Numerical control device, system, control method, and program

Abstract

To provide a numerical control device, a system, a control method, and a program which, when a loading condition has been changed, automatically estimate a time constant according to the changed loading condition, and which reflect the time constant in revolving operation of a tool magazine.SOLUTION: A control part resets a value of a loading condition setting if a macro variable of a loading condition setting reset is read (S11:YES) during NC program execution, and changes (S15) a time constant of acceleration of a magazine motor to a reference time constant. A reference time constant is a time constant that allows a magazine motor to operate in cases when a loading state of a tool is a reference loading state. The control part estimates (S18) inertia and an unbalanced load of the tool magazine, on the basis of a result of conducting revolving operation using the reference time constant during NC program execution, and reflects (S20) an estimation result in the loading condition setting.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a numerical control device, a system, a control method, and a program. [Background technology]

[0002] There is known a machine tool equipped with a tool magazine for carrying tools, which calculates the inertia around the rotation axis of the tool magazine and changes the rotation speed of the tool magazine according to the calculated inertia. Patent Document 1 discloses a machine tool that allows the operating speed of the tool magazine to be adjusted by a user's operation. The machine tool can adjust the operating speed of the tool magazine to an operating speed desired by the user. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6603282 Summary of the Invention [Problem to be solved by the invention]

[0004] In the machine tool of Patent Document 1, when the loading conditions (inertia and offset load) change due to a change in tool attachment or the like, it is necessary to re-adjust the operating speed and update the inertia and offset load. Therefore, for users who operate in a way that causes the loading conditions to change frequently, it is necessary to operate the machine and make adjustments each time, which is time-consuming. If the user forgets to re-adjust, the machine tool may operate under incorrect conditions. As a result, there is a possibility that the program operation may stop due to an error caused by a deterioration in the life of the reducer or insufficient torque.

[0005] An object of the present invention is to provide a numerical control device, system, control method, and program that, when loading conditions are changed, can automatically estimate a time constant corresponding to the changed loading conditions and reflect the changed loading conditions in the rotation operation of the tool magazine. [Means for solving the problem]

[0006] A numerical control device according to claim 1 is a numerical control device for outputting a command to a motor of a machine tool having a tool magazine capable of loading tools therein and rotating the tool magazine by being driven by the motor to transport the tools to a predetermined position, the numerical control device comprising: a memory unit for storing loading conditions defined by an inertia about a rotation axis of the tool magazine and an offset load; a calculation unit for calculating a time constant for acceleration and deceleration of the motor during the rotating operation of the tool magazine in accordance with the loading conditions stored in the memory unit; and a rotating control unit for executing the rotating operation of the tool magazine with the time constant calculated by the calculation unit. The present invention is characterized by comprising an execution unit, a change unit that changes the time constant during the rotation operation to a reference time constant at which the motor can operate when the tool loading state in the tool magazine is a reference loading state when reset information instructing a reset of the loading condition is read during execution of an NC program, an estimation unit that estimates the inertia and the offset load of the tool magazine based on the result of executing the rotation operation with the reference time constant during execution of an NC program, and a reflection unit that reflects the estimation result of the estimation unit in the loading condition stored in the storage unit. For example, when a tool is replaced in the tool magazine, the loading state of the tools changes, so that the loading conditions such as the inertia and the offset load change. Reset information is set in advance at a predetermined position in the NC program to be executed for the first time after the tool is replaced. When the reset information is read, the numerical control device executes the rotation operation with the reference time constant. The numerical control device automatically estimates the inertia and the offset load based on the result and reflects the result in the loading condition. As a result, the numerical control device calculates the time constant for the motor's acceleration and deceleration under the loading conditions that reflect the estimated results when the tool magazine is next rotated. Therefore, the numerical control device can automatically and optimally adjust the acceleration and deceleration during the tool magazine's rotation according to the current loading conditions of the tool magazine. Furthermore, the numerical control device can prevent operation at suboptimal acceleration due to forgetting to perform an estimation after changing tools in the tool magazine. This allows the numerical control device to prevent machine tool failures and errors due to insufficient motor torque.

[0007] The reset information of the numerical control device of claim 2 may be a macro variable. Since the reset information is a macro variable, the reset of the loading information can be easily set in the NC program.

[0008] The numerical control device of claim 3 further controls a tool changer that changes the tool in the tool magazine, and the reset information may be set in an NC program to be executed first after the tool changer changes the tool. When the tool changer changes the tool in the tool magazine, the tool loading situation changes, and the loading conditions such as inertia and offset load change. Here, the reset information is set in the NC program to be executed next. Therefore, when the numerical control device reads the reset information in the NC program to be executed first after the tool change, the numerical control device executes a turning operation with a reference time constant. The numerical control device can automatically estimate the inertia and offset load based on the result and reflect the result in the loading conditions. Therefore, the numerical control device can prevent operation with a non-optimal acceleration due to forgetting to perform the estimation after the tool change in the tool magazine. This allows the numerical control device to prevent a breakdown of the machine tool and a deterioration in the life of the reducer connected between the tool magazine and the motor.

[0009] A numerical control device according to claim 4 is a numerical control device for outputting a command to a motor of a machine tool having a tool magazine capable of loading tools thereon and rotating the tool magazine by being driven by the motor to transport the tools to a predetermined position, the numerical control device comprising: a memory unit for storing loading conditions defined by an inertia about a rotation axis of the tool magazine and an offset load; a calculation unit for calculating a time constant for acceleration and deceleration of the motor during the rotating operation of the tool magazine in accordance with the loading conditions stored in the memory unit; a rotation execution unit for executing the rotating operation of the tool magazine with the time constant calculated by the calculation unit; and a NC The present invention is characterized in that, when a PLC signal instructing to reset the loading conditions is received from a PLC that controls the numerical control device during program execution, the time constant during the rotation operation is changed to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state, an estimation unit is configured to estimate the inertia and the offset load of the tool magazine based on the result of executing the rotation operation with the reference time constant during NC program execution, and a reflection unit is configured to reflect the estimation result of the estimation unit in the loading conditions stored in the storage unit. For example, when a tool is replaced in the tool magazine, the loading state of the tools changes, so that the loading conditions such as the inertia and the offset load change. In such a case, a PLC signal instructing to reset the loading information is transmitted from the PLC to the numerical control device. When the numerical control device receives the PLC signal, the numerical control device executes the rotation operation with the reference time constant. The numerical control device can automatically estimate the inertia and the offset load based on the result and reflect the result in the loading conditions. Therefore, the numerical control device can prevent operation at suboptimal acceleration caused by forgetting to perform estimation after changing tools in the tool magazine, which can prevent breakdowns of the machine tool and shortened service life of the reducer connected between the tool magazine and the motor.

[0010] In the numerical control device of claim 5, the PLC controls the numerical control device and a tool changer that changes the tools in the tool magazine, and when the NC program is executed after the tool changer changes the tools in the tool magazine, the PLC may transmit the PLC signal to the numerical control device. The PLC transmits the PLC signal to the numerical control device when the tool changer changes the tools in the tool magazine. By receiving the PLC signal, the numerical control device executes a rotation operation with a reference time constant, and further estimates the loading conditions after the tool change, and reflects the results in the loading conditions stored in a storage unit.

[0011] The system of claim 6 is a system including a numerical control device that outputs a command to a motor of a machine tool having a tool magazine capable of loading tools and rotating the tool magazine by being driven by the motor to transport the tool to a predetermined position, and a PLC that controls the numerical control device, wherein the PLC includes a signal transmitting unit that transmits a PLC signal to the numerical control device to instruct the numerical control device to reset the loading conditions after the tool magazine is replaced with another tool, and the numerical control device includes a memory unit that stores loading conditions defined by the inertia around a rotation axis of the tool magazine and an offset load, and a control unit that controls the rotation movement of the tool magazine in accordance with the loading conditions stored in the memory unit. The present invention is characterized in that it comprises a calculation unit that calculates a time constant for acceleration and deceleration of the motor during operation, a rotation execution unit that executes the rotation operation of the tool magazine with the time constant calculated by the calculation unit, a change unit that changes the time constant during the rotation operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state when the PLC signal transmitted by the signal transmission unit is received, an estimation unit that estimates the inertia and the offset load of the tool magazine based on the result of executing the rotation operation with the reference time constant during the execution of the NC program, and a reflection unit that reflects the estimation result of the estimation unit in the loading conditions stored in the storage unit. For example, when a tool is replaced in the tool magazine, the loading state of the tools changes, so that the loading conditions such as the inertia and the offset load change. Therefore, the PLC transmits a PLC signal instructing a reset of loading information to the numerical control device. When the numerical control device receives the PLC signal, it executes the rotation operation with the reference time constant. The numerical control device can automatically estimate the inertia and unbalanced load based on the results and reflect the results in the loading conditions. Therefore, the system can prevent operation at suboptimal acceleration caused by forgetting to perform estimation after changing tools in the tool magazine. This makes it possible for the system to prevent breakdowns of the machine tool and shortened life of the reducer connected between the tool magazine and the motor.

[0012] The system of claim 7 may further include a tool changer that changes the tools in the tool magazine, and the PLC controls the numerical control device and the tool changer, and the PLC may include a signal transmission unit that transmits the PLC signal to the numerical control device after the tool changer changes the tools. The PLC transmits the PLC signal to the numerical control device when the tool changer changes the tools. This makes it possible for the numerical control device to effectively prevent operation at suboptimal acceleration caused by forgetting to perform estimation after changing tools in the tool magazine.

[0013] A numerical control device according to claim 8 is a numerical control device for outputting a command to a motor of a machine tool having a tool magazine capable of loading tools thereon and rotating the tool magazine by being driven by the motor to transport the tools to a predetermined position, the numerical control device comprising: a memory unit for storing loading conditions defined by an inertia about a rotation axis of the tool magazine and an offset load; a calculation unit for calculating a time constant for acceleration and deceleration of the motor during the rotating operation of the tool magazine in accordance with the loading conditions stored in the memory unit; a rotation execution unit for executing the rotating operation of the tool magazine with the time constant calculated by the calculation unit; and a NC The present invention is characterized in that, when a command signal for resetting the loading conditions is received from a PC capable of communicating with the numerical control device during program execution, the time constant during the rotation operation is changed to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation unit is configured to estimate the inertia and the offset load of the tool magazine based on the result of executing the rotation operation with the reference time constant during NC program execution; and a reflection unit is configured to reflect the estimation result of the estimation unit in the loading conditions stored in the storage unit. For example, when a tool is replaced in the tool magazine, the loading state of the tools changes, so that the loading conditions such as the inertia and the offset load change. In such a case, a command signal for resetting the loading information is transmitted from the PC to the numerical control device. When the numerical control device receives the command signal, the numerical control device executes the rotation operation with the reference time constant. The numerical control device can automatically estimate the inertia and the offset load based on the result and reflect the result in the loading conditions. Therefore, the numerical control device can prevent operation at suboptimal acceleration caused by forgetting to perform estimation after changing tools in the tool magazine, which can prevent breakdowns of the machine tool and shortened service life of the reducer connected between the tool magazine and the motor.

[0014] The system of claim 9 is a system including a numerical control device for outputting a command to a motor of a machine tool having a tool magazine capable of loading tools and rotating by the drive of the motor to transport the tools to a predetermined position, and a PC for controlling the numerical control device, wherein the PC includes a signal transmitting unit for transmitting a command signal to the numerical control device to instruct the numerical control device to reset the loading conditions after the tools are replaced in the tool magazine, and the numerical control device includes a memory unit for storing loading conditions defined by the inertia and offset load around a rotation axis of the tool magazine, and a memory unit for storing a loading condition when the tool magazine is rotated according to the loading condition stored in the memory unit. The present invention is characterized in that it comprises a calculation unit that calculates a time constant for acceleration and deceleration of the motor in the tool magazine, a rotation execution unit that executes the rotation operation of the tool magazine with the time constant calculated by the calculation unit, a change unit that changes the time constant during the rotation operation to a reference time constant at which the motor can operate when the tool loading state in the tool magazine is a reference loading state when the command signal transmitted by the signal transmission unit is received, an estimation unit that estimates the inertia and the offset load of the tool magazine based on the result of executing the rotation operation with the reference time constant during the execution of the NC program, and a reflection unit that reflects the estimation result of the estimation unit in the loading conditions stored in the storage unit. For example, when a tool is replaced in the tool magazine, the loading state of the tools changes, so that the loading conditions such as the inertia and the offset load change. Therefore, the PLC transmits a PLC signal instructing the reset of loading information to the numerical control device. When the numerical control device receives the PLC signal, it executes the rotation operation with the reference time constant. The numerical control device can automatically estimate the inertia and unbalanced load based on the results and reflect the results in the loading conditions. Therefore, the system can prevent operation at suboptimal acceleration caused by forgetting to perform estimation after changing tools in the tool magazine. This makes it possible for the system to prevent breakdowns of the machine tool and shortened life of the reducer connected between the tool magazine and the motor.

[0015] The system of claim 10 further includes a plurality of the machine tools, a plurality of the numerical control devices corresponding to the plurality of machine tools, and a plurality of tool changers corresponding to the tool magazines of the plurality of machine tools and changing the tools to the tool magazines, and the signal transmission unit of the PC may transmit the command signal to each of the plurality of numerical control devices. For example, in a system in which a plurality of numerical control devices in a factory are managed by a PC, a command signal can be transmitted simultaneously from the PC to each of the plurality of numerical control devices.

[0016] A control method according to claim 11 is a control method for a numerical control device which outputs a command to a motor for a machine tool having a tool magazine capable of loading tools thereon and which transports the tools to a predetermined position by rotating the tool magazine driven by the motor, the control method including the steps of: calculating a time constant for acceleration / deceleration of the motor during the rotating operation of the tool magazine in accordance with loading conditions stored in a storage unit which stores loading conditions defined by an inertia around a rotating axis of the tool magazine and an offset load; and performing a rotating operation of the tool magazine with the time constant calculated in the calculation step. a change process for changing the time constant during the turning operation to a reference time constant at which the motor can operate when the tool loading state in the tool magazine is a reference loading state when reset information instructing to reset the loading conditions is read during execution of an NC program, an estimation process for estimating the inertia and the unbalanced load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program, and a reflection process for reflecting the estimation result in the estimation process in the loading conditions stored in the storage unit. The numerical control device can obtain the effect recited in claim 1 by performing each of the above processes.

[0017] The program of claim 12 is a program executable by a computer of a numerical control device that outputs a command to a motor for a machine tool having a tool magazine capable of loading tools therein and rotating by the drive of the motor to transport the tools to a predetermined position, the program including a calculation step of calculating a time constant for acceleration / deceleration of the motor during the rotating operation of the tool magazine in accordance with loading conditions stored in a storage unit that stores loading conditions defined by inertia around a rotating axis of the tool magazine and an offset load, and a program for controlling the rotating operation of the tool magazine with the time constant calculated in the calculation step. a change step of changing the time constant during the rotation operation to a reference time constant at which the motor can operate when the tool loading state in the tool magazine is a reference loading state when reset information instructing to reset the loading conditions is read during execution of the NC program, an estimation step of estimating the inertia and the unbalanced load of the tool magazine based on the result of executing the rotation operation with the reference time constant during execution of the NC program, and a reflection step of reflecting the estimation result in the estimation step in the loading conditions stored in the storage unit. The computer of the numerical control device can obtain the effect recited in claim 1 by executing each of the above steps.

[0018] A control method according to claim 13 is a control method for a numerical control device which outputs a command to a motor for a machine tool having a tool magazine capable of loading tools therein and rotating the tool magazine by being driven by the motor to transport the tool to a predetermined position, the control method comprising the steps of: calculating a time constant for acceleration / deceleration of the motor during the rotating operation of the tool magazine in accordance with loading conditions stored in a storage unit which stores loading conditions defined by an inertia around a rotating shaft of the tool magazine and an offset load; executing the rotating operation of the tool magazine with the time constant calculated in the calculation step; The numerical control device further comprises a changing step of changing the time constant during the turning operation to a reference time constant at which the motor can operate when the tool loading state in the tool magazine is a reference loading state when a PLC signal instructing a reset of the loading conditions is received from a PLC controlling the numerical control device during execution of the NC program, an estimation step of estimating the inertia and the unbalanced load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of the NC program, and a reflecting step of reflecting the estimation result in the estimation step in the loading conditions stored in the storage unit.

[0019] The program of claim 14 is a program executable by a computer of a numerical control device that outputs a command to a motor for a machine tool having a tool magazine capable of loading tools and rotating the tool magazine by being driven by the motor to transport the tools to a predetermined position, the program including a calculation step of calculating a time constant of acceleration / deceleration of the motor during the rotating operation of the tool magazine in accordance with loading conditions stored in a storage unit that stores loading conditions defined by inertia around a rotating axis of the tool magazine and an offset load, and a rotating operation step of executing the rotating operation of the tool magazine with the time constant calculated in the calculation step. a changing step of changing the time constant during the turning operation to a reference time constant at which the motor can operate when the tool loading state in the tool magazine is a reference loading state when a PLC signal instructing to reset the loading conditions is received from a PLC controlling the numerical control device during execution of the NC program, an estimating step of estimating the inertia and the unbalanced load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of the NC program, and a reflecting step of reflecting the estimation result in the estimating step in the loading conditions stored in the storage unit. The computer of the numerical control device can obtain the effect recited in claim 4 by executing each of the above steps.

[0020] A control method according to claim 15 is a control method for a numerical control device which outputs a command to a motor for a machine tool having a tool magazine capable of loading tools therein and rotating the tool magazine by being driven by the motor to transport the tool to a predetermined position, the control method comprising the steps of: calculating a time constant for acceleration / deceleration of the motor during the rotating operation of the tool magazine in accordance with loading conditions stored in a storage unit which stores loading conditions defined by an inertia around a rotating shaft of the tool magazine and an offset load; executing the rotating operation of the tool magazine with the time constant calculated in the calculation step; The numerical control device further comprises a changing step of changing the time constant during the turning operation to a reference time constant at which the motor can operate when the tool loading state in the tool magazine is a reference loading state when a command signal instructing to reset the loading conditions is received from a PC capable of communicating with the numerical control device during execution of the NC program, an estimating step of estimating the inertia and the unbalanced load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of the NC program, and a reflecting step of reflecting the estimation result in the estimating step in the loading conditions stored in the storage unit. The numerical control device can obtain the effect recited in claim 8 by performing each of the above steps.

[0021] The program of claim 16 is a program executable by a computer of a numerical control device that outputs a command to a motor for a machine tool having a tool magazine capable of loading tools and rotating the tool magazine by being driven by the motor to transport the tools to a predetermined position, the program including a calculation step of calculating a time constant of acceleration / deceleration of the motor during the rotating operation of the tool magazine in accordance with loading conditions stored in a storage unit that stores loading conditions defined by inertia around a rotating axis of the tool magazine and an offset load, and a rotating operation step of executing the rotating operation of the tool magazine with the time constant calculated in the calculation step. a changing step of changing the time constant during the turning operation to a reference time constant at which the motor can operate when the tool loading state in the tool magazine is a reference loading state when a command signal instructing to reset the loading conditions is received from a PC capable of communicating with the numerical control device during execution of the NC program, an estimating step of estimating the inertia and the unbalanced load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of the NC program, and a reflecting step of reflecting the estimation result in the estimating step in the loading conditions stored in the storage unit. The computer of the numerical control device can obtain the effect recited in claim 8 by executing each of the above steps.

[0022] A computer-readable storage medium having the above program stored thereon is also novel and useful. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a front view of the machine tool 1 and the tool changer 70. [Diagram 2] 2 is a partially cutaway view of the periphery of the spindle head 7 as viewed from the right side. [Diagram 3] 13 is a diagram showing the tool magazine 21 when the angle θ of the magazine body 22 is 0 deg. [Figure 4] 13 is a diagram showing the tool magazine 21 when the angle θ of the magazine body 22 is a reference angle θa. [Diagram 5] 2 is a block diagram showing the electrical configuration of a numerical control device 40 and a machine tool 1. FIG. [Figure 6] FIG. 4 is a functional block diagram of a control unit 41. [Figure 7] 13 is a flowchart of a loading condition setting process. [Figure 8] FIG. 13 is a diagram showing a loading condition setting screen 51. [Figure 9] FIG. 13 is a diagram showing an example of an NC program in which macro variables are set. [Figure 10] FIG. 13 is a diagram showing a flow of resetting, estimating, and reflecting loading conditions. [Figure 11] 4 is a flowchart of a loading condition estimation process (first embodiment). [Figure 12] FIG. 2 is a block diagram showing the electrical configuration of the control system 100. [Figure 13] 13 is a flowchart of a PLC side signal transmission process. [Figure 14] 13 is a flowchart of a loading condition estimation process (second embodiment). [Figure 15] FIG. 2 is a block diagram showing the electrical configuration of the control system 300. [Figure 16] 13 is a flowchart of a PC-side signal transmission process. [Figure 17] 13 is a flowchart of a loading condition estimation process (third embodiment). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] A first embodiment of the present invention will be described. In the following description, left / right, up / down, and front / back directions are used as indicated by arrows in the drawings. The left / right, up / down, and front / back directions of the machine tool 1 are the X-axis, Y-axis, and Z-axis directions of the machine tool 1, respectively. The machine tool 1 shown in FIG. 1 is a vertical machining center with a spindle 9 extending in the up / down direction (Z-axis direction). "ATC" in this embodiment is an abbreviation for "Automatic Tool Changer." Also, "NC" in this embodiment is an abbreviation for "Numerical Control."

[0025] The structure of the machine tool 1 will be described with reference to Figs. 1 and 2. The machine tool 1 includes a base 2, a column 5, a control box 6, a table 13, a spindle head 7, a spindle 9, a tool changer 20, and a tool replacement device 70. The base 2 is a metal base having a substantially rectangular parallelepiped shape. The column 5 is erected at the rear of the upper part of the base 2. The control box 6 is provided on the rear side of the column 5. The control box 6 houses a numerical control device 40 (see Fig. 5), which will be described later. The table 13 is movable in two axial directions, the X-axis direction and the Y-axis direction. The spindle head 7 moves up and down in the Z-axis direction in front of the column 5. As shown in Fig. 2, the spindle 9 is rotatably supported inside the spindle head 7. The spindle motor 65 is fixed to the upper part of the spindle head 7. The spindle 9 is connected to a drive shaft 65A extending downward from the spindle motor 65. The spindle 9 is rotated by the drive of the spindle motor 65. The main shaft 9 is provided with a mounting hole 92, a shaft hole 91, a clamping portion 93, and a draw bar 94. The mounting hole 92 is provided at the lower end of the main shaft 9 and communicates with the shaft hole 91 which extends coaxially with the main shaft 9. The clamping portion 93 is provided above the mounting hole 92. The draw bar 94 is provided inside the shaft hole 91.

[0026] Tool 3 includes holder 17 and cutting tool 4. Holder 17 holds cutting tool 4 at one end, and includes mounting portion 17A and pull stud 17B at the other end. Mounting portion 17A is mounted in mounting hole 92. Pull stud 17B protrudes from the top of mounting portion 17A in the axial direction of cutting tool 4. An information medium (not shown) using a magnetic memory element is attached to pull stud 17B. Tool information such as tool number, tool length, tool length compensation value, tool diameter, tool diameter compensation value, and tool weight is recorded on the information medium. When mounting portion 17A is mounted in mounting hole 92, clamping portion 93 clamps pull stud 17B. When drawbar 94 presses clamping portion 93 downward, clamping portion 93 releases clamping of pull stud 17B.

[0027] The spindle head 7 is provided with a crank lever 30 and a tension coil spring (not shown) on the inside. The crank lever 30 is generally inverted L-shaped when viewed from the right side and can swing around a support shaft 31. The support shaft 31 extends in the left-right direction and is fixed inside the spindle head 7. The front end of the crank lever 30 engages from above with a pin 95 provided on a draw bar 94. A plate cam 32 is provided on the rear end of the crank lever 30. A cam follower 34 is supported forward on the upper front surface of the column 5. The cam follower 34 slides on the cam surface of the plate cam 32 which moves up and down. The tension coil spring constantly urges the crank lever 30 clockwise when viewed from the right side. Therefore, the crank lever 30 constantly releases the downward pressure of the pin 95.

[0028] The structure of the tool changer 20 will be described with reference to FIG. 2. The tool changer 20 includes a tool magazine 21, a support base 24, a reducer 25, and a magazine motor 64. The tool magazine 21 is of a turret type. The tool magazine 21 includes a magazine body 22, a rotating shaft 23, and a plurality of grip arms 8. The magazine body 22 is disk-shaped. The rotating shaft 23 is inclined obliquely downward with respect to the front of the machine tool 1. The axis of the rotating shaft 23 passes through a center Q (see FIG. 3) of the magazine body 22 described later. The rotating shaft 23 is provided at the center of rotation of the magazine body 22. The front surface of the magazine body 22 faces the front side of the machine tool 1. The grip arms 8 are provided at predetermined intervals in the circumferential direction on the outer periphery of the magazine body 22. In this embodiment, 28 grip arms 8 are provided on the magazine body 22. Therefore, the tool magazine 21 can load 28 tools 3. The grip arm 8 is provided so as to be swingable in the front-rear direction around a fulcrum 26 fixed to the outer periphery of the magazine body 22. The grip arm 8 has a gripping portion 81 at its tip. The gripping portion 81 detachably grips the holder 17. The spindle position of the tool magazine 21 is the lowest position of the magazine body 22, a position adjacent to and facing the spindle 9. The grip arm 8 at the spindle position faces the spindle 9 and is the target position for tool replacement.

[0029] The support base 24 is fixed to a frame (not shown). The frame is fixed to the column 5 and is provided near the spindle head 7. The support base 24 supports the rotating shaft 23. The reducer 25 is fixed to the upper part of the support base 24. The reducer 25 has a plurality of gears and cams (not shown). The magazine motor 64 is fixed to the upper part of the reducer 25. The drive shaft of the magazine motor 64 is connected to the reducer 25. The reducer 25 reduces the driving force of the magazine motor 64 and transmits it to the rotating shaft 23. Therefore, the tool magazine 21 rotates by the driving force of the magazine motor 64.

[0030] The ATC operation will be described with reference to FIG. 2. The ATC operation is a tool exchange operation, which is an operation for attaching and detaching the tool 3 to the spindle 9. With the attachment portion 17A of the tool 3 attached to the attachment hole 92 of the spindle 9, the spindle head 7 rises from the machining position of the workpiece fixed to the table 13. The cam follower 34 slides from top to bottom on the cam surface of the plate cam 32 of the crank lever 30. The crank lever 30 rotates counterclockwise as viewed from the right side about the support shaft 31. The front end of the crank lever 30 engages with the pin 95 from above and presses the draw bar 94 downward. The draw bar 94 urges the clamping portion 93 downward. Therefore, the clamping portion 93 releases the clamping of the pull stud 17B. The grip arm 8 at the spindle position swings counterclockwise as viewed from the right side about the fulcrum base 26 as the spindle head 7 rises. The gripping portion 81 of the grip arm 8 grips the tool 3 currently attached to the spindle 9 (hereinafter referred to as the “current tool 3”) at the same time as the clamping by the clamping portion 93 is released.

[0031] The spindle head 7 rises further toward the ATC origin. The current tool 3 held by the gripper 81 is released from the mounting hole 92 of the spindle 9. When the spindle head 7 reaches the ATC origin, the tool changer 20 rotates the magazine body 22 by rotating the magazine motor 64 based on a command from the numerical control device 40. The tool changer 20 indexes the next tool 3 to be mounted (hereinafter referred to as the "next tool 3") to the spindle position, as specified by a control command in the NC program. The next tool 3 indexed to the spindle position is positioned below the spindle 9.

[0032] The spindle head 7 descends from the ATC origin. The mounting portion 17A of the holder 17 of the next tool enters the mounting hole 92 of the spindle 9. With the mounting portion 17A inserted into the mounting hole 92, the spindle head 7 descends further. The cam follower 34 slides on the cam surface of the plate cam 32 from bottom to top. The crank lever 30 rotates clockwise around the support shaft 31 as viewed from the right side. The front end of the crank lever 30 moves upward away from the pin 95, releasing the downward pressure on the draw bar 94. The draw bar 94 releases the downward bias of the clamping portion 93. The clamping portion 93 clamps the pull stud 17B of the next tool 3. The next tool 3 is attached to the spindle 9. As the spindle head 7 descends further, the gripping portion 81 of the grip arm 8 comes off the next tool 3 attached to the spindle 9. This completes the tool change from the current tool 3 to the next tool 3 in the spindle 9.

[0033] The configuration of the tool changer 70 will be described with reference to Fig. 1. The tool changer 70 is, for example, a robot that receives a command from the numerical control device 40 and changes the tool 3 to the tool magazine 21. In this embodiment, the tool changer 70 is a multi-joint robot arm.

[0034] The tool changing device 70 includes a base 71, an arm 72, a tool gripping unit 73, and a stocker 75. The base 71 is installed to the right of the machine tool 1. The arm 72 is installed on the top surface of the base 71 and is a multi-joint arm consisting of multiple arms. The tool gripping unit 73 is attached to the tip of the arm 72 and includes a pair of claws 731. The pair of claws 731 can grip a tool 3. The tool gripping unit 73 is provided with an information reading and writing device 732. The information reading and writing device 732 includes a magnetic head and can read and write information from a magnetic memory element. The information reading and writing device 732 can read and write information from an information medium attached to the pull stud 17B of the holder 17 of the tool 3. The stocker 75 is installed on the top surface of the base 71 and can store multiple tools 3.

[0035] The tool changer 70 having the above structure can, in accordance with commands from the numerical control device 40, remove the tool 3 from the grip arm 8 located at the attachment / detachment position of the tool magazine 21 and transport the tool 3 to the stocker 75, and can also transport the tool 3 from the stocker 75 and attach the tool 3 to the grip arm 8 located at the attachment / detachment position of the tool magazine 21.

[0036] 3 and 4, the loading state of the tools 3 in the tool magazine 21 will be described. For example, as shown in FIG. 3, the tool magazine 21 is in a state in which the tools 3 are supported by 12 of the 28 grip arms 8, that is, grip arms 801-811 and 828. No tools 3 are attached to the grip arms 812-827. The tools 3 attached to the grip arms 801-811 and 828 are the tools 301-311 and 328. The weights G1-G28 of the tools 301-311 and 328 may all be the same or may be different from each other. Note that in this embodiment, the weights G1-G28 are all described as being the same.

[0037] When the tool magazine 21 is in the loaded state shown in Fig. 3, many of the tools 3 supported by the grip arm 8 are located on the left side of the magazine body 22. Therefore, an unbalanced load that tends to rotate the magazine body 22 around the center Q of the magazine body 22 acts on the magazine body 22 due to the tools 301-311, 328. The unbalanced load is a rotational moment. The unbalanced load due to the tools 301-311, 328 is a total unbalanced load. The total unbalanced load tends to rotate the magazine motor 64 in a specific direction (counterclockwise in the case of Fig. 3).

[0038] The total unbalanced load varies based on the position of the grip arm 8 supporting the tool 3, the weight of the tool 3 supported by the grip arm 8, and the angle θ of the magazine body 22. When the grip arm 801 is in the spindle position, the angle θ is 0 deg. When the angle θ is 0 deg and the magazine body 22 rotates clockwise around the center Q, the angle θ becomes positive. When the magazine body 22 rotates counterclockwise around the center Q, the angle θ becomes negative.

[0039] When the tool magazine 21 is in the state shown in FIG. 4 (angle θ=−58 deg), the offset loads of the tools 301-311, 328 acting on the magazine body 22 balance each other with the center Q as the fulcrum. The total offset load becomes zero. The angle θ of the magazine body 22 at which the total offset load becomes zero is the reference angle θ. a The loading state of the tools 3 in the tool magazine 21 changes when the tools 3 are replaced. The replacement of the tools 3 is an operation in which a user, a robot, or the like replaces the tools 3 loaded in the tool magazine 21 with tools 3 not loaded in the tool magazine 21 before the machine tool 1 processes a workpiece.

[0040] With reference to FIG. 5, the main parts of the electrical configuration of the numerical control device 40, the machine tool 1, and the tool changer 70 will be described. For the sake of convenience, in this embodiment, the electrical configuration for controlling the operation of the tool magazine 21 will be mainly described, and the description of the other electrical configurations will be omitted. The numerical control device 40 includes a control unit 41, a ROM 42, a RAM 43, a storage unit 44, an input / output unit 45, a drive circuit 48, and the like. The control unit 41 is connected to the drive circuit 48 via the input / output unit 45. The control unit 41 includes a CPU and the like, and controls the operation of the machine tool 1 by outputting commands to various motors that drive the machine tool 1. The ROM 42 stores various programs such as a loading condition setting program and a loading condition estimation program. The loading condition setting program is a program that executes a loading condition setting process (see FIG. 7) described later. The loading condition estimation program is a program that executes a loading condition estimation process (see FIG. 11) described later.

[0041] The RAM 43 stores various data generated during the execution of various processes. The storage unit 44 is a rewritable storage medium, such as an EPROM, an EEPROM, or a flash memory. The storage unit 44 stores the NC program, a reference inertia, a reference offset load, a reference time constant, and the like, which will be described later. The input / output unit 45 inputs and outputs various signals between the drive circuit 48, the drive circuit 49, an encoder 641, which will be described later, the control unit 41, the ROM 42, the RAM 43, the storage unit 44, the operation unit 18, and the display unit 19.

[0042] The drive circuit 48 corresponds to the magazine motor 64, and outputs a pulse signal to the magazine motor 64 based on a command output by the control unit 41. The encoder 641 detects the rotational position of the magazine motor 64, and feeds back the detection signal to the drive circuit 48 and the input / output unit 45. The encoder 641 is a general absolute value encoder, and is a position sensor that detects and outputs the absolute position of the rotational position. The drive circuit 49 corresponds to the motor that drives the tool changer 70, and outputs a pulse signal to the motor based on a command output by the control unit 41. The operation unit 18 accepts instructions input by a user's operation, and the display unit 19 displays information to notify the user. The display unit 19 is a liquid crystal touch panel, and also functions as an operation unit.

[0043] A configuration based on the functions of the control unit 41 will be described with reference to FIG. 6. Here, the control of the magazine motor 64 by the control unit 41 will be described. The control unit 41 includes a speed adjustment unit 411, a time constant calculation unit 412, and an inertia / offset load acquisition unit 413. The speed adjustment unit 411 receives a time series change (waveform) of the speed of the magazine motor 64, adjusts the speed waveform, and outputs it to the drive circuit 48. The speed adjustment unit 411 adjusts the speed waveform according to the fluctuation of the offset load generated in the magazine body 22 of the tool magazine 21. The speed adjustment unit 411 has a first filter 421, a second filter 422, and a third filter 423 that adjust and smooth the speed waveform. The first to third filters 421 to 423 are moving average filters. The first filter 421 is a filter for limiting the maximum acceleration during speed adjustment, and the second filter 422 and the third filter 423 are low-pass filters for suppressing the resonance of the rotating shaft 23. The time constant (hereinafter referred to as t1) of the first filter 421 varies depending on the position of the grip arm 8 supporting the tool 3, the weight of the tool 3 supported by the grip arm 8, and the angle θ of the magazine body 22. The time constant (hereinafter referred to as t2) of the second filter 422 and the time constant (hereinafter referred to as t3) of the third filter 423 are fixed values. The inertia / offset load acquisition unit 413 acquires the inertia and offset load of the tool magazine 21 during rotation based on feedback information from the encoder 641.

[0044] Next, a method for the inertia / offset load acquisition unit 413 to acquire the inertia and offset load will be described. The offset load (Tw) is defined as "Fθsin(θ)" (Equation 1). Fθ is the offset load coefficient. θ is the angle of the magazine body 22. Tw is minimum when θ=0°, and maximum when θ=90°. The inertia (J) is defined as "Jθ"=u-f" (Equation 2). θ" represents the second time differential of the angle θ. u is the torque output by the drive circuit 48 to the magazine motor 64, and is a measured value acquired from the drive circuit 48. f satisfies the following formula. ·f=Fθsin(θ)+Fcsign(θ′)+Dθ′ (Math 3) In the formula 3, θ′ represents a first time differential of the angle θ. Fc represents the Coulomb friction with respect to the tool magazine 21. D represents the viscous friction coefficient with respect to the tool magazine 21.

[0045] The inertia / offset load acquisition unit 413 acquires the offset load (Tw) and the inertia (J) from Equations 1 to 3 using the rotational position of the magazine motor 64 included in the feedback information from the encoder 641. Hereinafter, the inertia (J) and the offset load (Tw) acquired by the inertia / offset load acquisition unit 413 will be referred to as the acquired inertia J and the acquired offset load Tw, respectively. The time constant calculation unit 412 calculates a time constant t1 based on the acquired offset load Tw, the acquired inertia J, the reference inertia Jb, the reference offset load Twb, and the reference time constant tb. The reference inertia Jb, the reference offset load Twb, and the reference time constant tb are stored in the storage unit 44 as defaults.

[0046] The reference time constant tb is a time constant that allows the magazine motor 64 to operate without exceeding the maximum torque that can be output in a reference loading state. The reference loading state is a loading state in which the maximum inertia and maximum unbalanced load are determined by the machine specifications, and is, for example, a state in which the tools 3 are loaded with the tools biased to one side of the tool magazine 21 as shown in FIG. 1. The maximum inertia is the reference inertia Jb. The maximum unbalanced load is the reference unbalanced load Twb. The reference inertia Jb and the reference unbalanced load Twb are reference loading conditions and can be set by the user.

[0047] Here, a method for calculating the time constant t1 by the time constant calculation unit 412 will be described. Since torque in a rotational motion is the product of angular acceleration and inertia, it can be estimated that when Tw is at its maximum, that is, when θ is 90°, the following relationship holds: amaxb = (Tm - |Twb|) / Jb (Number 4) Here, amaxb is the angular acceleration, and Tm is the maximum torque of the magazine motor 64.

[0048] In this case, the reference time constant tb, which is inversely proportional to amaxb, can be expressed as follows: tb=Vmax / amaxb (Number 5) Note that Vmax is the maximum angular velocity.

[0049] From Equation 4 and Equation 5, the angular acceleration (a'max) during calculation and the time constant t1 to be obtained can be expressed by the following equation. ·a'max=(Tm-|Tw|) / J (number 6) t1=Vmax / a'max (equation 7) As described above, Tw and J are the obtained offset load Tw and the obtained inertia J.

[0050] Substituting equation 6 for a'max in equation 7, t1 is given by the following equation. t1=(JVmax) / (Tm-|Tw|) (Equation 8).

[0051] Then, when equation 4 is rewritten for Tm, it becomes Tm = Jbamaxb + |Twb|. When this is substituted for Tm in equation 8, t1 becomes the following equation. ·t1=(JVmax) / (Jbamaxb+|Twb|-|Tw|) (Number 9) Furthermore, when equation 5 is rewritten for amaxb, it becomes amaxb = Vmax / tb. Substituting this into amaxb in equation 9, t1 becomes the following equation. ·t1=Jtb / {Jb+tb(|Twb|-|Tw|) / Vmax} (Number 10)

[0052] The time constant calculation unit 412 calculates the time constant t1 using equation 10, and updates the reference time constant tb stored in the storage unit 44 to the time constant t1 obtained by the calculation. Thereafter, the speed adjustment unit 411 uses the updated time constant t1 to adjust and smooth the waveform of the speed of the magazine motor 64 output to the drive circuit 48, and also adjusts the acceleration of the turning operation to an optimum value.

[0053] The above explanation is a method for estimating the inertia and offset load of the entire tool magazine 21, but the inertia and offset load of the tools 3 loaded in the tool magazine 21 (hereinafter referred to as loaded tools) can be calculated using the following equations 11 and 12. The inertia and offset load of the loaded tools can be used for screen display or setting. Loaded tool inertia = inertia of tool magazine 21 (when tools are loaded) - inertia of tool magazine 21 (when no tools are loaded) (Equation 11) Loaded tool unbalanced load = Unbalanced load of tool magazine 21 (when tools are loaded) - Unbalanced load of tool magazine 21 (when no tools are loaded) (Equation 12)

[0054] The loading condition setting process will be described with reference to Figures 7 and 8. The loading conditions are the inertia and unbalanced load around the rotation axis 23 of the tool magazine 21. By setting appropriate loading conditions for the loading state of the tool magazine 21, the control unit 41 can optimally adjust the acceleration of the positioning operation of the tool magazine 21 when it is rotated. The user can set the loading conditions of the tool magazine 21 with the operation unit 18. When the control unit 41 receives an operation to set the loading conditions, it reads a loading condition setting program from the ROM 42 and executes this process.

[0055] The control unit 41 reads setting data from the memory unit 44 (S1). The setting data is various data including standard loading conditions, estimation results, loading condition settings, function settings, etc., which will be described later. The control unit 41 displays a loading condition setting screen 51 on the display unit 19 (S2).

[0056] As shown in FIG. 8, the loading condition setting screen 51 has display areas 511 to 515. The display area 511 displays the operation procedure and notes for setting the loading conditions. The display area 512 displays the reference loading conditions. The reference loading conditions are the reference inertia Jb and the reference offset load Twb described above. The display area 513 displays the estimation result of the loading conditions by the control unit 41 and the estimated date and time. The estimation of the loading conditions by the control unit 41 will be described later. The display area 514 displays the loading condition settings. The loading condition settings are the loading conditions currently being set, and are the inertia and offset load. The loading condition settings can be set by inputting them as well as automatically updated as described later. The display area 515 displays the enable or disable of each of the two function settings. The two function settings are magazine rotation acceleration adjustment and automatic update of the loading condition settings. The magazine rotation acceleration adjustment is a function for adjusting the acceleration of the rotation of the tool magazine 21 to an appropriate value for the set loading conditions. The automatic update of loading condition settings is a function for automatically updating the loading condition settings displayed in the display area 514 to loading conditions estimated by the control unit 41. The control unit 41 displays such a loading condition setting screen 51 on the display unit 19, so that the user can check the operation procedure for setting loading conditions, the standard loading conditions, the estimated results and estimated date and time, the loading condition settings, the function settings, and the like.

[0057] As shown in FIG. 7, the control unit 41 judges whether or not the setting of the loading condition has been accepted (S3). If the setting of the loading condition has not been accepted (S3: NO), the control unit 41 advances the process to S5 described later. If the setting of the loading condition has been accepted (S3: YES), the control unit 41 updates the loading condition setting value among the setting data stored in the storage unit 44 to the accepted content (S4), and displays the accepted loading condition setting value in the display area 514. Next, the control unit 41 judges whether or not the change of the function setting has been accepted (S5). If the change of the function setting has not been accepted (S5: NO), the control unit 41 advances the process to S7 described later. If the change of the function setting has been accepted (S5: YES), the control unit 41 changes the function setting data among the setting data stored in the storage unit 44 to the accepted content (S6). The control unit 41 judges whether or not the operation to end the loading condition setting has been accepted (S7). If the end operation has not been received (S7: NO), the control unit 41 returns to S3 and repeats the above process. If the end operation has been received (S7: YES), the control unit 41 ends this process.

[0058] With reference to FIG. 9 and FIG. 10, the loading condition setting reset function using the macro variable will be described. After the tool 3 is replaced by the tool changer 70 to the tool magazine 21, the loading conditions (inertia and unbalanced load) may have changed. If the tool magazine 21 is rotated at a non-optimal acceleration immediately after the loading conditions have changed, a large load is applied to the reducer 25 and the like. In this case, the life of the reducer 25 and the like may be shortened, and an error due to insufficient torque may cause the program to stop operating. Therefore, the control unit 41 resets the currently set loading condition setting value, estimates the optimal loading condition for the current loading state of the tool 3, and reflects the estimated result in the loading condition setting. In the first embodiment, a dedicated macro variable is set in the NC program to reset the loading condition setting. For example, "#30051" can be used as the macro variable for resetting the loading condition setting. "#30051=1" instructs the loading condition setting to be reset.

[0059] FIG. 9 is an example of an NC program in which a macro variable for resetting the loading condition setting is set. "♯30051=1" should be set in the first line of the NC program executed for the first time after the tool 3 is replaced. "G100T1" is a tool exchange command for the tool T1. Since the loading condition setting is reset in the first line of the NC program, the rotation of the tool magazine 21 during the ATC operation executed based on the tool exchange command is accelerated and decelerated at the reference time constant. This allows the tool magazine 21 to rotate safely and without problems in the NC program being executed. Then, the loading conditions (inertia and offset load) are estimated based on the drive data obtained by the rotation of the tool magazine 21. M30 is the end code of the NC program. After the NC program ends, the results estimated during the execution of the NC program are reflected in the loading condition setting.

[0060] 10, a case will be described in which three NC programs P1 to P3 are executed in sequence while changing tools in the tool magazine 21. First, the NC program P1 is executed in a state of change pattern A. After the NC program P1 is completed, the tool changer 70 changes the tools again, and the NC program P2 is executed in a state of change pattern B. After the NC program P2 is completed, the tool changer 70 changes the tools again, and the NC program P3 is executed in a state of change pattern C.

[0061] Since NC program P1 is the first program to be executed, the loading conditions corresponding to the current loading state of the tool magazine 21 are unknown. In addition, since NC programs P2 and P3 are the first programs to be executed after a tool change, it is highly likely that the loading conditions have changed. Therefore, "♯30051=1" is set in the first line of each of NC programs P1 to P3. By resetting the loading condition settings in the first line of the NC programs, it is possible to prevent the tool magazine 21 from being rotated when the loading conditions are set incorrectly.

[0062] The loading condition estimation process will be described with reference to Fig. 11. When an NC program is selected on the operation unit 18 and an operation to start execution of the selected NC program is performed, the control unit 41 reads the NC program from the storage unit 44 and starts execution of the NC program, and also reads the loading condition estimation program from the ROM 42 to execute this process.

[0063] The control unit 41 judges whether the loading condition setting has been reset by the macro variable (S11). If the loading condition setting has not been reset by the macro variable (S11: NO), the control unit 41 does not change the loading condition setting. Therefore, the control unit 41 calculates and sets a time constant with the current loading condition setting value stored in the memory unit 44 (S12). The control unit 41 stores the calculated time constant in the memory unit 44. When the control unit 41 performs a tool change within the NC program, it accelerates or decelerates the turning operation of the tool magazine 21 with the calculated time constant (S13). The control unit 41 judges whether the NC program has ended (S14). If the NC program has not ended (S14: NO), the control unit 41 returns to S14 and waits until the NC program ends. If the NC program has ended (S14: YES), the control unit 41 ends this process.

[0064] On the other hand, if the loading condition setting is reset by the macro variable (S11: YES), it is highly likely that the tool 3 has been replaced and the loading conditions have changed. Therefore, the control unit 41 resets the current loading condition setting value and changes the loading condition setting to the value of the standard loading condition (S15). At this time, it is advisable to update the display of the loading condition setting in the display area 514 of the loading condition setting screen 51 to the value of the standard loading condition. The control unit 41 sets a standard time constant based on the standard loading condition (S16).

[0065] Next, the control unit 41 executes the NC program operation (S17), and when a tool change is to be performed, the rotational motion of the tool magazine 21 is accelerated and decelerated with a reference time constant. The control unit 41 estimates the loading conditions (inertia and offset load) based on the drive data obtained during the rotational motion (S18). The control unit 41 stores the estimation results in the memory unit 44 and displays them in the display area 513 of the loading condition setting screen 51. The control unit 41 determines whether the NC program has ended (S19). If the NC program has not ended (S19: NO), the control unit 41 returns to S17 and repeatedly estimates the loading conditions if a tool change is to be performed until the NC program ends (S18, S19).

[0066] When the NC program is finished (S19: YES), the control unit 41 reflects the estimation result in the NC program in the loading condition setting stored in the storage unit 44 (S20). This allows the control unit 41 to automatically estimate the loading conditions after the tool is replaced and reflect them in the loading condition setting. At this time, it is advisable to update the display of the loading condition setting in the display area 514 of the loading condition setting screen 51 to the value of the estimated result. In this way, the control unit 41 ends this process. Then, when the control unit 41 next executes the NC program, it calculates a time constant based on the loading condition setting reflecting the estimation result estimated in the previous NC program, and sets it as the time constant for acceleration and deceleration of the turning operation. This allows the control unit 41 to turn the tool magazine 21 safely and in a short time with a time constant appropriate for the current loading conditions.

[0067] As described above, the machine tool 1 according to the first embodiment of the present invention includes the tool magazine 21. The tool magazine 21 can hold the tools 3, and the tool magazine 21 is rotated by the drive of the magazine motor 64 to transport the tools 3 to a predetermined position. The numerical control device 40 outputs a command to the machine tool 1 to instruct the drive conditions of the magazine motor 64. The storage unit 44 of the numerical control device 40 stores the loading conditions defined by the inertia around the rotation axis 23 of the tool magazine 21 and the offset load. The control unit 41 of the numerical control device 40 calculates the time constant of acceleration and deceleration of the magazine motor 64 during the rotation of the tool magazine 21 according to the loading conditions stored in the storage unit. The control unit 41 executes the rotation of the tool magazine 21 with the calculated time constant. When the control unit 41 reads a macro variable instructing to reset the loading condition setting during the execution of the NC program, the control unit 41 resets the value of the loading condition setting and changes the time constant of acceleration and deceleration of the magazine motor 64 to a reference time constant. The reference time constant is a time constant that allows the magazine motor 64 to operate without exceeding the maximum torque that can be output when the loading state of tools in the tool magazine 21 is the reference loading state. The reference loading state is a loading state in which the maximum inertia and maximum unbalanced load are determined by the machine specifications. The control unit 41 estimates the inertia and unbalanced load of the tool magazine 21 based on the result of executing the turning operation with the reference time constant during the execution of the NC program. The control unit 41 reflects the estimation result in the loading condition setting stored in the storage unit 44. As a result, the numerical control device 40 can calculate the acceleration / deceleration time constant of the magazine motor 64 under the loading condition in which the estimation result is reflected during the next turning operation of the tool magazine 21. Therefore, the numerical control device 40 can automatically and optimally adjust the acceleration / deceleration during the turning operation of the tool magazine 21 according to the current loading condition of the tool magazine 21. Furthermore, the numerical control device 40 can prevent operation at a non-optimal acceleration due to forgetting to perform estimation after changing tools in the tool magazine 21. This enables the numerical control device 40 to prevent errors caused by breakdowns in the machine tool 1 and insufficient torque in the magazine motor 64.

[0068] In the above description, the magazine motor 64 is an example of a motor of the present invention. The control unit 41 that executes the process of S12 is an example of a calculation unit. The control unit 41 that executes the process of S13 is an example of a turning execution unit. The control unit 41 that executes the process of S15 is an example of a change unit. The control unit 41 that executes the process of S18 is an example of an estimation unit. The control unit 41 that executes the process of S20 is an example of a reflection unit.

[0069] A second embodiment of the present invention will be described with reference to Figs. 12 to 14. As shown in Fig. 12, a control system 100 includes a numerical control device 40, a tool changer 70, and a PLC 150. The configurations of the numerical control device 40 and the tool changer 70 are the same as those of the first embodiment, and therefore the same reference numerals as those of the first embodiment are used and the description thereof will be omitted. The numerical control device 40 controls the operation of the machine tool 1. The PLC (programmable logic controller) 150 is communicably connected to the input / output unit 45 of the numerical control device 40 and the tool changer 70, and controls the operation of the numerical control device 40 and the tool changer 70. The PLC 150 includes a control unit 151 and a storage unit 152. The storage unit 152 stores various programs such as a PLC side signal transmission program. The PLC side signal transmission program is a program for executing a PLC side signal transmission process (see Fig. 13) described later.

[0070] The PLC side signal transmission process will be described with reference to FIG. 13. The PLC side signal transmission process is executed by the control unit 151 of the PLC 150. When the PLC 150 is started, the control unit 151 reads out a PLC side signal transmission program from the storage unit 152 and executes this process. The control unit 151 judges whether or not the tool 3 change by the tool changer 70 is completed (S31). The control unit 151 returns to S31 and waits until the tool 3 change is completed (S31: NO). When the tool 3 change is completed (S31: YES), the control unit 151 transmits a loading condition reset signal (BY100) to the numerical control device 40 (S32). The control unit 151 ends this process.

[0071] The loading condition estimation process will be described with reference to FIG. 14. The loading condition estimation process is executed by the control unit 41 of the numerical control device 40. When the machine tool 1 is started, the control unit 41 reads out the loading condition estimation program from the ROM 42 and executes this process. The control unit 41 judges whether or not the loading condition reset signal is transmitted from the PLC 150 and turned ON (S41). If the loading condition reset signal is not transmitted (S41: NO), the control unit 41 does not change the loading condition setting. Therefore, the control unit 41 calculates and sets a time constant with the current loading condition setting value stored in the storage unit 44 (S42). The control unit 41 stores the calculated time constant in the storage unit 44. When the control unit 41 performs a tool change, it accelerates or decelerates the turning operation of the tool magazine 21 with the calculated time constant (S43). The control unit 41 returns to S41 and repeats the process.

[0072] When the loading condition reset signal is sent from the PLC 150 and is turned ON (S41: YES), it is highly likely that the tools 3 have been replaced and the loading conditions have changed. Therefore, the control unit 41 resets the current loading condition setting values ​​and changes the loading condition settings to the values ​​of the standard loading conditions (S45). The control unit 41 sets a standard time constant based on the standard loading conditions (S46).

[0073] Next, the control unit 41 executes the NC program operation (S47), and when a tool change is to be performed, the rotational movement of the tool magazine 21 is accelerated and decelerated with a reference time constant. The control unit 41 estimates the loading conditions (inertia and offset load) based on the drive data obtained during the rotational movement (S48). The control unit 41 stores the estimation results in the memory unit 44, and displays them in the display area 513 of the loading condition setting screen 51. The control unit 41 judges whether the NC program has ended (S49). If the NC program has not ended (S49: NO), the control unit 41 returns to S47 and repeatedly estimates the loading conditions if a tool change is to be performed until the NC program ends (S48, S49).

[0074] When the NC program is finished (S49: YES), the control unit 41 reflects the estimation results of the NC program in the loading condition settings stored in the memory unit 44 (S50). This allows the control unit 41 to automatically estimate the loading conditions after changing the tools and reflect them in the loading condition settings. In this way, the control unit 41 ends this process. Then, when the control unit 41 next executes the NC program, it calculates a time constant based on the loading conditions reflecting the estimation results estimated in the previous NC program, and sets it as the time constant for acceleration and deceleration of the turning operation. This allows the control unit 41 to turn the tool magazine 21 safely and in a short time with a time constant appropriate for the current loading conditions.

[0075] As described above, the control system 100 according to the second embodiment of the present invention includes the numerical control device 40 and the PLC 150. The machine tool 1 includes the tool magazine 21. The tool magazine 21 can hold the tools 3, and transports the tools 3 to a predetermined position by rotating the magazine motor 64. The numerical control device 40 outputs a command to the machine tool 1 to instruct the driving conditions of the magazine motor 64. The PLC 150 controls the numerical control device 40. The control unit 151 of the PLC 150 transmits a loading condition reset signal to the numerical control device 40 after replacing the tools in the tool magazine 21. The storage unit 44 of the numerical control device 40 stores the loading conditions defined by the inertia around the rotation axis 23 of the tool magazine 21 and the offset load. The control unit 41 calculates the time constant of acceleration and deceleration of the magazine motor 64 during the rotating operation of the tool magazine 21 according to the loading conditions stored in the storage unit 44. The control unit 41 executes the rotating operation of the tool magazine 21 with the calculated time constant. When the control unit 41 receives the loading condition reset signal, it changes the time constant during the turning operation to the reference time constant. The control unit 41 estimates the inertia and offset load of the tool magazine 21 based on the result of the turning operation performed with the reference time constant during the execution of the NC program. The control unit 41 reflects the estimation result in the loading conditions stored in the storage unit 44. As a result, the numerical control device 40 can calculate the time constant of the acceleration and deceleration of the magazine motor 64 under the loading conditions reflecting the estimation result during the next turning operation of the tool magazine 21. Therefore, the numerical control device 40 can automatically and optimally adjust the acceleration and deceleration during the turning operation of the tool magazine 21 according to the current loading conditions of the tool magazine 21. Furthermore, the numerical control device 40 can prevent operation at a non-optimal acceleration due to forgetting to perform estimation after changing tools in the tool magazine 21. As a result, the numerical control device 40 can prevent a malfunction of the machine tool 1 and an error due to insufficient torque of the magazine motor 64.

[0076] In the above description, the control unit 41 that executes the process of S42 in Fig. 14 is an example of a calculation unit. The control unit 41 that executes the process of S43 is an example of a turning execution unit. The control unit 41 that executes the process of S45 is an example of a change unit. The control unit 41 that executes the process of S48 is an example of an estimation unit. The control unit 41 that executes the process of S50 is an example of a reflection unit.

[0077] A third embodiment of the present invention will be described with reference to Figs. 15 to 17. As shown in Fig. 15, a control system 200 includes one PC (Personal Computer) 80, three numerical control devices 40A to 40C, three machine tools 1A to 1C, and three tool changers 70A to 70C. The PC 250 is communicatively connected to the numerical control devices 40A to 40C via Ethernet or serial communication, and controls the operation of each of the numerical control devices 40A to 40C. The numerical control devices 40A to 40C and the machine tools 1A to 1C have the same electrical configurations as the numerical control device 40 and the machine tool 1 of the first embodiment, so they are denoted by the same reference numerals as in the first embodiment, and the electrical configurations will be described briefly.

[0078] The PC 250 comprises a control unit 251 and a memory unit 252. The memory unit 252 stores various programs such as a PC side signal transmission program. The PC side signal transmission program is a program that executes the PC side signal transmission process (see FIG. 16) described below. The numerical control device 40A comprises a control unit 41A. The control unit 41A controls the operation of each of the machine tool 1A and the tool changer 70A based on instructions from the PC 250. The numerical control device 40B comprises a control unit 41B. The control unit 41B controls the operation of each of the machine tool 1B and the tool changer 70B based on instructions from the PC 250. The numerical control device 40C comprises a control unit 41C. The control unit 41C controls the operation of each of the machine tool 1C and the tool changer 70C based on instructions from the PC 250.

[0079] The PC side signal transmission process will be described with reference to FIG. 16. The PC side signal transmission process is executed by the control unit 251 of the PC 250. When the PC 250 is started, the control unit 251 reads out a PC side signal transmission program from the storage unit 252 and executes this process. The control unit 251 judges whether or not the change of the tool 3 by the tool changer 70 has been completed (S51). The control unit 251 returns to S51 and waits until the change of the tool 3 has been completed (S51: NO). When the change of the tool 3 has been completed (S51: YES), the control unit 251 transmits a reset command (CWCLRESTVAL) to the numerical control device 40 (52). The control unit 251 ends this process.

[0080] The loading condition estimation process will be described with reference to FIG. 17. The loading condition estimation process is executed by the control units 41A-41C of the numerical control devices 40A-40C. Here, the case where the control unit 41 of the numerical control device 40A executes the process will be described as an example. When the machine tool 1 is started, the control unit 41A reads out the loading condition estimation program from the ROM and executes this process. The flow of the loading condition estimation process of the third embodiment shown in FIG. 17 is basically the same as the flow of the loading condition estimation process of the second embodiment shown in FIG. 14, and includes a judgment process of S61 instead of S41 shown in FIG. 14. In the judgment process of S61, the control unit 41A judges whether or not a reset command has been received from the PC 250. The other processes are the same as those in the flow shown in FIG. 14, and will not be described.

[0081] In the third embodiment, when the control unit 41A executes the next NC program, it calculates and sets the time constant based on the loading conditions that reflect the results estimated in the previous NC program. This allows the control unit 41A to rotate the tool magazine 21A safely and in a short time with a time constant appropriate for the current loading conditions.

[0082] In the control system 300, the operation of each of the three numerical control devices 40A to 40C is controlled by one PC 250. Therefore, for example, by simultaneously transmitting a reset command from the PC 250 to each of the numerical control devices 40A to 40C, the loading condition settings can be reset collectively in the numerical control devices 40A to 40C.

[0083] As described above, the control system 300 of the third embodiment of the present invention includes the PC 250 and the numerical control device 40A. The machine tool 1A includes the tool magazine 21. The tool magazine 21 can hold the tools 3, and transports the tools 3 to a predetermined position by rotating the magazine motor 64. The numerical control device 40A outputs a command to the machine tool 1A to indicate the drive conditions of the magazine motor 64. The PC 250 controls the numerical control device 40A. The control unit 251 of the PC 250 transmits a reset command to the numerical control device 40 after replacing the tools in the tool magazine 21. The storage unit 44 of the numerical control device 40A stores the loading conditions defined by the inertia around the rotation axis 23 of the tool magazine 21 and the offset load. The control unit 41A of the numerical control device 40A calculates the time constant of acceleration and deceleration of the magazine motor 64 during the rotating operation of the tool magazine 21 according to the loading conditions stored in the storage unit 44. The control unit 41 executes the turning operation of the tool magazine 21 with the calculated time constant. When the control unit 41 receives a reset command, it changes the time constant during the turning operation to the reference time constant. The control unit 41A estimates the inertia and offset load of the tool magazine 21 based on the result of executing the turning operation with the reference time constant during the execution of the NC program. The control unit 41A reflects the estimation result in the loading conditions stored in the storage unit 44. As a result, the numerical control device 40A can calculate the time constant of acceleration and deceleration of the magazine motor 64 with the loading conditions reflecting the estimation result at the next turning operation of the tool magazine 21. Therefore, the numerical control device 40A can automatically and optimally adjust the acceleration and deceleration during the turning operation of the tool magazine 21 according to the current loading conditions of the tool magazine 21. Furthermore, the numerical control device 40A can prevent operation with a non-optimal acceleration due to forgetting to perform estimation after changing tools in the tool magazine 21. As a result, the numerical control device 40A can prevent a failure of the machine tool 1 and an error due to insufficient torque of the magazine motor 64.

[0084] Moreover, the control system 300 includes three machine tools 1A-1C, three corresponding numerical control devices 40A-40C, and three tool changers 70A-70C. The tool changers 70A-70C correspond to the respective tool magazines 21 of the machine tools 1A-1C, and change tools to the tool magazines 21. The control unit 251 of the PC 250 transmits a reset command to each of the numerical control devices 40A-40C. As a result, in a system in which, for example, three numerical control devices 40A-40C in a factory are managed by the PC 250, the PC 250 can transmit a reset command to each of the numerical control devices 40A-40C simultaneously.

[0085] In the above description, the control unit 41 that executes the process of S42 in Fig. 17 is an example of a calculation unit. The control unit 41 that executes the process of S43 is an example of a turning execution unit. The control unit 41 that executes the process of S45 is an example of a change unit. The control unit 41 that executes the process of S48 is an example of an estimation unit. The control unit 41 that executes the process of S50 is an example of a reflection unit.

[0086] The present invention is not limited to the above embodiment, and various modifications are possible. Machine tool 1 is a vertical machine tool in which the axial direction of spindle 9 extends in the vertical direction, but it may be a horizontal machine tool in which the axial direction of the spindle extends in the front-rear direction. The method of estimating the loading conditions (inertia and offset load) and the direction of calculation of the time constant are not limited to the above embodiment, and other estimation methods and calculation methods may be used.

[0087] Although the tool changing device 70 in the above embodiment is a multi-joint robot arm, it may be a device other than a robot arm as long as it is a device capable of changing the tool 3 in the tool magazine 21. For example, the tool magazine may be configured as a circular main magazine and a sub-magazine, a tool transport arm may be provided in the sub-magazine, and a desired tool held by the sub-magazine may be attached to a temporary storage pot provided in the main magazine by the tool transport arm, and the tool attached to the temporary storage pot may be attached to a grip arm of the main magazine by a tool changing arm provided in the main magazine, thereby changing the tool.

[0088] In the first embodiment, the number of the macro variable that resets the loading condition setting is #30051, but a number other than #30051 may be used as long as it is a number used for a system variable (a variable used for a specific purpose), for example, a number such as #40001 may be used.

[0089] In the first embodiment, macro variables are used as the reset information to be set in the NC program, but any information that can be set in the NC program other than macro variables may be used, such as G code, M code, etc.

[0090] In the first embodiment, the tool changing device 70 is provided on the machine tool 1, but the machine tool 1 and the tool changing device 70 may be separate entities.

[0091] In the second embodiment, BY100 is used as the number of the PLC signal for resetting the loading condition settings, but a number other than BY100 may be used as long as it is within an allocatable range, for example, BY200.

[0092] In the third embodiment, the number of numerical control devices, machine tools, and tool changers constituting the control system 300 can be freely changed. Although CWCLRESTVAL is used as the character string of the reset command, other character strings may be used as long as they satisfy the requirements as a command character string, for example, CWCLRSTVL. [Explanation of symbols]

[0093] 1 Machine tools 3 tools 21 Tool Magazine 23 Swivel Axis 40 Numerical Control Device 41 Control section 64 Magazine Motor 70 Tool changing device 150 PLC 250 PC

Claims

1. A numerical control device for a machine tool including a tool magazine capable of loading tools thereon and rotating the tool magazine by being driven by a motor to transport the tools to a predetermined position, the numerical control device outputting a command to the motor, a storage unit that stores loading conditions defined by an inertia around a rotation axis of the tool magazine and an offset load; a calculation unit that calculates a time constant of acceleration / deceleration of the motor during the turning operation of the tool magazine in accordance with the loading conditions stored in the memory unit; a rotation execution unit that executes the rotation operation of the tool magazine using the time constant calculated by the calculation unit; a change unit which resets the loading conditions when reset information instructing to reset the loading conditions is read during execution of an NC program, and changes the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation unit that estimates the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection unit that reflects an estimation result of the estimation unit in the loading conditions stored in the storage unit; A numerical control device comprising:

2. The reset information is a macro variable. The numerical control device according to claim 1 .

3. The numerical control device further controls a tool changing device that changes the tools in the tool magazine, The reset information is set in an NC program that is executed first after the tool is changed by the tool changer.

3. The numerical control device according to claim 1 or 2,

4. A numerical control device for a machine tool including a tool magazine capable of loading tools thereon and rotating the tool magazine by being driven by a motor to transport the tools to a predetermined position, the numerical control device outputting a command to the motor, a storage unit that stores loading conditions defined by an inertia around a rotation axis of the tool magazine and an offset load; a calculation unit that calculates a time constant of acceleration / deceleration of the motor during the turning operation of the tool magazine in accordance with the loading conditions stored in the memory unit; a rotation execution unit that executes the rotation operation of the tool magazine using the time constant calculated by the calculation unit; a change unit which resets the loading conditions when a PLC signal instructing resetting of the loading conditions is received from a PLC controlling the numerical control device during execution of an NC program, and changes the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation unit that estimates the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection unit that reflects an estimation result of the estimation unit in the loading conditions stored in the storage unit; A numerical control device comprising:

5. The PLC controls the numerical control device and a tool changing device that changes the tools to the tool magazine, When the PLC executes the NC program after the tool changer changes the tool in the tool magazine, the PLC transmits the PLC signal to the numerical control device. The numerical control device according to claim 4 .

6. A system including: a numerical control device that outputs a command to a motor of a machine tool having a tool magazine that can load tools and rotates by the drive of a motor to transport the tools to a predetermined position; and a PLC that controls the numerical control device, The PLC includes a signal transmitting unit that transmits a PLC signal to the numerical control device after the tool is replaced in the tool magazine, The numerical control device includes: a storage unit that stores loading conditions defined by an inertia around a rotation axis of the tool magazine and an offset load; a calculation unit that calculates a time constant of acceleration / deceleration of the motor during the turning operation of the tool magazine in accordance with the loading conditions stored in the memory unit; a rotation execution unit that executes the rotation operation of the tool magazine using the time constant calculated by the calculation unit; a change unit that resets the loading condition when receiving the PLC signal transmitted by the signal transmission unit, and changes the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation unit that estimates the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection unit that reflects an estimation result of the estimation unit in the loading conditions stored in the storage unit; A system comprising:

7. The tool magazine further includes a tool changing device for changing the tools to the tool magazine. The PLC controls each of the numerical control device and the tool changing device, The signal transmission unit of the PLC transmits the PLC signal to the numerical control device after the tool is changed by the tool changer. The system of claim 6 .

8. A numerical control device for a machine tool including a tool magazine capable of loading tools thereon and rotating the tool magazine by being driven by a motor to transport the tools to a predetermined position, the numerical control device outputting a command to the motor, a storage unit that stores loading conditions defined by an inertia around a rotation axis of the tool magazine and an offset load; a calculation unit that calculates a time constant of acceleration / deceleration of the motor during the turning operation of the tool magazine in accordance with the loading conditions stored in the memory unit; a rotation execution unit that executes the rotation operation of the tool magazine using the time constant calculated by the calculation unit; a change unit which resets the loading conditions when a command signal instructing to reset the loading conditions is received from a PC capable of communicating with the numerical control device during execution of an NC program, and changes the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation unit that estimates the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection unit that reflects an estimation result of the estimation unit in the loading conditions stored in the storage unit; A numerical control device comprising:

9. A system including: a numerical control device that outputs a command to a motor of a machine tool having a tool magazine that can load tools and that rotates by being driven by a motor to transport the tools to a predetermined position; and a PC that controls the numerical control device, The PC includes a signal transmitting unit that transmits a command signal after the tool is replaced in the tool magazine, The numerical control device includes: a storage unit that stores loading conditions defined by an inertia around a rotation axis of the tool magazine and an offset load; a calculation unit that calculates a time constant of acceleration / deceleration of the motor during the turning operation of the tool magazine in accordance with the loading conditions stored in the memory unit; a rotation execution unit that executes the rotation operation of the tool magazine using the time constant calculated by the calculation unit; a change unit that resets the loading condition when receiving the command signal transmitted by the signal transmission unit, and changes the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation unit that estimates the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection unit that reflects an estimation result of the estimation unit in the loading conditions stored in the storage unit; A system comprising:

10. A plurality of the machine tools; A plurality of the numerical control devices corresponding to the plurality of machine tools; a plurality of tool changing devices corresponding to the respective tool magazines of the plurality of machine tools and changing the tools to the respective tool magazines; Further equipped with The signal transmission unit of the PC transmits the command signal to each of the plurality of numerical control devices. The system of claim 9 .

11. A method for controlling a numerical control device that outputs a command to a motor for a machine tool having a tool magazine capable of loading tools thereon and rotating the tool magazine by being driven by the motor to transport the tool to a predetermined position, comprising: a calculation step of calculating a time constant of acceleration / deceleration of the motor during the turning operation of the tool magazine in accordance with loading conditions stored in a storage unit that stores loading conditions defined by an inertia around a turning axis of the tool magazine and an offset load; a rotation execution step of executing the rotation operation of the tool magazine using the time constant calculated in the calculation step; a changing step of resetting the loading conditions when reset information instructing to reset the loading conditions is read during execution of an NC program, and changing the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation step of estimating the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection step of reflecting an estimation result in the estimation step in the loading conditions stored in the storage unit; A control method comprising:

12. A program executable by a computer of a numerical control device that outputs a command to a motor for a machine tool having a tool magazine that can hold tools and that rotates by being driven by a motor to transport the tools to a predetermined position, The computer includes: a calculation step of calculating a time constant of acceleration / deceleration of the motor during the swing operation of the tool magazine in accordance with loading conditions stored in a storage unit that stores loading conditions defined by an inertia around a swing axis of the tool magazine and an offset load; a rotation execution step of executing the rotation operation of the tool magazine with the time constant calculated in the calculation step; a changing step of resetting the loading conditions when reset information instructing to reset the loading conditions is read during execution of an NC program, and changing the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation step of estimating the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection step of reflecting an estimation result in the estimation step in the loading conditions stored in the storage unit; A program characterized by executing the above.

13. A method for controlling a numerical control device that outputs a command to a motor for a machine tool having a tool magazine capable of loading tools thereon and rotating the tool magazine by being driven by the motor to transport the tool to a predetermined position, comprising: a calculation step of calculating a time constant of acceleration / deceleration of the motor during the swing operation of the tool magazine in accordance with loading conditions stored in a storage unit that stores loading conditions defined by an inertia around a swing axis of the tool magazine and an offset load; a rotation execution step of executing the rotation operation of the tool magazine using the time constant calculated in the calculation step; a changing step of resetting the loading conditions when a PLC signal instructing resetting of the loading conditions is received from a PLC controlling the numerical control device during execution of an NC program, and changing the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation step of estimating the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection step of reflecting an estimation result in the estimation step in the loading conditions stored in the storage unit; A control method comprising:

14. A program executable by a computer of a numerical control device that outputs a command to a motor for a machine tool having a tool magazine that can hold tools and that rotates by being driven by a motor to transport the tools to a predetermined position, The computer includes: a calculation step of calculating a time constant of acceleration / deceleration of the motor during the swing operation of the tool magazine in accordance with loading conditions stored in a storage unit that stores loading conditions defined by an inertia around a swing axis of the tool magazine and an offset load; a rotation execution step of executing the rotation operation of the tool magazine with the time constant calculated in the calculation step; a changing step of resetting the loading conditions when a PLC signal instructing resetting of the loading conditions is received from a PLC controlling the numerical control device during execution of an NC program, and changing the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation step of estimating the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection step of reflecting an estimation result in the estimation step in the loading conditions stored in the storage unit; A program comprising:

15. A method for controlling a numerical control device that outputs a command to a motor for a machine tool having a tool magazine capable of loading tools thereon and rotating the tool magazine by being driven by the motor to transport the tool to a predetermined position, comprising: a calculation step of calculating a time constant of acceleration / deceleration of the motor during the swing operation of the tool magazine in accordance with loading conditions stored in a storage unit that stores loading conditions defined by an inertia around a swing axis of the tool magazine and an offset load; a rotation execution step of executing the rotation operation of the tool magazine using the time constant calculated in the calculation step; a changing step of resetting the loading conditions when a command signal instructing to reset the loading conditions is received from a PC capable of communicating with the numerical control device during execution of the NC program, and changing the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation step of estimating the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection step of reflecting an estimation result in the estimation step in the loading conditions stored in the storage unit; A control method comprising:

16. A program executable by a computer of a numerical control device that outputs a command to a motor for a machine tool having a tool magazine that can hold tools and that rotates by being driven by a motor to transport the tools to a predetermined position, The computer includes: a calculation step of calculating a time constant of acceleration / deceleration of the motor during the swing operation of the tool magazine in accordance with loading conditions stored in a storage unit that stores loading conditions defined by an inertia around a swing axis of the tool magazine and an offset load; a rotation execution step of executing the rotation operation of the tool magazine with the time constant calculated in the calculation step; a changing step of resetting the loading conditions when a command signal instructing to reset the loading conditions is received from a PC capable of communicating with the numerical control device during execution of the NC program, and changing the time constant during the turning operation to a reference time constant at which the motor can operate when the loading state of the tools in the tool magazine is a reference loading state; an estimation step of estimating the inertia and the offset load of the tool magazine based on a result of executing the turning operation with the reference time constant during execution of an NC program; a reflection step of reflecting an estimation result in the estimation step in the loading conditions stored in the storage unit; A program comprising:

Images