JP2012011492A - Tool arrangement computing device, tool arrangement computing program, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool arrangement computing device capable of surely computing an arrangement of a tool with a minimum changeover frequency of a tool magazine, a control program for the tool arrangement computing device, and a storage medium.SOLUTION: A CPU of a numerical control device reads out a tool changeover instruction from an NC program and memorizes a usage order L of the tool T (S11, S12). In the using order L, a singly-used tool continuation spot Mi in which the singly-used tool continues in the usage order L of the tool T of the NC program is memorized (S15). The singly-used tool continuation spot Mi is assumed as a piece of a tool and all of combinations of permutations W are generated (S17). Each of the permutation W is converted into a tool arrangement Q and the changeover frequency R is calculated (S18, S19). Accordingly, throughput relating to the calculation of the changeover frequency R is drastically reduced so that an optimal tool arrangement with a smallest changeover frequency R is calculated with reliability.

Description

  The present invention relates to a tool arrangement calculation device, a tool arrangement calculation program, and a storage medium that can calculate the arrangement of tools in a turret type tool magazine.

  Conventionally, a tool changer has a turret type tool magazine. The tool magazine is provided with a plurality of pots for mounting tools on the outer periphery. The tool change command in the NC program instructs to change to a tool having a specific pot number. A tool with a specific pot number is positioned at a predetermined tool change position by turning the tool magazine. The tool changer replaces the current tool mounted on the spindle of the machine tool with the next tool located at the tool change position. For example, if the tool magazine has 14 pots, if the current tool currently mounted on the spindle is pot number 1 and the next tool is pot number 8, the tool magazine is swung seven times. Switch position. The tool of the pot number 8 after the tool magazine is turned and the position is switched is located at the tool change position. The operator arranges the tools in the tool magazine so that the number of times of pot switching (hereinafter referred to as the number of times of switching) is minimized. Therefore, the tool change time is shortened.

  The method disclosed in Patent Document 1 reads a tool change command instructed in the NC program, preferentially arranges tools with the most tool change combinations in the adjacent pot, and places the remaining tools in the NC program. They are arranged in order of command.

JP-A-5-269635

  The calculation method described in Patent Document 1 does not consider all combinations of all patterns of tool arrangement. Therefore, depending on the order of tool use in the program, it may not be possible to calculate a tool arrangement that minimizes the number of times of switching.

  The present invention has been made to solve the above-described problems, and provides a tool placement calculation device, a tool placement calculation device control program, and a storage medium that can reliably calculate a tool placement that minimizes the number of times of switching between tool magazines. The purpose is to do.

  The tool arrangement calculation device according to the first aspect of the present invention is provided in a tool changer of a machine tool so as to be able to perform rotation indexing, and is arranged in each of a plurality of pots provided on the outer periphery of a substantially disk-shaped tool magazine that rotates forward or reverse. A tool arrangement calculation device for calculating the arrangement of a plurality of tools, based on a tool change command reading means for reading a tool change command from a machining program of the machine tool, and based on the tool change command read by the tool change command reading means. The use order specifying means for specifying the use order of the tools used in the machining program, and the arrangement locations in which the single tools used only once are continuously arranged in the use order specified by the use order specifying means. The arrangement location extracting means to be extracted and the arrangement location extracted by the arrangement location extraction means are regarded as one tool, and the tools used in the machining program are arranged in a line. In the permutation generating means for generating all the permutations obtained, and in the permutation calculated by the permutation generating means, when the tools are used in the order of use in the state where the array locations are returned to the single tool array, A switching number counting unit that counts the number of switchings necessary for pot switching, and a minimum number that is the smallest switching number among the plurality of switching times counted for each permutation by the switching number counting unit A minimum number of times specifying means; and an arrangement information output means for outputting arrangement information that is information of tool arrangement when tools are arranged in the pot based on the permutation corresponding to the minimum number of times specified by the minimum number of times specifying means; It has.

  In the first aspect, the tool change command reading means reads the tool change command from the machining program of the machine tool. The use order specifying means specifies the use order of the used tools used in the machining program based on the tool change command read by the tool change command reading means. The arrangement location extracting means extracts arrangement locations where single tools that are used only once are continuously arranged in the order of use specified by the usage order specification means. The permutation generation means regards the arrangement location extracted by the arrangement location extraction means as one tool, and generates a permutation obtained by arranging the tools used in the machining program in a row. The switching number counting unit counts the number of switchings required for pot switching when the tools are used in the order of use in a state where the arrangement position is returned to the single tool arrangement in the permutation calculated by the permutation generation unit. The minimum number of times specifying means specifies the minimum number of times that is the smallest number of times of switching from among a plurality of times of switching counted for each permutation by the number of times of switching counting. The arrangement information output means outputs arrangement information, which is information on tool arrangement when tools are arranged in the pot, based on the permutation corresponding to the minimum number specified by the minimum number specifying means. The extraction location extracted by the array location extraction means is a location where single-shot tools are continuously arranged in the order of use of tools in the machining program. If the single tools are arranged in the order of use at the extraction location, the number of pot switching is minimized. Therefore, the extracted part is regarded as one tool, and a permutation obtained by arranging the tools used in the machining program in a line is generated. Since the number of combinations of permutations can be reduced as compared with the case of generating all permutations of tools, the amount of calculation can be reduced. Since the minimum number is specified from a plurality of switching times counted for each permutation, it is possible to reliably calculate the arrangement of the tools that minimizes the number of times the tool magazine turns. Since the arrangement information related to the tool arrangement can be output, the operator can arrange the tools based on the output arrangement information.

  Further, in the first aspect, the switching number counting means is configured such that, in the permutation calculated by the permutation generation means, the arrangement locations are returned to the original arrangement that is the order of use of the single tool, and the tools are used in the order of use. May be used for each permutation, the number of times required for switching the pots may be counted. Therefore, the amount of processing related to the calculation of the number of pot switching can be minimized.

  The tool arrangement calculation program according to the second aspect of the present invention is provided in a tool changer of a machine tool so as to be able to perform rotation indexing, and is arranged in each of a plurality of pots provided on the outer periphery of a substantially disk-shaped tool magazine that rotates normally or reversely. A tool placement calculation program for controlling the operation of a tool placement calculation device that calculates the placement of a plurality of tools, a tool change command reading step for reading a tool change command from a machining program of the machine tool into a computer, and the tool change Based on the tool change command read in the command reading step, only once in the use order specifying step for specifying the use order of the tools used in the machining program and the use order specified in the use order specifying step. An array location extraction step for extracting the array locations where the single tools to be used are continuously arranged, and the array location extraction In the permutation calculating step for generating the permutation obtained by arranging the tools extracted in the step as one tool and arranging the tools used in the machining program in a row, and in the permutation calculated in the permutation calculating step, When the tools are used in the order of use in the state in which the arrangement location is returned to the single tool arrangement, the switching number counting step for counting the number of switching necessary for switching the pot, and the switching number counting step Based on the minimum number specifying step for specifying the minimum number of times that is the smallest number of times of switching among the plurality of switching times counted for each permutation, and the permutation corresponding to the minimum number of times specified in the minimum number of times specifying step. , An arrangement information output unit for outputting arrangement information which is information on arrangement of tools when tools are arranged in the pot. Characterized in that it is executed and-up.

  The second aspect is a tool arrangement calculation program executed by a computer. In the tool change command reading step, the tool change command is read from the machining program of the machine tool. In the use order specifying step, the use order of the tools used in the machining program is specified based on the tool change command read in the tool change command reading step. In the permutation calculation step, the arrangement location extracted in the arrangement location extraction step is regarded as one tool, and a permutation obtained by arranging the tools used in the machining program in a row is generated. In the switching number counting step, when the tools are used in the order of use in the state where the arrangement location is returned to the single tool arrangement in the permutation calculated in the permutation calculating step, the number of switching times required for pot switching is counted. In the minimum number specifying step, the minimum number, which is the smallest number of switching times, is specified from the plurality of switching times counted for each permutation in the switching number counting step. In the arrangement information output step, arrangement information, which is information on the arrangement of tools when the tools are arranged in the pot, is output based on the permutation corresponding to the minimum number specified in the minimum number specifying step. The extraction locations to be extracted in the array location extraction step are locations where single-shot tools are continuously arranged in the order of use of tools in the machining program. If the single tools are arranged in the order of use at the extraction location, the number of pot switching is minimized. Therefore, the extracted part is regarded as one tool, and a permutation obtained by arranging the tools used in the machining program in a line is generated. Since the number of combinations of permutations can be reduced as compared with the case of generating all permutations of tools, the amount of calculation can be reduced. Since the minimum number is specified from a plurality of switching times counted for each permutation, it is possible to reliably calculate the arrangement of the tools that minimizes the number of times the tool magazine turns. Since the arrangement information related to the tool arrangement can be output, the operator can arrange the tools based on the output arrangement information.

  A storage medium according to a third aspect of the present invention is readable by a computer and stores the tool arrangement calculation program according to claim 3.

  In the third aspect, since the control program according to claim 3 is stored, the effect according to claim 3 can be obtained.

1 is a front view of a machine tool 1. It is a perspective view of the machine tool 1 which removed the splash cover 4. FIG. 2 is a schematic view of the tool magazine 31 as viewed from the front. 3 is a block diagram showing an electrical configuration of a numerical control device 20. FIG. It is the figure which showed an example of NC program. It is a main flowchart of a tool arrangement | positioning calculation process. It is a flowchart of switching frequency calculation processing. It is the figure which showed the tool arrangement | positioning table 50 displayed on the display.

  Hereinafter, an embodiment of a tool arrangement calculating device according to the present invention will be described with reference to the drawings. The numerical control device 20 (see FIG. 4) of the present embodiment controls the operation of the machine tool 1 (see FIG. 1) according to the NC program. The NC program is a machining program in which NC commands are arranged. The machine tool 1 is a machine that cuts a workpiece by relative movement of the workpiece and a tool.

  The structure of the machine tool 1 will be briefly described. As shown in FIG. 1, a machine tool 1 is located on an iron base 2, an upper part of the base 2, a machine main body 3 (see FIG. 2) for cutting a workpiece, and an upper part of the machine main body 3. A tool changer 30 (see FIG. 2) for exchanging a tool T mounted on a main shaft (not shown) of the machine body 3, and a splash cover 4 surrounding the machine body 3 and the tool changer 30. Yes.

  The splash cover 4 has an opening 5 on the front surface. The opening 5 includes an opening / closing door 6. An operation panel 10 for operating the machine tool 1 is located on the right side of the opening 5. The operation panel 10 includes a display 11 at the top and a keyboard 12 at the bottom. The display 11 displays various screens such as an operation screen, a setting screen, and a tool arrangement table 50 (see FIG. 8) described later. The operator performs various inputs, settings, operations, and the like using the keyboard 12 while checking the screen displayed on the display 11.

  The configuration of the machine body 3 will be briefly described. As shown in FIG. 2, the machine body 3 includes a prismatic column 15, a spindle head (not shown), a spindle (not shown), and a table 19. The column 15 is erected on the upper rear side of the base 2. The spindle head moves up and down along the front surface of the column 15. The spindle head moves in the Z-axis direction by driving a Z-axis motor 53 (see FIG. 4). The spindle is provided below the spindle head. The spindle has a mounting hole (not shown) for mounting the tool T, and rotates by driving the spindle motor 54 (see FIG. 4). The table 19 is provided in the upper center of the base 2. The table 19 is moved in the XY-axis direction by an X-axis motor 51 (see FIG. 4), a Y-axis motor 52 (see FIG. 4), and a guide mechanism (not shown). The X-axis direction is the left-right direction in FIG. The Y-axis direction is a direction perpendicular to the paper surface of FIG. The Z-axis direction is the vertical direction in FIG. The numerical controller 20 is stored in a control box (not shown) located on the back side of the column 15.

  The configuration of the tool changer 30 will be described. As shown in FIGS. 2 and 3, the tool changer 30 includes a turret type tool magazine 31. The tool magazine 31 has a disk shape. The tool magazine 31 is turned around its axis by driving a magazine motor 55 (see FIG. 4). As shown in FIG. 3, the tool magazine 31 includes 21 pots P <b> 1 to P <b> 21 on the outer periphery in the circumferential direction (clockwise in front view). An operator attaches / detaches the tool T to / from the pots P1 to P21. P1 to P21 indicate pot numbers. The position of the pot P located at the lowermost part of the tool magazine 31 corresponds to a “tool changing position” for exchanging the tool with the spindle of the machine tool 1. In the example shown in FIG. 3, the tool change position is the position of the pot P12.

  The tool magazine 31 can be rotated forward (clockwise in front view) and reversed (counterclockwise in front view). Forward rotation and reversal are determined by the relative positional relationship between the pot P of the current tool currently mounted on the spindle and the pot P of the next tool mounted on the spindle after the next tool change. The numerical control device 20 controls the tool magazine 31 to turn in the direction where the number of switching times of the tool magazine 31 from the current tool pot P to the next tool pot P is smaller.

  The turning operation of the tool magazine 31 will be briefly described. When there is a tool change command (M06 command) in the NC program, the CPU 21 (see FIG. 4) of the numerical controller 20 determines the position of the pot P of the next tool T to be changed. The pot P of the current tool is in the tool change position. The CPU 21 calculates the number of times of switching of the tool magazine 31 required until the pot P of the next tool is transported from the current position to the tool change position. The tool changer 30 removes the current tool T from the main shaft. The tool magazine 31 is rotated by the number of times of switching calculated by the CPU 21 when the magazine motor 55 is driven. The next tool T to be mounted on the pot P is located at the tool change position. The tool changer 30 mounts the next tool T on the main shaft.

  The number of times of switching is defined as the number of times that the position of the pot P of the tool magazine 31 is switched to the position of the adjacent pot P (hereinafter referred to as “number of times of switching”). For example, in FIG. 3, the number of times of switching required when the tool T in the pot P1 is switched to the tool T in the pot P4 is “3 times”.

  The operator may attach the tool T to all of the pots P1 to P21, but if the number of tools is smaller than the total number of pots, an empty pot P may be provided. In order to reduce the number of times the pot P is switched, it is preferable to close the space between the tool T and the tool T.

  Next, the electrical configuration of the numerical controller 20 will be described with reference to FIG. The numerical controller 20 includes a microcomputer having a CPU 21, ROM 22, RAM 23, and flash memory 24, an input interface 25, and an input / output interface 26. The input interface 25 is connected to the keyboard 12 of the operation panel 10.

  The input / output interface 26 is a drive circuit 41 that drives the X-axis motor 51, a drive circuit 42 that drives the Y-axis motor 52, a drive circuit 43 that drives the Z-axis motor 53, and a drive that drives the spindle motor 54. The circuit 44, a drive circuit 45 that drives the magazine motor 55, a drive circuit 46 that drives the display 11 of the operation panel 10, and the like are connected. Driving of the X-axis motor 51 and the Y-axis motor 52 moves the table 19 in the X-axis direction and the Y-axis direction. The drive of the Z-axis motor 53 moves a spindle head (not shown) in the Z-axis direction.

  Each of the X-axis motor 51, the Y-axis motor 52, the Z-axis motor 53, the main shaft motor 54, and the magazine motor 55 includes an encoder (not shown) that detects the position of the motor. Each encoder is connected to each drive circuit 41, 42, 43, 44, 45.

  Next, the tool placement calculation process by the CPU 21 will be described with reference to the flowcharts of FIGS. In the present embodiment, when the NC program shown in FIG. 5 is executed, the optimum tool arrangement (Qopt) with the smallest number of switching times of the tool magazine 31 is calculated. The NC program shown in FIG. 5 is one in which 21 tools T are sequentially replaced in 29 steps. The NC program shown in FIG. 5 omits intermediate cutting commands for convenience of explanation.

  In this process, when the operator selects a tool placement calculation button (not shown) displayed on the display 11, the CPU 21 stores a tool placement calculation program stored in the ROM 22 (see FIG. 4) (“tool placement calculation program of the present invention”). ”).

  The CPU 21 reads a tool change command from the NC program (see FIG. 5) stored in the flash memory 24 (S11). The tool change command is “M06”. Based on the read tool change command, the CPU 21 specifies the use order L of the tools used in the NC program and stores it in the RAM 23. (S12). In the example of the NC program shown in FIG. 5, there are 29 blocks including a tool change command. Therefore, the information on the usage order L is information on the order in which 21 tools T are used in 29 blocks constituting the NC program.

The CPU 21 counts the number of times each tool T is used in the usage order L and stores it in the RAM 23 (see FIG. 4) (S13). In the example of the NC program shown in FIG. 5, the number of times each tool T is used is as follows.
・ T1 ・ ・ ・ 2 times ・ T2 ・ ・ ・ 4 times ・ T5 ... 3 times ・ T6 ... 3 times ・ T3, T4, T7, T8, T9 to T21 ... 1 time

CPU21 extracts and memorize | stores the location (henceforth single tool continuous location Mi) where the "single tool" used only once in the order of use L continues (S15). In the example of the NC program shown in FIG. 5, the single tool continuous portion Mi is the following four locations. i is an integer of 1 to N. In this embodiment, N = 4. The tool number is shown in parentheses.
・ Location A {3,4}
・ Location B {7,8}
-Location C {9, 10, 11, 12, 13, 14, 15, 16}
・ Location D {17, 18, 19, 20, 21}

  The CPU 21 extracts a tool Tj that is not included in the single tool continuous portion Mi in the usage order L, and stores it in the RAM 23 (S16). In the example of the NC program shown in FIG. 5, there are four T1, T2, T5, and T6. j is an integer of 1 to U. In this embodiment, U = 4.

  The CPU 21 generates a permutation W (S17). The permutation W is generated by arranging the tools used in the NC program in a line, considering the single tool continuous portion Mi as one tool. The single tool continuous locations Mi stored in the RAM 23 are four locations A to D. In this embodiment, locations A to D are regarded as virtual tools A to D, and T1, T2, T5, and T6 are regarded as virtual tools E to H. The CPU 21 generates all combinations of the permutations W of the eight virtual tools A to H.

The total combination of 8 virtual tools is 8! = 40,320. When the single tool continuous portion Mi is calculated without considering it as one tool, it is necessary to generate all combinations of permutations W of 21 tools. All combinations of permutations W of 21 tools are 21! ≈5 × 10 ¹⁹ ways. When the number of times of switching described later is calculated for all combinations of 21 tool permutations W, the processing amount becomes enormous and the processing time becomes long. In the present embodiment, the permutation W of the tool T used by regarding the single tool continuous portion Mi as one tool is generated, and the number of times of switching is calculated in a state where each permutation W is converted into the tool arrangement Q. Therefore, the amount of processing related to the calculation of the number of switching times is significantly reduced.

  The CPU 21 executes a switching number calculation process (S18). In the switching frequency calculation process, when the tools T are arranged according to the generated permutation W, the switching frequency R of the pot P required when using each tool T in the usage order L is calculated.

  The switching number calculation process will be described with reference to the flowchart of FIG. The CPU 21 converts the permutation W into the tool arrangement Q (S31). The CPU 21 returns the single arrangement locations A to D regarded as one virtual tool in the permutation W to the single tool arrangement. The order of the single tools in the single array locations A to D follows the order of use L stored in the RAM 23. Single-shot tools are continuous in single-shot arrangement locations A to D. Therefore, according to the order of use of the single-shot tool arrangement, the pot P is simply switched to the adjacent position sequentially, so that the number of switching can be minimized.

For example, the tool arrangement Q1 of the permutation W1 = ABCDEFGH is as follows. The tool number is shown in parentheses.
Q1: {3,4,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,1,2,5,6}

  The CPU 21 stores the pot number of the tool T to be used last (hereinafter referred to as Pbef) and the pot number of the tool T to be used first (hereinafter referred to as Paft) in the RAM 23 (S32). In the NC program shown in FIG. 5, the number of the tool T to be used last is 21. In the above-described tool arrangement Q1, the number 21 tool T is the 17th from the beginning, so the number of the pot P is the number 17. Therefore, Pbef is “17”. The number of the tool T to be used first is number 1. In the above-described tool arrangement Q1, since the first tool T is the 18th from the beginning, the number of the pot P is the 18th. Therefore, Paft is “18”.

  CPU21 calculates the absolute value of the difference of Pbef and Paft, and memorize | stores it in RAM23 as switching frequency CHG (S33). Since Pbef is “17” and Paft is “18”, the absolute value of the difference between 17 and 18 is 1. Therefore, the number of switching times CHG is 1.

  The CPU 21 determines whether or not the number of switching times CHG is (total number of pots / 2) +1 or more (S34). The total number of pots in the tool magazine 31 is 21. In this process, when the position of the tool magazine 31 is switched, it is determined whether the tool magazine 31 is rotated forward or reversed. When the total number of pots in the tool magazine 31 is 21, (total number of pots / 2) + 1≈11. Truncate after the decimal point. When the switching count CHG is 1, it is less than 11 (S34: NO), so the CPU 21 sets the calculated switching count CHG to the switching count R and resets the Pbef pot number to the Paft pot number. (S36). The number R of times of switching is 1, and Pbef is “18”. The CPU 21 stores the switching count R and Pbef in the RAM 23.

  When the number of switching times CHG is 11 or more (S34: YES), the number of switching times CHG can be reduced by reverse rotation rather than forward rotation. Therefore, in order to consider the case of inversion, the CPU 21 resets the value obtained by subtracting the switching number CHG from the total number of pots as the switching number CHG (S35). The CPU 21 sets the reset switching number CHG to the switching number R, and resets the Pbef pot number to the Paft pot number (S36). The CPU 21 stores the switching count R and Pbef in the RAM 23.

  The CPU 21 sets the number of calculations S stored in the RAM 23 to 1 (S37). The CPU 21 determines whether or not the number of calculations S is smaller than the number of elements in the usage order L (S38). The usage order L is stored in the RAM 23. In the example of the NC program shown in FIG. 5, the tool T is switched 29 times in the usage order L. Therefore, the number of elements in the usage order L is 29. The CPU 21 adds 1 to the number of calculations S (S39) because the number of calculations S is less than the number of elements in the usage order L (S38: YES). The number of calculations S is 2.

  CPU21 sets the pot number of the S-th tool number from the head of the use order L to Paft, and memorize | stores it in RAM23 (S40). Pbef is updated in S36. Similarly to the above, the CPU 21 calculates the absolute value of the difference between Pbef and Paft and stores it in the RAM 23 as the number of switching times CHG (S41). Pbef is “18”. The number of calculations S is 2, and the second tool number from the top of the usage order L is 2. Referring to the tool arrangement Q1 converted in S31, the pot number of the tool number 2 is 19th. The absolute value of the difference between Pbef and Paft is the absolute value of the difference between 18 and 19. The absolute value of the difference between Pbef and Paft is 1. The CPU 21 stores the number of switching times CHG in the RAM 23 as 1.

  The CPU 21 determines whether or not the number of switching times CHG is (total number of pots / 2) +1 or more (S42). The total number of pots in the tool magazine 31 is 21. When the switching count CHG is 1, it is less than (total number of pots / 2) +1 (S42: NO), so the CPU 21 adds the switching count CHG to the switching count R stored in the RAM 23, and the Pbef pot number Is reset to the Pot number of Paft (S44). Therefore, the switching count R is 2. Pbef is “19”. The CPU 21 stores the switching count R and Pbef in the RAM 23.

  When the number of switching times CHG is equal to or greater than (total number of pots / 2) +1 (S42: YES), the number of switching times CHG can be reduced by reverse rotation rather than normal rotation. Therefore, in order to consider the case of inversion, the CPU 21 resets the value obtained by subtracting the switching number CHG from the total number of pots as the switching number CHG (S43). The CPU 21 adds the switching count CHG to the switching count R stored in the RAM 23, and resets the Pbef pot number to the Paft pot number (S44).

  The CPU 21 returns the process to S38, and determines whether or not the number of calculations S is smaller than the number of elements in the usage order L (S38). When the number of calculations S is smaller than the number of elements in the usage order L (S38: YES), the CPU 21 repeats the processes of S39 to S44 as described above. When the calculation count S reaches the number of elements in the usage order L (S38: NO), the switching count R stored in the RAM 23 becomes the switching count R of the tool arrangement Q1. CPU21 complete | finishes the process of S18 of FIG.

  When the process of S18 in FIG. 6 is finished, the CPU 21 stores the current tool arrangement Q1 as Qopt in the RAM 23. The CPU 21 stores the number of times R of switching the tool arrangement Q1 as Ropt in the RAM 23. CPU21 memorize | stores 1 in RAM23 as the calculation frequency (henceforth NUM) of the switching frequency R about the tool arrangement | positioning Q (S19).

  The CPU 21 determines whether or not the NUM stored in the RAM 23 is different from the (N + U) factorial (S20). In the present embodiment, as described above, N is the number of single-shot tool continuous locations Mi. U is the number of tools Tj that are not included in the single tool continuous portion Mi. Therefore, N = 4 and U = 4. The factorial of (N + U) is 8! 40,320. The determination in S20 is to confirm whether or not the number of times of switching R has been calculated for all 40,320 combinations of tool arrangements Q.

  When the NUM stored in the RAM 23 has not reached the factorial of 8 (S20: YES), the CPU 21 adds 1 to the value of the NUM stored in the RAM 23 (S21). The CPU 21 generates the next permutation W (S22). The CPU 21 executes the switching number calculation process in the same manner as described above for the generated tool arrangement Q2 of the next permutation W (S23).

  When the switching count calculation process in S23 is completed, the CPU 21 determines whether or not the switching count R for the tool arrangement Q2 stored in the RAM 23 is smaller than the current Ropt stored in the RAM 23 (S24). When the switching count R for the tool placement Q2 is smaller than the current Ropt (S24: YES), the CPU 21 sets the tool placement Q2 as Qopt, sets the switching count R of the tool placement Q2 as Ropt, and stores the contents stored in the RAM 23. Update (S25). After updating the stored contents of the RAM 23, the CPU 21 returns the process to S20. When the switching number R for the tool placement Q2 is larger than the current Ropt (S24: NO), the current Qopt is the optimal tool placement with the smallest number of switching times R. Returns the process to S20.

  When the NUM stored in the RAM 23 reaches the factorial of 8 (S20: NO), the number of switching times R is calculated for all combinations of 40,320 tool arrangements Q. Therefore, Qopt and Ropt finally stored in the RAM 23 are the optimum tool arrangement Qopt when the NC program shown in FIG. 5 is executed, and the optimum switching frequency Ropt. The CPU 21 displays the results of Qopt and Ropt stored in the RAM 23 on the display 11 (S26).

  As shown in FIG. 8, the display 11 displays a tool arrangement table 50 based on a display command from the CPU 21. The tool arrangement table 50 shows a pot number and a tool number corresponding to the pot number in association with each other. In the present embodiment, 21 tools are mounted on 21 pots P, respectively. Therefore, the tool arrangement table 50 displays the tools T1 to 21 corresponding to the pots P1 to P21. A tool arrangement table 50 shown in FIG. 5 is a result of Qopt in the present embodiment.

In Qopt, the tool T is arranged as follows with respect to the pots P1 to P21.
Qopt: {2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 1, 17, 18, 19, 20, 21, 3, 4}

  Below the tool arrangement table 50, Ropt is displayed. The Ropt of this embodiment is 51 times. In addition, when the tools T1 to T21 are continuously arranged for the pots P1 to P21, the switching frequency R is 59 times.

  The operator installs 21 tools in each pot P of the tool magazine 31 according to the tool arrangement table 50 displayed on the display 11. Therefore, the machine tool 1 can perform the cutting process in a short time because the time required for the tool change is minimized.

  In the above description, the CPU 21 that executes the process of S11 shown in FIG. 6 corresponds to the “tool change command reading means” of the present invention. The CPU 21 that executes the process of S12 corresponds to the “use order specifying unit” of the present invention. The CPU 21 that executes the process of S15 corresponds to the “array location extracting means” of the present invention. The CPU 21 that executes the processes of S17 and S22 corresponds to the “permutation generation unit” of the present invention. The CPU 21 that executes the processes of S18 and S23 corresponds to the “switching number counting means” of the present invention. The CPU 21 that executes the processes of S24 and S25 corresponds to the “minimum number specifying means” of the present invention. The CPU 21 that executes the process of S26 corresponds to “arrangement information output means” of the present invention.

  As described above, the numerical controller 20 according to the present embodiment can calculate the optimum tool arrangement that can minimize the number of times of switching the pot P with respect to the tool arrangement in the tool magazine 31 of the tool changer 30. The CPU 21 reads a tool change command from the NC program and stores the usage order L of the tools T. In the usage order L, the CPU 21 stores a single tool continuous portion Mi where the single tools are continuous in the order of use of the tools of the NC program. The CPU 21 regards the single tool continuous portion Mi as one virtual tool and generates all combinations of the permutations W. CPU21 converts each permutation W into the tool arrangement | positioning Q, and calculates the frequency | count R of switching, respectively. That is, the CPU 21 does not calculate the number of times of switching R for all combinations of the arrangement of the tools T used in the NC program, but considers all the permutations W that are generated by regarding the single tool continuous portion Mi as one virtual tool. For the combination, the number of switching times R is calculated in the state converted into the tool arrangement Q. Therefore, the CPU 21 can remarkably reduce the processing amount related to the calculation of the number of times of switching R, so that the calculation result can be output quickly. The tool placement Q with the smallest number of switching times R is the optimum tool placement Qopt that can perform the tool change in the shortest time. When the operator places the tools in the tool magazine 31 according to the optimum tool placement Qopt, the machine tool 1 can perform cutting in a short time.

  Needless to say, the tool arrangement calculating apparatus of the present invention is not limited to the above-described embodiment, and various modifications are possible. In the above embodiment, the numerical control device 20 has been described as a tool arrangement calculation device. However, for example, a general PC (personal computer) may be used. The operator can mount the tool T on the tool magazine 31 while printing the tool arrangement table 50 with the printer for the optimum tool arrangement Qopt calculated by the CPU of the PC and checking the printed tool arrangement table.

  In the above embodiment, the tool magazine 31 has 21 pots P, but the number of pots is not limited to 21.

  In the embodiment described above, the tool T is arranged clockwise when the tool magazine 31 is viewed from the front, but may be arranged counterclockwise. In the case of arranging counterclockwise, in the switching number calculation process of FIG. 7, YES and NO in S34 and YES and NO in S42 are reversed.

DESCRIPTION OF SYMBOLS 1 Machine tool 11 Display 12 Keyboard 20 Numerical control apparatus 21 CPU
23 RAM
30 Tool changer 31 Tool magazine P Pot T Tool

Claims (4)

A tool placement calculation device that is provided in a tool changer of a machine tool so as to be able to perform rotation indexing and calculates the placement of a plurality of tools that are respectively placed in a plurality of pots provided on the outer periphery of a substantially disk-shaped tool magazine that rotates forward or reverse. And
Tool change command reading means for reading a tool change command from the machining program of the machine tool;
Based on the tool change command read by the tool change command reading means, use order specifying means for specifying the use order of the tools used in the machining program;
In the use order specified by the use order specifying means, array location extracting means for extracting the array locations where single tools that are used only once are continuously arranged; and
A permutation generating means for generating the permutation obtained by arranging the tools used in the machining program in a line, considering the array locations extracted by the array location extracting means as one tool;
In the permutation calculated by the permutation generation means, when the tools are used in the order of use in a state in which the array location is returned to the single tool array, the number of times of switching that counts the number of times of switching required to switch the pot. Counting means;
A minimum number specifying means for specifying a minimum number of switching times among a plurality of the switching times counted for each permutation by the switching number counting means;
And arrangement information output means for outputting arrangement information, which is information of tool arrangement when tools are arranged in the pot, based on the permutation corresponding to the minimum number specified by the minimum number specifying means. A tool placement calculation device. The switching number counting means includes
In the permutation calculated by the permutation generation means, when the tools are used in the order of use in a state in which the array locations are returned to the original array that is the order of use of the single tool, switching necessary for switching the pot The tool arrangement calculating device according to claim 1, wherein the number of times is counted for each permutation. Operation of the tool placement calculation device for calculating the placement of a plurality of tools respectively arranged in a plurality of pots provided on the outer periphery of a substantially disk-shaped tool magazine that is provided on a tool changer of a machine tool so that it can be rotated and indexed or reversed. A tool placement calculation program for controlling
On the computer,
A tool change command reading step for reading a tool change command from the machining program of the machine tool;
Based on the tool change command read in the tool change command reading step, a use order specifying step for specifying the use order of tools used in the machining program,
In the use order specified in the use order specifying step, an array location extraction step for extracting an array location where single tools that are used only once are continuously arranged; and
A permutation calculation step for generating a permutation obtained by arranging the tools used in the machining program in a row, considering the array locations extracted in the array location extraction step as one tool;
In the permutation calculated in the permutation calculation step, when the tools are used in the order of use in a state where the array location is returned to the single tool array, the number of times of switching that counts the number of times of switching necessary for the pot switching. Counting step;
Among the plurality of switching times counted for each permutation in the switching number counting step, a minimum number specifying step for specifying a minimum number that is the smallest number of switching times;
An arrangement information output step of outputting arrangement information, which is information of tool arrangement when tools are arranged in the pot, based on the permutation corresponding to the minimum number specified in the minimum number specifying step. A tool placement calculation program.   A computer-readable storage medium storing the tool arrangement calculation program according to claim 3.

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