Control apparatus, control method, and storage medium

Abstract

To provide a control device, a control method, and a program capable of securing convenience while reducing power consumption by controlling power supply to a servo motor according to an operation state of a machine tool.SOLUTION: In the continuous operation mode, the numerical controller releases the holding brake by supplying power to the magazine motor based on the fact that the spindle is at the tool change position, and applies the holding brake by interrupting the power supply to the magazine motor based on the fact that the spindle is at the origin position. In the maintenance mode, the numerical controller supplies power to the magazine motor to release the holding brake based on the fact that the spindle is located between the preparation position and the origin position, and interrupts the power supply to the magazine motor to apply the holding brake based on the fact that the spindle is located in the machining area. Therefore, the power consumption can be reduced in the continuous operation mode, and the convenience can be enhanced in the maintenance mode.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a control device, a control method, and a program for controlling a machine tool equipped with a tool changer. [Background technology]

[0002] Patent Document 1 discloses a tool changer that reduces power consumption in a servo motor that rotates a tool magazine. The tool changer reduces power consumption by stopping the power supply to the servo motor if the next tool change command is not output within a predetermined time after the completion of a tool indexing operation in the tool magazine. The servo motor is provided with an electromagnetic brake that activates when the power supply is stopped. While the servo motor is stopped, the electromagnetic brake inhibits rotation of the tool magazine. When the next tool change command is output, the tool changer resumes power supply to the servo motor. While power is being supplied to the servo motor, the electromagnetic brake is deactivated. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-192434 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it is more convenient to control the timing of stopping and restarting the power supply to the servo motor in accordance with the operating state of the machine tool.

[0005] An object of the present invention is to provide a control device, a control method, and a program that can reduce power consumption while ensuring convenience by controlling the power supply to a servo motor according to the operating state of a machine tool. [Means for solving the problem]

[0006] According to a first aspect of the present invention, there is provided a control device having a control unit for controlling the operation of a machine tool which includes a spindle capable of moving to a machining area where a workpiece is machined using the tool and a tool changing area where the tool is changed, and a tool magazine capable of storing the tool and transporting the tool to be attached to the spindle by driving a servo motor, wherein the control unit executes a supply process for supplying power to the servo motor, an interruption process for interrupting the supply of power to the servo motor, and a judgment process for judging the operating state of the machine tool, and controls the execution of the supply process and the interruption process based on the operating state of the machine tool.

[0007] If the power supply to the servo motor is limited to the minimum necessary, it will be inconvenient when, for example, a user wants to replace a tool stored in a tool magazine. By controlling whether or not to supply power to the servo motor that drives the tool magazine based on the operating mode of the machine tool, the control device can ensure convenience while reducing power consumption.

[0008] In the first aspect, the control unit may further perform a detection process to detect the position of the spindle, and control the execution of the supply process and the interruption process based on the operating state of the machine tool and the position of the spindle.The control device can ensure convenience while reducing power consumption by controlling whether or not to supply power to a servo motor that drives a tool magazine based on the operating mode of the machine tool and the position of the spindle.

[0009] In a first aspect, the operating states of the machine tool include a first operating state in which the machine tool operates according to instructions written in a machining program for controlling the operation of the machine tool, and a second operating state in which the machine tool individually receives instructions for operation and performs a single operation corresponding to the instructions. The control unit may execute the supply process to supply power to the servo motor when the determination process determines that the operating state of the machine tool is the first operating state and the detection process detects that the spindle is at a tool change position within the tool change area where the tool to be attached to the spindle is changed. The control unit may execute the supply process to supply power to the servo motor when the determination process determines that the operating state of the machine tool is the second operating state and the detection process detects that the spindle is at a preparation position between the machining area and the tool change position. In the first operating state, the machine tool operates according to instructions from the machining program. Therefore, the control device can reduce power consumption by supplying power to the servo motor when the machine tool is in the first operating state and the spindle is at the tool change position. On the other hand, in the second operating state, the machine tool performs a single operation corresponding to each individual instruction each time it receives the instruction. Therefore, the control device can ensure convenience by supplying power to the servo motor based on the second operating state and the spindle being in the ready position.

[0010] In a first aspect, the control unit may execute the supply process to supply power to the servo motor based on the determination process determining that the operating state of the machine tool is the first operating state, the detection process detecting that the spindle is at the tool change position, and execution of a command to move the spindle from the tool change position toward an origin position that is the origin of an axial movement range of the spindle and is apart from the tool change position in the axial direction within the tool change region, and may execute the supply process to supply power to the servo motor based on the determination process determining that the operating state of the machine tool is the second operating state and the spindle is located between the preparation position and the origin position, including the preparation position. The control device can reduce power consumption by supplying power to the servo motor based on the first operating state, the spindle being at the tool change position, and execution of a command to move the spindle from the tool change position to the origin position. In addition, in the second operating state, the control device supplies power based on the fact that the spindle is located at the ready position, but further, by maintaining the supply of power to the servo motor based on the fact that the spindle is located between the ready position and the origin position, convenience can be ensured.

[0011] In a first aspect, the operating states of the machine tool include a first operating state in which the machine tool operates in accordance with instructions written in a machining program for controlling operation of the machine tool, and a second operating state in which the machine tool individually accepts instructions for operation of the machine tool and performs a single operation corresponding to the instructions, and the control unit may execute the interruption process to interrupt the supply of power to the servo motor when the determination process determines that the operating state of the machine tool is the first operating state and the detection process detects that the spindle is at an origin position that is an origin of the axial movement range of the spindle and is axially separated from a tool change position within the tool change area where the tool to be attached to the spindle is changed, and may execute the interruption process to interrupt the supply of power to the servo motor when the determination process determines that the operating state of the machine tool is the second operating state and the detection process detects that the spindle is in the machining area. In the first operating state, the machine tool operates in accordance with instructions from the machining program. Therefore, the control device can reduce power consumption by interrupting the power supply to the servo motor based on the fact that the machine is in the first operating state and the spindle is in the home position. On the other hand, in the second operating state, the machine tool performs a single operation corresponding to an individual instruction each time it receives that instruction. Therefore, the control device can reduce power consumption while maintaining convenience by interrupting the power supply to the servo motor based on the fact that the machine is in the second operating state and the spindle is in the machining area.

[0012] In a first aspect, the control unit may execute the interruption process to interrupt the power supply to the servo motor based on the following: the determination process determines that the operating state of the machine tool is the first operating state; the detection process detects that the spindle is at the origin position; and a command to move the spindle from the origin position toward the tool change position is executed; the control unit may execute the interruption process to interrupt the power supply to the servo motor based on the following: the determination process determines that the operating state of the machine tool is the second operating state; the detection process detects that the spindle is at a preparation position between the machining area and the tool change position; the command to move the spindle from the preparation position toward the machining area is executed; and the detection process detects that the spindle is in the machining area. The control device can reduce power consumption by interrupting the power supply to the servo motor based on the following: the operating state is the first operating state; the spindle is at the origin position; and the command to move the spindle from the origin position to the tool change position is received. On the other hand, when the control device detects that the spindle is in the second operating state, the spindle is in the preparation position, and an instruction to move the spindle from the preparation position to the machining area is executed, the control device interrupts the power supply to the servo motor based on the detection that the spindle is in the machining area, thereby ensuring convenience and reducing power consumption.

[0013] In a first aspect, the control unit may execute a setting process to set a constant power supply mode in which power is always supplied to the servo motor, or a controlled power supply mode in which execution of the supply process and the interruption process is controlled, and when the constant power supply mode is set in the setting process, the control unit may execute the supply process to supply power to the servo motor regardless of the position of the spindle, and when the controlled power supply mode is set in the setting process, the control unit may execute the supply process or the interruption process to supply power to the servo motor based on the operating state of the machine tool and the position of the spindle. Since a user can set the constant power supply mode or the controlled power supply mode as needed, convenience can be improved.

[0014] According to a second aspect of the present invention, there is provided a control method for a control device having a control unit for controlling operation of a machine tool including a spindle capable of mounting a tool and moving between a machining area where a workpiece is machined using the tool and a tool changing area where the tool is changed, and a tool magazine capable of storing the tool and transporting the tool mounted on the spindle by driving a servo motor, the control method comprising causing the control unit to execute a supply step of supplying power to the servo motor, an interruption step of interrupting the power supply to the servo motor, and a determination step of determining an operating state of the machine tool, and controlling the execution of the supply step and the interruption step based on the operating state of the machine tool, thereby achieving the same effect as the first aspect.

[0015] According to a third aspect of the present invention, there is provided a program for causing a computer of a control device to execute processing for controlling the operation of a machine tool including a spindle capable of moving to a machining area where a workpiece is machined using the tool and a tool changing area where the tool is changed, and a tool magazine capable of storing the tool and driving a servo motor to transport the tool to be attached to the spindle, the program causing the computer to execute a supply step of supplying power to the servo motor, an interruption step of interrupting the power supply to the servo motor, and a determination step of determining the operating state of the machine tool, and controlling the execution of the supply step and the interruption step based on the operating state of the machine tool, thereby achieving the same effect as the first aspect. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 2 is a perspective view of the machine tool 1 as seen from the front upper right. [Figure 2] FIG. 2 is a perspective view of the machine tool 1 as seen from the lower front right. [Figure 3] FIG. 2 is a right side view of the machine tool 1. [Figure 4] 2 is a cross-sectional view of the tool changer 30 taken along line II in FIG. 1 . [Figure 5]2 is a block diagram showing the electrical configuration of the machine tool 1. FIG. [Figure 6] FIG. 10 is a diagram showing the outward path of the tool changing operation. [Figure 7] FIG. 10 is a diagram showing the return path of the tool changing operation. [Figure 8] 3A and 3B are diagrams illustrating control settings of a holding brake and operation modes of the machine tool 1. [Figure 9] 10 is a flowchart of a main process. [Figure 10] 10 is a continuation of the flowchart of the main process in FIG. 9. [Figure 11] 11 is a continuation of the flowchart of the main process in FIG. 10 . [Figure 12] 10 is a continuation of the flowchart of the main process in FIG. 9. [Figure 13] 13 is a continuation of the flowchart of the main process in FIG. 12. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will be described. In the following description, left and right, front and rear, and up and down will be used as indicated by arrows in the drawings. The left and right direction, up and down direction, and front and rear direction of machine tool 1 correspond to the X-axis direction, Y-axis direction, and Z-axis direction of machine tool 1, respectively. Machine tool 1 shown in Fig. 1 is a horizontal type machine tool in which the rotation axis of main spindle 7 extends in the front and rear direction (Z-axis direction), and a column traverse type machine tool in which column 5 moves in the X-axis and Z-axis directions.

[0018] The structure of machine tool 1 will be described with reference to Figures 1 to 3. Machine tool 1 includes a base 2, an X-axis movement mechanism 11, a Z-axis movement mechanism 12, a column 5, a Y-axis movement mechanism 13 (see Figure 1), a spindle head 6, a spindle 7 (see Figure 3), a control box 8, a rotary table 9, a tool changer 30 (see Figure 4), a magazine cover 10, etc.

[0019] The base 2 is an iron base with a roughly rectangular parallelepiped shape that is long in the Z-axis direction. The X-axis movement mechanism 11 is provided at the rear of the upper surface of the base 2, and supports the movable body 15 so that it can move in the X-axis direction. The Z-axis movement mechanism 12 is provided on the upper surface of the movable body 15. The Z-axis movement mechanism 12 supports the column 5 so that it can move in the Z-axis direction. The column 5 is an upright pillar that extends in the vertical direction. A vertically elongated rectangular through-hole (not shown) that penetrates the column 5 in the front-to-rear direction is formed in the column 5. The frame cover 20 is attached to the front of the column 5. The frame cover 20 is a frame body that is vertically elongated in a front view, and covers the space between the column 5 and the spindle head 6. The Y-axis movement mechanism 13 is provided in front of the column 5, and supports the spindle head 6 so that it can move in the Y-axis direction. The X-axis moving mechanism 11, Z-axis moving mechanism 12, and Y-axis moving mechanism 13 each include, for example, a guide, a ball screw, and a motor (X-axis motor, Z-axis motor, Y-axis motor), and the power of the motors moves the moving body 15, column 5, and spindle head 6, respectively, along the guides.

[0020] The spindle head 6 extends in the Z-axis direction and is provided so as to be movable in the Y-axis direction along the front surface of the column 5 by a Y-axis movement mechanism 13. The spindle head 6 is movable in the Y-axis direction between the machining area and the tool changing area (see FIG. 3). The machining area is an area where machining of a workpiece fixed to the rotary table 9 is performed. The machining area is provided in a space on the base 2 side (below) of the Y-axis origin. The Y-axis origin is the position where the Y-axis machine coordinate is 0. The tool changing area is an area where tool changing is performed by the tool changer 30. The tool changing area is provided in a space on the opposite side (above) of the machining area with respect to the Y-axis origin. The tool changing area is provided above the machining area in the Y-axis direction and at a position overlapping with the machining area in the Z-axis direction. In this embodiment, the Y-axis origin is assumed to be included in the tool changing area.

[0021] The spindle head 6 is equipped with an upper cover 28 and an armor cover 85. The upper cover 28 is fixed to the rear end of the upper surface of the spindle head 6. The upper cover 28 is a metal plate that is roughly rectangular in front view, and extends upward from the rear end of the upper surface of the spindle head 6. The armor cover 85 is fixed to the rear end of the lower surface of the spindle head 6 in a suspended state. The armor cover 85 comprises multiple metal plates lined up in the vertical direction, and expands and contracts in a nested manner in the vertical direction. The upper cover 28 moves up and down together with the spindle head 6, thereby always covering the area above the spindle head 6 on the front surface of the column 5. The armor cover 85 expands and contracts in the vertical direction in response to the up and down movement of the spindle head 6, thereby always covering the area below the spindle head 6 on the front surface of the column 5.

[0022] The spindle 7 is provided coaxially with the spindle head 6 within the spindle head 6. That is, the rotation axis of the spindle 7 extends in the front-to-rear direction (Z-axis direction). The spindle head 6 rotatably supports the spindle 7. A motor holding box 27 (see Figure 3) is fixed to the rear of the spindle head 6. The motor holding box 27 extends rearward from the rear of the spindle head 6 and holds a spindle motor 26 (see Figure 5) inside. The motor holding box 27 protrudes rearward from a through-hole in the column 5. The output shaft of the spindle motor 26 extends forward and is coaxially connected to the rear end of the spindle 7.

[0023] The spindle 7 is equipped with a tool mounting hole 40 and a holder retaining member 19. The tool mounting hole 40 is provided at the tip (front end) of the spindle 7. The tool mounting hole 40 expands in diameter in a generally conical shape toward the tip of the spindle 7. The holder retaining member 19 is provided at the back side of the tool mounting hole 40. A tool holder 90 (see FIG. 4) is detachably attached to the tool mounting hole 40. The tool holder 90 holds a tool 91 at one end, and is equipped with a tapered portion and a pull stud 93 (see FIG. 4) at the other end. The tapered portion is generally conical and fits tightly into the tool mounting hole 40 of the spindle 7. The pull stud 93 protrudes in the axial direction from the top of the tapered portion. When the tapered portion is attached to the tool mounting hole 40, the holder retaining member 19 holds the pull stud 93, fixing the tool holder 90 to the spindle 7.

[0024] A pair of support members 17, 18 are provided at the rear of the base 2. The support members 17, 18 are spaced apart from each other in the left-right direction and extend upward, supporting the control box 8 from below. The control box 8 houses a numerical control device 50 (see Figure 5) inside. The numerical control device 50 controls the operation of the machine tool 1. The operation panel 25 (see Figure 5) is provided on the outer wall of a cover (not shown) that covers the machine tool 1, and has an operation unit 25A and a display unit 25B (see Figure 5). The operation unit 25A receives input of various information, instructions, etc., and outputs them to the numerical control device 50. The display unit 25B displays various screens based on commands from the numerical control device 50. A work table 16 is provided on the front top surface of the base 2. A rotary table 9 is attached to the work table 16. The rotary table 9 is located in front of the spindle head 6. The rotary table 9 has a workpiece fixed to its upper surface with a jig (not shown), and is rotatable 360 ​​degrees around a rotation axis parallel to the Y-axis direction.

[0025] A pair of support columns 21, 22 are provided on the front and left and right sides of the upper surface of the base 2. A connecting plate 23 (see FIG. 4) is fixed between the opposing upper parts of the support columns 21 and 22. As shown in FIG. 4, the tool changer 30 is fixed to the front surface of the connecting plate 23. Therefore, the tool changer 30 is located between the column 5 and the rotary table 9 and above the spindle head 6 by the support columns 21, 22. The tool changer 30 includes a tool magazine 31, a reducer 32, a magazine motor 33, etc. The tool magazine 31 includes a magazine base 37 and multiple grip arms 35. The magazine base 37 is substantially disk-shaped and is rotatably supported on the front surface of the connecting plate 23 around a rotation axis 37A that extends in the front-rear direction and whose front side is inclined downward relative to the rear side. The reducer 32 and the magazine motor 33 are attached to the tool magazine 31. An output shaft (not shown) of the magazine motor 33 meshes with a rotation shaft 37A of the magazine base 37 via the reducer 32. The power of the magazine motor 33 is transmitted to the rotation shaft of the magazine base 37 via the reducer 32.

[0026] The multiple grip arms 35 are arranged side by side along the outer periphery of the magazine base 37 and extend radially outward. The grip arms 35 grip the tool holder 90 in the Y-axis direction perpendicular to the tool holder 90 when the tool holder 90 is laid horizontally. When changing a tool, the grip arms 35 move to a tool change position C (see FIG. 6) of the tool magazine 31. The tool change position C is the lowest position of the tool magazine 31. At the tool change position C, the up-down direction, left-right direction, and front-rear direction of the grip arms 35 are aligned with the Y-axis direction, X-axis direction, and Z-axis direction of the machine tool 1, respectively.

[0027] As shown in Figures 1 to 4, a magazine cover 10 is fixed to the front of the upper part of each of the support columns 21, 22. The magazine cover 10 covers the periphery of the tool magazine 31. The magazine cover 10 prevents chips and splashes of coolant (cutting fluid) from adhering to the tool magazine 31 when a workpiece is machined.

[0028] The magazine cover 10 has a rectangular box shape with a chamfered lower right corner when viewed from the front. An opening 110 is provided in the bottom wall 101 and rear wall 102 of the magazine cover 10. The opening 110 is formed near the right wall 103 and has a rectangular opening extending from the bottom wall 101 to the rear wall 102. The size of the opening 110 is such that the front end of the spindle head 6 and the tool 91 held by the spindle 7 can pass through the bottom wall 101 and a portion of the rear wall 102 in the vertical direction and enter the magazine cover 10. The opening 110 has a rectangular shape when viewed from the bottom and is located directly below the tool change position C. A shutter 120 is provided in the opening 110. The shutter 120 opens and closes the opening 110 under the control of the numerical control device 50. When the shutter 120 is in the open state, the spindle 7 can pass through the opening 110 while holding the tool 91 and move to the tool change position C.

[0029] The right wall 103 of the magazine cover 10 has an inclined wall 106 below the center in the vertical direction. The inclined wall 106 extends diagonally upward to the right from the right end of the bottom wall 101 and connects to the lower end of the right wall 103. The center of the inclined wall 106 is open, and an opening / closing door 106A (see FIG. 2) is provided. A user can open the opening / closing door 106A to attach and detach a tool holder 90 that holds a tool 91 to and from the grip arm 35 of the tool magazine 31, or to perform maintenance inside the magazine cover 10.

[0030] The electrical configuration of machine tool 1 will be described with reference to Figure 5. Numerical control device 50 of machine tool 1 has CPU 51, ROM 52, RAM 53, storage device 54, input / output interface 56, and drive circuits 61-66. CPU 51 controls numerical control device 50 overall. ROM 52 stores various setting information. RAM 53 temporarily stores various information. Storage device 54 is non-volatile and stores a plurality of NC programs (described below), a control program for executing main processing (see Figure 9), etc. NC programs are machining programs made up of a plurality of lines. Each line of the NC program includes control commands for performing various operations including axis movement and tool change of machine tool 1. Numerical control device 50 executes the control commands that make up the NC program line by line to control the operation of machine tool 1.

[0031] The input / output interface 56 inputs and outputs various signals between the CPU 51, ROM 52, RAM 53, storage device 54, drive circuits 61-66, operation unit 25A, and display unit 25B. Drive circuit 61 is connected to the spindle motor 26 and encoder 26B. Drive circuit 62 is connected to the X-axis motor 11A and encoder 11B. Drive circuit 63 is connected to the Z-axis motor 12A and encoder 12B. Drive circuit 64 is connected to the Y-axis motor 13A and encoder 13B. Drive circuit 65 is connected to the magazine motor 33 and encoder 33B. Drive circuit 66 is connected to the air cylinder 34 and sensor 34B.

[0032] Drive circuits 61-65 output drive currents to spindle motor 26, X-axis motor 11A, Z-axis motor 12A, Y-axis motor 13A, and magazine motor 33, respectively, based on commands input from CPU 51. Spindle motor 26, X-axis motor 11A, Z-axis motor 12A, Y-axis motor 13A, and magazine motor 33 are all servo motors that rotate in response to the input drive current. Encoders 26B, 11B, 12B, 13B, and 33B are all absolute value encoders that detect the rotational positions of spindle motor 26, X-axis motor 11A, Z-axis motor 12A, Y-axis motor 13A, and magazine motor 33, respectively.

[0033] Encoders 26B, 11B, 12B, 13B, and 33B output feedback signals indicating the detected rotational positions to drive circuits 61 to 65, respectively. Based on the feedback signals, drive circuits 61 to 65 perform feedback control on spindle motor 26, X-axis motor 11A, Z-axis motor 12A, Y-axis motor 13A, and magazine motor 33, respectively. CPU 51 detects the rotational position of spindle 7, the position of spindle 7 in the X-axis direction, the position of spindle 7 in the Z-axis direction, the position of spindle 7 in the Y-axis direction, and the rotational position of tool magazine 31, based on the feedback signals output by encoders 26B, 11B, 12B, 13B, and 33B, respectively.

[0034] The magazine motor 33 has a holding brake 33A. The holding brake 33A is a non-excitation type electromagnetic brake that operates without consuming power. The holding brake 33A holds the rotating shaft of the magazine motor 33 when power is not supplied to the magazine motor 33, and keeps the rotational position of the tool magazine 31 from shifting. When power is supplied to the magazine motor 33, the holding brake 33A releases the holding of the rotating shaft of the magazine motor 33, allowing the tool magazine 31 to rotate by the magazine motor 33. When power is supplied to the magazine motor 33, the drive circuit 65 feedback controls the magazine motor 33 based on a command that determines the rotational position of the tool magazine 31, and maintains the rotational position of the tool magazine 31.

[0035] Supplying power to the magazine motor 33 means that the CPU 51 of the numerical control device 50 sends a command to the drive circuit 65, and in accordance with the command, the drive circuit 65 supplies power for driving the magazine motor 33. Note that power supply to the magazine motor 33 may also be performed by the numerical control device 50 supplying power to the drive circuit 65, and the drive circuit 65 transmitting the power to the magazine motor 33.

[0036] The drive circuit 66 drives the air cylinder 34 by supplying or discharging air to or from the air cylinder 34 based on commands input from the CPU 51. The air cylinder 34 is connected to the shutter 120. Drive of the air cylinder 34 causes the shutter 120 to move between an open state in which the opening 110 is opened and a closed state in which the opening 110 is closed. The sensor 34B is a magnetic sensor that detects the open state and closed state of the shutter 120. The drive circuit 66 controls the drive state of the air cylinder 34 based on the detection signal of the sensor 34B.

[0037] An overview of the tool changing operation will be described with reference to Figures 6 and 7. When the machine tool 1 is in a machining state cutting a workpiece W, the spindle 7 is located in the machining area. After machining using the tool 91 attached to the spindle 7 is completed, the machine tool 1 executes a tool changing operation. The tool changing operation includes a tool storing operation in which the used tool 91 is stored in the tool magazine 31, and a tool loading operation in which the next tool 92 to be used is loaded onto the spindle 7 and moved to a position where machining starts. The path traveled by the spindle 7 when storing the tool is referred to as the outgoing path, and the path traveled by the spindle 7 when loading the tool is referred to as the returning path. In this embodiment, "moving the spindle 7" is synonymous with "moving the spindle head 6."

[0038] The forward path is the path along which the spindle 7 moves from the machining end position Q1 to the origin position D (see Figure 6). The return path is the path along which the spindle 7 moves from the origin position D to the machining start position Q2 (see Figure 7). The machining end position Q1 is the position of the spindle 7 when machining of the workpiece W is completed according to the NC program. The origin position D is a reference point for tool change that is set in the tool change area. The origin position D is located away from the tool change position C in the Z+ direction and is the origin of the movement range of the spindle 7 in the Z-axis direction. The movement range of the spindle 7 in the Z-axis direction is the range from the origin position D in the Z+ direction to a position in the Z- direction where the workpiece W can be machined. The machining start position Q2 is the position of the spindle 7 when machining of the workpiece W begins according to the NC program and is the target position to which the spindle 7 moves after the tool change.

[0039] The forward path will now be described. As shown in FIG. 6, the machine tool 1 moves the spindle 7 from the machining end position Q1 in the positive direction of the Z axis, passes through the first return position A1, and moves to the preparation position B. The first return position A1 is set at a position away from the machining end position Q1 in the positive direction of the Z axis so that the tool 91 attached to the spindle 7 does not come into contact with the workpiece W or the jig fixed on the rotary table 9. The first return position A1 is at the same coordinate position as the machining end position Q1 in the X-axis and Y-axis directions. The preparation position B is at the same coordinate position as the tool change position C in the X-axis and Z-axis directions. The tool change position C is a position where the grip arm 35 of the tool magazine 31 grips the tool holder 90 that holds the tool 91. The preparation position B is at the position away from the tool change position C in the negative direction of the Y axis so that the spindle 7 is positioned so that the grip arm 35 can grip and release the tool holder 90 in the Y-axis direction.

[0040] By driving the air cylinder 34, the shutter 120 of the magazine cover 10 is opened. The machine tool 1 raises the spindle 7 from the preparation position B to the tool change position C. The tool change position C is inside the magazine cover 10. At this time, the tool holder 90 attached to the spindle 7 engages from below with the empty grip arm 35 located directly below the tool magazine 31. In this state, the machine tool 1 moves the spindle 7 backward in the + direction of the Z axis from the tool change position C to the origin position D. At this time, the tool holder 90 is withdrawn from the spindle 7. This completes the forward movement of the spindle 7 when storing tools.

[0041] The return path will now be described. The machine tool 1 rotates the tool magazine 31 and transports the grip arm 35, which holds the next tool 92 to be loaded, to directly below the tool magazine 31. At this time, the next tool 92 is positioned in front of the spindle 7. In this state, as shown in FIG. 7, the machine tool 1 moves the spindle 7, which is at the origin position D, forward in the negative direction of the Z axis, and moves it to the tool change position C. As a result, the next tool 92 is loaded onto the spindle 7.

[0042] When the next tool 92 is attached to the spindle 7, the machine tool 1 lowers the spindle 7 from the tool change position C to the preparation position B. The shutter 120 of the magazine cover 10 is closed by driving the air cylinder 34. The machine tool 1 moves the spindle 7 from the preparation position B to the second return position A2, and then moves it to the machining start position Q2. The second return position A2 is set away from the machining start position Q2 in the positive direction of the Z axis, so that the tool 91 attached to the spindle 7 does not come into contact with the workpiece W or jig fixed on the rotary table 9. The second return position A2 is at the same coordinate as the machining start position Q2 in the X-axis and Y-axis directions. This completes the return movement of the spindle 7 when attaching the tool, and completes the tool change operation sequence.

[0043] The holding brake control settings and the operation modes of the machine tool 1 will be described with reference to FIG. 8. The numerical control device 50 can set the holding brake control to enabled or disabled in the initial operation settings of the machine tool 1. As shown in FIG. 8(B), when the holding brake control setting is disabled, the numerical control device 50 always supplies power to the magazine motor 33, regardless of the position of the spindle 7 shown in FIG. 8(A). Therefore, in this case, the holding brake 33A is always in a released state, regardless of the position of the spindle 7. When the holding brake control setting is disabled, no consideration is given to reducing power consumption.

[0044] The numerical control device 50 maintains the rotational position of the tool magazine 31 by driving the magazine motor 33 based on the feedback signal from the encoder 33B. For example, the tool magazine 31 may rotate from a designated rotational position due to an unbalanced load caused by the storage state of the tools 91. In this case, the drive circuit 65 drives the magazine motor 33 based on the feedback signal to rotate the tool magazine 31 so that the tool magazine 31 is positioned at the designated rotational position. In this way, when the holding brake control setting is disabled, the numerical control device 50 drives the magazine motor 33 to maintain the rotational position of the tool magazine 31, which constantly consumes power.

[0045] When the holding brake control setting is enabled, the numerical controller 50 controls the supply of power to the magazine motor 33 or the interruption of the power supply depending on the position of the spindle 7. Furthermore, when the holding brake control is enabled, the numerical controller 50 supplies power according to each of the multiple operation modes of the machine tool 1. Examples of operation modes include a continuous operation mode and a maintenance mode. The continuous operation mode is an operation mode in which the machine tool 1 operates in accordance with instructions written in an NC program. The maintenance mode is an operation mode in which a single operation corresponding to an instruction is performed in accordance with an individual instruction given for the operation of the machine tool 1. The operation instruction may be given, for example, by a user inputting an instruction via the operation unit 25A, or the instructions of the NC program may be executed one by one in accordance with a user instruction.

[0046] In the continuous operation mode, the numerical control device 50 continuously performs various operations, including the operation of replacing the tool 91 attached to the spindle 7, in accordance with various commands. Therefore, during the continuous operation mode, for example, the user will not open the opening / closing door 106A of the magazine cover 10 to perform maintenance work or to attach, remove, or replace the tool 91 to the tool magazine 31. As shown in FIG. 8(C), in the continuous operation mode, when it is not necessary to rotate the tool magazine 31, such as when the spindle 7 is in the machining area or when the grip arm 35 is used to attach or remove the tool 91 to or from the spindle 7, power is not supplied to the magazine motor 33.

[0047] Specifically, the numerical controller 50 does not supply power to the magazine motor 33 before T1 or after T10 while the workpiece W is being machined, and instead uses the holding brake 33A to hold the rotational position of the tool magazine 31. When a tool change operation is performed, the numerical controller 50 does not supply power to the magazine motor 33 during the tool storage operation from T1, when the tool storage operation starts, until T4, when the spindle 7 is located at the tool change position C. By using the holding brake 33A to hold the rotational position of the tool magazine 31 during this time, power consumption can be reduced. The numerical controller 50 performs an indexing operation, rotating the tool magazine 31 to transport the next tool 92 and placing it at the tool change position C, when the spindle 7 is located at the origin position D. Therefore, the numerical controller 50 supplies power to the magazine motor 33 and releases the holding brake 33A at T4, when a command is issued to move the spindle 7 from the tool change position C to the origin position D. The command to move from the tool change position C to the origin position D is executed based on the fact that the spindle 7 is located at the tool change position C.

[0048] After the indexing operation is completed, the numerical controller 50 performs the tool loading operation, which is part of the tool changing operation. During the tool loading operation, the numerical controller 50 executes a command to move the spindle 7 from the origin position D to the tool changing position C based on the fact that the spindle 7 is located at the origin position D at time T6 when the tool loading operation starts. At time T6 when the command is executed, the numerical controller 50 interrupts the power supply to the magazine motor 33 and causes the holding brake 33A to hold the rotational position of the tool magazine 31. The numerical controller 50 does not supply power to the magazine motor 33 until time T10 when the tool loading operation is completed and the spindle 7 reaches the machining start position Q2. Furthermore, the numerical controller 50 does not supply power to the magazine motor 33 after time T10 while the workpiece W is being machined. In this way, the numerical controller 50 reduces power consumption by causing the holding brake 33A to hold the rotational position of the tool magazine 31 when rotation of the tool magazine 31 is not required.

[0049] On the other hand, in the maintenance mode, the numerical control device 50 performs a single operation corresponding to an instruction. Therefore, between the single operations, for example, a user may open the opening / closing door 106A of the magazine cover 10 to perform maintenance work or to attach, remove, or replace a tool 91 in the tool magazine 31. As shown in FIG. 8(D), in the maintenance mode, when the spindle 7 is in the machining area, power is not supplied to the magazine motor 33 to reduce power consumption, but when it is in the tool replacement area, power is supplied to the magazine motor 33, ensuring greater convenience than in the continuous operation mode.

[0050] Specifically, the numerical control device 50 does not supply power to the magazine motor 33 before T1 or after T10 while the workpiece W is being machined, and instead causes the holding brake 33A to hold the rotational position of the tool magazine 31. Furthermore, for example, when a user inputs instructions one by one from the operation unit 25A and moves the spindle 7 for each single operation to sequentially perform each step of the tool changing operation, the numerical control device 50 does not supply power to the magazine motor 33 from T1, when the spindle 7 is located in the machining area, until T3, when the spindle 7 reaches the standby position B. During this time, the holding brake 33A holds the rotational position of the tool magazine 31, thereby reducing power consumption.

[0051] Based on the fact that the spindle 7 is located at the ready position B at T3, the numerical control device 50 supplies power to the magazine motor 33 and releases the holding brake 33A. From T3 to T8, while the spindle 7 is located in the tool change area extending from the ready position B via the tool change position C to the home position D, the numerical control device 50 maintains the supply of power to the magazine motor 33. This allows the user to perform operations such as changing the tool 91 between single operations corresponding to instructions, regardless of the position of the spindle 7 in the tool change area.

[0052] If the spindle 7 is at the ready position B at T8 and the next instruction causes the spindle 7 to move below the ready position B, the numerical control device 50 interrupts the power supply to the magazine motor 33 based on the fact that the spindle 7 is located in the machining area. By not supplying power to the magazine motor 33 after T3, the numerical control device 50 causes the holding brake 33A to hold the rotational position of the tool magazine 31, thereby reducing power consumption.

[0053] 9 to 13, the main processing executed by CPU 51 will be described. When machine tool 1 and numerical control device 50 are powered on, the main processing starts by calling a control program for the main processing from storage device 54 and executing the called control program.

[0054] As shown in FIG. 9, when the main processing starts, CPU 51 reads the initial settings for the main processing from storage device 54 (S11). In the initial settings, holding brake control is set to enabled. The user can set holding brake control to disabled by input from operation unit 25A. Also, in the initial settings, the operation mode of machine tool 1 is set to continuous operation mode. Furthermore, the operation mode of machine tool 1 can be shifted from continuous operation mode to maintenance mode by operating operation unit 25A while the main processing is being executed.

[0055] If the setting of the holding brake control is valid, the CPU 51 turns the valid flag ON (S12: YES, S13), and if the setting is invalid, the CPU 51 turns the valid flag OFF (S12: NO, S14). The CPU 51 does not supply power to the magazine motor 33, and applies the holding brake 33A to hold the rotational position of the tool magazine 31 (S16). If no operation to change the operation mode of the machine tool 1 has been performed on the operation unit 25A and the machine tool 1 is in the continuous operation mode (S17: NO), the CPU 51 determines whether or not a machining start instruction has been input (S18). The machining start instruction is an instruction to start machining the workpiece W. If the CPU 51 has not received a machining start instruction on the operation unit 25A (S18: NO), the process returns to S16.

[0056] When the CPU 51 receives a machining start instruction (S18: YES), it determines whether the valid flag is ON. If the valid flag is OFF (S19: NO), the CPU 51 constantly supplies power to the magazine motor 33, so when machining starts, it starts supplying power to the magazine motor 33 and releases the holding brake 33A (S21). On the other hand, if the valid flag is ON (S19: YES), the power supply to the magazine motor 33 is controlled, so power is not supplied to the magazine motor 33 when machining starts.

[0057] The CPU 51 reads one specified NC program from a plurality of NC programs stored in the storage device 54 (S22). It is assumed that the spindle 7 is positioned in the machining area when machining the workpiece W. The CPU 51 interprets one block of control commands from the read NC program (S23). The CPU 51 determines whether the control command in the interpreted block is an end command (M30 command) or not (S24).

[0058] If the interpreted control command is not an end command (S24: NO), the CPU 51 determines whether the interpreted control command is a tool change command (G100 command or M06 command) (S26). If the interpreted control command is not a tool change command (S26: NO), the CPU 51 executes various processes based on the interpreted control command (S27) and returns the process to S23. Examples of the various processes executed in S27 include positioning of the spindle 7 and rotation of the spindle 7. If the interpreted control command is a tool change command (S26: YES), the CPU 51 shifts the process to S31.

[0059] As shown in FIG. 9, the CPU 51 performs movement processing of the spindle 7 on the outward path of the tool change operation. For convenience, when movement processing on the outward path is performed, the spindle 7 is assumed to be located at a machining end position Q1 where machining of the workpiece W is completed. The CPU 51 calculates a movement command for moving the spindle 7 from the machining end position Q1 to the first return position A1 based on the coordinate value of the first return position A1 included in the control command (S31). Since this movement command is not a movement command for moving the spindle 7 from the tool change position C to the origin position D (S32: NO), the CPU 51 outputs the movement amount and movement speed of the spindle 7 specified in the movement command to the drive circuit 63 (S33). The drive circuit 63 moves the spindle 7 to the first return position A1 through feedback control of the Z-axis motor 12A. The CPU 51 returns the process to S31 and calculates the next movement command. By similar processing, the CPU 51 calculates a movement command from the first return position A1 to the preparation position B and a movement command from the preparation position B to the tool change position C, and moves the spindle 7 to the tool change position C in accordance with each movement command.

[0060] Next, if the movement command calculated by the CPU 51 in S31 is a movement command for moving the spindle 7 from the tool change position C to the origin position D (S32: YES), the CPU 51 determines whether or not the spindle 7 is at the tool change position C (S36). The positions of the spindle 7 in the X-, Z-, and Y-axis directions are constantly monitored based on feedback control of the drive circuits 62 to 64 by the encoders 11B, 12B, and 13B. If the spindle 7 is moving in accordance with the previously executed movement command and has not yet reached the tool change position C (S36: NO), the CPU 51 waits until the movement of the spindle 7 is completed.

[0061] If the spindle 7 is at the tool change position C (S36: YES), the CPU 51 outputs to the drive circuit 63 the movement amount and movement speed of the spindle 7 specified in the movement command for moving the spindle 7 from the tool change position C to the origin position D (S37). The drive circuit 63 starts moving the spindle 7 toward the origin position D by feedback control of the Z-axis motor 12A. The CPU 51 starts supplying power to the magazine motor 33 and releases the holding brake 33A (S38). This makes the tool magazine 31 rotatable, and the rotation position is held by feedback control.

[0062] During the process in which the spindle 7 moves from the tool change position C to the origin position D, the tool 91 is detached from the spindle 7, gripped by the grip arm 35 of the tool magazine 31, and stored in the magazine cover 10 (S39). The CPU 51 waits for the spindle 7 to reach the origin position D (S41: NO). When the spindle 7 reaches the origin position D (S41: YES), the CPU 51 drives the magazine motor 33 using the drive circuit 65 to rotate the tool magazine 31 (S42) and performs an indexing operation for the next tool 92 (S43: NO). When the next tool 92 is transported and placed at the tool change position C and the indexing operation is completed (S43: YES), the CPU 51 shifts the process to S51. The drive circuit 65 maintains the state in which the next tool 92 is placed at the tool change position C through feedback control.

[0063] As shown in FIG. 10, the CPU 51 performs a process for moving the spindle 7 on the return path of the tool change operation. The CPU 51 calculates a movement command for moving the spindle 7 from the origin position D to the tool change position C (YES in S51 and S52). The spindle 7 is at the origin position D. The CPU 51 outputs to the drive circuit 63 the movement amount and movement speed of the spindle 7 specified in the movement command for moving the spindle 7 from the origin position D to the tool change position C (S57). The drive circuit 63 starts moving the spindle 7 toward the tool change position C through feedback control of the Z-axis motor 12A. If the valid flag is ON (YES in S58), the CPU 51 interrupts the power supply to the magazine motor 33 and applies the holding brake 33A. The rotational position of the tool magazine 31 is held by the holding brake 33A with the next tool 92 positioned at the tool change position C (S59). On the other hand, if the valid flag is OFF (S58: NO), the CPU 51 maintains the state in which power is supplied to the magazine motor 33. In the process in which the spindle 7 moves from the origin position D to the tool change position C, the next tool 92 is attached to the spindle 7 (S61). The CPU 51 returns the process to S51.

[0064] The CPU 51 calculates the next movement command. The CPU 51 calculates a movement command from the tool change position C to the preparation position B and a movement command from the preparation position B to the second return position A2 by similar processing (S51), and moves the spindle 7 to the second return position A2 in accordance with each movement command (S52: NO, S53, S54: NO). Next, if the movement command calculated by the CPU 51 in S51 is a movement command for moving the spindle 7 from the second return position A2 to the machining start position Q2 (S52: NO, S53, S54: YES), the CPU 51 waits until the spindle 7 reaches the tool change position C (S56: NO). When the spindle 7 reaches the tool change position C (S56: YES), the CPU 51 returns the processing to S23 and ends the series of processes based on the tool change command.

[0065] The CPU 51 interprets the control commands for the next block (S23). If the interpreted control command is an end command (S24: YES), the CPU 51 ends the machining of the workpiece W based on the NC program (S28) and returns the process to S16. When the series of machining steps based on the NC program ends, the power supply to the magazine motor 33 is interrupted in S16 even if the holding brake control setting is disabled.

[0066] Next, the operation in the maintenance mode will be described. When an instruction to start machining the workpiece W has not been received (S16, S17: NO, S18: NO), if an operation is performed on operation unit 25A to switch the operation mode of machine tool 1 to the maintenance mode (S17: YES), CPU 51 transitions the process to S71.

[0067] 12, the CPU 51 determines whether or not an input of an instruction to start a maintenance operation has been received (S71). The instruction to start a maintenance operation is an instruction to start processing to perform a single operation corresponding to one instruction, such as input from the operation unit 25A or reading of one block of an NC program. If the CPU 51 has not received an instruction to start a maintenance operation from the operation unit 25A (S71: NO), the CPU 51 returns the process to S16 and waits.

[0068] When the CPU 51 receives a maintenance operation start instruction (S71: YES), it determines whether the valid flag is ON. If the valid flag is OFF (S72: NO), the CPU 51 constantly supplies power to the magazine motor 33, so that when the maintenance operation starts, the power supply to the magazine motor 33 is started and the holding brake 33A is released (S73). On the other hand, if the valid flag is ON (S72: YES), the power supply to the magazine motor 33 is controlled, so that when the maintenance operation starts, power is not supplied to the magazine motor 33.

[0069] The CPU 51 receives an instruction input from, for example, the operation unit 25A (S74). It is assumed that the spindle 7 is positioned in the machining area when the maintenance operation is performed. If an operation to end the maintenance mode is not performed on the operation unit 25A (S75: NO), the CPU 51 interprets the received instruction (S76). The CPU 51 determines whether the interpreted instruction is an instruction for single-action tool change (S77). An instruction for single-action tool change is an instruction to perform a series of operations during tool change in a single action (for each individual operation). If the interpreted instruction is not an instruction for single-action tool change (S77: NO), the CPU 51 executes a single operation based on the interpreted instruction (S78) and returns the process to S74. If the interpreted instruction is an instruction for single-action tool change (S77: YES), the CPU 51 proceeds to S81.

[0070] As shown in FIG. 13, if the single-action tool change instruction is not an instruction to attach a tool (S81: NO), the CPU 51 calculates a single-action movement command corresponding to the instruction (S84). If the calculated movement command is not a movement command to move the spindle 7 from the machining area to the preparation position B (S86: NO), the CPU 51 determines the positions of the spindle 7 in the X-axis, Z-axis, and Y-axis directions (S87). If the position of the spindle 7 is not the preparation position B (S87: NO), the CPU 51 outputs the movement amount and movement speed of the spindle 7 specified in the calculated movement command to the drive circuits 62 to 64 (S89). The drive circuits 62 to 64 move the spindle 7 to the position corresponding to the instruction by feedback control of the X-axis motor 11A, Z-axis motor 12A, and Y-axis motor 13A. The CPU 51 returns the process to S74 and accepts input of the next instruction. The CPU 51 performs similar processing to move the spindle 7 within the machining area in accordance with a single-action movement command in response to the instruction.

[0071] If the movement command calculated in S84 is a single-action movement command to move the spindle 7 from the machining area to the standby position B (S86: YES), the CPU 51 outputs the movement amount and movement speed of the spindle 7 specified in the movement command to the drive circuits 62 to 64 (S91). The drive circuits 62 to 64 move the spindle 7, which is located in the machining area, toward the standby position B through feedback control of the X-axis motor 11A, the Z-axis motor 12A, and the Y-axis motor 13A. The CPU 51 waits for the spindle 7 to reach the standby position B (S92: NO). When the spindle 7 reaches the standby position B (S92: YES), the CPU 51 starts supplying power to the magazine motor 33 and releases the holding brake 33A (S93). This makes the tool magazine 31 rotatable, and the rotation position is maintained through feedback control. The CPU 51 returns the process to S74 and accepts input of the next command. The spindle 7 is located in the tool change area.

[0072] If the input single-action tool change command is a command to attach a tool (S81: YES), the CPU 51 drives the magazine motor 33 by the drive circuit 65 to rotate the tool magazine 31 so that the grip arm 35 specified by the command moves to the position of the opening / closing door 106A (S82). The user opens the opening / closing door 106A and attaches the next tool 92 to the grip arm 35 (S83). The CPU 51 returns the process to S74 and accepts input of the next command.

[0073] The CPU 51 calculates a single-action movement command in accordance with the input single-action tool change command (S84), and performs single-action tool change by moving the spindle 7 along the tool change path within the tool change area (S89). When the spindle 7 reaches the standby position B (S87: YES) and the movement command calculated at that time is a movement command to move the spindle 7 from the standby position B to the machining area (S88: YES), the CPU 51 outputs the movement amount and movement speed of the spindle 7 specified in the movement command to the drive circuits 62 to 64 (S96). The drive circuits 62 to 64 move the spindle 7, which is located at the standby position B, toward the machining area through feedback control of the X-axis motor 11A, Z-axis motor 12A, and Y-axis motor 13A. The CPU 51 waits until the spindle 7 is located in the machining area (S97: NO). When the spindle 7 is positioned in the machining area (S97: YES), the CPU 51 determines whether the valid flag is ON (S98). If the valid flag is ON (S98: YES), the CPU 51 interrupts the power supply to the magazine motor 33, applies the holding brake 33A (S99), and returns the process to S74. The rotational position of the tool magazine 31 is held by the holding brake 33A. On the other hand, if the valid flag is OFF (S98: NO), the CPU 51 maintains the power supply to the magazine motor 33 and returns the process to S74.

[0074] 12, when an instruction input from the operation unit 25A is received (S74), and an operation to end the maintenance mode is performed (S75: YES), the CPU 51 ends the maintenance mode (S79) and returns the process to S16. Note that when the maintenance mode ends, the power supply to the magazine motor 33 is interrupted in S16 even if the holding brake control setting is invalid.

[0075] As described above, if the power supply to magazine motor 33 is limited to the minimum necessary, convenience is reduced when, for example, a user wants to replace a tool 91 stored in tool magazine 31. By controlling whether or not to supply power to magazine motor 33 that drives tool magazine 31 based on the operation mode of machine tool 1, numerical control device 50 can ensure convenience while reducing power consumption.

[0076] Furthermore, by controlling whether or not to supply power to the magazine motor 33 that drives the tool magazine 31 based on the operating mode of the machine tool 1 and the position of the spindle 7, the numerical control device 50 can ensure convenience while reducing power consumption.

[0077] In the continuous operation mode, the machine tool 1 operates in accordance with the control commands of the NC program. Therefore, the numerical control device 50 can reduce power consumption by supplying power to the magazine motor 33 based on the continuous operation mode and the spindle 7 being at the tool change position C. On the other hand, in the maintenance mode, the machine tool 1 performs a single operation corresponding to an individual instruction each time it receives that instruction. Therefore, the numerical control device 50 can ensure convenience by supplying power to the magazine motor 33 based on the maintenance mode and the spindle 7 being at the ready position B.

[0078] The numerical control device 50 can reduce power consumption by supplying power to the magazine motor 33 when the numerical control device 50 is in the continuous operation mode, the spindle 7 is at the tool change position C, and a movement command for moving the spindle 7 from the tool change position C to the origin position D is executed. Furthermore, in the maintenance mode, the numerical control device 50 supplies power based on the spindle 7 being at the ready position B, but furthermore, by maintaining the power supply to the magazine motor 33 based on the spindle 7 being between the ready position B and the origin position D, i.e., in the tool change area, convenience can be ensured.

[0079] In the continuous operation mode, the machine tool 1 operates in accordance with the control commands of the NC program. Therefore, the numerical control device 50 can reduce power consumption by interrupting the power supply to the magazine motor 33 based on the fact that the machine tool is in the continuous operation mode and the spindle 7 is at the origin position D. On the other hand, in the maintenance mode, the machine tool 1 performs a single operation corresponding to an individual instruction each time it receives that instruction. Therefore, the numerical control device 50 can reduce power consumption while maintaining convenience by interrupting the power supply to the magazine motor 33 based on the fact that the machine tool is in the maintenance mode and the spindle 7 is in the machining area.

[0080] The numerical control device 50 can reduce power consumption by interrupting the power supply to the magazine motor 33 when the numerical control device 50 is in the continuous operation mode, the spindle 7 is at the origin position D, and based on receiving an instruction to move the spindle 7 from the origin position D to the tool change position C. On the other hand, when the numerical control device 50 is in the maintenance mode, the spindle 7 is at the standby position B, and further, based on executing an instruction to move the spindle 7 from the standby position B to the machining area, the numerical control device 50 can reduce power consumption while ensuring convenience by interrupting the power supply to the magazine motor 33 based on detecting that the spindle 7 is in the machining area.

[0081] The user can set the holding brake control to be enabled or disabled as needed, thereby improving convenience.

[0082] In the above description, the magazine motor 33 is an example of a "servo motor" of the present invention. The CPU 51 is an example of a "control unit" of the first and second aspects of the present invention and a "computer" of the third aspect. The processes of S21, S38, S73, and S93 are an example of a "supply process" of the first aspect of the present invention and a "supply step" of the second and third aspects of the present invention. The processes of S16, S59, and S99 are an example of an "interruption process" of the first aspect of the present invention and an "interruption step" of the second and third aspects of the present invention. The process of S17 is an example of a "determination process" of the first aspect of the present invention and a "determination step" of the second and third aspects of the present invention. The operation mode is an example of an "operating state" of the machine tool. The numerical control device 50 is an example of a "control device" of the present invention. The processes of S36, S41, S87, and S92 are an example of a "detection process" of the first aspect of the present invention and a "detection step" of the second and third aspects of the present invention. The continuous operation mode is an example of a "first operating state" of the present invention. The maintenance mode is an example of a "second operating state" of the present invention. A case where the holding brake control is disabled is an example of a "constant power supply mode" of the present invention. A case where the holding brake control is enabled is an example of a "controlled power supply mode" of the present invention. The processing of S13 and S14 is an example of a "setting process" of the present invention.

[0083] The present invention is not limited to the above embodiment, and various modifications can be made. Machine tool 1 is a horizontal machine tool, but it may also be a vertical machine tool in which the axial direction of the spindle is vertical. Machine tool 1 moves column 5 in the X-axis direction, spindle 7 in the Z-axis direction, and spindle 7 in the Y-axis direction, thereby moving workpiece W and tool 91 relatively in the X-axis, Y-axis, and Z-axis directions, but other structures are also possible. For example, column 5 may be moved in two axes, the X-axis and the Z-axis, and spindle 7 may be moved in the Y-axis direction.

[0084] In the continuous operation mode, on the outward path of the tool changing operation, the spindle 7 is moved to the origin position D in response to a movement command, so power is supplied to the magazine motor 33 based on the fact that the spindle 7 is located at the tool changing position C, but power may also be supplied to the magazine motor 33 based on the fact that the spindle 7 has reached the origin position D. Also, on the return path of the tool changing operation, the spindle 7 is moved to the tool changing position C in response to a movement command, so power is supplied to the magazine motor 33 based on the fact that the spindle 7 is located at the origin position D, but power may also be supplied to the magazine motor 33 based on the fact that the spindle 7 has reached the tool changing position C.

[0085] In the maintenance mode, power is not supplied to the magazine motor 33 based on the fact that the spindle 7 is in the machining area, and power is supplied to the magazine motor 33 based on the fact that the spindle 7 is in the tool change area including the preparation position B. Without being limited to this, the power supply to the magazine motor 33 may be interrupted when a single instruction for the spindle 7 to move from the tool change area to the machining area is received, and power may be supplied to the magazine motor 33 when a single instruction for the spindle 7 to move from the machining area to the tool change area is received.

[0086] Although the continuous operation mode and maintenance mode have been given as examples of machine tool operation modes for controlling the power supply to the magazine motor 33, other modes may also be used. For example, there may be a robot replacement mode in which a tool 91 stored in the tool magazine 31 is replaced by a robot arm. In the robot replacement mode, the power supply to the magazine motor 33 is interrupted when the spindle 7 is in the machining area, and when the tool 91 stored in the tool magazine 31 is replaced by the robot arm, the power supply to the magazine motor 33 may be resumed even if the spindle 7 is in the machining area. Also, in the robot replacement mode, the power supply to the magazine motor 33 may be interrupted regardless of the position of the spindle 7, and power may be supplied to the magazine motor 33 only temporarily while the tool 91 stored in the tool magazine 31 is replaced by the robot arm. [Explanation of symbols]

[0087] 1 Machine tools 7 Spindle 31 Tool magazine 33 Magazine motor 33A Holding Brake 50 Numerical Control Device 51 CPU 91 Tools B Ready position C Tool change position D Origin position W Work material

Claims

1. A control device having a control unit for controlling the operation of a machine tool, the control device including: a spindle to which a tool can be attached and which is movable to a machining area where a workpiece is machined using the tool and a tool exchange area where the tool is exchanged; and a tool magazine to which the tool can be stored and which transports the tool attached to the spindle by driving a servo motor, The control unit a supply process for supplying power to the servo motor; an interruption process for interrupting the supply of power to the servo motor; a determination process for determining an operating state of the machine tool; Run Controlling the execution of the supply process and the interruption process based on the operating state of the machine tool. A control device characterized by:

2. The control unit further performing a detection process for detecting the position of the spindle; Controlling the execution of the supply process and the interruption process based on the operating state of the machine tool and the position of the spindle. The control device according to claim 1 ,

3. The operating state of the machine tool is a first operating state in which the machine tool operates in accordance with commands written in a machining program for controlling the operation of the machine tool; a second operating state in which instructions for operation of the machine tool are individually received and a single operation corresponding to the instructions is performed; Including, The control unit executing the supply process to supply power to the servo motor based on the determination in the determination process that the operating state of the machine tool is the first operating state and the detection process that the spindle is at a tool change position within the tool change area where the tool to be attached to the spindle is changed; and executing the supply process to supply power to the servo motor based on the determination process that the operating state of the machine tool is the second operating state and the detection process that the spindle is detected to be in a preparation position between the machining area and the tool change position. The control device according to claim 2 ,

4. The control unit and executing the supply process to supply power to the servo motor based on the determination process that the operating state of the machine tool is the first operating state, the detection process that detects that the spindle is at the tool change position, and the execution of a command to move the spindle from the tool change position toward an origin position that is the origin of a movement range of the spindle in the axial direction and is spaced apart from the tool change position in the tool change region in the axial direction. The control device according to claim 3 ,

5. The operating state of the machine tool is a first operating state in which the machine tool operates in accordance with commands written in a machining program for controlling the operation of the machine tool; a second operating state in which instructions for operation of the machine tool are individually received and a single operation corresponding to the instructions is performed; Including, The control unit executing the interruption process to interrupt the supply of power to the servo motor based on the determination in the determination process that the operating state of the machine tool is the first operating state and the detection process that the spindle is at an origin position that is the origin of the movement range of the spindle in the axial direction and that is separated in the axial direction from a tool change position where the tool attached to the spindle is changed within the tool change area, executing the interruption process to interrupt the supply of power to the servo motor based on the determination that the operating state of the machine tool is the second operating state in the determination process and the detection that the spindle is in the machining area in the detection process; The control device according to claim 2 ,

6. The control unit executing the interruption process to interrupt the supply of power to the servo motor when the determination process determines that the operating state of the machine tool is the first operating state, the detection process detects that the spindle is at the origin position, and a command to move the spindle from the origin position toward the tool change position is executed. The control device according to claim 5 ,

7. The control unit executing a setting process to set a constant power supply mode in which power is constantly supplied to the servo motor and a controlled power supply mode in which execution of the supply process and the interruption process is controlled; When the constant power supply mode is set in the setting process, the power supply process is executed to supply power to the servo motor regardless of the position of the spindle, When the controlled power supply mode is set in the setting process, the supply process or the interruption process is executed based on the operating state of the machine tool and the position of the spindle, and power is supplied to the servo motor.

7. The control device according to claim 2, wherein:

8. A control method for a control device having a control unit for controlling an operation of a machine tool, the machine tool having a spindle capable of being moved to a machining area where a tool can be attached and where a workpiece is machined using the tool and a tool exchange area where the tool is exchanged, and a tool magazine capable of storing the tool and which transports the tool attached to the spindle by driving a servo motor, the method comprising: The control unit a supply step of supplying power to the servo motor; an interruption step of interrupting the supply of power to the servo motor; a determination step of determining an operating state of the machine tool; and Controlling the execution of the supplying step and the interrupting step based on the operating state of the machine tool. A control method characterized by:

9. A program for causing a computer of a control device to execute processing to control an operation of a machine tool, the machine tool comprising: a spindle capable of moving to a machining area where a tool can be attached and where a workpiece is machined using the tool, and a tool exchange area where the tool is exchanged; and a tool magazine capable of storing the tool and which transports the tool attached to the spindle by driving a servo motor, The computer, a supply step of supplying power to the servo motor; an interruption step of interrupting the supply of power to the servo motor; a determination step of determining an operating state of the machine tool; and Controlling the execution of the supplying step and the interrupting step based on the operating state of the machine tool. A program characterized by.

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