spindle rotation angle of (3 / 2) × 360 - 180 = 360°, and a valley value (second change point C2) is set at a spindle rotation angle of (3 / 2) × 360 + 180 = 720°, then the spindle phase of the peak and valley values ​​is aligned. This effectively breaks up the chips.

[0080] When the "chip length coefficient A1" is greater than 1, it is not limited to an integer. The peak and valley values ​​can also be set in the same way when A1>3, 2<A1<3, or 1<A1<2. However, since the feed rate Fd of the forward motion is sometimes too large when 1<A1<2, it is preferable that A1 is 2 or more.

[0081] Although not illustrated, the valley value (second change point C2) can be set at the spindle rotation angle at the midpoint (A1 / 2) of one cycle of vibration, and the peak value (first change point C1) can be set at the spindle rotation angle at -180°.

[0082] Based on the above, when A1>1, the NC device 70 controls the difference between the first change point C1 (where the vibration changes from forward motion M1 to backward motion M2 within one cycle) and the second change point C2 (where the vibration changes from backward motion M2 to forward motion M1 within one cycle) of the main shaft rotation angle to be 360°.

[0083] Additionally, if A1 > 2, then the valley or peak value can be set at a spindle rotation angle of -360° and a peak or valley value at a spindle rotation angle of +360°, starting from the midpoint of one vibration cycle (A1 / 2). If A1 > 3, then the valley or peak value can be set at a spindle rotation angle of -540° and a peak or valley value at a spindle rotation angle of +540°, starting from the midpoint of one vibration cycle (A1 / 2). To reduce the number of spindle rotations required for powder cutting and to cut the powder finer, the most effective method is to set the peak or valley value at a spindle rotation angle of -180° and a valley or peak value at a spindle rotation angle of +180°, starting from the midpoint of one vibration cycle (A1 / 2).

[0084] The NC device 70 controls the tool TO1 to move in the cutting direction (feed axis F1) without changing the feed rate from the normal cutting command speed. This can be achieved by ensuring that the total movement of tool TO1 per spindle rotation is the same as the normal cutting feed rate F. Since the chip length coefficient A1 is the spindle speed 11 required for one cycle of tool TO1 vibration, the movement of tool TO1 in the cutting direction per cycle of vibration is A1 × F. Figure 3 , 5 As shown, in tool TO1, during one vibration cycle, the forward movement M1 with a distance of (D+E1) / 2, the backward movement M2 with a distance of E1, and the forward movement M1 with a distance of (D+E1) / 2 are controlled sequentially. Therefore,

[0085] A1×F={(D+E1) / 2}×2-E1

[0086] This is true. According to the given formula, the forward amount D is expressed by the following formula.

[0087] D=A1×F…(1)

[0088] The feed rate Fd of the forward motion of tool TO1 is expressed by the following formula.

[0089] Fd={(D+E1) / 2} / {(A1-1) / 2}

[0090] =(D+E1) / (A1-1)

[0091] =(A1×F+E1) / (A1-1)…(2)

[0092] In addition, the feed rate Fd of the forward motion is the maximum feed rate of tool TO1 (set as Fmax).

[0093] The feed rate B of the backward motion of tool TO1 is expressed by the following formula.

[0094] B = E1 / 1

[0095] =E1…(3)

[0096] Based on the above, if the NC device 70 receives inputs of "normal cutting feed rate F", "chip length coefficient A1", and "retraction amount E1" in the cutting direction (feed axis F1) when A1>1, then it can determine the advance amount D and speeds Fd and B according to the aforementioned equations (1), (2), and (3). After determining the advance amount D and speeds Fd and B, the NC device 70 can control the position of the tool TO1 during feed movement based on the advance amount D and speeds Fd and B in the cutting direction. Therefore, it is possible to consider a vibration feed command specifying "normal cutting feed rate F", "chip length coefficient A1", and "retraction amount E1", for example, Figure 9 The illustrated vibration feed command CM1 serves as the instruction for machining program PR2. Here, it is assumed that the vibration feed command has the format "G***X(U)_Y(V)_Z(W)_A**_F**_E**". The "***" after G indicates the sequence number of the vibration feed command, "X(U)_Y(V)_Z(W)" indicates the position of the endpoint P2, the "**" after A indicates the value of the chip length coefficient A1, and the "**" after F indicates the normal cutting feed rate F (in...). Figure 9 The value of E is the feed rate up to the endpoint, and the "**" after E indicates the value of the backlash amount E1.

[0097] Figure 6The illustration schematically shows how the NC device 70 controls the position of the tool TO1 during feed movement based on the forward feed amount D and speeds Fd and B obtained from the vibration feed command CM1. Based on the forward feed amount D and speeds Fd and B, the NC device 70 sets multiple positions P3 along the cutting direction (feed axis F1) from the current position P1, repeating the forward movement M1 and the backward movement M2 until reaching the endpoint P2, and sequentially outputs position commands to move the tool TO1 to position P3 to the servo amplifier 31 or servo amplifier 32. Figure 6 Each position P3 is represented by a white circle. The set position P3 is not limited to the change point (the first change point C1 and the second change point C2) or the end point P2, but may also include the position in the middle of the forward movement M1 or the backward movement M2. By repeating the position command, the position of the tool TO1 during feed movement is controlled based on the forward amount D and the speeds Fd and B.

[0098] Based on the above, by specifying the "normal cutting feed rate F," "chip length coefficient A1," and "retraction amount E1" in the machining program PR2, the operator can perform vibratory cutting with the same machining time as normal cutting. Here, if the "chip length coefficient A1" is increased, the chip becomes longer; on the other hand, the amplitude decreases. The preferred values ​​of the "chip length coefficient A1" and "retraction amount E1" depend on the tracking performance of the servo system that moves the tool TO1, and are determined by the spindle speed per unit time and the feed rate of the tool TO1. Therefore, as... Figure 10 As illustrated, for the combination of "chip length coefficient A1" and "retraction amount E1", target values ​​corresponding to "spindle speed S per unit time" and "normal cutting feed rate F" are prepared in advance as information table TA1. This allows the operator to easily specify the "chip length coefficient A1" and "retraction amount E1". For example... Figure 10 As shown, in information table TA1, multiple combinations of A1 and E1 are associated with various combinations of S and F. If the identification sequence number for the combination identifying A1 and E1 is set to j, then... Figure 10 For example, we can establish a correspondence between multiple combinations represented by A1=a1j and E1=e1j and combinations represented by S=S1 and F=F1. Figure 10 The information table TA1 shown can also be called an information table that outputs multiple recommended combinations of "chip length coefficient A1" and "retraction amount E1" for the inputs of "spindle speed S per unit time" and "normal cutting feed rate F". Of course, the number of combinations of A1 and E1 is limited.

[0099] Therefore, after determining the "spindle speed S per unit time" and the "normal cutting feed rate F", you can select the combination of "chip length coefficient A1" and "retraction amount E1" from information table TA1. See details for reference. Figure 9As will be described later, however, by pre-storing the information table TA1 in the RAM 73 of the NC device 70, the NC device 70 can prompt recommended values ​​for the "chip length coefficient A1" and "retraction amount E1" based on the "spindle speed S per unit time" and the "normal cutting feed rate F".

[0100] Figure 7 This illustration shows the tool position relative to the spindle rotation angle when the chip length coefficient A1 is 2 / 3. In this specific example, when 0 < A1 < 1, during one cycle of vibration, the tool TO1 is controlled by a forward movement M1 of distance (D+E1) in the first half and a backward movement M2 of amount E1 in the second half. Figure 8 The schematic illustration shows the tool position relative to the spindle phase when A1 = 2 / 3.

[0101] When 0 < A1 < 1, to effectively achieve air vibration, the "chip length coefficient A1" is limited by A1 = 2 / 3, 2 / 5, 2 / 7, ..., i.e., an odd number with a denominator of 3 or more and a numerator of 2. To ensure that the peak value (first change point C1) and the valley value (second change point C2) are consistent in the phase of the spindle 11, for example, the peak value can be set at the spindle rotation angle in the middle (A1 / 2) of one vibration cycle, and the valley value can be set at the spindle rotation angle at the end (A1) of one vibration cycle. When A1 = 2 / 3, if the peak value is set at a spindle rotation angle of (2 / 3) / 2 × 360 = 120° and the valley value is set at a spindle rotation angle of (2 / 3) × 360 = 240°, then... Figure 8 As shown, the principal axis phases of the peak and trough values ​​are consistent. The principal axis phases of the peak and trough values ​​are 120°, 240°, and 360°.

[0102] When A1 = 2 / 5, if the peak value is set at a spindle rotation angle of (2 / 5) / 2 × 360 = 72° and the valley value is set at a spindle rotation angle of (2 / 5) × 360 = 144°, then the spindle phase of the peak and valley values ​​will be consistent. The spindle phases of the peak and valley values ​​that are consistent are 72°, 144°, 216°, 288°, and 360°.

[0103] The "chip length coefficient A1" can be 2 / 7 or less. However, when A1 < 2 / 3, based on the servo system's ability to follow control, it is sometimes necessary to set the feed rate of tool TO1 or the spindle speed 11 per unit time to be very low, so A1 is preferably 2 / 3.

[0104] Although not illustrated, the valley value can be set at the spindle rotation angle in the middle (A1 / 2) of one vibration cycle, and the peak value can be set at the spindle rotation angle at the end (A1) of one vibration cycle.

[0105] Based on the above, when the denominator of the "chip length coefficient A1" is an odd number of 3 or more and the numerator of the "chip length coefficient A1" is 2, the NC device 70 will control the difference between the first change point C1, which changes from forward action M1 to backward action M2 within one cycle of vibration, and the second change point C2, which changes from backward action M2 to forward action M1 within one cycle of vibration, to be {(A1 / 2)×360}°.

[0106] The NC device 70 controls the tool TO1 in the cutting direction (feed axis F1) to move without changing its feed rate from the normal cutting command speed. This can be achieved by controlling the movement of tool TO1 per revolution of the spindle to be the same as the normal cutting feed rate F. As described above, the movement of tool TO1 in the cutting direction per cycle of vibration is A1 × F. Figure 7 , 8 As shown, for tool TO1, during one vibration cycle, the forward movement M1 (distance (D+E1)) and the backward movement M2 (reverse movement E1) are controlled sequentially. Therefore,

[0107] A1×F=(D+E1)-E1

[0108] This is true. According to the given formula, the forward amount D is expressed by the following formula.

[0109] D=A1×F…(4)

[0110] The feed rate Fd of the forward motion of tool TO1 is expressed by the following formula.

[0111] Fd=(D+E1) / (A1 / 2)

[0112] =2(D+E1) / A1

[0113] =2(A1×F+E1) / A1…(5)

[0114] Here, the feed rate Fd of the forward motion is also the maximum feed rate Fmax of tool TO1.

[0115] The feed rate B of the backward motion of tool TO1 is expressed by the following formula.

[0116] B = E1 / (A1 / 2)

[0117] =2E1 / A1…(6)

[0118] Based on the above, if the NC device 70 receives inputs of the "normal cutting feed rate F", "chip length coefficient A1", and "retraction amount E1" in the cutting direction (feed axis F1) when A1 < 1, then it can determine the feed amount D and speeds Fd and B according to the formulas (4), (5), and (6). After determining the feed amount D and speeds Fd and B, the NC device 70 can control the position of the tool TO1 during feed movement based on the feed amount D and speeds Fd and B in the cutting direction. Figure 6 As shown, the NC device 70, based on the feed amount D and speeds Fd and B, sets multiple positions P3 along the cutting direction, repeating the forward motion M1 and the backward motion M2 from the current position P1 until reaching the endpoint P2. It then sequentially outputs position commands to move the tool TO1 to position P3 to either the servo amplifier 31 or the servo amplifier 32. By repeating these position commands, the position of the tool TO1 during feed movement is controlled based on the feed amount D and speeds Fd and B.

[0119] Furthermore, to prevent chipping or welding of the tool TO1, the feed rate of the tool TO1 is one of the important cutting conditions when selecting the tool TO1. The feed rate is a target value provided by the tool manufacturer and varies depending on the material of the workpiece, the material of the tool, and its type. Since the NC device 70 executing the vibration feed command CM1 sets the machining time for vibration cutting to be the same as that for normal cutting, and automatically calculates the feed amount D and speeds Fd and B from the parameters F, A1, and E1, the calculated feed rate Fd for the forward movement is greater than the normal cutting feed rate F. Because the operator does not know the maximum feed rate Fmax, which is the feed rate Fd for the forward movement, it is impossible to properly select the tool TO1 and set the parameters for vibration cutting appropriately.

[0120] Therefore, in this specific example, to support the creation of the vibration feed command CM1, the value of the maximum feed speed Fmax, which corresponds to the parameters F, A1, and E1, is displayed on the display unit 82 (see reference). Figure 2 This simplifies tool selection and parameter settings for F, A1, and E1.

[0121] Figure 9 The diagram illustrates the setting screen for the vibration feed command CM1. When the NC device 70 receives an instruction from the input unit 81 (not shown) to display a screen 501 showing support for creating the vibration feed command CM1, it proceeds to... Figure 9 The screen 501 shown is processed by the display unit 82.

[0122] Figure 9The screen 501 shown includes a spindle speed input bar 511, a travel distance input bar 512, a feed rate input bar to the endpoint 513, a chip length coefficient input bar 514, a back travel input bar 515, a command input bar 516, a format switching button 521, an Fmax value prediction button 522, a break check button 523, a command copy button 524, a recommended value setting button 525, and a vibration waveform display bar 530, etc.

[0123] The spindle speed input field 511 allows you to input "spindle speed per unit time S". The unit for "spindle speed per unit time S" is, for example, rev / min. The travel distance input field 512 allows you to input the total distance "travel distance W" that the tool TO1 travels along the cutting direction (feed axis F1) from the start position to the end position during the execution of the vibration feed command CM1. The unit for "travel distance W" is, for example, mm. Note that "travel distance W" is different from the W in the endpoint "X(U)_Y(V)_Z(W)" included in the vibration feed command CM1. The feed rate input field 513 allows you to input "normal cutting feed rate F". The unit for "normal cutting feed rate F" is, for example, mm / rev. The chip length coefficient input field 514 allows you to input "chip length coefficient A1". The unit for "chip length coefficient A1" is, for example, rev. Additionally, in... Figure 9 This is represented as "chip length coefficient A". Figure 11 Similarly, the retraction amount input field 515 allows you to input "retraction amount E1". The unit for "retraction amount E1" is, for example, mm. Additionally, in... Figure 9 This is represented as "backward amount E". Figure 11 , 12 The same applies.

[0124] The operator can use the recommended value setting button 525 to display the recommended value of "Chip Length Coefficient A1" in the chip length coefficient input field 514 and the recommended value of "Retraction Amount E1" in the retraction amount input field 515. To display the recommended values, the operator will... Figure 10 The information table TA1 shown is stored in RAM 73, and the NC device 70 performs the following processing.

[0125] When the NC device 70 receives an operation from the recommended value setting button 525 in the input section 81, it displays one of the combinations of "chip length coefficient A1" and "retraction amount E1" corresponding to the combination of "spindle speed S per unit time" input into the spindle speed input field 511 and "normal cutting feed rate F" input into the feed rate input field 513 in the chip length coefficient input field 514 and the retraction amount input field 515. If there are multiple combinations of A1 and E1 corresponding to S and F in the information table TA1, the NC device 70 can switch the combination of A1 and E1 and display it in the chip length coefficient input field 514 and the retraction amount input field 515 each time the recommended value setting button 525 is received. Of course, the NC device 70 can accept changes to the "chip length coefficient A1" when the recommended value of "chip length coefficient A1" is displayed in the chip length coefficient input field 514, and can accept changes to the "retraction amount E1" when the recommended value of "retraction amount E1" is displayed in the retraction amount input field 515.

[0126] With values ​​already entered in the input fields (511-515), the operator can display the maximum feed rate Fmax and cutting time (denoted as CT) corresponding to the parameters F, A1, and E1 by operating the Fmax value prediction button 522. The unit of the maximum feed rate Fmax is, for example, mm / rev. The cutting time CT is the time from the current position P1 to the endpoint P2 (reference) according to the vibration feed command CM1. Figure 3 The time taken for the tool TO1 to feed and move while accompanied by vibration. The cutting time CT is in minutes, assuming the spindle speed S is in rev / min.

[0127] When the NC device 70 receives the operation of the Fmax value prediction button 522 in the input section 81, it first calculates the "maximum feed rate Fmax" of the tool TO1 based on the "normal cutting feed rate F", "chip length coefficient A1" and "retraction amount E1" in the cutting direction (feed axis F1).

[0128] When A1>1, the feed rate Fd of the forward motion is obtained from the parameters F, A1, and E1, as stated in equation (2), and the maximum feed rate Fmax is expressed by the following equation.

[0129] F max=(A1×F+E1) / (A1-1)…(7)

[0130] When A1 < 1, the feed rate Fd of the forward motion is obtained from the parameters F, A1, and E1, and the following formula represents the maximum feed rate Fmax.

[0131] F max=2(A1×F+E1) / A1…(8)

[0132] In addition, the NC device 70 calculates the "cutting time CT" of the vibration feed command CM1 based on the "spindle speed S per unit time", "travel distance W" and "normal cutting feed rate F" in the cutting direction. The "cutting time CT" is expressed by the following formula.

[0133] CT=W / (F×S)…(9)

[0134] After calculating the maximum feed rate Fmax according to equation (7) or equation (8) and the cutting time CT according to equation (9), the NC device 70 displays the prediction result as a prediction. Figure 9 The screen shown is 501. The NC device 70 displays, for example, the maximum feed rate Fmax in mm / rev and the cutting time CT in minutes and seconds.

[0135] Through the above, the unknown values ​​representing the maximum feed rate Fmax and cutting time CT from the input fields (511-515) are displayed on the display unit 82. The operator can easily determine whether the vibration feed command CM1 matches the desired cutting time CT by browsing the value of the cutting time CT. Furthermore, the operator can easily select the tool TO1 for vibration cutting by browsing the value of the maximum feed rate Fmax, and can easily set the parameters for vibration cutting.

[0136] In addition, the NC device 70 displays the vibration waveform of the tool position relative to the spindle phase in the vibration waveform display bar 530 based on the parameters F, A1, and E1. The overlapping areas of the vibration waveforms at different spindle rotation angles are the chip breaking regions.

[0137] The operator can input the vibration feed command CM1 into the command input field 516 by pressing the command copy button 524. When the NC device 70 receives the operation of the command copy button 524 in the input section 81, it generates the vibration feed command CM1 based on the parameters F, A1, and E1, and displays it in the command input field 516. In addition, the NC device 70 processes the input vibration feed command CM1 into the machining program PR2.

[0138] Consideration is given to situations where the operator, after viewing the displayed maximum feed rate Fmax, intends to adjust it based on the cutting conditions of tool TO1. For example, if the maximum feed rate Fmax exceeds the upper limit of the handheld tool TO1's feed rate, it is considered to slow down the maximum feed rate Fmax to match the upper limit of tool TO1's feed rate. Additionally, if the operator wishes to improve the lifespan of tool TO1 or increase the surface roughness of workpiece W1, it is also considered to slow down the maximum feed rate Fmax. When the maximum feed rate Fmax decreases, the cutting time CT is delayed. Conversely, if the maximum feed rate Fmax is slower than the upper limit of tool TO1's feed rate, it is also considered to shorten the cutting time CT by increasing the maximum feed rate Fmax within the upper limit of tool TO1's feed rate.

[0139] In addition, there is consideration for situations where the operator wants to know the extent to which the cutting time CT changes due to a change in the maximum feed rate Fmax.

[0140] Therefore, in this specific example, by changing the value of the maximum feed rate Fmax displayed on screen 502 (reference)... Figure 11 The maximum feed rate Fmax is displayed on the display unit 82, making it easier to change.

[0141] Figure 11 Screen 502 schematically illustrates the processing of changes to the maximum feed rate Fmax. For example, the NC device 70 receives a change in the input unit 81. Figure 9 In screen 501 shown, a dialog box (not shown) appears along with the prediction results, asking "Do you want to change the maximum feed rate Fmax?". When switching screens, you can... Figure 11 The screen 502 shown is displayed on the display unit 82. Additionally, the NC device 70 can receive data set in the input unit 81. Figure 9 In the case of operating the screen switching button (not shown) on screen 501, [the following will occur] Figure 11 The image 502 shown is displayed on the display unit 82.

[0142] Figure 11 The image shown is replaced by 502. Figure 9 The feed rate input field 513, shown to the endpoint, has a maximum feed rate input field 517, and instead of the Fmax value prediction button 522, it has an F value prediction button 526. The NC device 70 displays the following information in the spindle speed input field 511, travel distance input field 512, chip length coefficient input field 514, and retraction amount input field 515: Figure 9The value entered in screen 501 is shown. Since the recommended value is not displayed in the chip length coefficient input field 514 and the backlash input field 515, there is no recommended value setting button 525 in screen 502. The NC device 70 displays the maximum feed rate input field 517. Figure 9 The maximum feed rate Fmax is displayed, and the operation to change the maximum feed rate Fmax is processed in the input unit 81. Therefore, the operator can change the maximum feed rate Fmax with the help of tools such as TO1.

[0143] With values ​​already entered in the input fields (511, 512, 517, 514, 515), the operator can use the F-value prediction button 526 to display the values ​​of the normal cutting feed rate F and cutting time CT corresponding to the parameters Fmax, A1, and E1.

[0144] When the NC device 70 receives the operation of the F value prediction button 526 in the input section 81, it first calculates the "normal cutting feed rate F" of the tool TO1 based on the "maximum feed rate Fmax", "chip length coefficient A1" and "retraction amount E1" in the cutting direction (feed axis F1).

[0145] When A1>1, the normal cutting feed rate F is expressed by the following formula according to the above formula (7).

[0146] F={Fmax×(A1-1)-E1} / A1…(1O)

[0147] When A1 < 1, the normal cutting feed rate F is expressed by the following formula according to the above formula (8).

[0148] F=(Fmax / 2)-(E1 / A1)…(11)

[0149] In addition, the NC device 70 calculates the "cutting time CT" of the vibration feed command CM1 based on the "spindle speed S per unit time", "travel distance W" in the cutting direction, and the modified "normal cutting feed rate F". The "cutting time CT" is expressed by the following formula.

[0150] CT=W / (F×S)…(12)

[0151] The revised "normal cutting feed rate F" is calculated based on the revised "maximum feed rate Fmax", "chip length coefficient A1", and "retraction amount E1". Therefore, the revised cutting time CT is calculated based on the revised "maximum feed rate Fmax", "chip length coefficient A1", and "retraction amount E1".

[0152] After calculating the normal cutting feed rate F according to equation (10) or equation (11) and the cutting time CT according to equation (12), the NC device 70 displays the prediction result as a prediction. Figure 11 The screen shown is 502. The NC device 70 displays, for example, the value of the changed normal cutting feed rate F as "feed rate F to the endpoint" in mm / rev units, and the value of the changed cutting time CT in minutes and seconds. Figure 9 , 11 In the example shown, the maximum feed rate Fmax is changed from 0.07 mm / rev to 0.05 mm / rev, resulting in the normal cutting feed rate F changing from 0.03 mm / rev to 0.02 mm / rev.

[0153] Through the above, the unknown values ​​in the input fields (511, 512, 517, 514, 515) representing the normal cutting feed rate F and cutting time CT are displayed on the display unit 82. The operator can change the maximum feed rate Fmax with the tool TO1, and can confirm the normal cutting feed rate F. In addition, the operator can view the value of the changed cutting time CT to confirm the cutting time CT required for the feed movement of the vibrating tool TO1 at the changed maximum feed rate Fmax.

[0154] The operator can input the vibration feed command CM1 into the command input field 516 by pressing the command copy button 524. When the NC device 70 receives the operation of the command copy button 524 in the input section 81, it generates the vibration feed command CM1 based on the modified "normal cutting feed rate F", the "chip length coefficient A1" input into the chip length coefficient input field 514, and the "retraction amount E1" input into the retraction amount input field 515, and displays it in the command input field 516. In addition, the NC device 70 processes the input vibration feed command CM1 into the machining program PR2.

[0155] In addition, the NC device 70 receives the input in the input section 81. Figure 11 In screen 502 shown, a dialog box (not shown) appears along with the prediction results, asking "Do you want to change the normal cutting feed rate F?". When switching screens, you can... Figure 9 The screen 501 shown is displayed on the display unit 82. Additionally, the NC device 70 can receive data set in the input unit 81. Figure 11 In the case of operating the screen switching button (not shown) in screen 502, [the following will occur] Figure 9 The image 501 shown is displayed on the display unit 82.

[0156] exist Figure 9, 11 In the screens 501 and 502 shown, the operator can create an operation format switching function using the operation format switching button 521. Figure 12 The illustrated vibration feed command is CM2. Figure 12 The schematic illustration shows the setting screen for the vibration feed command CM2. The NC device 70 receives the command in the input section 81. Figure 9 , 11 When the format switching button 521 shown is operated, the format switching button will be used to switch the format to the desired format. Figure 12 The screen 503 shown is processed by the display unit 82.

[0157] Figure 12 The screen 503 shown includes a spindle speed input bar 511, a travel distance input bar 512, a forward feed input bar 541, a feed rate input bar 542 for forward movement, a retraction input bar 515, a feed rate input bar 543 for retraction movement, a standby time input bar 544 for retraction position, a command input bar 516, a format switching button 521, a cutting time prediction button 527, a break-out check button 523, a command copy button 524, and a vibration waveform display bar 530, etc.

[0158] In the feed amount input field 541, you can input "feed amount D". The unit of "feed amount D" is, for example, mm. In the feed rate input field 542, you can input the maximum feed rate Fmax, which is also called "feed rate Fd". The unit of "feed rate Fd" is, for example, mm / rev. Additionally, Figure 12 The "F" shown indicates the maximum feed rate Fmax, which is the "feed rate Fd of the forward motion," not... Figure 9 , 11 The input field 543 shows the "feed rate F up to the endpoint". In the feed rate input field 543 for the reverse motion, you can input the "feed rate B for the reverse motion". The unit for the "feed rate B for the reverse motion" is, for example, mm / rev. In the idle time input field 544 at the reverse position, you can input the "idle time J at the reverse position" (in...). Figure 12 The middle position represents the dwell time (J) at the reverse position. The unit for "standby time (J) at the reverse position" is, for example, min.

[0159] With values ​​already entered in the input fields (511, 512, 515, 541-544) described later, the operator can display the cutting time CT value, which represents the feed movement of the tool TO1 accompanied by vibration from the current position to the endpoint according to the vibration feed command CM2, by operating the cutting time prediction button 527.

[0160] When the NC device 70 receives the operation of the cutting time prediction button 527 in the input unit 81, it calculates the "cutting time CT" of the vibration feed command CM2 based on the "spindle speed S per unit time", "travel distance W", "forward amount D", "feed speed Fd for forward movement", "reverse amount E1", "feed speed B for reverse movement", and "standby time J for reverse position" in the cutting direction (feed axis F1). The "cutting time CT" is expressed by the following formula.

[0161] [Number 1]

[0162]

[0163] After the NC device 70 calculates the cutting time CT according to the above formula (13), in Figure 12 The image shown in 503 displays the value of the cutting time CT as a prediction result.

[0164] Through the above, the unknown value representing the cutting time CT from the input fields (511, 512, 515, 541-544) is displayed on the display unit 82. The operator can easily determine whether the vibration feed command CM2 is the desired cutting time CT by browsing the value representing the cutting time CT.

[0165] Since the vibration feed command CM2 requires the operator to set the parameters D, Fd, E1, B, and J, it is unknown whether these parameters meet the conditions for chip breaking. Therefore, the operator can confirm whether the parameters D, Fd, E1, B, and J meet the conditions for chip breaking by operating the chip breaking check button 523.

[0166] For example, when the NC device 70 receives an operation of the chip breaking check button 523 in the input section 81, it can display the vibration waveform of the tool position relative to the spindle phase in the vibration waveform display bar 530 based on the parameters D, Fd, E1, B, and J. The NC device 70 can display the chip breaking area in the vibration waveform display bar 530 when there are overlapping vibration waveforms at different spindle rotation angles. The operator can check the chip breaking area to confirm that the parameters D, Fd, E1, B, and J meet the conditions for chip breaking. If the chip breaking area is not displayed, the operator can confirm that the parameters D, Fd, E1, B, and J do not meet the conditions for chip breaking.

[0167] In addition, the NC device 70 receives data in the input section 81. Figure 12 When the format switching button 521 shown is operated, the format switching button will be used to switch the format to the desired format. Figure 9 The screen 501 shown is processed by the display unit 82.

[0168] As explained above, the maximum feed rate (Fmax), which is not present in the vibration feed command CM1 with parameters F, A1, and E1, is displayed on screen 501 (reference). Figure 9 Therefore, the operator can easily select the tool TO1 for vibratory cutting and easily set the parameters for vibratory cutting. Furthermore, the operator can change the maximum feed rate Fmax when desired (see reference). Figure 11 This allows confirmation of the changed normal cutting feed rate F and cutting time CT. Furthermore, since the value representing the cutting time CT, which is difficult to understand from the vibration feed command CM2 with parameters D, Fd, E1, B, and J, is displayed on screen 503 (reference). Figure 12 Therefore, the operator can also confirm the cutting time CT in the vibration feed command CM2.

[0169] (3) Example of variation:

[0170] This invention considers various variations.

[0171] For example, the driving object moving along the cutting direction is not limited to tool TO1; it can also be the spindle 11 that holds the workpiece W1, or both tool TO1 and spindle 11. When the driving object is spindle 11, the NC device 70 only needs to control the feed movement of spindle 11 by vibrating along the cutting direction while cutting the workpiece W1. When the driving objects are both tool TO1 and spindle 11, the NC device 70 only needs to control the feed movement of both tool TO1 and spindle 11 by vibrating along the cutting direction while cutting the workpiece W1.

[0172] The vibration cutting condition setting device can also be set in computer 100 (reference). Figure 1 Instead of a machine tool. In this case, the display device 106 is an example of the display unit U3, and the CPU 101, ROM 102, RAM 103, storage device 104, and input device 105 are examples of the control unit U4. The computer 100, which includes the vibration cutting condition setting device 3, can be connected to the machine tool 1, but it can also be in a state where it is not connected to the machine tool 1.

[0173] Showing Figure 9 The value of the changed "maximum feed rate Fmax" shown in screen 501 can be the ratio (including percentage) of "maximum feed rate FmaxF" to "normal cutting feed rate F", or the difference between "normal cutting feed rate F" and "maximum feed rate FmaxF". In this case, the operator can relatively control the "maximum feed rate Fmax".

[0174] Showing Figure 11The value of the changed "normal cutting feed rate F" shown in screen 502 can be the ratio (including percentage) of the changed "normal cutting feed rate F" to the original "normal cutting feed rate F", or the difference between the original "normal cutting feed rate F" and the changed "normal cutting feed rate F". In this case, the operator can relatively grasp the change in "normal cutting feed rate F" caused by the change in "maximum feed rate Fmax".

[0175] Showing Figure 11 The value of the changed "cutting time CT" shown in screen 502 can be the ratio (including percentage) of the changed "cutting time CT" to the original "cutting time CT", or the difference between the original "cutting time CT" and the changed "cutting time CT". In this case, the operator can relatively grasp the change in "cutting time CT" caused by the change in "maximum feed rate Fmax".

[0176] exist Figure 9 , 11 In the screens 501 and 502 shown, the NC device 70 can accept operations to change the cutting time CT. In this case, the NC device 70 can calculate the normal cutting feed rate F and the maximum feed rate Fmax based on the cutting time CT before and after the change, and display the calculated normal cutting feed rate F and maximum feed rate Fmax on screens 501 and 502. For example, if the NC device 70 receives an operation on the cutting time change button (not shown) provided on screens 501 and 502 in the input unit 81, it can accept the input of the changed cutting time (denoted as CTa) in the input unit 81.

[0177] Here, the original cutting time is set as CTb, the changed normal cutting feed rate is set as Fa, and the original normal cutting feed rate is set as Fb. The changed normal cutting feed rate Fa can be calculated using the following formula.

[0178] Fa=(CTb / CTa)×Fb…(14)

[0179] The NC device 70 can display the calculated modified normal cutting feed rate Fa on the feed rate input field 513 to the end point on screen 501 or the prediction result on screen 502.

[0180] The modified maximum feed rate (denoted as Famax) can be calculated according to the formulas (7) and (8) mentioned above, and then calculated according to the following formula.

[0181] When A1>1,

[0182] Fa max=(A1×Fa+E1) / (A1-1)…(15)

[0183] When A1 < 1,

[0184] Fa max=2(A1×Fa+E1) / A1…(16)

[0185] The NC device 70 can display the calculated modified maximum feed rate Famax on the prediction result on screen 501 or the maximum feed rate input field 517 on screen 502.

[0186] Since the operator can confirm the normal cutting feed rate F or the maximum feed rate Fmax that changes by changing the cutting time CT, it is easy to select the tool TO1 for vibratory cutting and to easily set the parameters for vibratory cutting.

[0187] Alternatively, the NC device 70 may display the changed maximum feed rate Famax on screens 501 and 502 instead of the changed normal cutting feed rate Fa, or it may display the changed maximum feed rate Famax on screens 501 and 502 instead of the changed normal cutting feed rate Fa.

[0188] like Figure 13 As illustrated, this technique can also be applied to waveforms representing tool positions relative to the spindle rotation angle, in addition to waveforms of sinusoidal vibrations superimposed on the normal cutting feed. Figure 13 Another example illustrating the tool position relative to the spindle rotation angle. Figure 13 In the diagram, the component of the normal cutting feed rate F is represented by a dashed line, and the maximum feed rate Fmax is represented by a fine dotted dashed line.

[0189] from Figure 13 The waveform shown is a sine wave with a period of A2 and an amplitude of E2 after removing the component of the normal cutting feed rate F. Therefore, the period A2 is an example of a first parameter related to the period of vibration, and the amplitude E2 is an example of a second parameter related to the amplitude of vibration. Figure 13 The slope of the sine wave shown, from the trough C4 to the midpoint C5 of the peak C3, represents the maximum feed rate Fmax. Therefore, the maximum feed rate Fmax is obtained by substituting the spindle rotation angle at the midpoint C5 into the feed rate formula derived from the formula for calculating the tool position from the spindle rotation angle.

[0190] NC device 70 (or computer 100) will only need to perform with Figure 9A screen similar to screen 501 is displayed on the display unit U3, which can handle the processing of the normal cutting feed rate F, cycle A2, and amplitude E2. The NC device 70 only needs to perform the following processing: based on the normal cutting feed rate F, cycle A2, and amplitude E2, it calculates the maximum feed rate Fmax using the calculation method, and displays the calculated value representing the maximum feed rate Fmax on the display unit U3.

[0191] As shown above, since the value of the maximum feed rate Fmax is unknown in the display settings, the operator can easily select the tool TO1 for vibratory cutting by browsing the value of the maximum feed rate Fmax, and can easily set the parameters for vibratory cutting.

[0192] In addition, the NC device 70 can be connected with Figure 11 A screen similar to screen 502 is displayed on display unit U3. Based on the changed maximum feed rate Fmax, period A2, and amplitude E2, the normal cutting feed rate F is changed by performing the inverse operation of the calculation. NC device 70 can calculate the cutting time CT according to the above formula (12) and display the changed normal cutting feed rate F and cutting time CT on display unit U3.

[0193] By doing so, since the changed normal cutting feed rate F and cutting time CT can be confirmed, setting parameters such as the normal cutting feed rate F becomes easy.

[0194] (4) Summary:

[0195] As explained above, according to the present invention, a technique can be provided that facilitates the selection of tools or the setting of parameters for vibration cutting in various aspects. Of course, even a technique that only includes the constituent elements of an independent technical solution can achieve the aforementioned basic functions and effects.

[0196] Furthermore, configurations that involve substituting or changing the combinations of the components disclosed in the examples, as well as configurations that involve substituting or changing the combinations of well-known technologies and the components disclosed in the examples, are also possible. The present invention also includes such configurations.

[0197] [Symbol Explanation]

[0198] 1. Machine Tool

[0199] 3. Vibration cutting condition setting device

[0200] 10 Spindle Table

[0201] 11 Spindle

[0202] 12. Holding Section

[0203] 13A, 13B motors

[0204] 14 Spindle Table Drive Unit

[0205] 20 Tool Tables

[0206] 31,32 Servo Amplifiers

[0207] 33, 34 Servo Motors

[0208] 35, 36 Encoders

[0209] 70 NC device

[0210] 80 Operations Department

[0211] 81 Input Section

[0212] 82 Display Section

[0213] 100 computers

[0214] 201 Tool position during normal cutting

[0215] 202 Tool position during vibration cutting

[0216] AX1 spindle centerline

[0217] C1 First point of change

[0218] C2 Second Change Point

[0219] CM1, CM2 Vibration feed commands

[0220] F1 feed axis

[0221] M1 forward motion

[0222] M2 backward motion

[0223] P1 Current position

[0224] P2 End Point

[0225] P3 position

[0226] PR1 Control Program

[0227] PR2 processing procedure

[0228] PR3 support program

[0229] TO1 Tools

[0230] U1 Rotary Drive Unit

[0231] U2 Feed Drive Unit

[0232] U3 Display Section

[0233] U4 Control Unit

[0234] W1 is the workpiece.

Claims

1. A vibration cutting condition setting device for a machine tool, the machine tool comprising: a rotary drive unit for rotating a spindle holding a workpiece, and a feed drive unit for moving a drive object that moves at least one of a tool for cutting the workpiece and the spindle; wherein, when cutting the workpiece, the feed movement of the drive object is controlled by vibration accompanying a forward movement including a forward movement of the tool moving towards the workpiece in the cutting direction and a backward movement in the opposite direction to the forward movement; and the vibration cutting condition setting device for the machine tool further comprising: Display unit; and The control unit receives the feed speed (F) of the driven object when it is not vibrating, a first parameter (A) related to the period of the vibration, and a second parameter (E) related to the amplitude of the vibration, as settings for controlling the feed movement of the driven object in a manner that accompanies the vibration; and The control unit Based on the non-vibration feed rate (F) of the driven object, the first parameter (A), and the second parameter (E), the maximum feed rate (Fmax) of the driven object is calculated; and The calculated maximum feed rate (Fmax) is displayed on the display unit; The control unit Accepts operations to change the maximum feed rate (Fmax) displayed on the display unit; Based on the modified maximum feed rate (Fmax), the first parameter (A), and the second parameter (E), the feed rate (F) of the driven object when it is not vibrating is modified; and The value of the feed rate (F) of the modified drive object when it is not vibrating is displayed on the display unit.

2. A vibration cutting condition setting device for a machine tool, the machine tool comprising: a rotary drive unit for rotating a spindle holding a workpiece, and a feed drive unit for moving a drive object that moves at least one of a tool for cutting the workpiece and the spindle; wherein, when cutting the workpiece, the feed movement of the drive object is controlled by vibration accompanying a forward movement including a forward movement of the tool moving towards the workpiece in the cutting direction and a backward movement in the opposite direction to the forward movement; and the vibration cutting condition setting device for the machine tool further comprising: Display unit; and The control unit receives the feed speed (F) of the driven object when it is not vibrating, a first parameter (A) related to the period of the vibration, and a second parameter (E) related to the amplitude of the vibration, as settings for controlling the feed movement of the driven object in a manner that accompanies the vibration; and The control unit Based on the non-vibration feed rate (F) of the driven object, the first parameter (A), and the second parameter (E), the maximum feed rate (Fmax) of the driven object is calculated; and The calculated maximum feed rate (Fmax) is displayed on the display unit; The control unit Accepts operations to change the maximum feed rate (Fmax) displayed on the display unit; Based on the modified maximum feed rate (Fmax), the first parameter (A), and the second parameter (E), the cutting time (CT) required for the feed movement of the driven object accompanied by the vibration at the modified maximum feed rate (Fmax) is calculated; and The calculated cutting time (CT) value is displayed on the display unit.

3. The vibration cutting condition setting device for a machine tool according to claim 1 or 2, wherein... The control unit The system accepts operations that modify the cutting time (CT) required for the feed movement of the driven object accompanying the vibration. Based on the modified cutting time (CT), the feed rate parameter is modified by at least one of the non-vibration feed rate (F) and the maximum feed rate (Fmax) of the driven object; and The value of the changed feed rate parameter is displayed on the display unit.

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