JP5187518B2 - Numerically controlled machine tool - Google Patents

Description

  The present invention relates to a numerically controlled machine tool including a tool breakage detection device, and more particularly to a machine tool that can set a stop mode for a machining operation being executed when a tool breakage is detected.

  In a machine tool, a tool may be broken during cutting of a workpiece, and there is a possibility that a portion cut by a broken tool is not processed normally. Therefore, it is necessary to detect whether or not the workpiece is normally processed by detecting breakage of the tool used for the latest cutting every time when the cutting is completed. When a tool breakage is detected, it is important what kind of processing is performed for the machining operation being executed.

In the unmanned operation control device for a machine tool described in Patent Document 1, in accordance with the type of failure that occurs in the machine tool, whether the machine tool can be continued or not is classified in advance, and the machine tool has a failure. It has been proposed to perform processing corresponding to the occurrence of the problem. In this apparatus, for example, when a drill breaks during drilling, if there is a spare tool, the tool is replaced and the machining operation is continued.
JP-A-2-243243

  For example, when drilling with different tools at two different machining positions, even if the tool used for the previous drilling is broken, the subsequent drilling will not be affected and the machining operation will continue. There is no problem. However, when performing tapping, if the tool breaks during drilling of the pilot hole, the pilot hole may not be normally opened. Therefore, if tapping is performed at the same machining position, the machining accuracy may be reduced. Furthermore, the tap tool may be broken by broken pieces of the tool.

  In addition, when the breakage of the tool used for the previous drilling process is detected during the facing process, if the processing operation is temporarily stopped, the processing surface where the facing process is interrupted becomes rough. In this case, there is a possibility that the desired processing accuracy cannot be obtained even if the facing processing is resumed after removing the broken pieces of the broken tool. Therefore, when tool breakage is detected, it is desirable that the stop mode for the machining operation being executed can be set according to the type of machining.

  However, Patent Document 1 only describes that if a drill breaks, if there is a spare tool, the tool is replaced and the machining operation is continued, and the machine tool can continue to operate for the type of machining. There is no clear description regarding the category of “No”. Therefore, in the apparatus of Patent Document 1, it is unclear whether the stop mode for the machining operation being executed can be set according to the type of machining.

  An object of the present invention is to provide a numerically controlled machine tool capable of setting a stop mode for a machining operation being executed according to the type of machining when tool breakage is detected.

  The numerically controlled machine tool according to claim 1 is a numerically controlled machine tool provided with a tool breakage detecting device for detecting breakage of a tool used for the latest cutting at the end of cutting. As a stop mode when breakage is detected, an immediate stop to stop immediately, a block stop to stop at the end of the machining operation of the block being executed, and a stop after the end of the machining program to be stopped at the end of the running machining program The present invention is characterized in that stop mode setting means that can alternatively be set is provided.

  In this numerically controlled machine tool, when the breakage of the tool is detected by the tool breakage detecting device, the stop mode setting means immediately stops to stop immediately, and the block stop to stop at the end of the machining operation of the block being executed, Alternatively, stop after completion of the machining program to be stopped when the machining program being executed is terminated. Therefore, when breakage of the tool used for the cutting process is detected at the end of the cutting process, it is possible to set an optimum stop mode according to the type of the machining operation being performed.

  The numerically controlled machine tool according to claim 2 is characterized in that, in the invention according to claim 1, the tool breakage detecting device is arranged in a tool magazine of an automatic tool changer.

  A numerically controlled machine tool according to a third aspect is the invention according to the first or second aspect, wherein the stop mode setting means performs a cutting process with a tool whose breakage is detected after the breakage of the tool is detected by the tool breakage detection device. When cutting is performed at the same position as the position, an immediate stop is set.

  A numerically controlled machine tool according to a fourth aspect is the invention according to any one of the first to third aspects, wherein the stop mode setting means performs cutting with a tool for which breakage is detected after the tool breakage is detected by the tool breakage detection device. When cutting is performed at a position different from the position where the machining is performed, a stop is set after the machining program ends.

  According to a fifth aspect of the present invention, in the numerically controlled machine tool according to any one of the first to fourth aspects, the stop mode setting means is configured such that after the tool breakage is detected by the tool breakage detecting device, the tool used for cutting is milled. In the case of a tool or an end mill tool, a block stop is set.

  The numerically controlled machine tool according to claim 6 is the invention according to claim 1, wherein the stop mode setting means includes a first code for instructing an immediate stop, a second code for instructing a block stop, and a stop after completion of the machining program. Among the third codes for instructing, the stop mode is set based on a code set in advance in association with each block of the machining program.

According to a seventh aspect of the present invention, there is provided the numerically controlled machine tool according to the sixth aspect , wherein the first, second and third codes are set in advance immediately before a block instructing tool change in the machining program. Yes.

  According to the invention of claim 1, as a stop mode when a tool breakage is detected by the tool breakage detection device, an immediate stop to stop immediately, a block stop to stop at the end of the machining operation of the block being executed, and execution Since there is a stop mode setting means that can alternatively be set to stop after the end of the processing program to stop at the end of the processing program, when a breakage of the tool used for the cutting is detected at the end of the cutting process, An optimum stop mode can be set according to the type of machining for the machining operation being executed.

  According to the invention of claim 2, since the tool breakage detecting device is arranged in the tool magazine of the automatic tool changer, cutting of the next block is performed in the machining program while detecting breakage of the tool used for the latest cutting work. Processing can be performed. Also in this case, an optimum stop mode corresponding to the type of machining can be set for the machining operation being executed.

  According to the invention of claim 3, the stop mode setting means immediately stops when the tool breakage is detected by the tool breakage detecting device and the cutting is performed at the same position as the position at which the tool was cut with the breakage detected tool. Therefore, when tapping is performed after drilling the lower hole, when the tool breaks during the drilling of the lower hole, the tap machining at the same position can be stopped immediately. Therefore, it is possible to prevent the tap tool from being broken by broken pieces of the tool.

  According to the invention of claim 4, the stop mode setting means, when the tool breakage is detected by the tool breakage detection device, when the cutting is performed at a position different from the position at which the tool was cut with the breakage detected tool, the machining program Since stop is set after completion, when drilling with different tools at two different machining positions, etc., even if the tool used for the previous drilling is broken, it does not affect the subsequent drilling Can continue the machining operation.

  According to the invention of claim 5, the stop mode setting means sets the block stop when the tool used for cutting is a milling tool or an end mill tool after the tool breakage is detected by the tool breakage detecting device. Even if the breakage of the tool used for the previous drilling process is detected during the sawing process, the machining operation is not immediately stopped. In this way, by continuing the processing operation of the block being executed at the time of facing processing, a desired processing accuracy can be obtained without making the processing surface rough.

  According to the invention of claim 6, the stop mode setting means includes a first code for instructing an immediate stop, a second code for instructing a block stop, and a third code for instructing a stop after completion of the machining program. Since the stop mode is set based on the code set in advance in association with each block of the program, the operator can set the desired code in the machining program according to the type of machining. It is possible to easily set the stop mode according to the type of the.

  According to the invention of claim 7, since the first, second, and third codes are set in advance immediately before the block for instructing the tool change in the machining program, the stop mode can be reliably set at the time of the tool change. it can.

  Hereinafter, the best mode for carrying out the present invention will be described.

Embodiments of the present invention will be described below with reference to the drawings. First, a schematic configuration of the numerically controlled machine tool 1 will be described.
As shown in FIGS. 1 and 2, a numerically controlled machine tool 1 (hereinafter referred to as a machine tool) moves a workpiece and a tool (not shown) relative to each other to perform a desired cutting process (for example, “medium”). Machines that perform drilling, milling, drilling, etc.). The machine tool 1 includes a cast iron base 2, a machine body 3, a splash cover 4, and the like.

First, the base 2 will be described.
As shown in FIGS. 1 and 2, the base 2 has a substantially rectangular parallelepiped shape that is long in the Y-axis direction (the depth direction of the machine body 3). At the lower four corners of the base 2, leg portions 2 a that can be adjusted in height are provided.

Next, the splash cover 4 will be described.
As shown in FIG. 1, the splash cover 4 has a substantially rectangular parallelepiped box shape covering the machine body 3 and the upper part of the base 2. The splash cover 4 is fixed to the upper part of the base 2. A machining area of the machine main body 3 (see FIG. 2) is provided inside the splash cover 4. An opening (not shown) is provided on the front surface of the splash cover 4.

  A pair of sliding opening / closing doors 5 and 6 for opening and closing the opening is provided. Rectangular glass window portions 5a and 6a are provided at substantially the center of the open / close doors 5 and 6, respectively. A handle 5 b is provided at the right end of the open / close door 5, and a handle 6 b is provided at the left end of the open / close door 6. An operator can open and close the opening by opening the grip portions 5b and 6b away from each other, and the workpiece can be attached to and detached from the table 10 on the upper portion of the base 2.

  An operation panel 80 is provided on the right side of the front opening. The operation panel 80 has a rectangular shape in front view for operating the machine tool 1. The operation panel 80 includes a keyboard 81 having a numeric keypad and various operation keys, and a display 82. The display 82 is for displaying a setting screen or an execution operation, and is provided in the upper part of the keyboard 81.

Next, the machine body 3 will be described.
As shown in FIG. 2, the machine main body 3 is on the upper side of the base 2, and the machine main body 3 cuts the workpiece according to the machining program. The machine body 3 includes a spindle head 7, a spindle 9, a column 16, an automatic tool changer (ATC) 20, a table 10, and the like. The rectangular parallelepiped column 16 is positioned on the column seat 17 at the rear of the base 2 and extends vertically upward. A box-shaped control box 19 is provided on the back of the column 16. The control box 19 is provided with a control device 50 (see FIG. 3) having a numerical control function for controlling the operation of the machine tool 1. The electrical configuration of the control device 50 will be described later.

Next, the moving mechanism of the table 10 will be described.
As shown in FIG. 2, the table 10 is provided on the base 2. The table 10 fixes a workpiece to be cut so as to be detachable. An X-axis motor 71 (see FIG. 3), which is a servo motor, moves the table 10 in the X-axis direction (left-right direction in FIG. 1). A Y-axis motor 72 (see FIG. 3), which is a servo motor, moves the table 10 in the Y-axis direction.

This XY moving mechanism will be described.
The pair of Y-axis feed guides extend along the longitudinal direction (front-rear direction) of the base 2 on the upper side of the base 2. A rectangular parallelepiped support base 12 is movably supported on the pair of Y-axis feed guides. A pair of X-axis feed guides (not shown) extending in the X-axis direction are provided on the support table 12 below the table 10. The table 10 is movably supported by the pair of X-axis feed guides.

  With such an XY movement mechanism, the X-axis motor 71 moves the table 10 in the X-axis direction along the X-axis feed guide via the ball screw mechanism. The Y-axis motor 72 moves the support 12 and the table 10 in the Y-axis direction along the Y-axis feed guide via the ball screw mechanism.

Next, the raising / lowering mechanism of the spindle head 7 will be described.
As shown in FIG. 2, a Z-axis motor 73 (see FIG. 3) formed of a servo motor drives the spindle head 7 up and down in the Z-axis direction (the vertical direction of the machine body 2 in FIG. 2). The spindle head 7 is connected to a Z-axis ball screw shaft (not shown) extending in the vertical direction on the front side of the column 16 by a nut (not shown). This nut portion constitutes a ball screw mechanism in cooperation with the Z-axis ball screw shaft. The Z-axis motor 73 drives the spindle head 7 up and down in the Z-axis direction by driving the Z-axis ball screw shaft to rotate in the forward and reverse directions.

  As shown in FIG. 2, telescopic covers 13 and 14 that contract telescopically are provided on both the left and right sides of the X-axis feed guide with the table 10 in the center. A telescopic cover 15 and a Y-axis rear cover (not shown) are provided on both the front and rear sides of the Y-axis feed guide with the support base 12 in the center.

  The Y-axis rear cover is formed by forming a thin steel plate with a cross-sectional mountain shape. This Y-axis rear cover is accommodated in a cover accommodation hole (not shown) provided on the lower side of the column 16. Even if the table 10 is moved in either the X-axis direction or the Y-axis direction by these plural covers, the telescopic covers 13, 14, 15 and the Y-axis rear cover are always used as the X-axis feed guide and the Y-axis feed guide. Covering. That is, it prevents the chips scattered from the processing region, the splash of cutting oil, and the like from falling on each guide.

As shown in FIGS. 1 and 2, the automatic tool changer 20 includes a tool magazine 21 that stores a plurality of tool holders that support a tool 18 (see FIGS. 4A and 4B), and the spindle 9. And a tool change arm 22 for gripping and transferring the tool holder attached to the other tool holder and the other tool holder.
Inside the tool magazine 21 shown in FIG. 4A, a plurality of tool pots 23 that support the tool holder and a transfer mechanism 25 that transfers the tool pots 23 in the tool magazine 21 are provided.

Next, the electrical configuration of the control system of the machine tool 1 will be described.
As shown in FIG. 3, the control device 50 includes a microcomputer, and includes an input / output interface 54, a CPU 51, a ROM 52, a RAM 53, axis control circuits 37a, 61a to 64a, 75a, and a servo. Amplifiers 61 to 64, differentiators 71b to 74b, and the like are provided. The axis control circuits 61a to 64a are connected to the servo amplifiers 61 to 64, respectively. The servo amplifiers 61 to 64 are connected to the X-axis motor 71, the Y-axis motor 72, the Z-axis motor 73, and the main shaft motor 74, respectively. The axis control circuit 75 a is connected to the magazine motor 75, and the axis control circuit 37 a is connected to the tool breakage detection device 37.

  The X-axis motor 71 and the Y-axis motor 72 are for moving the table 10 in the X-axis direction and the Y-axis direction, respectively. The Z-axis motor 73 drives the spindle head 7 to move up and down in the Z-axis direction. The magazine motor 75 is for rotating the tool magazine 21. The main shaft motor 74 is for rotating the main shaft 9. The X-axis motor 71, Y-axis motor 72, Z-axis motor 73, and main shaft motor 74 are provided with encoders 71a to 74a, respectively.

  The axis control circuits 61a to 64a receive a movement command amount from the CPU 51 and output a current command amount (motor torque command value) to the servo amplifiers 61 to 64. The servo amplifiers 61 to 64 receive this command and output a drive current to the motors 71 to 74. The axis control circuits 61a to 64a receive position feedback signals from the encoders 71a to 74a and perform position feedback control. The differentiators 71b to 74b differentiate the position feedback signals input from the encoders 71a to 74a to convert them into speed feedback signals, and output the speed feedback signals to the axis control circuits 61a to 64a.

The axis control circuits 61a to 64a receive speed feedback signals from the differentiators 71b to 74b and control the speed feedback. Current detectors 61b to 64b detect drive currents output from servo amplifiers 61 to 64 to motors 71 to 74. The drive current detected by the current detectors 61b to 64b is fed back to the axis control circuits 61a to 64a. The axis control circuits 61a to 64a perform current (torque) control based on the fed back drive current.
The axis control circuit 75a receives the movement command amount from the CPU 51 and drives the magazine motor 75.

  The ROM 52 stores a main control program for causing the machining program of the machine tool 1 to function, a control program for the stop mode setting control shown in FIGS. 10 and 11, and the like. The RAM 53 stores a tool information table shown in FIG. In this table, information such as a tool, a tool name, a tool offset, and a tool radius correction is stored in association with the tool number.

  The RAM 53 is provided with a machining position information area and a broken machining position information area shown in FIG. The machining position information area is an area for registering the machining position set in the machining program when the stop mode setting control is executed. The breakage machining position information area is an area for registering the machining position at which cutting has been performed with the tool 18 when the breakage of the tool 18 is detected during execution of the stop mode setting control.

Next, the tool breakage detection device 37 disposed in the tool magazine 21 of the automatic tool changer 20 will be described. First, the structure of the tool magazine 21 will be described.
As shown in FIG. 4A, the tool magazine 21 includes a plurality of tool pots 23, and the tool pots 23 are attached to a transfer mechanism 25 disposed inside the magazine base 24.

  The transfer mechanism 25 includes a pair of sprockets 26 and 27 rotatably disposed inside the magazine base 24, an endless chain 28 spanned between the sprockets 26 and 27, and an outer peripheral side of the chain 28. A bracket 29 and the like fixed to the are provided. The plurality of tool pots 23 are respectively attached to the bracket 29, and when one of the sprockets 26 is rotationally driven by the magazine motor 75, the path of circulation with the chain 28 is transferred.

  The plurality of tool pots 23 are all attached to the bracket 29 so as to be rotatable. However, the inner wall surface 24a of the outer peripheral portion of the magazine base 24 is used as a tool in the most part of the transfer path of the tool pot 23. It is in a state of contacting the pot 23. Therefore, the inner wall surface 24a is in a state of restricting the rotation of the tool pot 23, and the tool pot 23 maintains a state in which the tool 18 faces the front as shown in FIG. To do.

  On the other hand, a split outlet 24b is formed on the lower end side of the magazine base 24. Only when the index outlet 24b is formed (hereinafter referred to as an index position), the tool pot 23 removes the tool 18 from the stored state. It can be rotated to a downward direction (a state indicated by a two-dot chain line in the figure; hereinafter referred to as a replaceable state). A tilting mechanism (not shown) that rotates the tool pot 23 to the retracted state or the replaceable state is disposed at the index position.

  In addition, an actuator case 30 is provided on the upper part of the magazine base 24, and a magazine motor 75 for driving the sprocket 26 and the like are accommodated in the actuator case 30.

  As shown in FIGS. 5, 6 (a), and 6 (b), in the tool breakage detection device 37, a motor cover 40 including a linear drive motor 39 is provided inside the cases 38 </ b> L and 38 </ b> R. A pinion 41 is attached to the rotation shaft of the linear drive motor 39, and the pinion 41 meshes with a rack 43 for linearly displacing the contact sensor unit 42.

  A holder 44 that extends downward is attached to a side surface of the rack 43, and a contact sensor unit 42 is attached to the tip of the holder 44. A guide stay 45 for attaching the tool breakage detection device 37 to the tool magazine 21 is incorporated on the base end side of the cases 38L and 38R. Here, the linear drive motor 39, the pinion 41, and the rack 43 constitute a linear actuator 46.

  That is, when the linear drive motor 39 rotates the pinion 41, the contact sensor 42 together with the rack 43 is held in the longitudinal direction of the tool breakage detecting device 37, that is, the tool pot 23, and the length of the tool 18 in the retracted state. Move linearly along the direction. The contact sensor unit 42 has a built-in needle turning motor 47, which turns the detection needle 48 attached to the rotating shaft of the needle turning motor 47 and breaks the tool 18 depending on whether or not it contacts the tool 18. Is supposed to be detected.

  For example, when the detection needle 48 turns from the horizontal position, which is the initial position, when the detection needle 48 comes in contact with the tool 18 (the drill 19 or the like) in the middle and the turning stops halfway, the contact sensor unit 42 The internal switch does not turn on. On the other hand, when the tool 18 is broken, if the turning of the detection needle 48 is swung to the final position without stopping, the breakage of the tool 18 is detected by turning on the switch.

Next, the machining program will be described.
The control device 50 can process the workpiece into a desired shape by controlling the operation of the machine body 3 based on the machining program displayed on the display 82 of the operation panel 80. As shown in FIG. 9, this machining program is an NC program written in the NC language. This NC program is composed of an array of a plurality of program blocks.

  Each program block includes information necessary for causing the machine body 3 to execute one specific operation (movement, stop, spindle rotation, etc.), and constitutes a complete control command for each program block. . Therefore, a specific operation in the machine body 3 can be performed based on the control commands of those program blocks. The machining program of the machine tool 1 is mainly composed of a G code for determining an operation mode (various position determination, movement, etc.) of the machine and an M code for instructing an auxiliary function other than the operation.

Next, main G codes and M codes will be described.
“G100” is a command code for instructing replacement of the tool 18 mounted on the spindle 9, “G81” is a command code for instructing drilling, “G84” is a command code for instructing tapping, and “G0” is positioning. A command code for commanding, “G1” is a command code for commanding cutting, and “M30” is a command code for commanding the end of the machining program.

Next, stop mode setting control executed by the control device 50 will be described based on the machining program in FIG. 9 and the flowcharts in FIGS. 10 and 11. In the figure, Si (i = 1, 2,...) Indicates each step.
When the control device 50 executes the machining program of FIG. 9, first, one block interpretation is performed (S1). Since the first block is a G100T1 tool change command (S2; No, S3; Yes), the process proceeds to S15. In S15, since it is the first tool change, the tool T1 is changed without performing breakage detection (S4). Here, since the block stop flag is not set (S5; No) and the program is not finished (S6; No), the process returns to S1.

Next, the fixed cycle command of G81 is interpreted (S1), and after preparing for the fixed cycle machining (S2; No, S3; No, S4), the process returns to S1 through S5 and S6 as described above. Hereinafter, description of the same processing as described above will be omitted.
Next, X50. Y50. The block is interpreted (S1). This is a machining command in a fixed cycle (S2; Yes). In the first machining, since there is no breakage machining position information (S8; No), machining position X50. Y50. Is registered in the processing position information area (S9). After processing the block (S4), the process returns to S1 to interpret the next block (S1).

  Processing position X50. Y150. And X150. Y150. And X150. Y50. Also, by performing the same process as described above, each machining position information is registered in the machining position information area (S9), and machining is performed on each machining position (S4). Thus, at the end of machining of the tool T1, the machining position information area has X50. Y50. And X50. Y150. And X150. Y150. And X150. Y50. The four pieces of processing position information are registered.

  Next, the block of G100T2 is interpreted (S1). Since this command is a tool change command (S3; Yes), breakage detection of the tool T1 is executed (S15). When the tool T1 is not broken (S16; No), the machining position information in the machining position information area is cleared (S17). That is, the machining position X50. Y50. And X50. Y150. And X150. Y150. And X150. Y50. Is deleted from the processing position information area. When the tool T1 is broken (S16; Yes), the machining position information in the machining position information area is registered in the broken machining position information area (S18). After registering the broken machining position information, the machining position information in the machining position information area is cleared (S17). The tool T1 is replaced with the tool T2 (S4), and the process returns to S1.

  After the G81 fixed cycle command is interpreted (S1) and the fixed cycle preparation is performed (S4), the process returns to S1. Next X100. Y100. When this block is interpreted (S1), since it is a processing command (S2; Yes), it is determined whether or not the fracture processing position information is registered in the fracture processing position area (S8). If the tool T1 is not broken, the broken machining position information is not registered (S8; No), so the machining position X100. Y100. Is registered in the machining position information area as machining position information (S9). Next X200. Y200. The same processing is performed for these blocks.

  However, when the tool T1 is broken, the broken machining position information is registered (S8; Yes). Next, it is determined whether or not the machining tool to be performed is milling (S10). Since the tool T2 is a drill tool (S10; No), the machining position X100. Y100. Is determined in the breakage processing position information (S12). At this time, X50. Y50. And X50. Y150. And X150. Y150. And X150. Y50. Are registered, so X100. Y100. Is not applicable (S12; No). Therefore, a stop flag is set after completion of the machining program (S13), and X100. Y100. Is processed (S4). X200. Y200. The same processing is performed for these blocks.

  Next, the block of G100T3 is interpreted (S1). Since this command is a tool change command (S3; Yes), breakage of the tool T2 is detected (S15). When the tool T2 is not broken (S16; No), the machining position information is cleared (S17). When the tool T2 is broken (S16; Yes), the machining position information is registered in the broken machining position information area (S18). After registering the broken machining position information, the machining position information in the machining position information area is cleared (S17). The tool T2 is replaced with the tool T3 (S4), and the next block is interpreted.

  The G84 fixed cycle command is interpreted (S1), and fixed cycle preparation is performed (S4). Next X100. Y100. When the block is interpreted (S1), since it is a machining command (S2; Yes), it is determined whether or not the broken machining position information is registered in the broken machining position information area (S8). If both the tools T1 and T2 are not broken, the broken machining position information is not registered (S8; No), so the machining position X100. Y100. Is registered in the processing position information area (S9). Next X200. Y200. The same processing is performed for these blocks.

  When only the tool T1 is broken, the broken machining position information is registered (S8; Yes), but the tool T3 is not a milling tool (S10; No), and the machining position X100. Y100. Is not in the breakage processing position information area (S12; No). After the machining program ends, a stop flag is set (S13), and X100. Y100. Is processed (S4). X200. Y200. The same processing is performed for these blocks.

  When only the tools T1 and T2 or T2 are broken, the machining position X100. Y100. (S12; Yes), a “tool breakage” alarm is displayed on the display 82 and immediately stopped (S14). In this case, if tapping is performed in a state where the prepared hole is not normally opened, the tapping tool may be broken, and it is necessary to stop immediately.

  If it is not stopped immediately, then the G100T4 block is interpreted (S1). Since this command is a tool change command (S3; Yes), breakage of the tool T3 is detected (S15). When the tool T3 is not broken (S16; No), the machining position information in the machining position information area is cleared (S17). When the tool T3 is broken (S16; Yes), the machining position information in the machining position information area is registered in the broken machining position information area (S18). After registration in the breakage machining position information area, the machining position information in the machining position information area is cleared (S17). The tool T3 is replaced with the tool T4 (S4), and the next block is interpreted.

  The G0 command is interpreted (S1) and executed (S4). Next, the G1 command is interpreted (S1), and since it is a machining command (S2; Yes), it is determined whether or not the broken machining position information is registered in the broken machining position information area (S8). If none of the tools T1, T2 and T3 are broken, the broken machining position information is not registered (S8; No), so the machining position X282. Y0. Is registered in the processing position information area (S9), and processing is performed (S4).

  If any of the tools T1, T2 and T3 has a breakage, since the breakage machining position information is registered in the breakage machining position information area (S8; Yes), it is determined whether or not the tool T4 is a milling tool. (S10). Since the tool T4 is a milling tool (S10; Yes), a block stop flag is set (S11), and machining is performed (S4). Since the block stop flag is set after the end of machining (S5; Yes), a “tool breakage” alarm is displayed on the display to stop the machining operation being executed (S19).

If the tools T1, T2 and T3 are not broken, the end of program M30 is finally interpreted (S6; Yes). If the stop flag is not set after the machining program ends (S7; No), the machining program End execution.
On the other hand, if the stop flag is set after completion of the machining program (S7; Yes), a “tool breakage” alarm is displayed on the display to stop the machining operation (S20). In addition, CPU51 which performs S8-S14 is equivalent to a stop mode setting means.

Next, the operation and effect of the numerically controlled machine tool 1 described above will be described.
Thus, as a stop mode when the breakage of the tool 18 is detected by the tool breakage detection device 37, an immediate stop to be stopped immediately, a block stop to be stopped at the end of the machining operation of the block being executed, and the machining being executed Since the machining program to be stopped at the end of the program is configured to be selectively set at the end of the machining program, the machining operation being executed when the breakage of the tool 18 used for the machining is detected at the end of the machining. However, it is possible to set an optimal stop mode according to the type of processing.

  Since the tool breakage detection device 37 is arranged in the tool magazine 21 of the automatic tool changer 20, it is possible to perform cutting processing of the next block in the machining program while detecting breakage of the tool 18 used for the latest cutting processing. it can. Also in this case, an optimum stop mode corresponding to the type of machining can be set for the machining operation being executed.

  After the breakage of the tool 18 is detected by the tool breakage detection device 37, when cutting is performed at the same position as the position where the tool 18 has been detected for breakage, an immediate stop is set. When the tool 18 breaks during the drilling process, the tapping for the same position can be stopped immediately. Therefore, it is possible to prevent the tap tool from being broken by broken pieces of the tool 18.

  After the breakage of the tool 18 is detected by the tool breakage detection device 37, when cutting is performed at a position different from the position at which the tool 18 has been detected for breakage, a stop is set after the processing program is finished, so two different processes are performed. When drilling with a different tool 18 for the position, etc., if the tool 18 used for the previous drilling process is broken, it does not affect the subsequent drilling process, and the processing operation can be continued. .

  After the breakage of the tool 18 is detected by the tool breakage detection device 37, when the tool 18 used for cutting is a milling tool, the block stop is set. Therefore, the breakage of the tool 18 used for the previous drilling process during the facing process is set. Even if is detected, the machining operation is not immediately stopped. In this way, by continuing the processing operation of the block being executed at the time of facing processing, a desired processing accuracy can be obtained without making the processing surface rough.

Next, a second embodiment of the present invention will be described with reference to FIGS. However, the same reference numerals are given to the same components as those in the above embodiment, and only different components will be described.
In the second embodiment, a command code for alternatively setting a stop mode when a breakage of the tool 18 is detected is set in advance in the machining program. Based on this command code, an immediate stop, block It is alternatively set to stop and stop after completion of the machining program.

  As shown in FIGS. 12 to 14, “M205” to “M207” alternatively execute stop mode setting control at the time of automatic tool change, and alternatively set the stop mode when the breakage of the tool 18 is detected. Command code for “M205” is a command code (first code) for instructing immediate stop to stop immediately, “M206” is a command code (second code) for instructing block stop to be stopped at the end of the machining operation of the block being executed, “ “M207” is a command code (third code) for instructing a stop after the machining program to be stopped when the machining program being executed is terminated.

  The operator inputs one command code from “M205” to “M207” in advance immediately before “G100” that commands tool replacement. Thereby, as a stop mode when the breakage of the tool 18 is detected by the tool breakage detection device 37, an immediate stop, a block stop, and a stop after completion of the machining program can be alternatively set.

Next, stop mode setting control executed by the control device 50 will be described based on the machining program of FIGS. 12 to 14 and the flowchart of FIG. In the figure, Si (i = 30, 31...) Indicates each step.
First, a case where the control device 50 executes the machining program of FIG. 12 will be described. FIG. 12 shows a machining program when drilling is executed using different tools 18 for two different points.

  When the control device 50 executes the machining program, each block is read in turn, the tool is changed to the drill tool T1 by the “G100T1” command, and the X-100. Y-100. Execute drilling at the position of. Next, the control device 50 executes stop mode setting control in accordance with the “M207” command and the “G100T2” command.

  The breakage detection of the tool 18 used for the latest cutting is performed by the tool breakage detection device 37 (S30). When breakage of the tool 18 is detected (S31; Yes), it is determined whether or not the M code is an “M207” command. In this case, since it is the “M207” command (S32; Yes), the automatic tool changer 20 replaces the tool T1 with the tool T2 after setting the stop command after the machining program for stopping the machining operation with the “M30” command. To do.

  The X-200. Y-200. Is drilled at the position, and is stopped by an “M30” command, and a “tool breakage” alarm is displayed on the display 82. However, when breakage of the tool 18 is not detected (S31; No), after the automatic tool changer 20 executes automatic tool change, the X-200. Y-200. Is drilled at the position of, and the machining operation is stopped by the “M30” command.

Next, a case where the machining program of FIG. 13 is executed will be described. FIG. 13 shows a machining program when the facing process is executed after the drilling process is executed.
When the control device 50 executes the machining program, the process based on the “G100T1” command and the “G81” command is executed as in the case described above. Next, the control device 50 executes stop mode setting control in accordance with the “M206” command and the “G100T3” command.

  The control device 50 processes S30 and S31 in the same manner as described above, and since the M code is an “M206” command (S32; No, S34; Yes), after setting the block stop (S35), the automatic tool The exchange device 20 exchanges the tool T1 with the tool T3. Next, the X-150. Y-150. Facing processing is executed at the position of, and stopped at the end of the processing operation of this block, and a “tool breakage” alarm is displayed on the display 82.

  However, when breakage of the tool 18 is not detected (S31; No), after the automatic tool changer 20 executes automatic tool change, the X-150. Y-150. And X-50. And Y-100. And X-150. Facing processing is executed at the position of, and the processing operation is stopped by an “M30” command.

Next, a case where the machining program of FIG. 14 is executed will be described. FIG. 14 shows a machining program in the case where tapping is performed after execution of the lower hole drilling.
When the control device 50 executes the machining program, the process based on the “G100T1” command and the “G81” command is executed as in the case described above. Next, the control device 50 executes stop mode setting control in accordance with the “M205” command and the “G100T3” command.

  The control device 50 processes S30 and S31 in the same manner as described above, and sets the immediate stop because the M code is the “M205” command (S32; No, S34; No) (S36). The execution of this machining program is immediately stopped and a “tool breakage” alarm is displayed on the display 82. However, when the breakage of the tool 18 is not detected (S31; No), after the automatic tool changer 20 executes the automatic tool change, the X-100. Y-100. The tap machining is executed at the position of, and the machining program is terminated by the “M30” command. In addition, CPU51 which performs S32-S36 is equivalent to a stop mode setting means.

  As described above, the first code for instructing immediate stop, the second code for instructing block stop, and the third code for instructing stop after completion of the machining program are set in advance in association with each block of the machining program. Since the stop mode is set based on the code, the operator can easily set the stop mode according to the type of processing by setting the desired code in the processing program according to the type of processing. can do. Since the first, second, and third codes are set in advance immediately before the block instructing the tool change in the machining program, it is possible to reliably set the stop mode at the time of the tool change.

Next, a modified example in which the above embodiment is partially modified will be described.
1] As the tool breakage detection device 37, various devices such as an optical sensor type can be applied in addition to the device of the above-described embodiment. For example, the breakage of the tool 18 currently used may be detected by obtaining the torque applied to the tool 18 during cutting. In this case, the torque applied to the tool 18 is calculated based on the drive current flowing through the spindle motor detected by the current detector 64b. When the calculated torque exceeds a predetermined range, it is determined that the tool 18 is broken, and stop mode setting control is performed.

2] Information about the end mill tool may be stored in the table shown in FIG. 7, and the block stop flag may be set in the case of the end mill tool in S10.

1 is a front view of a numerically controlled machine tool according to an embodiment of the present invention. It is a perspective view of the machine main body of a machine tool. It is a block diagram which shows the control system of a machine tool. (A) is a front view of a tool magazine, (b) is a side view of a tool magazine. It is a perspective view of a tool breakage detection apparatus. (A) is a disassembled perspective view of a tool breakage detection device, (b) is a front view of the tool breakage detection device with the case removed. It is a figure which shows the table of the tool information memorize | stored in ROM. It is explanatory drawing which shows the storage area of RAM. It is an example of a processing program. It is a part of flowchart of a stop mode setting control program. It is the remainder of the flowchart of a stop mode setting control program. It is an example of the processing program in the case of performing drilling in two different points. It is an example of the processing program in the case of performing a facing process after a drilling process. It is an example of the processing program in the case of performing tapping after under-drilling. It is a flowchart of the stop mode setting control program in Example 2.

DESCRIPTION OF SYMBOLS 1 Numerically controlled machine tool 18 Tool 20 Automatic tool changer 21 Tool magazine 37 Tool breakage detector 51 CPU

Claims (7)

In a numerically controlled machine tool equipped with a tool breakage detection device that detects the breakage of the tool used for the latest cutting every time cutting is completed,
As a stop mode when a tool breakage is detected by the tool breakage detection device, an immediate stop to stop immediately, a block stop to stop at the end of the machining operation of the block being executed, and a stop at the end of the machining program being executed A numerically controlled machine tool comprising stop mode setting means that can alternatively set a stop after completion of a machining program.   The numerically controlled machine tool according to claim 1, wherein the tool breakage detecting device is arranged in a tool magazine of an automatic tool changer.   The stop mode setting means sets an immediate stop when performing cutting at the same position as the position where cutting was performed with the tool whose breakage was detected after the breakage of the tool was detected by the tool breakage detecting device. The numerically controlled machine tool according to claim 1 or 2.   The stop mode setting means sets the stop after the end of the machining program when performing cutting at a position different from the position at which cutting was performed with the tool whose breakage was detected after the breakage of the tool was detected by the tool breakage detecting device. The numerically controlled machine tool according to any one of claims 1 to 3.   The said stop mode setting means sets a block stop, when the tool used for a cutting process is a milling tool or an end mill tool after the tool breakage detection by the said tool breakage detection apparatus. A numerically controlled machine tool according to any one of the above.   The stop mode setting means is associated with each block of the machining program among the first code for instructing immediate stop, the second code for instructing block stop, and the third code for instructing stop after completion of the machining program. The numerically controlled machine tool according to claim 1, wherein the stop mode is set based on a preset code. The numerically controlled machine tool according to claim 6 , wherein the first, second, and third codes are set in advance immediately before a block that commands tool change in a machining program.