JP6237226B2 - Numerical controller - Google Patents

Description

  The present invention relates to a numerical control device.

  The machine tool includes a cover. The cover covers at least the machining area of the machine tool, and a plurality of chip showers are attached inside. The tip shower ejects cutting fluid and adheres to the cover to wash away the accumulated chips. Patent Document 1 discloses a machine tool capable of arranging a pipe for supplying a cutting fluid to a cutting fluid nozzle with a useless length. As a method for cleaning the inside of the cover using a tip shower, for example, in a machining program, it is common to start the ejection of cutting fluid at the head of the program and stop the ejection at the end of the program.

JP 2007-30135 A

  In the above cleaning method, the cutting fluid is always flowed once the ejection of the cutting fluid is started. Therefore, the cutting fluid is unnecessarily flowed particularly in processing with a small amount of chips, and there is a problem that the cutting fluid and power are wasted. .

  The objective of this invention is providing the numerical control apparatus which can eject a cutting fluid according to the generation amount of a chip.

  The numerical control device according to claim 1 of the present invention rotates with the cover covering the machining area and the tool mounted on the spindle, and when machining the workpiece by bringing the tool into contact with the workpiece, In a numerical controller for controlling a machine tool provided with a jetting mechanism for jetting and flushing cutting fluid to the generated chips accumulated in the cover, the motor for rotating the spindle and the tool are applied to the workpiece First acquisition means for acquiring a non-machining power amount, which is a power consumption amount of the motor when the main shaft rotates in a non-contact state, and the non-machining power amount acquired by the first acquisition means A first storage means for storing in one storage unit and a machining power amount that is a power consumption amount of the motor when the spindle rotates and the workpiece is processed while the tool is in contact with the workpiece is constant. The first to get every hour An obtaining means; and a calculating means for calculating a difference between the machining power amount acquired by the second obtaining means and the non-machining power amount stored in the first storage unit for each predetermined time; and A second storage means for integrating the difference calculated by the calculation means at every predetermined time and storing the result as an integrated value in the second storage unit; and whether the integrated value stored in the second storage unit exceeds a predetermined value Determining means for determining whether or not the integrated value exceeds the predetermined value, the ejection control means for controlling the ejection mechanism to eject the cutting fluid for a predetermined time, and And a first initialization unit that initializes the integrated value stored in the second storage unit when the ejection control unit controls the ejection mechanism to eject the cutting fluid for the predetermined time. It is characterized by that. The numerical control device estimates the cutting volume of the workpiece based on the power consumed by the motor that rotates the spindle during workpiece machining. Therefore, the estimation accuracy is improved. The numerical control device integrates the difference between the power consumption when the workpiece is processed with the tool in contact with the workpiece and the power consumption when the tool is not in contact with the workpiece at regular intervals. The integrated value corresponds to the amount of chips generated as the workpiece is processed. Therefore, the numerical control device can estimate the amount of chips based on the integrated value, and can eject the cutting fluid with good timing according to the timing when the chips accumulate in the cover. Since the integrated value is initialized after the cutting fluid has flowed for a predetermined time, the ejection mechanism can be similarly controlled in the subsequent workpiece machining.

  A numerical control device according to a second aspect of the invention, in addition to the configuration of the invention according to the first aspect, performs the idling operation of rotating the spindle in the same process as the work machining process without the work. The first acquisition unit is configured to acquire the non-machining power amount at the predetermined time during the idle operation executed by the idle operation execution unit, and the first storage unit , Storing the non-machining power amount acquired by the first acquisition unit at the predetermined time in the first storage unit, and the calculation unit acquired by the second acquisition unit at the predetermined time period. A difference between the machining power amount and the non-working power amount acquired at the same timing as the second acquisition means in the non-working power amount stored in the first storage unit is calculated. And The numerical control device can obtain power consumption other than the power consumption of the motor used when the tool comes into contact with the workpiece by executing the idle operation. Therefore, the numerical control device can determine the power consumption of the motor used when the tool contacts the workpiece by subtracting the power consumption during idle operation from the power consumption of the motor during workpiece machining.

The perspective view seen from the back of the machine tool 1. FIG. 1 is a front view of a machine tool 1. The top view of the machine tool 1. FIG. FIG. 4 is a cross-sectional view taken along the line I-I in FIG. 3. The figure which shows the state in which the tool T with which the main axis | shaft 7 mounts process the workpiece | work W. FIG. FIG. 3 is a block diagram showing an electrical configuration of the numerical control device 30 and the machine tool 1. The conceptual diagram which shows the various storage area of RAM33. The graph which shows the change of the power consumption acquired from the motor control part 52A at the time of an actual process. The graph which shows the change of the power consumption acquired from the motor control part 52A at the time of idle driving | running | working. The wiring diagram which shows the electrical connection of motor control parts 52A-55A. The flowchart of the main process. Flow chart of idling process. Flow chart of actual processing. The flowchart of an ejection process.

  An embodiment of the present invention will be described with reference to the drawings. In the following description, the front side, the depth direction, the left side, the right side, the upper side, and the lower side in FIG. 2 are defined as the front, rear, left, right, upper, and lower sides of the machine tool 1. The left-right direction, the front-rear direction, and the up-down direction of the machine tool 1 are the X-axis direction, the Y-axis direction, and the Z-axis direction of the machine tool 1, respectively.

  The outline of the structure of the machine tool 1 will be described with reference to FIGS. The machine tool 1 includes a base 2, a machine body 3, a cover 4, a table 8 (see FIG. 3), a tool changer 13 (see FIG. 4), a control box 15 and the like. The base 2 is a substantially rectangular parallelepiped iron base. The machine body 3 is provided at the upper rear of the base 2 and cuts a workpiece (not shown) held on the upper surface of the table 8. The kind of cutting process is a drill, a tap, a milling process etc., for example. The cover 4 is provided in the upper part of the base 2 and has a substantially rectangular parallelepiped box shape covering the periphery of the machine body 3 and the upper part of the base 2. The cover 4 prevents chips and sprays of cutting fluid from being scattered outside. As shown in FIG. 4, the table 8 is provided in the upper center of the base 2, and an X-axis motor 53 (see FIG. 6), a Y-axis motor 54 (see FIG. 6), an X-axis guide mechanism, and a Y-axis guide mechanism (not shown). For example, it is possible to move in the X-axis direction and the Y-axis direction. Each guide mechanism includes a linear guide, a ball screw, a nut (not shown), and the like. The table 8 can fix a work (not shown) on the upper surface with a jig or the like.

  As shown in FIG. 4, the tool changer 13 includes a tool magazine 14. The disk-shaped tool magazine 14 includes a plurality of grip arms 14A on the outer periphery. The grip arm 14 </ b> A grips a tool at the tip, and can swing between a later-described main shaft 7 (see FIG. 9) of the machine body 3. The tool changer 13 swings the grip arm 14A at the tool change position, and attaches / detaches the tool attached to the main shaft 7. The tool change position is the lowest position of the tool magazine 14 and the position closest to the main shaft 7. As shown in FIG. 1, the control box 15 is provided on the back side of the cover 4 and stores the numerical control device 30 (see FIG. 6) inside. The numerical control device 30 controls the operation of the machine tool 1.

  The configuration of the machine body 3 will be described with reference to FIGS. The machine body 3 includes a column 5, a spindle head 6, a spindle 7 (see FIG. 5), and the like. The column 5 is erected on the upper rear side of the base 2. The spindle head 6 can be moved up and down in the Z-axis direction along the front surface of the column 5 by a Z-axis moving mechanism. The Z-axis moving mechanism includes a linear guide, a ball screw, a nut (not shown), and the like. As shown in FIG. 5, the spindle head 6 supports a spindle 7 in a rotatable manner. The spindle 7 is equipped with a tool T at its lower end, and rotates by driving a spindle motor 52 (see FIGS. 3 and 6). The machine tool 1 can cut the workpiece W by relative movement between the workpiece W (see FIG. 5) held on the upper surface of the table 8 and the tool T mounted on the spindle 7.

  The structure of the cover 4 will be described with reference to FIGS. The cover 4 includes a front wall 41, a left wall 42, a right wall 43, a left back wall 44 (see FIGS. 3 and 4), and a right back wall 45 (see FIGS. 3 and 4) and is formed in a substantially rectangular parallelepiped box shape. To do. The lower ends of the walls 41 to 45 are fixed to the upper part of the base 2. As shown in FIGS. 3 and 4, the left back wall 44 and the right back wall 45 constitute the back wall of the cover 4. The left back wall 44 is fixed to the front end of the left side surface of the column 5 and extends to the left side. The right back wall 45 is fixed to the front end of the right side surface of the column 5 and extends rightward. The cover 4 covers the machining area of the machine tool 1. The machining area is an area that the machine tool 1 needs for workpiece machining, and includes at least a movable range in the Z-axis direction of the spindle head 6 and the spindle 7 and a movable range in the XY direction of the table 8. is there. The cover 4 includes a cutting fluid ejection mechanism (corresponding to the ejection mechanism of the present invention). The cutting fluid ejection mechanism ejects the cutting fluid within the cover 4. Therefore, the machine tool 1 can wash away the chips generated by the workpiece machining and deposited and deposited in the cover 4. The structure of the cutting fluid ejection mechanism will be described later.

  As shown in FIG. 2, the front wall 41 includes an opening 46, an opening / closing door 47, and an operation panel 10. The opening 46 is provided substantially at the center of the front wall 41 and has a rectangular shape in front view. The opening / closing door 47 is provided to be slidable in the left-right direction at the opening 46. For example, the operator can open and close the door 47 and attach / detach the workpiece on the upper surface of the table 8. The operation panel 10 is provided on the right side of the opening 46. The operation panel 10 is connected to the numerical control device 30 (see FIG. 6) with a harness (not shown). The operation panel 10 includes an input unit 11 and a display unit 12. The input unit 11 is a device that can input various operation instructions, machining programs, tool types, tool diameters, various parameters, and the like of the machine tool 1. The machining program is composed of a plurality of blocks including various control commands, and controls various operations including axis movement of the machine tool 1, tool change, and the like in units of blocks. The display unit 12 can display various input screens or operation screens in response to an instruction from the numerical control device 30.

  The structure of the cutting fluid ejection mechanism will be described with reference to FIGS. The cutting fluid ejection mechanism is composed of an ejection part and a supply part. The ejection part is provided inside the cover 4, and the cutting fluid is ejected in the cover 4. A supply part is provided in the cover 4 outer side, and supplies cutting fluid with respect to an ejection part.

  With reference to FIG. 4, the structure of the ejection part will be described. The ejection part is composed of a pair of flexible pipes 71 and 72, a pair of cutting fluid nozzles 74 and 75, a pair of cutting fluid pipes 81 and 82, a plurality of tip showers 83 and 84, and the like. The flexible pipe 71 extends from a through hole 94 provided in the left back wall 44 toward the upper surface of the table 8. The through hole 94 is provided at a substantially middle position in the vertical direction on the right end side of the left back wall 44. The cutting fluid nozzle 74 is provided at the tip of the flexible pipe 71. The flexible pipe 72 extends from a through hole 92 provided in the right back wall 45 toward the upper surface of the table 8. The through hole 92 is provided at a substantially middle position in the vertical direction on the left end side of the right back wall 45. The cutting fluid nozzle 75 is provided at the tip of the flexible pipe 72. The cutting fluid nozzles 74 and 75 bend the flexible pipes 71 and 72 to face the upper surface of the table 8.

  The cutting fluid pipe 81 extends forward and horizontally from a through hole 93 (see FIG. 3) provided in the upper left side of the left back wall 44. The cutting fluid piping 82 extends forward and horizontally from a through hole 91 (see FIG. 3) provided in the upper right side of the right back wall 45. The cutting fluid pipe 81 is provided with a plurality of holes (not shown) at predetermined intervals in the lower part. The tip shower 83 is attached to each of a plurality of holes provided below the cutting fluid pipe 81. The cutting fluid pipe 82 is also provided with a plurality of holes (not shown) at predetermined intervals in the lower part. The tip shower 84 is attached to each of a plurality of holes provided below the cutting fluid pipe 82. The tip showers 83 and 84 direct the ejection direction of the cutting fluid downward.

  The configuration of the supply unit will be described with reference to FIGS. As shown in FIG. 1, the supply unit includes a tank 20, pumps 22 and 23, main hoses 25 and 26, branch hoses 27 and 28, T-shaped joints 61 and 62, joints 63 and 64 (see FIG. 3), and the like. . The tank 20 is installed behind the base 2 and stores cutting fluid. The pumps 22 and 23 are provided adjacent to the right side of the tank 20. The main hose 25 is connected to the pump 22. The main hose 26 is connected to the pump 23. The pump 22 pumps up the cutting fluid in the tank 20 and supplies it to the main hose 25. The pump 23 pumps up the cutting fluid in the tank 20 and supplies it to the main hose 26.

  The T-shaped joint 61 is connected from the outside of the cover 4 to a through hole 91 provided at the upper right side of the right back wall 45. The T-shaped joint 62 is connected from the outside of the cover 4 to a through hole 92 provided at the middle position on the left end side in the vertical direction of the right back wall 45. As shown in FIG. 3, the joint 63 is connected from the outside of the cover 4 to a through hole 93 provided in the upper left end of the left back wall 44. The joint 64 is connected from the outside of the cover 4 to a through hole 94 (see FIG. 4) provided at the middle position of the left back wall 44 on the right end side in the vertical direction.

  The main hose 25 and the branch hose 27 are connected to the T-shaped joint 61, respectively. The branch hose 27 extends to the left side of the column 5 via the back side of the notch portion 5A (see FIG. 1) provided on the upper back side of the column 5 and is connected to a joint 63 provided on the left back wall 44 (see FIG. 3). . The cutout portion 5A is a portion where the upper back side of the column 5 is cut obliquely. The main hose 26 and the branch hose 28 are connected to the T-shaped joint 62, respectively. The branch hose 28 passes through a hole 5B (see FIG. 1) provided in the column 5 and extends to the left side of the column 5 and is connected to a joint 64 provided on the left back wall 44 (see FIG. 3). The hole 5B is provided at the middle position of the column 5 in the vertical direction and penetrates in the horizontal direction.

  The operation of the cutting fluid supply mechanism will be described with reference to FIGS. When the pump 23 is driven, the cutting fluid flows through the main hose 26. The cutting fluid branches at the T-shaped joint 62, and one flows to the flexible pipe 72 through the through hole 92, and the other flows to the branch hose 28. The cutting fluid that has flowed into the flexible pipe 72 is ejected vigorously from the cutting fluid nozzle 75. The cutting fluid that has flowed to the branch hose 28 flows through the flexible pipe 71 from the joint 64 on the opposite side across the column 5 through the through hole 94, and is ejected vigorously from the cutting fluid nozzle 74. The cutting fluid nozzles 74 and 75 can directly apply the cutting fluid from both the left and right sides to a workpiece portion (not shown) fixed to the upper surface of the table 8 with a jig or the like. The cutting fluid can wash away the chips adhering to the part to be processed.

  When the pump 22 is driven, the cutting fluid flows through the main hose 25. The cutting fluid branches at the T-shaped joint 61, one flows through the cutting fluid pipe 82 through the through hole 91, and the other flows to the branch hose 27. The cutting fluid that has flowed into the cutting fluid piping 82 is ejected vigorously downward from the plurality of tip showers 84. The cutting fluid that has flowed to the branch hose 27 flows from the joint 63 on the opposite side across the column 5 through the through-hole 93 to the cutting fluid pipe 81, and is ejected vigorously downward from the plurality of tip showers 83. Therefore, the cutting fluid can wash away the chips adhering to the inside of the cover 4 and accumulating.

  With reference to FIG. 6, the electrical configuration of the numerical control device 30 and the machine tool 1 will be described. The numerical control device 30 includes a CPU 31, a ROM 32, a RAM 33, a nonvolatile storage device 34, an input / output unit 35, motor control units 51A to 55A, drive control units 56A and 57A, and the like. The CPU 31 performs overall control of the numerical control device 30. The ROM 32 stores a control program and the like. The control program executes a control process (see FIG. 8) described later. The RAM 33 includes various storage areas described later (see FIG. 6). The non-volatile storage device 34 stores a plurality of machining programs input by the operator through the input unit 11 of the operation panel 10 and registered, and a reference power amount to be described later.

  The motor control unit 51A is connected to the Z-axis motor 51 and the encoder 51B. The motor control unit 52A is connected to the spindle motor 52 and the encoder 52B. The motor control unit 53A is connected to the X-axis motor 53 and the encoder 53B. The motor control unit 54A is connected to the Y-axis motor 54 and the encoder 54B. The motor control unit 55A is connected to the magazine motor 55 and the encoder 55B. The drive control unit 56 </ b> A is connected to the pump 22. The drive control unit 57A is connected to the pump 23. The motor control units 51A to 55A receive commands from the CPU 31 and output drive currents to the corresponding motors 51 to 55, respectively.

  The motor controllers 51A to 55A receive feedback signals from the encoders 51B to 55B, and perform position and speed feedback control. The input / output unit 35 is connected to the input unit 11 and the display unit 12, respectively. The drive controllers 56A and 57A receive commands from the CPU 31 and output drive currents to the corresponding pumps 22 and 23, respectively. The pumps 22 and 23 are each driven by a drive current. The Z-axis motor 51, the main shaft motor 52, the X-axis motor 53, the Y-axis motor 54, and the magazine motor 55 are all servo motors. In the following description, the Z-axis motor 51, the main shaft motor 52, the X-axis motor 53, the Y-axis motor 54, and the magazine motor 55 are collectively referred to as motors 51 to 55.

Various storage areas of the RAM 33 will be described with reference to FIG. The RAM 33 includes an idle operation power storage area 331, an idle operation acquisition count storage area 332, an actual machining acquisition count storage area 333, an integrated value storage area 334, and the like. Note that the idling operation means an operation in which the same machining program as the actual machining is executed without a workpiece. Actual machining means machining the workpiece W by rotating the tool T mounted on the spindle 7 based on the machining program. The idling power storage area 331 stores idling power information. The idling power information is power consumption information acquired from the motor control unit 52A every predetermined time during idling. The power consumption acquired during the idling operation corresponds to the non-machining power amount of the present invention. The number-of-obtained acquisition times storage area 332 stores the number of times (i) the power consumption is acquired from the motor control unit 52A every predetermined time during the idle operation. The actual machining acquisition count storage area 333 stores the number of times (j) the power consumption is acquired from the motor control unit 52A every predetermined time during actual machining. The power consumption acquired during actual machining corresponds to the power consumption during machining of the present invention. The integrated value storage area 334 stores the integrated value ( _PSUM ). The integrated value is an integrated value of power consumption of the spindle motor 52 calculated every predetermined time to be described later.

  With reference to FIG. 8, the mechanism of power supply from the external power source to the various motors 51 to 55 will be described. The motor control unit 52A includes a converter 522 and an inverter 521. Converter 522 is connected to an external power source (not shown) and inverter 521. The inverter 521 is connected to the spindle motor 52. The motor control unit 53A includes an inverter 531. Inverter 531 is connected to wiring electrically connected to converter 522 and X-axis motor 53. The motor control unit 54A includes an inverter 541. Inverter 541 is connected to Y-axis motor 54 and wiring electrically connected to converter 522. The motor control unit 51A includes an inverter 511. The inverter 511 is connected to the wiring electrically connected to the converter 522 and the Z-axis motor 51. The motor control unit 55A includes an inverter 551. Inverter 551 is connected to magazine motor 55 and wiring electrically connected to converter 522. Converter 522 converts AC (alternating current power) supplied from an external power source into DC (direct current power). Inverters 521, 531, 541, 511, and 551 convert the DC power output from converter 522 into driving AC power, and input the AC power to various motors 51 to 55, respectively.

  With reference to FIGS. 9 and 10, the relationship between the amount of chips generated during workpiece machining and the power consumption of the spindle motor 52 will be described. The graph of FIG. 9 shows a change in power consumption acquired from the motor control unit 52A during the actual tapping. The power consumption increased instantaneously when the spindle motor 52 was started up and then decreased immediately, and stabilized at a low value until the tool T mounted on the spindle 7 contacted the workpiece W. When the tool T contacts the workpiece W, the power consumption increases, and when the tool T moves away from the workpiece W, the power consumption decreases. When the machining program was completed and the spindle motor 52 was stopped, the power consumption increased instantaneously in the same way as at the start, and then decreased immediately thereafter. Except for a momentary increase in power consumption when the spindle motor 52 is started and stopped, a plurality of peaks of power consumption measured during that time corresponds to the time when the tool T contacts the workpiece W and cuts the workpiece W. The more the tool T is loaded, the higher the power consumption. Therefore, the numerical controller 30 can estimate the amount of chips generated by cutting the workpiece W based on the change in the power consumption acquired from the motor control unit 52A except when the spindle motor 52 is started and stopped.

  Here, as shown in FIG. 8, as described above, the electric power input to the motor control unit 52A is converted from alternating current to direct current by the converter 522, and then output to the motor control units 53A, 54A, 51A, and 55A. Therefore, the electric power acquired from the motor control unit 52A includes not only electric power used by the spindle motor 52 but also electric power used by the other motors 51, 53, 54, and 55, respectively. In order to accurately estimate the amount of generated chips, it is necessary to acquire only the power consumption of the spindle motor 52 used when the tool T contacts the workpiece W and cuts the workpiece W (cutting). Therefore, the numerical control device 30 performs the idling operation before actual machining, and stores the power consumption acquired from the motor control unit 52A in the RAM 33 during the idling operation. The numerical control device 30 calculates the difference between the power consumption acquired from the motor control unit 52 </ b> A during actual machining and the power consumption acquired during idle driving stored in the RAM 33. The difference corresponds to the power consumption used by the spindle motor 52 for cutting the workpiece W. The numerical control device 30 can accurately estimate the amount of chips generated along with the cutting by calculating and integrating the difference every predetermined time.

  The graph of FIG. 10 shows a change in power consumption when the same machining program as the tap machining is executed in the idle operation. The idling operation is performed in the same manner as in actual machining without fixing the workpiece W on the upper surface of the table 8. As shown in the graph of FIG. 10, the power consumption during the idling operation increased instantaneously when the spindle motor 52 was started and stopped, as in the case of actual machining. Between the start time and the stop time, the tool T does not come into contact with the workpiece W, so that the power used by the spindle motor 52 for cutting the workpiece W does not occur. Therefore, the big fluctuation | variation of the power consumption accompanying contact with the workpiece | work W at the time of an actual process was not seen. Therefore, the numerical control device 30 consumes the power used for the machining of the spindle motor 52 by subtracting the power consumption during idle operation shown in FIG. 10 from the power consumption during actual machining shown in FIG. The power can be estimated accurately.

  The main processing executed by the CPU 31 will be described with reference to the flowcharts of FIGS. When the operator selects one machining program with the input unit 11 and inputs a start instruction, the CPU 31 reads the machining program selected with the input unit 11 from the nonvolatile storage device 34, reads the main program from the ROM 32, and executes this processing. To do. In the present embodiment, description will be made focusing on the cutting fluid ejection operation of the tip showers 83 and 84. As shown in FIG. 11, first, the CPU 31 executes an idling process (S1).

  The idling process will be described with reference to FIG. Based on the machining program, the CPU 31 attaches the tool T at the end of the machining program to the spindle 7 (S11). The CPU 31 moves the machining start position of the spindle 7 to the position at the end of the machining program (S12). As described above, when performing the idling operation, the machine tool 1 needs to perform exactly the same movement as during actual operation. When machining is repeated, the next machining starts from the position at the end of the machining program. Therefore, the CPU 31 matches the position where the idling operation is started and the tool T mounted on the spindle 7 with the actual machining.

  The CPU 31 executes the machining program (S13). The tool T mounted on the spindle 7 rotates at a high speed and moves according to the machining program. The CPU 31 initializes idling power information (S14). The idle operation power information is stored in the idle operation power storage area 331 of the RAM 33. The CPU 31 initializes the number of acquisition times (i) during idling to zero (S15). The number of times of idle operation acquisition (i) is stored in the number of acquisition times storage area 332 of the RAM 33. The CPU 31 initializes the acquisition time counter to zero and starts the acquisition time count (S16). The acquisition time is a period of time for acquiring the idling power information. The count value of the acquisition time counter is stored in the RAM 33.

  The CPU 31 determines whether or not a predetermined time has elapsed from the start of measurement (S17). The CPU 31 determines whether or not the acquisition time has elapsed based on whether or not the count value stored in the RAM 33 has reached a predetermined time (for example, 64 msec). Until the acquisition time elapses, the CPU 31 returns to S17 and waits for processing. When the acquisition time has elapsed (S17: YES), the CPU 31 acquires power consumption (Pi) from the motor control unit 52A (S18). The CPU 31 stores the acquired power consumption (Pi) in the idle operation power storage area 331 of the RAM 33 as idle operation power information (S19).

  The CPU 31 determines whether or not the machining program has been completed (S20). When the machining program is continuing (S20: NO), the CPU 31 adds 1 to the number of times (i) of idle operation stored in the RAM 33 (S21). CPU31 returns to S16 and repeats acquisition of power consumption for every predetermined time (S16-S19). When the machining program ends (S20: YES), the CPU 31 returns to the main process in FIG. 11 and advances the process to S2 in FIG. The idling power storage area 331 of the RAM 33 stores the power consumption (Pi) acquired every predetermined time from the start to the stop of the spindle motor 52. The information on the power consumption (Pi) acquired every predetermined time is the idling power information.

As shown in FIG. 11, the CPU 31 initializes an integrated value ( _PSUM ) (S2). The integrated value (P _SUM ) is stored in the integrated value storage area 334 of the RAM 33. The CPU 31 executes actual processing (S3).

  The actual machining process will be described with reference to FIG. Before executing the actual machining process, the operator temporarily stops the operation of the machine tool 1 and fixes the workpiece W on the table 8. After the work W is fixed, the operator inputs an operation resumption instruction for the machine tool 1 on the operation panel 10.

  First, the CPU 31 executes the same machining program as in the idling operation (S25). The CPU 31 initializes the number of acquisition times (j) during actual machining to zero (S26). The actual machining acquisition count (j) is stored in the actual machining acquisition count storage area 333 of the RAM 33. The tool T mounted on the spindle 7 rotates at a high speed and moves while contacting the workpiece W according to the machining program. The tool T performs cutting of the workpiece W. As the workpiece W is cut, chips are scattered from the workpiece W and accumulate in the cover 4.

  The CPU 31 determines whether or not the machining program has been completed (S27). When it is determined that the machining program is finished (S27: YES), the CPU 31 returns the process to S4 of FIG. When the machining program is continuing (S27: NO), the CPU 31 starts measuring the acquisition time (S28). The acquisition time is the same acquisition time (for example, 64 msec) as that during idling. The CPU 31 determines whether the acquisition time has elapsed (S29). Until the acquisition time elapses (S29: NO), the CPU 31 returns to S29 and waits for processing.

When the acquisition time has elapsed (S29: YES), the CPU 31 acquires power consumption (Pj) from the motor control unit 52A (S30). Next, the CPU 31 calculates the power consumption (Pj) acquired in S30 and the power consumption (Pi) during the idling operation of i = j among the idling power information stored in the idling power storage area 331 of the RAM 33. Calculate the difference. For example, when the number j of times of acquisition of power consumption from the motor control unit 52 </ b> A is 1, the power consumption of i = 1 is read from the idle operation power information stored in the RAM 33. The CPU 31 compares the power consumption at the same time during idle operation and actual machining, and calculates the difference between the power consumption (Pi) during idle operation and the power consumption (Pj) during actual machining. Therefore, the CPU 31 can obtain the power consumption used by the spindle motor 52 for cutting the workpiece W. The CPU 31 integrates the calculated difference with the integrated value ( _PSUM ) stored in the integrated value storage area 334 of the RAM 33, and updates the integrated value ( _PSUM ) (S31).

The CPU 31 determines whether or not the integrated value ( _PSUM ) stored in the integrated value storage area 334 exceeds the reference power amount (S32). The reference power amount is stored in advance in the nonvolatile storage device 34. The reference power amount can be set freely. When the integrated value ( _PSUM ) is equal to or less than the reference power amount (S32: NO), the amount of chips accumulated in the cover 4 is small, and there is no need to eject cutting fluid from the tip showers 83 and 84. Therefore, the CPU 31 adds 1 to the actual machining acquisition number (j) stored in the RAM 33 without driving the pump 22 (S35).

The CPU 31 returns to S27 and determines whether or not the machining program has ended (S27). When the machining program is continuing (S27: NO), the above process is repeated every predetermined time (S28 to S33). As the workpiece cutting progresses, the integrated value ( _PSUM ) stored in the integrated value storage area 334 increases. When the integrated value ( _PSUM ) exceeds the reference power amount (S32: YES), there is a high possibility that a considerable amount of chips has accumulated in the cover 4. The inside of the cover 4 is a situation where it is desirable to eject the cutting fluid from the chip showers 83 and 84 to wash away the chips. Therefore, the CPU 31 notifies the start of the ejection process of the chip showers 83 and 84 (S33). The CPU 31 initializes the integrated value ( _PSUM ) (S34), and adds 1 to the actual machining acquisition count (j) (S35). The CPU 31 returns to S27 and repeats the process.

  The ejection process will be described with reference to FIG. The CPU 31 receives the ejection process start notification, reads the ejection control program from the ROM 32, and executes this process. The CPU 31 determines whether or not the cutting fluid is being ejected (S36). Regarding the ejection of the cutting fluid, the CPU 31 determines whether or not the pump 22 is being driven. When the pump 22 is being driven, the tip showers 83 and 84 are ejecting cutting fluid. When the pump 22 is stopped, the tip showers 83 and 84 do not eject cutting fluid.

  When the cutting fluid is not ejected (S36: NO), the CPU 31 sets the ejection time (S37). The count value of the ejection time counter is the ejection time. The ejection time is, for example, 10 seconds. The ejection time can be freely set by the operator using the input unit 11 of the operation panel. The CPU 31 starts counting the ejection time (S39). The CPU 31 drives the pump 22 and starts to eject cutting fluid from the tip showers 83 and 84 (S40). The cutting fluid ejected from the tip showers 83 and 84 washs away the chips adhering to and depositing in the cover 4.

  The CPU 31 determines whether or not the count value has reached the ejection time (S41). Until the ejection time is reached (S41: NO), the CPU 31 returns to S41 and continues to eject the cutting fluid. When the ejection time is reached (S41: YES), the chips accumulated in the cover 4 are washed away. Therefore, the CPU 31 stops the pump 22 and ends the ejection of the cutting fluid from the tip showers 83 and 84 (S42). The CPU 31 ejects the cutting fluid from the tip showers 83 and 84 when the amount of chips generated with the work processing exceeds a certain amount, and stops when a sufficient time has passed to wash away the chips. Therefore, the numerical controller 30 can effectively save the cutting fluid. The CPU 31 ends this process.

In addition, the integrated value ( _PSUM ) may exceed the reference power amount again before the ejection time has elapsed since the start of the previous ejection process (S32 in FIG. 13: YES). In the tip showers 83 and 84, the cutting fluid is being ejected (S36 in FIG. 14: YES), but in addition to the remaining ejection time that is currently being ejected, one more ejection time should be ejected. In the present embodiment, a certain amount of cutting fluid is ejected in order to flow a certain volume of chips. Therefore, a certain amount of cutting fluid is also ejected with respect to the volume of the chips that are determined to require ejection of the next cutting fluid during the current ejection. The CPU 31 sets the count value of the ejection time counter to a value obtained by adding the ejection time to the remaining count value (S38). The remaining count value is the remaining count value currently being ejected. Therefore, since the numerical controller 30 can eject the amount of cutting fluid for two times from the chip showers 83 and 84 (S39 to S42), the chips accumulated in the cover 4 can be sufficiently washed away. For example, when the reference power amount is exceeded 5 seconds after the start of the previous ejection, 15 seconds can be ejected by adding 10 seconds to the remaining 5 seconds.

  As shown in FIG. 11, the CPU 31 determines whether or not to continue the operation with the same machining program (S4). When operating with the same machining program (S4: YES), the CPU 31 returns the process to S3 and executes the actual machining process again (S3). As long as the numerical control device 30 executes the same machining program that once executed the idle operation process, it is not necessary to perform the idle operation process again. Therefore, when mass production processing is performed, it is only necessary to execute the idling process once, so that the operation can be performed promptly. When not operating by the same processing program (S4: NO), CPU31 ends this processing.

  In the above description, the cover 4 shown in FIG. 1 corresponds to the cover of the present invention, the CPU 31 that executes the processing of S18 corresponds to the first acquisition means of the present invention, and the idle operation power storage area 331 of the RAM 33 is the main storage. The CPU 31 that corresponds to the first storage unit of the invention and that executes the process of S19 corresponds to the first storage means of the invention, and the CPU 31 that executes the processes of S16 to S18 corresponds to the second acquisition means of the invention, The CPU 31 that executes the process of S31 corresponds to the calculation unit and the second storage unit of the present invention, the integrated value storage area 334 of the RAM 33 corresponds to the second storage unit of the present invention, and the CPU 31 that executes the process of S32 performs the present process. The CPU 31 that corresponds to the determination means of the invention and that executes the processing of S33 and the ejection processing of FIG. 14 corresponds to the ejection control means of the present invention, and the CPU 31 that executes the processing of S2 and S34 corresponds to the first initialization means of the present invention. Equivalent to, the CPU31 that performs the processing of S1, corresponding to an empty operation execution means of the present invention.

  As described above, the numerical control device 30 according to the present embodiment controls the machine tool 1 including the cutting fluid ejection mechanism. The cutting fluid ejection mechanism includes chip showers 83 and 84 and a pump 22 provided in the cover 4. The CPU 31 performs idle operation before workpiece machining, acquires the power consumption of the spindle motor 52 when the spindle 7 rotates without contacting the workpiece from the motor control unit 52A, and stores it in the RAM 33. Next, the CPU 31 processes the workpiece while the workpiece W is fixed on the table 8. During the workpiece machining, the CPU 31 rotates the spindle 7 while the tool T is in contact with the workpiece W, and acquires the power consumption of the spindle motor 52 at regular intervals. The CPU 31 calculates a difference between the actual machining power amount acquired at regular time intervals and the idle operation power energy stored in the RAM 33, accumulates the differential amounts calculated at regular time intervals, and stores them in the RAM 33 as needed. When the integrated value exceeds the reference power amount, there is a high possibility that chips generated during work processing are accumulated in the cover 4. Therefore, the CPU 31 drives the pump 22 and ejects the cutting fluid from the tip showers 83 and 84. The cutting fluid ishes away the chips accumulated in the cover 4. The time for ejecting the cutting fluid from the tip showers 83 and 84 is a certain ejection time (for example, 10 seconds). When the ejection time has elapsed, the CPU 31 stops the pump. The numerical control device 30 can perform the ejection of the cutting fluid according to the amount of chips accumulated in the cover 4. The numerical control device 30 can prevent wasteful use of electric power by processing with less chips and improve the energy saving effect. Since the numerical controller 30 estimates the cutting volume of the workpiece based on the power consumption used for the cutting of the spindle motor 52, the estimation accuracy is improved.

  Moreover, CPU31 initializes the integrated value memorize | stored in RAM33, when a cutting fluid is ejected from the tip shower 83,84 during fixed ejection time. After the cutting fluid is ejected into the cover 4, chips are not deposited in the cover 4. Therefore, by initializing the integrated value to zero, the volume of chips generated in the next workpiece machining can be estimated well.

  Although not described in the present embodiment, the cutting fluid ejection operation from the cutting fluid nozzles 74 and 75 may be driven at least during the cutting process in which the tool T contacts the workpiece W, for example.

  The present invention is not limited to the above embodiment, and various modifications can be made. In the above embodiment, the cutting fluid is ejected from the tip showers 83 and 84 for 10 seconds after the end of the cutting process, but may be ended as it is after the end of the cutting process.

  In the said embodiment, although the ejection time of the cutting fluid of the tip showers 83 and 84 is uniformly set to 10 seconds, you may vary the ejection time according to the material of a workpiece | work, for example. Even if the chip has the same volume, the weight varies depending on the material of the workpiece. Therefore, when machining a workpiece made of a heavy material, it is possible to effectively prevent chips from remaining in the cover 4 by making the ejection time longer than when machining a workpiece made of a light material. Further, when machining a workpiece made of light material, the ejection time can be shortened compared to machining a workpiece made of heavy material, so that cutting fluid and power consumption can be further saved.

DESCRIPTION OF SYMBOLS 1 Machine tool 4 Cover 7 Spindle 22 Pump 25 Main hose 27 Branch hose 30 Numerical control apparatus 31 CPU
33 RAM
34 Non-volatile storage device 52 Spindle motor 52A Motor control unit 83, 84 Chip shower 331 Empty operation power storage area 334 Integrated value storage area T Tool W Workpiece

Claims (2)

A cover that covers the machining area, and rotates with the tool mounted on the spindle, and when machining the workpiece by bringing the tool into contact with the workpiece, against the chips generated in the workpiece and accumulated in the cover In a numerical control device that controls a machine tool equipped with an ejection mechanism that ejects and flushes cutting fluid,
A motor for rotating the spindle;
First acquisition means for acquiring a non-machining power amount that is a power consumption amount of the motor when the spindle rotates in a state where the tool is not in contact with a workpiece;
First storage means for storing in the first storage unit the non-machining power amount acquired by the first acquisition means;
A second acquisition means for acquiring a machining power amount, which is a power consumption amount of the motor when the spindle rotates in a state in which the tool is in contact with the workpiece, and performs the workpiece machining;
A calculation means for calculating a difference between the machining power amount acquired by the second acquisition means and the non-machining power amount stored in the first storage unit for each predetermined time;
A second storage means for integrating the difference calculated by the calculation means for each predetermined time and storing the result as an integrated value in a second storage unit;
Determining means for determining whether or not the integrated value stored in the second storage unit exceeds a predetermined value;
An ejection control means for controlling the ejection mechanism to eject the cutting fluid for a predetermined time when the determination means determines that the integrated value exceeds the predetermined value;
A first initialization unit that initializes the integrated value stored in the second storage unit when the ejection control unit controls the ejection mechanism to eject the cutting fluid for the predetermined time; A numerical control device characterized by comprising. In the same step as the workpiece machining step, provided with an idle operation executing means for executing an idle operation of rotating the spindle without the workpiece,
The first acquisition means includes
During the idle operation executed by the idle operation execution means, the non-working power amount is acquired at every predetermined time,
The first storage means
Storing the non-machining power amount acquired by the first acquisition means at regular intervals in the first storage unit;
The calculating means includes
The machining power amount acquired by the second acquisition unit and the non-machining power amount stored in the first storage unit at the same time as the second acquisition unit. The numerical control apparatus according to claim 1, wherein a difference from the non-machining power amount is calculated.

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