JP2012179668A - Machine tool and tool replacement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machine tool and a tool replacement method in which a tool mounted on a machining shaft can be replaced from a large diameter tool to a standard tool in a short period of time.SOLUTION: After machining with a standard tool (No.4) is finished, the standard tool (No.4) mounted on a machining shaft 9 is replaced with a standard tool (No.6). A tool magazine 10 is rotated and a large diameter tool (No.5) is positioned in an opening 10b. The standard tool (No.6) is replaced with the large diameter tool (No.5), and machining is performed using the large diameter tool (No.5). The standard tool (No.6) is housed in the tool pot 31 of the large diameter tool (No.5). The standard tool (No.6) is positioned in the opening 10b. After machining with the large diameter tool (No.5) is finished, the large diameter tool (No.5) is replaced with the standard tool (No.6).

Description

  The present invention relates to a machine tool and a tool changing method for exchanging a tool housed in a housing portion and a tool mounted on a processing portion for machining a workpiece.

  Generally, a machining center (machine tool) performs various processes such as milling, boring or tapping. The machine tool takes out a predetermined tool from a storage unit that stores a plurality of tools based on a command from the control unit. Then, the tool is exchanged with a tool mounted on the machining axis (machining part) and the target machining is performed.

  Patent Document 1 discloses a machine tool including a machining shaft, a tool magazine (accommodating portion), an exchange arm, and a control device (control portion). The tool magazine includes a plurality of tool pots for storing tools. The tool magazine rotates and transports the tool pot to a replaceable position. The exchange arm includes an arm and a finger. Fingers are provided at both ends of the arm, respectively. Each finger grips a tool housed in a tool pot and a tool mounted on a machining shaft. The exchange arm descends after gripping the tool with each finger. After that, the tool is changed by rotating and raising the exchange arm 180 degrees.

  The tool is mounted on the machining axis and rotates around the axis. Tools are broadly classified into large diameter tools and standard tools. The standard tool has a smaller diameter than the large diameter tool. When the large-diameter tool is accommodated in the tool pot, the tool pot adjacent to the tool pot is emptied. This is because when the tool is accommodated in the adjacent tool pot, the large-diameter tool comes into contact with the tool accommodated in the adjacent tool pot.

  When exchanging the large-diameter tool mounted on the machining axis and the standard tool accommodated in the tool pot, the tool magazine is first rotated to transport the empty tool pot accommodating the large-diameter tool to an exchangeable position. . The exchange arm rotates and accommodates the large-diameter tool from the machining axis into the tool pot. The tool magazine rotates and transports the tool pot containing the standard tool to a replaceable position. The exchange arm rotates, and the standard tool stored in the tool pot is mounted on the machining axis.

JP-A-11-114757

  In the machine tool described in Patent Document 1, when changing from a standard tool to a large-diameter tool and then from a large-diameter tool to a standard tool, the operation of transferring the tool pot to a replaceable position immediately before rotating the exchange arm is performed twice. Exists. Therefore, it takes a long time for replacement.

  The present invention has been made in view of such circumstances, and a tool to be mounted on a machining shaft (machined portion) is exchanged in a short time from a standard tool to a large-diameter tool and from a large-diameter tool to a standard tool. An object of the present invention is to provide a machine tool and a tool change method capable of performing the above.

  A machine tool according to the present invention includes a storage unit that stores a plurality of tools, a processing unit that mounts the tool stored in the storage unit to process a workpiece, and an exchange unit that replaces the tool mounted in the processing unit. A storage unit for storing a command for exchanging the tool, identification information for identifying the tool, a tool information table for storing the dimension information indicating the size of the tool, the tool information table, A machine tool including a control unit that controls replacement by the replacement unit based on a command stored in the storage unit, wherein the control unit is stored in the storage unit, and the first tool is a second tool It is determined whether or not the second tool is larger than the first tool based on the first replacement command indicating that the tool is to be replaced and the identification information and the dimension information stored in the tool information table. Means to do this The second tool is executed after the first replacement command when the second tool is determined to be larger than the first tool, and indicates that the tool mounted on the processing unit is replaced. The means for searching for the replacement command in the storage unit, and when the second replacement command is searched for by the means, the second replacement command is based on the identification information and the dimension information stored in the tool information table. Means for determining whether or not a command to replace a third tool that is smaller than the second tool is indicated; in this means, a third tool in which the second replacement command is smaller than the second tool; And determining the third tool as a tool to be mounted on the machining portion next to the first tool, and determining the second tool as a second tool. The tool to be mounted on the machining axis next to the third tool is determined. It characterized by having a 2 decision means.

  In the machine tool according to the present invention, the control unit is determined by the first determination unit, and includes the third tool housed in the housing unit and the first tool mounted on the machining unit. Means for exchanging, and means for exchanging the third tool mounted on the processing part by the means and the second tool determined by the second determining means and accommodated in the accommodating part. It is characterized by that.

  In the machine tool according to the present invention, the processing unit moves with the replacement unit between a processing position for processing a workpiece and a replacement position for exchanging a tool, and the storage unit stores a tool. A movable storage unit and an actuator for moving the storage unit toward or away from the replacement position, and the control unit is configured to control operations of the processing unit and the storage unit, In the case of moving the processing unit from the replacement position to the processing position, the processing unit includes means for executing the movement of the processing unit and the separation of the storage unit with respect to the replacement position in parallel.

  The tool changing method according to the present invention is a tool changing method for exchanging a receiving part for storing a tool and a tool attached to a processing part for processing a workpiece, the first tool attached to the processing part, and the first tool When exchanging a second tool larger than the first tool, which is to be mounted on the processing section next to the tool, the first tool and the accommodating section are accommodated, and the first tool A step of replacing a third tool smaller than the second tool to be mounted on the processing unit after the second tool, and the third tool mounted on the processing unit by the step; A step of replacing the second tool housed in the housing portion is provided.

  In the present invention, for example, when the tool mounted on the machining axis is changed from one standard tool (first tool) to a large diameter tool (second tool), the tool is mounted on the machining axis after the large diameter tool. Find another standard tool (third tool) to be used. Prepare to mount tools on the machining axis in the order of one standard tool, another standard tool, and a large-diameter tool.

  In the present invention, for example, tools are mounted on the processing axis in the order of one standard tool (first tool), a large diameter tool (second tool), and another standard tool (third tool). After the machining with one standard tool is completed, the one standard tool mounted on the machining axis is replaced with another standard tool. The tool magazine rotates and transports the large diameter tool to a replaceable position. The exchange arm rotates and replaces other standard tools with large-diameter tools. Other standard tools are contained in the tool pot of the large diameter tool. The machining axis performs machining with a large-diameter tool. After the machining with the large-diameter tool is completed, the exchange arm rotates to exchange the large-diameter tool with another standard tool.

  In the present invention, when the machining axis moves from the exchange position to the machining position, the tool pot (storage portion) moves away from the exchange position substantially simultaneously with the movement of the machining axis. The large-diameter tool accommodated in the tool pot does not contact the exchange arm (exchange part).

  In the machine tool and the tool changing method according to the present invention, for example, one standard tool (first tool), a large-diameter tool (second tool), and another standard tool (third tool) in this order. Mount the tool on the machining axis. After the machining with one standard tool is completed, the one standard tool mounted on the machining axis is replaced with another standard tool. Then replace the other standard tool with a large-diameter tool. The machining axis performs machining with a large-diameter tool. Other standard tools are contained in the tool pot of the large diameter tool. After machining with the large-diameter tool is completed, replace the large-diameter tool with another standard tool. In the tool change from the standard tool to the large-diameter tool and from the large-diameter tool to the standard tool executed after the machining is completed, the first tool to be changed becomes the standard tool. Therefore, each tool can be transported to a replaceable position during machining, and can be exchanged in a short time from the standard tool to the large-diameter tool and then again from the large-diameter tool to the standard tool.

  In the machine tool according to the present invention, when the machining axis moves from the exchange position to the machining position, the tool pot (storage unit) moves away from the exchange position almost simultaneously with the movement of the machining axis. The movement of the machining axis and the separation of the tool pot can be performed substantially simultaneously, thereby shortening the working time. Further, the large-diameter tool mounted on the machining shaft does not contact the replacement arm (exchange part).

1 is an external view schematically showing a machining center according to Embodiment 1. FIG. It is a longitudinal cross-sectional view which outlines the structure of the process axis vicinity. It is a front view which briefly shows a tool magazine. It is a longitudinal cross-sectional view which briefly shows a tool magazine. FIG. 6 is a bottom view schematically showing an exchange arm. It is a block diagram of a machining center. It is a figure which shows an example of the machining / tool exchange program memorize | stored in EEPROM, and an example of a tool information table. It is a schematic diagram which shows an example of the tool accommodated in each tool pot. It is a schematic diagram which shows an example of the tool accommodated in each tool pot. It is a flowchart explaining the tool exchange process by a control apparatus. It is a flowchart explaining the tool exchange process by a control apparatus. It is a flowchart explaining the prefetch process by a control apparatus. It is a figure which shows an example of the machining / tool exchange program memorize | stored in EEPROM in the modification of Embodiment 1. FIG. It is a figure which shows an example of the program input manually which performs prefetch exchange processing in the machining center which concerns on Embodiment 2. FIG.

(Embodiment 1)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a machining center according to a first embodiment. FIG. 1 is an external view schematically showing a machining center, and FIG. 2 is a longitudinal sectional view schematically showing a configuration in the vicinity of a machining axis. The machining center includes a base 1. A column 2 stands upright on the base 1. On one side of the column 2, there are provided guide rails 4, 4 that are elongated vertically. The guide rails 4 and 4 are opposed to each other with an appropriate interval. The shaft base 3 is connected to the guide rails 4 and 4. The guide rail 4 guides the shaft base 3 in the vertical direction. The shaft base 3 is equipped with a machining axis which will be described later. A Z-axis feed motor 5 is provided at the top of the column 2. A feed screw 6 is connected to the rotary shaft of the Z-axis feed motor 5. The feed screw 6 extends downward between the guide rails 4 and 4. The shaft base 3 is connected to a feed screw 6 and moves in the vertical direction (Z-axis direction) by the rotation of the Z-axis feed motor 5.

  A table 7 is disposed below the shaft 3. The table 7 is provided on the base 1 and is movable in the horizontal plane direction (X-axis direction or Y-axis direction). A work is placed on the table 7. The shaft base 3 is equipped with a machining axis motor 8, a machining axis (machining part) 9, and a tool magazine (accommodating part) 10. The machining shaft 9 moves between an upper exchange position and a lower machining position by the vertical movement of the shaft base 3 (see FIG. 4 described later). The machining shaft 9 is rotated by the rotation of the machining shaft motor 8. As shown in FIG. 2, the machining shaft 9 includes a tool attachment portion 11, a draw bar 53, and a tool release pin 54. The tool attachment portion 11 holds the tool 24 in a detachable manner. The tool release pin 54 is connected to the tool mounting portion 11 via the draw bar 53. As shown in FIG. 1, a tool change motor 15 is provided on the shaft base 3. The tool change motor 15 is connected to the tool release pin 54 via a cam mechanism. When the tool release pin 54 is pushed down by driving the tool changing motor 15, the tool 24 is detached from the tool mounting portion 11.

  FIG. 3 is a front view schematically showing the tool magazine 10. As shown in FIG. 3, the tool magazine 10 includes an annular tool passage 10a. An opening 10b is provided at the lowermost part of the tool passage 10a. A plurality of tool pots 31 are accommodated in the tool passage 10a. Each tool pot 31 stores each different tool 24 in a detachable manner. As shown in FIG. 1, the tool magazine 10 is provided with a magazine motor 14. The tool pot 31 moves in the tool path 10 a by driving the magazine motor 14. When the tool 24 mounted on the machining shaft 9 and the tool 24 stored in the tool pot 31 are exchanged, the predetermined tool pot 31 moves to the opening 10b.

  FIG. 4 is a longitudinal sectional view schematically showing the tool magazine 10. The tool magazine 10 includes a support shaft 161 that supports the tool pot 31. The support shaft 161 rotatably supports the tool pot 31. A latch mechanism is provided inside the tool pot 31. The latch mechanism includes a recess 33, a compression spring 34, and a ball 35. The recess 33 is formed on the inner peripheral surface of the tool pot 31. The compression spring 34 is provided in the recess 33 and urges the ball 35 toward the inside of the tool pot 31. The tool 24 has a pull stud 121 at the base end. When the tool 24 is strongly pushed into the tool pot 31, the pull stud 121 is engaged with the ball 35, and the tool pot 31 holds the tool 24. When the tool 24 is strongly pulled out from the tool pot 31, the ball 35 is detached from the pull stud 121 and the tool 24 is detached from the tool pot 31.

  A pin 162 is provided at the rear end of the tool pot 31. The tool magazine 10 includes a slider 164 that slides in the vertical direction. The slider 164 has a U-shaped groove 163 that engages with the pin 162. The upper part of the slider 164 is connected to the rod 171. The rod 171 is connected to the air cylinder 170. The air cylinder 170 is driven by a control signal to raise or lower the rod 171. When the tool pot 31 moves to the opening 10b, the pin 162 engages with the U-shaped groove 163.

  As indicated by the phantom line in FIG. 4, when the rod 171 is lifted by driving the air cylinder 170, the tool pot 31 rotates 90 degrees downward with the support shaft 161 as a fulcrum. The tool 24 faces downward and can be exchanged by the exchange arm 18 described later. When the rod 171 is lowered by driving the air cylinder 170, the tool pot 31 rotates 90 degrees upward with the support shaft 161 as a fulcrum. The tool 24 is turned sideways and cannot be exchanged by the exchange arm 18. Further, when the tool 24 is turned sideways, the tool pot 31 can be moved in the tool path 10 a by driving the magazine motor 14.

The shaft 3 is provided with a rotating shaft 19 protruding downward. The rotating shaft 19 is located between the machining shaft 9 and the tool magazine 10. An exchange arm 18 is provided at the lower end of the rotating shaft 19. FIG. 5 is a bottom view schematically showing the exchange arm 18.
The exchange arm 18 includes an arm body 16 and finger pairs 17 and 17 that can be opened and closed. Each finger pair 17, 17 is provided at both ends of the arm body 16. The finger pairs 17, 17 are arranged at positions symmetrical with respect to the center of the arm body 16. The finger pairs 17, 17 extend outward from the arm body 16. The finger pairs 17 and 17 are provided with springs 58 and 59. A cam shaft 51 is provided on the arm body 16. The pair of fingers 17 and 17 are opened and closed by the drive of the cam shaft 51 and the urging force of the springs 58 and 59.

  The rotating shaft 19 is connected to a cam mechanism. The cam mechanism converts the rotary motion of the tool change motor 15 into a vertical motion. The rotary shaft 19 moves in the vertical direction (axial direction) by driving the tool change motor 15. A cylindrical gear is fitted on the outer side of the rotating shaft 19. The cylindrical gear is located above the arm body 16. The cylindrical gear is connected to the tool change motor 15 through a transmission mechanism. When the rotating shaft 19 rises, the cylindrical gear and the cam shaft 51 are connected. The rotational force of the tool change motor 15 is transmitted to the cam shaft 51 through a cylindrical gear. At this time, the finger pairs 17 and 17 open and close. The finger pairs 17 and 17 hold the tool 24 mounted on the machining shaft 9 or the tool 24 stored in the tool pot 31 (refer to Japanese Patent Laid-Open No. 10-151542 for details).

  When the tool 24 stored in the tool pot 31 faces downward, the tool 24 is positioned between the finger pair 17, so that the finger pair 17 can grip the tool 24. On the other hand, when the tool 24 stored in the tool pot 31 faces sideways, the tool 24 is not positioned between the finger pair 17, so the finger pair 17 cannot grip the tool 24.

  When the rotating shaft 19 is lowered, the connection between the cylindrical gear and the cam shaft 51 is released. The rotational force of the tool change motor 15 is transmitted to the rotary shaft 19 through a transmission mechanism. At this time, the arm body 16 rotates and the tool 24 is exchanged. While the tool change motor 15 rotates a predetermined number of times, the opening and closing operation of the finger pairs 17 and 17 and the vertical movement and rotation operation of the change arm 18 are performed.

  The exchange arm 18 moves in the vertical direction together with the machining shaft 9 by the vertical movement of the shaft base 3 (see FIG. 4). When the exchange arm 18 is located on the upper side together with the machining shaft 9, the exchange operation described above is performed.

  The machining center includes a control device (control unit) 60 that controls the machining operation and the tool change operation. FIG. 6 is a block diagram of the machining center. The control device 60 includes a CPU (Central Processing Unit) 61, a ROM (Read Only Memory) 62 storing a control program, a RAM (Random Access Memory) 63 for temporarily storing data, and an EEPROM (Electrically Erasable Programmable Read). Only Memory) 64. The CPU 61 reads the control program stored in the ROM 62 into the RAM 63, and executes a tool change process and a pre-read process, which will be described later. The control device 60 includes an input interface 65 and an output interface 66. The EEPROM 64 stores a machining / tool exchange program and a tool information table which will be described later. Note that another rewritable nonvolatile memory may be used instead of the EEPROM 64. For example, flash memory or EPROM (Erasable Programmable Read Only Memory) may be used.

The machining center includes an input device 50, an arm sensor 180, a Z-axis sensor 90, a pot lowering sensor 31a, and a pot raising sensor 31b. The input device 50 includes a keyboard or a touch panel and receives operations. The arm sensor 180 detects whether or not the exchange arm 18 has been raised to the origin. The Z-axis sensor 90 detects whether or not the machining axis 9 has been raised to an exchange position for exchanging tools. The pot lowering sensor 31a detects whether or not the tool pot 31 is directed downward at the opening 10b. The pot raising sensor 31b detects whether or not the tool pot 31 is turned sideways at the opening 10b. The pot lowering sensor 31a and the pot raising sensor 31b physically detect the pot lowering / raising. The drive of the exchange arm 18 and the magazine motor 14 is prohibited until the time (confirmation time) until the vibration at the time of stopping of the tool pot 31 converges after detecting the lowering / raising in each sensor.
The input device 50, the arm sensor 180, the Z-axis sensor 90, the pot lowering sensor 31a, and the pot raising sensor 31b input signals to the control device 60 via the input interface 65.

  The machining center includes an X motor 71, a Y motor 72, and a display device 51. The table 7 is moved in the arrow X direction in FIG. 1 by driving the X motor 71, and is moved in the arrow Y direction in FIG. 1 by driving the Y motor 72. The display device 51 displays various information. The control device 60 sends control signals to the X motor 71, the Y motor 72, the air cylinder 170, the display device 51, the Z axis feed motor 5, the machining axis motor 8, the magazine motor 14 and the tool change motor 15 via the output interface 66. Output.

  The machining center includes a pot identification sensor 40. The pot identification sensor 40 includes a light projecting element 41, a light receiving element 42, and a pot identification plate 43. The light projecting element 41 and the light receiving element 42 are opposed to each other with the pot identification plate 43 interposed therebetween. The pot identification plate 43 is provided in the tool magazine 10. The pot identification plate 43 includes a light transmission part that can identify each tool pot 31 individually. The light transmitting portion has a pattern corresponding to each tool pot 31. The pot identification plate 43 rotates integrally with the plurality of tool pots 31.

  The control device 60 inputs a light projection signal to the light projecting element 41 via the output interface 66. The light receiving element 42 receives light corresponding to each pattern of the light transmitting portion. The light receiving element 42 outputs a light receiving signal to the input interface 65. The CPU 61 detects which tool pot 31 has been conveyed to the opening 10b based on the light reception signal. When it is detected that the predetermined tool pot 31 has been conveyed, the magazine motor 14 is stopped and the predetermined tool 24 is positioned in the opening 10b.

  FIG. 7A is a diagram showing an example of a machining / tool change program stored in the EEPROM 64. The CPU 61 reads the machining / tool change program one line at a time. In the figure, G100 indicates a tool change command, and T indicates an identification number of the tool 24 to be mounted on the machining shaft 9 next. L indicates the identification number of the tool 24 to be mounted on the machining shaft 9 after T. For example, the p-th line in FIG. 7A is a tool change command (G100), the next tool 24 to be changed is No. 4 (T4), and the next tool 24 to be changed is No. 5 (L5). ). The r-th line is a machining command (G50), which indicates that machining is performed at the Xn, Yn, and Zn positions with the sixth tool. Xn, Yn, and Zn indicate positions in the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. In the rightmost column, the presence or absence of the prefetch flag is indicated by “1” or “0”.

  FIG. 7B is a diagram illustrating an example of a tool information table stored in the EEPROM 64. In the tool information table, identification numbers, dimension information, and position information are stored in association with each other. The identification number identifies the tool 24. The dimension information indicates whether the tool 24 is a large diameter tool or a standard tool. The position information indicates whether the tool 24 is located in each tool pot 31 or the machining axis 9. The CPU 61 rewrites the tool information table according to the replacement of the tool 24.

  FIGS. 8 and 9 are schematic views showing an example of the tool 24 accommodated in each tool pot 31. In the drawing, the number indicates the identification number of the tool 24, and “empty” indicates that the tool pot 31 is empty. The machining center is equipped with tools 1-9. In FIG. 8A, the fifth tool is a large-diameter tool and is accommodated in a tool pot 31 between empty tool pots 31 and 31. Numbers 1-4 and 6-9 are standard tools. A fourth tool is positioned in the opening 10b, and a third tool is mounted on the machining shaft 9.

  10 and 11 are flowcharts for explaining tool change processing by the control device 60. In order to facilitate understanding, description will be made with reference to the program shown in FIG. 7A and FIGS. 8 and 9. The CPU 61 reads the machining program (see FIG. 7) and executes machining of the workpiece according to the description code of each block. FIG. 9 is a flowchart when the CPU 61 reads a program (p-line in FIG. 7A) indicating a tool change command (G100). Further, it is assumed that the positional relationship of the tools at the start is the state shown in FIG. 8A.

  When reading the p-th line in FIG. 7A, the CPU 61 outputs a drive signal to the Z-axis feed motor 5 and moves the machining axis 9 to the exchange position (step S1). Whether or not the machining axis 9 is a standard tool is checked with reference to the position information and dimension information in the tool information table (step S2). When the machining axis 9 is the standard tool (No. 3) (step S2: YES, see FIG. 8A), the tool information table is referred again, and whether the standard tool identification number is described in T of the tool replacement instruction or not. Is determined (step S3). When the standard tool (T4) is described (step S3: YES), a drive signal is output to the tool change motor 15, and the standard tool (No. 3) mounted on the machining shaft 9 is commanded by T (4) No.) (step S4: see FIG. 8B).

  Since the standard tool (No. 4) is mounted, the CPU 61 moves the machining axis 9 to the machining position, and starts machining processing at the machining position according to the commands described in the p + 1th line and thereafter in FIG. 7A ( Step S5). At this time, since the tool (No. 3) stored in the tool pot 31 turned downward is a standard tool, even if the machining shaft 9 moves between the machining position and the exchange position, the exchange arm 17 and Do not touch. Further, the processing after step S5 and the processing after the (p + 1) th row in this flowchart are executed in parallel.

  The CPU 61 executes a prefetch process described later (step S6). The CPU 61 determines whether or not a flag has been set for the read tool change command by the pre-read process (step S7). A flag is set by pre-reading processing to be described later, and for example, a pre-reading tool having an identification number 6 is extracted. Therefore, when the flag is set by the pre-reading process (step S7: YES), the CPU 61 outputs a drive signal to the magazine motor 14 and positions the pre-reading tool (No. 6) determined by the pre-reading process (step S8, FIG. 8C). Although details are omitted, if the tool pot 31 is downward, before the drive signal is output to the magazine motor 14, the air cylinder 170 is driven to turn the tool pot 31 sideways and wait until the confirmation time elapses. .

  The CPU 61 outputs a drive signal to the air cylinder 170, turns the tool pot 31 downward (step S9), and waits until the confirmation time elapses (step S10: NO). After the confirmation time has elapsed (step S10: YES), the process ends. Here, since the tool stored in the downward tool pot 31 is a standard tool (No. 6), even if the machining shaft 9 moves between the machining position and the exchange position, it does not contact the exchange arm 17.

When the CPU 61 reads a program (the q-th line in FIG. 7A) indicating the tool change command (G100), the CPU 61 starts the tool change process in FIG. 9 again. The CPU 61 moves the machining shaft 9 to the replacement position (step S1) and determines whether or not a standard tool is mounted on the machining shaft 9 (step S2). When the standard tool (No. 4) is mounted on the machining axis 9 (step S2: YES), it is determined whether or not the standard tool identification number is described in T of the tool change command (step S3). When a large-diameter tool (No. 5) is described (step S3: NO), a drive signal is output to the tool change motor 15, and a standard tool (No. 4) mounted on the machining shaft 9 is read in advance (No. 6). (See step S11, FIG. 9D).
The CPU 61 outputs a drive signal to the air cylinder 170, turns the tool pot 31 sideways (step S12), and waits until the confirmation time elapses (step 13: NO). After the confirmation time has elapsed (step S13: YES), the CPU 61 outputs a drive signal to the magazine motor 14 to position the large-diameter tool (No. 5) described in T of the tool change command (step S14, FIG. 9E).

  The CPU 61 outputs a drive signal to the air cylinder 170, turns the tool pot 31 accommodating the large-diameter tool (No. 5) downward (step S15), and waits until the confirmation time elapses (step 16: NO). After the confirmation time has elapsed (step S16: YES), the CPU 61 outputs a drive signal to the tool change motor 15, and replaces the pre-read tool (No. 6) of the machining axis 9 with a large diameter tool (No. 5) (Step S17, (See FIG. 9F). At this time, the pre-reading tool (No. 6) is accommodated in the tool pot 31 in the downward state.

  The CPU 61 moves the machining axis 9 to the machining position, and starts machining processing at the machining position in accordance with instructions sequentially described from the q + 1th line in FIG. 7A (step S5). Since the tool (No. 6) stored in the downward tool pot 31 is a standard tool, even if the machining shaft 9 moves between the machining position and the exchange position, it does not contact the exchange arm 17. Further, the processing after this step in the flowchart and the processing after the q + 1th row are executed in parallel.

The CPU 61 executes a prefetch process described later (step S6). The CPU 61 determines whether or not a flag has been set for the read tool change command by the pre-read process (step S7). If the flag is not set (step S7: NO), the CPU 61 outputs a drive signal to the magazine motor 14. Then, the next tool (No. 6) described in the tool change command L is positioned (step S18). Then, it is determined whether or not the next tool is a standard tool (step S19). When the next tool is the standard tool (No. 6) (step S19: YES), the CPU 61 executes steps S9 and S10. When the next tool is not a standard tool (step S19: NO), the CPU 61 ends the process.
If the next tool (No. 6), which is a standard tool, has already been positioned in the opening 10b and the tool pot 31 is facing downward, Step 18 and Steps 9 and 10 can be omitted. In this case, since the tool stored in the tool pot 31 remains the standard tool (No. 6), even if the machining shaft 9 moves between the machining position and the exchange position, it does not contact the exchange arm 17.

  When the CPU 61 reads a program (the r-th line in FIG. 7A) indicating the tool change command (G100), the CPU 61 starts the tool change process in FIGS. 10 and 11 again. The CPU 61 moves the machining shaft 9 to the replacement position (step S1) and determines whether or not a standard tool is mounted on the machining shaft 9 (step S2). When a large-diameter tool (No. 5) is mounted on the machining axis 9 (step S2: NO), whether or not the standard tool identification number is described in T of the tool change command with reference to the tool information table. Judgment is made (step S20). When the identification number of the large-diameter tool is described in T (step S20: NO), a drive signal is output to the air cylinder 170, and the tool pot 31 is turned downward (step S21). And it waits until confirmation time passes (step S22: NO). If the confirmation time has elapsed (step S22: YES), the process proceeds to step S23 described later. As described in the r-th line of FIG. 7A, when the standard tool identification number (6) is described in T of the tool change command (step S20: YES), the CPU 61 drives the tool change motor 15. A signal is output, and the large-diameter tool (No. 5) of the machining shaft 9 is replaced with a tool (No. 6) commanded by T (see Step S23, FIG. 9G).

The CPU 61 outputs a drive signal to the air cylinder 170 to turn the tool pot 31 storing the large diameter tool (No. 5) sideways (step S24). Here, after the pot raising sensor 31b detects the horizontal orientation of the tool pot 31, the CPU 61 does not wait for the confirmation time to elapse. The CPU 61 moves the machining axis 9 to the machining position, and starts machining processing at the machining position in accordance with the commands sequentially described from the (r + 1) -th line in FIG. 7A (step S25).
When the tool stored in the tool pot 31 is a large-diameter tool (No. 5), when the machining shaft 9 moves between the machining position and the replacement position with the tool pot 31 facing downward, The exchange arm 17 comes into contact. By executing step S24 prior to step S25, the contact described above can be prevented.
Further, when the air cylinder 170 is driven in step S24 and the pot raising sensor 31b detects the horizontal direction, the machining shaft 9 is moved even when the vibration of the tool pot 31 is not converged (see FIG. Step S25). This is because even if the machining shaft 9 moves between the machining position and the exchange position, the large-diameter tool and the exchange arm 17 do not contact each other.

  Thereafter, the CPU 61 waits until the confirmation time has elapsed (step S26: NO), and after the confirmation time has elapsed (step S26: YES), proceeds to step S6.

  The processing after step S25 and the machining command after the tool change command are executed in parallel. About the raising operation | movement of the tool pot 31 of step S24, the downward movement operation | movement of the process axis | shaft 9 in step S25 is performed substantially simultaneously, and work time can further be shortened.

  When the diameter of the large-diameter tool is larger than the inner diameter of the finger pair 17, 17, when the machining shaft 9 is moved to the machining position with the tool pot 31 storing the large-diameter tool lowered, the finger pair 17, 17 is Contact large tools. Since the tool pot 31 that accommodates the large-diameter tool is separated from the replacement position in step S24, contact of the large-diameter tool with the finger pair 17, 17 can be avoided.

FIG. 12 is a flowchart for explaining prefetching processing by the control device 60.
The CPU 61 refers to the tool information table and determines whether or not the identification number of the large diameter tool is described in L (step S41). If the identification number of the large-diameter tool is not described in L (step S41: NO), the process ends.

  When the identification number of the large-diameter tool is described in L (step S41: YES), the CPU 61 reads the next line program (step S42) and determines whether the read program is a tool change command. (Step S43). When the read program is not a tool change command (step S43: NO), the CPU 61 returns the process to step S42. When the read program is a tool change command (step S43: YES), the CPU 61 refers to the tool information table and determines whether or not a standard tool is described in T or L of the read program. (Step S44).

  When the standard tool is not described (step S44: NO), the CPU 61 returns the process to step S42. When the standard tool is described (step S44: YES), the standard tool described is determined as a pre-reading tool (step S45). For example, when the p-th line in FIG. 7A is read, the CPU 61 reads the programs in order. When the q-th line which is a tool exchange command is read, since the standard tool (No. 6) is described in L, No. 6 is determined as the pre-reading tool. Information indicating the determined pre-reading tool is stored in the EEPROM 64.

  The CPU 61 determines the large-diameter tool described in L of the tool change command read in step S1 as a tool to be mounted on the machining axis 9 after the pre-read tool (step S46). For example, the large-diameter tool (No. 5) described in L of the p-th row in FIG. 7A is determined as a tool to be mounted on the machining shaft 9 after the pre-reading tool. Information indicating the determined tool is stored in the EEPROM 64.

  Next, the CPU 61 sets a prefetch flag in association with the program read in step S1 (step S47). For example, the prefetch flag “1” is set in the EEPROM 64 in association with the p-th line in FIG. 7A.

  After machining with the standard tool (No. 4) is completed (see FIG. 8C), the standard tool (No. 4) mounted on the machining shaft 9 is replaced with a pre-reading tool (No. 6) which is a standard tool (see FIG. 9D). . The tool magazine 10 is rotated to position the large-diameter tool (No. 5) in the opening 10b (see FIG. 9E). The pre-reading tool (# 6) is replaced with a large-diameter tool (# 5) (see FIG. 9F). The machining shaft 9 performs machining with a large-diameter tool (No. 5). The pre-reading tool (No. 6) is stored in the tool pot 31 of the large diameter tool (No. 5). At this time, the pre-reading tool (No. 6) is positioned in the opening 10b. After the machining with the large-diameter tool (No. 5) is completed, the large-diameter tool (No. 5) is replaced with a pre-reading tool (No. 6) (see FIG. 9G).

  For this reason, when exchanging the tool between the standard tool (No. 4) and the large-diameter tool (No. 5), the tool positioned in the opening 10b in advance is the standard tool (No. 6). The tool that is positioned in the opening 10b in advance when the large-diameter tool (No. 5) and the standard tool (No. 6) are exchanged is also the standard tool (No. 6). In both cases, it is possible to keep the tool pot 10 downward in advance. For this reason, the replacement arm 18 can be replaced immediately after the machining shaft 9 has been lifted. Further, when the lateral movement of the tool pot 10 is executed after exchanging the large-diameter tool (No. 5) and the standard tool (No. 6), the lowering operation of the machining shaft 9 is performed in parallel without waiting for the confirmation time to elapse. Execute. When the downward movement of the tool pot 10 is executed, it is necessary to wait for the confirmation time to elapse. However, the lowering operation of the machining axis 9 is executed in parallel without waiting for the confirmation time to be shortened. Tools can be changed in time.

  Next, a detailed description will be given based on the drawings showing modifications of the machining center according to the first embodiment. FIG. 13 is a diagram showing an example of a machining / tool change program stored in the EEPROM 64 in the modification. In FIG. 13, T and L indicate the identification numbers 4 to 7 of the tool 24. Nos. 4 and 6 indicate standard tools, and Nos. 5 and 7 indicate large-diameter tools. FIG. 13 shows that the tool 24 of the machining shaft 9 is replaced in the order of the standard tool (No. 4), the large diameter tool (No. 5), the large diameter tool (No. 7), and the standard tool (No. 6).

  The control device 60 executes the above-described prefetching process in a modified example. When the p-th line in FIG. 13 is read, the control device 60 executes the pre-reading process because the standard tool (No. 4) is described in T. The control device 60 reads the program in order. When the r-th line which is a tool change command is read, since the standard tool (No. 6) is described in L, No. 6 is determined as the pre-reading tool. Further, the large-diameter tool (No. 5) is determined as a tool to be mounted on the machining shaft 9 next to the pre-reading tool.

  The control device 60 replaces the standard tool (No. 4) mounted on the machining shaft 9 with a pre-reading tool (No. 6). Next, the look-ahead tool (No. 6) mounted on the machining shaft 9 is replaced with a large-diameter tool (No. 5). At this time, the pre-reading tool (No. 6) is accommodated in the tool pot 31 of the large-diameter tool (No. 5). Next, the large diameter tool (No. 5) is replaced with a large diameter tool (No. 7). Then, the large-diameter tool (No. 7) is replaced with a pre-reading tool (No. 6).

  As a result, even when a large-diameter tool is continuous, the tool that is positioned in the opening 10b in advance when the tool between the standard tool (No. 4) and the large-diameter tool (No. 5) is replaced is the standard tool. The tool that is positioned in the opening 10b in advance when replacing the large diameter tool (No. 7) and the standard tool (No. 6) is the standard tool (No. 6). It becomes possible to keep the pot 10 in the downward state, and the exchange by the exchange arm 18 becomes possible as soon as the raising of the machining shaft 9 is completed. Further, in the sideways movement of the tool pot 10 necessary after replacing the large diameter tool (No. 7) and the standard tool (No. 6), the time until the confirmation time elapses compared to the downward movement of the tool pot 10. The lowering operation of the machining shaft 9 can be executed, and the tool can be changed comprehensively in a short time.

(Embodiment 2)
Hereinafter, the present invention will be described in detail with reference to the drawings showing a machining center according to a second embodiment. The operator can set the machining / tool change program by operating the input device 5, and can check the program by the display device 51. The set program is stored in the EEPROM 64.

  FIG. 14 is a diagram showing an example of a manually input program for executing the prefetch exchange process. The program replaces the tool 24 of the machining shaft 9 in the order of the standard tool (No. 4), the large diameter tool (No. 5), the large diameter tool (No. 7) and the standard tool (No. 6). Set 6 to L in the p-th row. As a result, the tool magazine 10 rotates after the standard tool (No. 4) is mounted on the machining shaft 9, and the standard tool (No. 6) is positioned in the opening 10b.

K6 is set in the q-th row. K indicates a tool 24 to be replaced before T. The control device 60 replaces the standard tool (No. 4) with the standard tool (No. 6) by K, and then replaces the standard tool (No. 6) with the large diameter tool (No. 5). The standard tool (No. 6) is stored in the tool pot 31 of the large diameter tool (No. 5). The r-th and s-th lines are the same as in FIG. Even when the program is manually set, the tool can be changed from a large diameter tool to a standard tool in a short time.
The machining center is an example of a machine tool, and the present invention can be applied to various machine tools. For example, in the present embodiment, the tool pot 31 is positioned from the side to the bottom so that the tool pot 31 is changed to the replacement position. It may be possible to move.

  In the first and second embodiments, the tool information table is stored in the EEPROM 64, but a rewritable nonvolatile memory may be provided separately and stored in the memory. Moreover, a hard disk may be provided and a tool information table may be stored in the hard disk.

  The embodiment described above is an exemplification of the present invention, and the present invention can be implemented in various modified forms within the scope defined by the matters described in the claims and the description of the claims. it can.

9 Machining axis (machining part)
10 Tool magazine (container)
18 Exchange arm (exchange unit)
24 tools 31 tool pot (storage part)
60 Control device (control unit)
61 CPU
62 ROM
63 RAM
161 Support shaft (contact / separation part)
162 pin (contact / separation part)
164 Slider (contact / separation part)
170 Air cylinder (contact / separation part)
171 Rod (contact / separation part)

Claims (4)

A storage unit that stores a plurality of tools, a processing unit that mounts the tool stored in the storage unit to process a workpiece, a replacement unit that replaces the tool mounted in the processing unit, and a command to replace the tool are stored. A storage unit, identification information for identifying a tool, a tool information table that is associated with the identification information and stores dimension information indicating the size of the tool, and a command stored in the tool information table and the storage unit In a machine tool comprising a control unit for controlling the exchange by the exchange unit based on
The controller is
Based on the first change command stored in the storage unit and indicating the replacement of the first tool with the second tool, and the identification information and the dimension information stored in the tool information table, the second Means for determining whether the tool is larger than the first tool;
When it is determined by the means that the second tool is larger than the first tool, the tool that is executed after the first replacement command and that is mounted on the machining unit is replaced. Means for searching the storage unit for a second exchange command indicating
When the second replacement command is searched for by the means, a third tool in which the second replacement command is smaller than the second tool based on the identification information and the dimension information stored in the tool information table. Means for determining whether or not to indicate a replacement instruction,
When it is determined by the means that the second replacement command indicates a command to replace the third tool with a smaller size than the second tool, the third tool is placed next to the first tool. First determining means for determining a tool to be mounted on the processing portion and second determining means for determining the second tool as a tool to be mounted on the processing axis next to the third tool A machine tool characterized by that. The controller is
Means for exchanging the third tool accommodated in the accommodating portion, which is determined by the first determining means, and the first tool attached to the machining portion, and is attached to the machining portion by the means The machine tool according to claim 1, further comprising means for exchanging the third tool and the second tool determined by the second determining means and accommodated in the accommodating portion. . The machining unit is configured to move together with the exchange unit between a machining position for machining a workpiece and an exchange position for exchanging a tool.
The accommodating portion is
A movable storage section for storing the tool;
An actuator for moving the storage unit toward or away from the replacement position;
The controller is
The operation of the processing unit and the storage unit is controlled,
2. The apparatus according to claim 1, further comprising means for executing in parallel the movement of the machining unit and the separation of the storage unit with respect to the exchange position when the machining unit is moved from the exchange position to the machining position. Or the machine tool of 2. In the tool exchange method for exchanging the accommodation part for accommodating the tool and the tool mounted on the machining part for machining the workpiece,
When exchanging the first tool mounted on the processing unit and the second tool larger than the first tool to be mounted on the processing unit next to the first tool,
Exchanging the first tool with a third tool smaller than the second tool, which is accommodated in the accommodating portion and is to be attached to the processing portion after the second tool; A tool exchanging method comprising: exchanging the third tool mounted on the processing unit by the step and the second tool accommodated in the accommodating unit.

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