Numerical controller, machine tool, control method, program, and storage medium

Abstract

The invention provides a numerical controller, a machine tool, a control method, a program, and a storage medium capable of driving a cutting fluid discharge mechanism at an appropriate timing. The CPU controls a discharge mechanism that discharges a cutting fluid into the cover by the driving of the pump and flushes chips generated by machining a workpiece disposed in the cover on the basis of a machining program. A CPU determines whether or not a specific time Tsp before a first predetermined time from a time when a machining program ends has reached on the basis of a machining time from the start of machining to the end of machining based on the machining program (S13, S21). When it is determined that the specific time (Tsp) has been reached (S13: YES, S21: YES), the CPU drives the pump for a first predetermined time from the specific time (Tsp) to the end of the machining program (S29).

Description

Technical Field

[0001] The present invention relates to a numerical control device, a working machine, a control method, a program, and a storage medium. Background Art

[0002] The control device described in Patent Document 1 determines whether, during the execution of a numerical control (NC) program, any of the multiple blocks constituting the NC program have a block in which an operating unit, such as a spindle or coolant pump, is in a standby state. If a block is in a standby state, the control device determines whether power to the power source corresponding to the operating unit, such as the spindle motor or coolant pump, can be cut off while the block is executing.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-067346 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] Since the control device is powered off only when in the standby state, there is a possibility that the coolant supply portion may be oversupplied with coolant, and power consumption by the coolant supply portion may not be appropriately suppressed.

[0008] An object of the present invention is to provide a numerical control device, a machine tool, a control method, a program, and a storage medium that can control a cutting fluid ejection mechanism at an appropriate timing.

[0009] Technical means to solve the problem

[0010] The numerical control device of claim 1 controls a working machine including a spray mechanism, wherein the spray mechanism flushes chips by spraying cutting fluid into a cover using a pump drive, and the chips are generated by processing a workpiece arranged in the cover based on a processing program. The numerical control device is characterized in that it includes: a first judgment unit, which judges whether a specific moment before the first prescribed time from the end of the processing program is reached based on the processing time from the start to the end of the processing based on the processing program; and a first pump driving unit, which drives the pump for the first prescribed time from the specific moment to the end of the processing program when the first judgment unit judges that the specific moment has been reached.

[0011] The numerical control device can reliably flush the chips by driving the pump for the first predetermined time until the end of the machining program. Therefore, the numerical control device can drive the cutting fluid ejection mechanism at an appropriate timing.

[0012] The numerical controller of claim 2 may include a second pump driving unit that intermittently drives the pump during execution of the machining program. This reduces power consumption compared to a case where the numerical controller constantly drives the pump.

[0013] Alternatively, in the numerical controller of claim 3, the second pump driving unit may repeatedly drive the pump for a first time and, after driving the pump for the first time, stop the pump for a second time, wherein the first predetermined time is shorter than the first time. Depending on the machining program, only a small amount of chips may be generated in the second half of machining. In this case, even if the first predetermined time is shorter than the first time, the chips can be sufficiently flowed, thereby reducing power consumption.

[0014] Alternatively, in the numerical control device of claim 4, the second pump driving unit may repeatedly drive the pump for a first time and, after driving the pump for the first time, stop the pump for a second time during execution of the machining program, wherein the first predetermined time is longer than the first predetermined time. Prior to the end of the machining program, the numerical control device drives the pump for the first predetermined time, which is longer than the repeated first time of pump driving. Therefore, the numerical control device can more reliably flush chips until the end of the machining program.

[0015] Alternatively, the numerical control device of claim 5 includes: a second pump driving unit that repeatedly performs the following operations during execution of the machining program: driving the pump for a first time and stopping the pump for a second time after the pump has been driven for the first time; a second determination unit that determines whether a second predetermined time from the last time the pump stopped driving before the end of the machining program to the specific time is shorter than a predetermined reference time; and a setting unit that, if the second determination unit determines that the second predetermined time is shorter than the reference time, sets the time from the last time the pump started driving the first time to the end of the machining program to the first predetermined time, and the first pump driving unit drives the pump for the first predetermined time set by the setting unit. The numerical control device can prevent the pump from being repeatedly stopped and driven within a short period of time by resetting the first predetermined time. Therefore, the numerical control device can achieve low power consumption.

[0016] The working machine of claim 6 is characterized in that it includes: the ejection mechanism, which flushes the chips by ejecting the cutting fluid into the cover by utilizing the drive of the pump, and the chips are generated by processing the workpiece arranged in the cover based on the processing program; and the numerical control device according to any one of claims 1 to claim 5.

[0017] The machine tool achieves the same effects as the numerical control device according to any one of claims 1 to 5 .

[0018] The control method of claim 7 is a control method for a numerical control device that controls a working machine including a spray mechanism, wherein the spray mechanism flushes chips by spraying cutting fluid into a cover driven by a pump, and the chips are generated by processing a workpiece arranged in the cover based on a processing program. The control method is characterized in that it includes: a first judgment step, judging whether a specific moment before the first prescribed time from the end of the processing program is reached based on the processing time from the start to the end of the processing based on the processing program; and a first pump driving step, when the first judgment step judges that the specific moment has been reached, the pump is driven for the first prescribed time from the specific moment to the end of the processing program.

[0019] The control method achieves the same effects as the numerical control device of claim 1 .

[0020] The program of claim 8 is characterized in that a computer of a numerical control device that controls a working machine including a spray mechanism executes the following steps, wherein the spray mechanism flushes chips by spraying cutting fluid into a cover driven by a pump, and the chips are generated by processing a workpiece arranged in the cover based on a processing program; a first judgment step, based on the processing time from the start to the end of processing based on the processing program, judging whether a specific moment before the first prescribed time from the end of the processing program is reached; and a first pump driving step, when the first judgment step judges that the specific moment has been reached, the pump is driven for the first prescribed time from the specific moment to the end of the processing program.

[0021] The program achieves the same effects as the numerical control device of claim 1.

[0022] The storage medium of claim 9 is characterized in that it stores a program, which causes a computer of a numerical control device that controls a working machine including a spray mechanism to execute the following steps: the spray mechanism flushes chips by spraying cutting fluid into a cover by utilizing the drive of a pump, and the chips are generated by processing a workpiece arranged in the cover based on a processing program; a first judgment step, based on the processing time from the start to the end of processing based on the processing program, judging whether a specific moment before the first prescribed time from the end of the processing program has been reached; and a first pump driving step, when the first judgment step judges that the specific moment has been reached, driving the pump for the first prescribed time from the specific moment to the end of the processing program.

[0023] The storage medium achieves the same effects as the numerical control device according to claim 1. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] [ Figure 1 ] is a perspective view of the working machine 1 as viewed from the rear.

[0025] [ Figure 2 ] is a front view of the working machine 1.

[0026] [ Figure 3 ] is a plan view of the working machine 1.

[0027] [ Figure 4 ]yes Figure 3 The cross-sectional view in the direction of the arrow line II is shown.

[0028] [ Figure 5 ] is a diagram showing a state in which a tool T mounted on the spindle 7 is processing a workpiece W.

[0029] [ Figure 6 ] is a block diagram showing the electrical configuration of the numerical control device 30 and the machine tool 1.

[0030] [ Figure 7 ] is a chart showing parameters used for flag setting.

[0031] [ Figure 8 ] is a diagram showing the pump drive symbol.

[0032] [ Figure 9 ] is a chart showing parameters used for flag setting.

[0033] [ Figure 10 ] is a diagram showing the pump drive symbol.

[0034] [ Figure 11 ] is a diagram showing the relationship between operation mode A, operation mode B and the driving state of the pump 22.

[0035] [ Figure 12 ] is the flow chart of the main processing.

[0036] [ Figure 13 ] is a diagram showing a symbol of pump driving according to a modified example. DETAILED DESCRIPTION

[0037] An embodiment of the present invention will be described with reference to the accompanying drawings. Figure 2 The front direction, depth direction, left, right, top, and bottom of the paper are respectively the front, rear, left, right, top, and bottom of the machine tool 1. The left-right direction, front-back direction, and top-bottom direction of the machine tool 1 are respectively the X-axis direction, Y-axis direction, and Z-axis direction of the machine tool 1.

[0038] Reference Figures 1 to 4 , the outline of the structure of the working machine 1 is described. The working machine 1 includes a base 2, a machine body 3, a cover 4, a workbench 8 (refer to Figure 3 )、Tool changing device 13 (refer to Figure 4 ), control box 15, etc. The base 2 is a substantially rectangular iron base. The machine body 3 is set on the upper part of the base 2 and is used to hold the workpiece W (see Figure 5 ) for cutting. Examples of cutting processes include drilling, tapping, and milling. The cover 4 is provided on the upper portion of the base 2 and is a roughly rectangular box-shaped cover covering the periphery of the machine body 3 and the upper portion of the base 2. The cover 4 prevents chips and cutting fluid from flying to the outside. Figure 4 As shown, the workbench 8 is arranged at the center of the upper part of the base 2 and can be driven by the X-axis motor 53 (see Figure 6 )、Y-axis motor 54 (refer to Figure 6 ), X-axis guide mechanism and Y-axis guide mechanism (omitted from the figure) etc. move along the X-axis direction and the Y-axis direction. Each guide mechanism includes a linear guide rail, a ball screw, a nut (omitted from the figure) etc. The workbench 8 can fix the workpiece W on the upper surface by using a clamp etc. (refer to Figure 5 ).

[0039] like Figure 4 As shown, the tool changing device 13 includes a tool magazine 14. The disc-shaped tool magazine 14 includes a plurality of gripping arms 14A on the outer periphery. The gripping arms 14A hold the tool T at the front end (see FIG. Figure 5 ), which can be connected to the main shaft 7 (see Figure 5 ) between. The tool changing device 13 swings the clamping arm 14A located at the tool changing position to load and unload the tool T installed on the spindle 7. The tool changing position is the lowest position of the tool magazine 14 and the position closest to the spindle 7. Figure 1As shown, the control box 15 is provided on the back side of the cover 4, and the numerical control device 30 (see Figure 6 The numerical controller 30 controls the operation of the machine tool 1 .

[0040] Reference Figures 1 to 4 The structure of the machine body 3 is described. The machine body 3 includes a column 5, a spindle head 6, and a spindle 7 (see Figure 5 ) etc. The column 5 is erected at the rear of the upper part of the base 2. The spindle head 6 can be raised and lowered along the Z-axis direction along the front surface of the column 5 by using a Z-axis moving mechanism (omitted from the figure). The Z-axis moving mechanism includes a linear guide rail, a ball screw, a nut (omitted from the figure), etc. Figure 5 As shown in FIG, the spindle head 6 internally supports the spindle 7 in a rotatable manner. The spindle 7 is provided with a tool T at its lower end and is driven by a spindle motor 52 (see FIG. Figure 3 、 Figure 6 ) is driven to rotate. The machine tool 1 can be rotated by holding the workpiece W (refer to Figure 5 ) and the relative movement of the tool T mounted on the spindle 7 to perform cutting processing on the workpiece W.

[0041] Reference Figures 1 to 4 The structure of the cover 4 will be described. The cover 4 includes a front wall 41, a left wall 42, a right wall 43, and a left rear wall 44 (see Figure 3 、 Figure 4 )、Right back wall 45 (refer to Figure 3 、 Figure 4 ), formed into a roughly rectangular box shape. The lower end of each wall 41 to 45 is fixed to the upper part of the base 2. Figure 3 、 Figure 4 As shown, 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 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 of the column 5 and extends to the right side. The cover 4 covers the processing area of ​​the working machine 1. The processing area is the area required for the working machine 1 to process the workpiece, and is an area that at least includes the movable range of the spindle head 6 and the spindle 7 in the Z-axis direction, and the movable range of the worktable 8 in the XY direction. The cover 4 includes a cutting fluid spraying mechanism (hereinafter referred to as the "spraying mechanism"). The spraying mechanism sprays cutting fluid in the cover 4. Therefore, the working machine 1 can flush the chips generated during the workpiece processing and adhered and accumulated in the cover 4. In addition, the structure of the spraying mechanism will be described later.

[0042] like Figure 2As shown, the front wall 41 includes an opening 46, an opening and closing door 47, and an operating panel 10. The opening 46 is provided in the approximate center of the front wall 41 and is rectangular in shape when viewed from the front. The opening and closing door 47 is provided so as to be movable in the left and right directions at the opening 46. The operator opens the opening and closing door 47 to load and unload the workpiece W on the upper surface of the workbench 8. The operating panel 10 is provided on the right side of the opening 46. The operating panel 10 is connected to the numerical control device 30 (see FIG. 1 ) by a wiring harness (not shown). Figure 6 ) is connected. The operating 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, etc. of the machine tool 1. The machining program includes multiple blocks containing various control instructions. The numerical control device 30 controls various operations of the machine tool 1, including axis movement and tool replacement, based on the machining program in blocks. The display unit 12 receives instructions from the numerical control device 30 and can display various input screens and operation screens.

[0043] Reference Figure 1 、 Figure 3 、 Figure 4 The structure of the ejection mechanism will be described. The ejection mechanism includes an ejection unit and a supply unit. The ejection unit is located inside the cover 4 and ejects the cutting fluid from the cover 4. The supply unit is located outside the cover 4 and supplies the cutting fluid to the ejection unit.

[0044] Reference Figure 4 The structure of the ejection unit is described below. The ejection unit includes a pair of flexible tubes 71, 72, a pair of cutting fluid nozzles 74, 75, a pair of cutting fluid piping 81, 82, a plurality of chip showers 83, 84, and the like. The flexible tube 71 extends from a through-hole 94 provided in the left back wall 44 toward the upper surface of the workbench 8. The through-hole 94 is provided at a position approximately in the middle of the vertical direction on the right end side of the left back wall 44. The cutting fluid nozzle 74 is provided at the front end of the flexible tube 71. The flexible tube 72 extends from a through-hole 92 provided in the right back wall 45 toward the upper surface of the workbench 8. The through-hole 92 is provided at a position approximately in the middle of the vertical direction on the left end side of the right back wall 45. The cutting fluid nozzle 75 is provided at the front end of the flexible tube 72. The cutting fluid nozzles 74 and 75 bend the flexible tubes 71 and 72 and direct them toward the upper surface of the workbench 8.

[0045] The cutting fluid pipe 81 is connected to the through hole 93 (see FIG. Figure 3 ) extends forward and horizontally. The cutting fluid pipe 82 is connected to the through hole 91 (see Figure 3) extends forward and horizontally. The cutting fluid piping 81 includes a plurality of holes (not shown) at predetermined intervals in its lower portion. The chip sprayers 83 are respectively installed in the plurality of holes provided in the lower portion of the cutting fluid piping 81. The cutting fluid piping 82 also includes a plurality of holes (not shown) at predetermined intervals in its lower portion. The chip sprayers 84 are respectively installed in the plurality of holes provided in the lower portion of the cutting fluid piping 82. The chip sprayers 83 and 84 direct the ejection direction of the cutting fluid downward.

[0046] Reference Figure 1 、 Figure 3 The structure of the supply unit is described below. Figure 1 As shown, the supply unit includes a tank 20, a pump 22, a pump 23, a main hose 25, a main hose 26, a branch hose 27, a branch hose 28, a T-joint 61, a T-joint 62, a joint 63, and a joint 64 (see Figure 3 ) etc. Tank 20 is located behind base 2 and stores cutting fluid. Pumps 22 and 23 are located adjacent to each other on the right side of tank 20. A main hose 25 is connected to pump 22. A main hose 26 is connected to pump 23. Pump 22 draws cutting fluid from tank 20 and supplies it to main hose 25. Pump 23 draws cutting fluid from tank 20 and supplies it to main hose 26.

[0047] The T-joint 61 is connected from the outside of the cover 4 to the through hole 91 provided at the upper portion of the right end of the right back wall 45. The T-joint 62 is connected from the outside of the cover 4 to the through hole 92 provided at the middle position in the vertical direction of the left end of the right back wall 45. Figure 3 As shown, the joint 63 is connected from the outside of the cover 4 to the through hole 93 provided at the upper portion of the left end side of the left back wall 44. The joint 64 is connected from the outside of the cover 4 to the through hole 94 provided at the middle position of the right end side of the left back wall 44 in the vertical direction (see Figure 4 ).

[0048] The main hose 25 and the branch hose 27 are connected to the T-joint 61. The branch hose 27 extends to the left side of the column 5 through the back side of the column 5 and is connected to the joint 63 provided on the left back wall 44 (see FIG. Figure 3 The main hose 26 and the branch hose 28 are connected to the T-joint 62. The branch hose 28 is inserted through the hole 5B provided in the column 5 (see Figure 1 ) and extends to the left side of the column 5 and is connected to the joint 64 provided on the left back wall 44 (refer to Figure 3 The hole 5B is provided in the middle of the vertical direction of the column 5 and penetrates in the left-right direction.

[0049] Reference Figure 1 、 Figure 3 、 Figure 4The operation of the ejection mechanism will be described. When the pump 23 is driven, the cutting fluid flows in the main hose 26. The cutting fluid branches at the T-joint 62, one of which flows to the flexible tube 72 via the through hole 92, and the other flows to the branch hose 28. The cutting fluid flowing to the flexible tube 72 is violently ejected from the cutting fluid nozzle 75. The cutting fluid flowing to the branch hose 28 flows from the joint 64 on the opposite side of the column 5 to the flexible tube 71 via the through hole 94 and is violently ejected from the cutting fluid nozzle 74. The cutting fluid nozzle 74 and the cutting fluid nozzle 75 can allow the cutting fluid to directly contact the processed part of the workpiece W fixed to the upper surface of the workbench 8 by a clamp or the like from both sides (not shown). The cutting fluid can wash away the chips attached to the processed part.

[0050] When the pump 22 is driven, cutting fluid flows through the main hose 25. The cutting fluid branches at the T-joint 61, with one branch flowing through the through-hole 91 into the cutting fluid piping 82 and the other flowing into the branch hose 27. The cutting fluid flowing into the cutting fluid piping 82 is violently ejected downward from the multiple chip sprayers 84. The cutting fluid flowing into the branch hose 27 flows from the joint 63 on the opposite side of the column 5 through the through-hole 93 into the cutting fluid piping 81 and is violently ejected downward from the multiple chip sprayers 83. This helps the cutting fluid wash away chips that have adhered to and accumulated inside the cover 4.

[0051] Reference Figure 6 The electrical structure of the numerical control device 30 and the machine tool 1 is described. The numerical control device 30 includes a central processing unit (CPU) 31, a read-only memory (ROM) 32, a random access memory (RAM) 33, a non-volatile storage device 34, an input / output unit 35, motor control units 51A to 55A, a drive control unit 56A, a drive control unit 57A, etc. The CPU 31 performs overall control of the numerical control device 30. The ROM 32 stores control programs, etc. The control program executes the main processing described later (see Figure 12). RAM 33 includes various storage areas. The non-volatile storage device 34 stores a plurality of machining programs input by the operator using the input unit 11 of the operating panel 10, etc. In addition, the control program stored in ROM 32 can also be stored in a readable external storage medium (Universal Serial Bus (USB) memory, Compact Disc-Read Only Memory (CD-ROM), etc.). CPU 31 can also read the program from the storage medium and store it in the non-volatile storage device 34, and execute the control program stored in the non-volatile storage device 34. In addition, the working machine 1 can also communicate with other machines (servers, etc.) via a communication line. The control program can also be stored in the storage device of other machines. CPU 31 can also store the control program obtained by communicating with other machines in the non-volatile storage device 34. The control program is equivalent to the program of the present invention. USB memory, CD-ROM, server, other machines, etc. are equivalent to storage media.

[0052] 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 storage motor 55 and the encoder 55B. The drive control unit 56A 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 instructions from the CPU 31 and output drive currents to the corresponding motors 51 to 55.

[0053] The motor control unit 51A to the motor control unit 55A receive feedback signals from the encoders 51B to 55B and perform feedback control of the position and speed. The input and output unit 35 is connected to the input unit 11 and the display unit 12, respectively. The drive control unit 56A and the drive control unit 57A receive instructions from the CPU 31 and output drive currents to the corresponding pumps 22 and 23, respectively. The pumps 22 and 23 are driven by the drive currents, respectively. The Z-axis motor 51, the spindle motor 52, the X-axis motor 53, the Y-axis motor 54, and the library motor 55 are all servo motors. In addition, in the following description, when the Z-axis motor 51, the spindle motor 52, the X-axis motor 53, the Y-axis motor 54, and the library motor 55 are collectively referred to as the motors 51 to 55.

[0054] Reference Figure 7 、 Figure 8An example of parameter and flag settings for the pump 22 will be described. The operator operates the operating panel 10 to set various parameters related to driving the pump 22. For ease of explanation, the machining time is set to 100 seconds. The machining time is the time from the start to the completion of machining of the workpiece W based on the machining program. The machining time is associated with each machining program and stored in the non-volatile storage device 34.

[0055] like Figure 7 As shown, the pump 22 is driven and stopped once in one cycle Tcyc, and one cycle Tcyc is 56 seconds. The stop time of the pump 22 (hereinafter referred to as the second time Toff) is 39 seconds, and the drive time of the pump 22 (hereinafter referred to as the first time Ton) is 17 seconds. The drive time of the pump 22 before the end of the processing (hereinafter referred to as the first prescribed time Tend) is set to 15 seconds for each operation of the processing program. The first prescribed time Tend is shorter than the first time Ton. The moment 85 seconds after the start of the processing is called the specific moment Tsp. That is, when the specific moment Tsp is reached after the start of the processing, the pump 22 is driven until the end of the processing program.

[0056] like Figure 8 As shown, the flag for pump 22 is set by CPU 31 based on parameters set by the operator. When the flag is "0," pump 22 is stopped. When the flag is "1," pump 22 is driven. Numerical control device 30 begins machining workpiece W at time 0 seconds. During the second time period Toff (39 seconds) from time 0 seconds to time 39 seconds, the flag is "0." During the first time period Ton (17 seconds) from time 39 seconds to time 56 seconds, the flag is "1."

[0057] At time 56 seconds, the second cycle Tcyc begins. At this point, the flag becomes "0." After time 56 seconds and until the second time Toff has elapsed, the flag remains "0." At time 85 seconds, upon reaching the specific time Tsp, the flag again becomes "1." The flag remains "1" for the first predetermined time Tend, from time 85 seconds to time 100 seconds, until the machining is completed, which is the specific time Tsp.

[0058] Reference Figure 9 、 Figure 10 An example of parameter setting and flag setting of the pump 22 is described below. Figure 7 、 Figure 8 The same is true for 100 seconds. Figure 9 、 Figure 10 In the case of Figure 7 、 Figure 8 Compared with the case of , the time of one cycle Tcyc is longer. Figure 9As shown, one cycle, Tcyc, is set to 83 seconds. The second time, Toff, is set to 10 seconds, and the first time, Ton, is set to 73 seconds. The first predetermined time, Tend, is set 15 seconds before the end of processing. That is, the specific time, Tsp, is 85 seconds. The first predetermined time, Tend, is shorter than the first time, Ton.

[0059] like Figure 10 As shown, machining begins at time 0 seconds. During the second time period Toff (10 seconds) from time 0 seconds to time 10 seconds, the flag is "0." During the first time period Ton (73 seconds) from time 10 seconds to time 83 seconds, the flag is "1." At time 83 seconds, the second time period Toff of the next cycle Tcyc begins. However, two seconds later, the specific time Tsp reaches 85 seconds. At this time, because the pump 22 is stopped and driven in a short period of time, the machine tool 1 consumes more power than necessary.

[0060] In this case, the flag remains set to "1" even at 83 seconds, the start time of the second cycle Tcyc. This prevents the pump 22 from stopping and driving for a short period of time. For example, if the time from the last stop of the pump 22 before the end of the machining program to the specific time Tsp (hereinafter also referred to as the second predetermined time Tsub) is shorter than the reference time Tref, the flag remains "1." The reference time Tref is, for example, 3 seconds, which can be determined based on the specifications of the pump 22.

[0061] Reference Figure 11 Briefly explain the operation mode A and operation mode B of the machining program. Figures 7 to 10 Unlike the example shown, the machining time is longer than one cycle Tcyc. Therefore, starting at time t0 when machining begins, pump 22 is repeatedly driven and stopped for multiple cycles Tcyc. This repetition of cycles Tcyc allows the ejection mechanism to discharge the generated chips. Even in operating modes A and B, pump 22 is intermittently driven, thereby reducing power consumption by the numerical controller 30.

[0062] Operation mode A occurs when the second predetermined time Tsub is longer than the reference time Tref. Pump 22 is stopped from the start of the final second time Toff until a specific time Tsp. At the specific time Tsp, pump 22 is activated. From the specific time Tsp until the end of the machining program, time te, pump 22 is activated. Therefore, the numerical controller 30 can use cutting fluid to remove chips generated during long machining cycles, while also removing chips generated between the specific time Tsp and time Te, during a repetitive cycle Tcyc.

[0063] Operation mode B is when the second predetermined time Tsub is shorter than the reference time Tref. In this case, at time t10, the pump 22 does not stop for the second time Toff. The numerical controller 30 uses time t7 as the specific time Tsp and resets the period from time t7 to time Te to the first predetermined time Tend. That is, the pump 22 continues to drive from time t7 until time te, the end of the machining program. Therefore, the numerical controller 30 can reduce power consumption caused by the machine tool 1 repeatedly driving and stopping the pump 22 in a short period of time.

[0064] Reference Figure 12 The main process will be described. The following description assumes that the parameters for driving the pump 22 have been set. The operator selects a machining program using the input unit 11 and inputs a start instruction. The CPU 31 reads the machining program selected by the input unit 11 from the nonvolatile storage device 34 and executes this process.

[0065] The CPU 31 refers to the nonvolatile storage device 34 and reads the machining time corresponding to the machining program selected by the operator ( S1 ).

[0066] The CPU 31 determines whether the second predetermined time Tsub is greater than or equal to the reference time Tref (S5). If the second predetermined time Tsub is greater than or equal to the reference time Tref (S5: YES), the CPU 31 maintains the first predetermined time Tend in the parameter accepted in S1 and advances the processing to S9. Figure 11 That is, the specific time Tsp does not change from the time when the parameters are set.

[0067] If it is determined that the second predetermined time Tsub is shorter than the reference time Tref (S5: NO), the CPU 31 resets the time from the last first time Ton when the pump 22 is started to the end of the machining program to the first predetermined time Tend (S7). Figure 11 Operation mode B. In this case, the specific time Tsp is earlier than the specific time Tsp at the time of parameter setting. The first predetermined time Tend is longer than the parameter setting time in the process of S1.

[0068] The CPU 31 starts executing the machining program (S9). The CPU 31 starts measuring the elapsed time since the start of the machining program (S11). The CPU 31 determines whether a specific time Tsp, which is a first predetermined time Tend before the end time te of the machining program, has been reached (S13). If the specific time Tsp has not been reached (S13: No), the CPU 31 sets a flag to 0 and stops the pump 22 (S15). The CPU 31 starts measuring the stop time since the pump 22 was stopped (S17).

[0069] The CPU 31 determines whether the pump 22 has been stopped for a second time period Toff (S19). If the pump 22 has not been stopped for a second time period Toff (S19: No), the CPU 31 returns the process to S13. The CPU 31 stops the pump 22 until the second time period Toff has elapsed. There are cases where the specific time period Tsp is reached while the pump 22 is stopped. In this case, the CPU 31 determines that the specific time period Tsp has been reached (S13: Yes), and the process proceeds to S29.

[0070] If it is determined that the pump 22 has been stopped for the second time period Toff seconds (S19: YES), the CPU 31 determines whether the specific time Tsp has been reached (S21), similar to the process in S13. If it is determined that the specific time Tsp has not been reached (S21: NO), the CPU 31 sets the flag to "1" and drives the pump 22 (S23).

[0071] The CPU 31 begins measuring the driving time of the pump 22 (S25). The CPU 31 determines whether the driving time of the pump 22 has exceeded the first time Ton (S27). If the CPU 31 determines that the driving time of the pump 22 has not exceeded the first time Ton (S27: No), the CPU 31 returns the process to S21. In other words, the CPU 31 drives the pump 22 until the first time Ton has passed. Here, the specific time Tsp may be reached during the driving of the pump 22. In this case, the CPU 31 determines that the specific time Tsp has been reached (S21: Yes), and the CPU 31 proceeds to S29.

[0072] On the other hand, if the driving time of the pump 22 has exceeded the first time Ton (S27: YES), the CPU 31 returns the process to S13. At this time, if the specific time Tsp has not been reached (S13: NO), the CPU 31 stops driving the pump 22 and controls the pump 22 for the next cycle Tcyc (S13 to S27).

[0073] Since the specific time Tsp has been reached, the CPU 31 sets the flag to "1" and drives the pump 22 (S29). The CPU 31 maintains the flag “1” and drives the pump 22 .

[0074] The CPU 31 determines whether the machining program has ended, that is, whether the first prescribed time Tend has passed (S31). If it is determined that the machining program has not ended (S31: No), the CPU 31 returns the process to standby. At this time, the CPU 31 continues to drive the pump 22. If it is determined that the machining program has ended (S33: Yes), the CPU 31 sets the flag to "0" and stops the pump 22 (S33). That is, when the CPU 31 determines that the specific time Tsp has been reached (S9: Yes, S17: Yes), it drives the pump 22 for the first prescribed time Tend from the specific time Tsp to the end of the machining program. The CPU 31 ends the process.

[0075] As described above, the CPU 31 determines whether the specific time Tsp, which is the first predetermined time Tend before the time te at which the machining program ends, has been reached based on the machining time from the start to the end of the machining program. If the CPU 31 determines that the specific time Tsp has been reached, the pump 22 is driven for the first predetermined time Tend from the specific time Tsp to the end of the machining program.

[0076] The numerical controller 30 can reliably flush the chips until the end of the machining program by driving the pump 22 for the first predetermined time Tend. Therefore, the numerical controller 30 can drive the cutting fluid ejection mechanism at an appropriate timing.

[0077] The CPU 31 intermittently drives the pump 22 during the execution of the machining program. Therefore, compared with the case where the numerical controller 30 constantly drives the pump 22, power consumption can be reduced.

[0078] The CPU 31 repeatedly drives the pump 22 for a first time Ton and then stops the pump 22 for a second time Toff after the first time Ton. The first predetermined time Tend is shorter than the first time Ton. Depending on the machining program, only a small amount of chips may be generated in the second half of machining. In this case, even if the first predetermined time Tend is shorter than the first time Ton, the chips can be fully flowed, thereby reducing power consumption.

[0079] During execution of the machining program, the CPU 31 repeatedly drives the pump 22 for a first time Ton and then stops the pump 22 for a second time Toff after the pump 22 has been driven for the first time Ton. The CPU 31 determines whether the second predetermined time Tsub, from the last time the pump 22 stopped driving before the end of the machining program to a specific time Tsp, is shorter than a predetermined reference time Tref. If the CPU 31 determines that the second predetermined time Tsub is shorter than the reference time Tref, the CPU 31 sets the time from the last time the pump 22 started driving for the first time Ton to the end of the machining program as the first predetermined time Tend, and then drives the pump 22 for the first predetermined time Tend. By resetting the first predetermined time Tend, the numerical controller 30 prevents the pump 22 from being stopped and driven in a short period of time. Consequently, the numerical controller 30 can achieve low power consumption.

[0080] In the above description, the CPU 31 executing S13 and S21 is an example of the first determination unit of the present invention. The CPU 31 executing S29 is an example of the first pump drive unit of the present invention. The CPU 31 executing S13 to S27 is an example of the second pump drive unit of the present invention. The CPU 31 executing S5 is an example of the second determination unit of the present invention. The CPU 31 executing S7 is an example of the setting unit of the present invention.

[0081] The present invention is not limited to the above embodiment and can be modified in various ways. In the above embodiment, the flag for pump 22 is set while the main process is being executed, but this is not limiting. For example, the flag for pump 22 may be set before setting parameters. In this case, CPU 31 can simply drive pump 22 based on the set flag.

[0082] In the embodiment described above, the first prescribed time Tend is shorter than the first time Ton, but the present invention is not limited thereto. Figure 13 As shown, the first predetermined time Tend can be longer than the first time Ton. Before the end of the machining program, the numerical controller 30 drives the pump 22 for the first predetermined time Tend, which is longer than the first time Ton during which the pump 22 is repeatedly driven. Therefore, the numerical controller 30 can more reliably flush chips until the end of the machining program. In other words, the operator sets the parameters in this way when prioritizing chip removal over energy conservation.

[0083] In the above embodiment, the pump 22 is driven and stopped for at least one cycle Tcyc, but the present invention is not limited thereto. For example, when the specific time Tsp is reached before the end of one cycle Tcyc, the pump 22 may be started to be driven as in the above embodiment.

[0084] In the above embodiment, intermittent driving is performed by driving the pump 22 for a first time Ton and stopping it for a second time Toff, but the present invention is not limited to this. For example, the CPU 31 may detect the flow rate of the cutting fluid using a sensor for detecting the flow rate of the cutting fluid and stop the pump 22 when a predetermined flow rate is detected. Alternatively, the pump 22 may be stopped when a liquid level sensor within the tank 20 detects a predetermined position, that is, when a predetermined amount of cutting fluid has flowed out.

[0085] Explanation of Figure Numbers

[0086] 1: Working machinery

[0087] 4: Hood

[0088] 22: Pump

[0089] 30: Numerical control device

[0090] 31: CPU

[0091] W: workpiece

[0092] Tsp: specific time

[0093] Ton: First time

[0094] Toff: Second time

[0095] Tend: First stipulated time

[0096] Tsub: Second stipulated time

[0097] Tref: reference time

Claims

1. A numerical control device for controlling a machine tool including a spray mechanism, wherein the spray mechanism flushes chips by spraying cutting fluid into a housing driven by a pump. The chips are generated by machining a workpiece disposed within the housing according to a machining program, the numerical control device comprising: a first determination unit for determining, based on a machining time from the start to the end of machining according to the machining program, whether a specific time has arrived before a first predetermined time from the end of the machining program; as well as The first pump driving unit drives the pump for the first predetermined time from the specific time to the end of the machining program when the first determining unit determines that the specific time has arrived.

2. The numerical control device according to claim 1, wherein A second pump driving unit is included that intermittently drives the pump during execution of the machining program.

3. The numerical control device according to claim 2, wherein: The second pump driving unit repeatedly drives the pump for a first time, and stops the pump for a second time after the first time of driving the pump. The first prescribed time is shorter than the first time.

4. The numerical control device according to claim 2, wherein: The second pump driving unit repeatedly performs the following operations during the execution of the machining program: driving the pump for a first time, and stopping the pump for a second time after the pump is driven for the first time, The first prescribed time is longer than the first time.

5. The numerical control device according to claim 1, characterized in that include: a second pump driving unit that repeatedly performs the following operations during execution of the machining program: driving the pump for a first time, and stopping the pump for a second time after driving the pump for the first time; a second determination unit for determining whether a second predetermined time period from the last stop of driving of the pump before the end of the machining program to the specific time period is shorter than a predetermined reference time period; as well as a setting unit that sets the time from the last start of driving the pump at the first time to the end of the machining program as the first prescribed time when the second determining unit determines that the second prescribed time is shorter than the reference time, The first pump driving unit drives the pump for the first predetermined time set by the setting unit.

6. A working machine, characterized in that include: The ejection mechanism flushes the chips generated by machining the workpiece disposed in the cover based on the machining program by ejecting the cutting fluid into the cover using the pump; as well as The numerical control device according to any one of claims 1 to 5.

7. A control method for a numerical control device for controlling a machine tool including a spray mechanism, wherein the spray mechanism flushes chips by spraying cutting fluid into a housing driven by a pump, the chips being generated by machining a workpiece disposed within the housing according to a machining program, the control method comprising: A first determination step of determining whether a specific time before a first predetermined time from the end of the machining program has been reached based on the machining time from the start to the end of the machining program according to the machining program; and The first pump driving step drives the pump for the first predetermined time from the specific time to the end of the machining program when the first determining step determines that the specific time has arrived.

8. A program, characterized in that The computer of a numerical control device that controls a machine tool including a spray mechanism that flushes chips generated by machining a workpiece disposed in the cover based on a machining program by spraying cutting fluid into the cover by a pump. A first determination step of determining whether a specific time before a first predetermined time from the end of the machining program has been reached based on the machining time from the start to the end of the machining program according to the machining program; and The first pump driving step drives the pump for the first predetermined time from the specific time to the end of the machining program when the first determining step determines that the specific time has arrived.

9. A storage medium, characterized in that A program is stored that causes a computer of a numerical control device that controls a machine tool including a spray mechanism to execute the following steps, wherein the spray mechanism sprays cutting fluid into a cover by a pump to flush chips generated by machining a workpiece disposed in the cover based on a machining program, A first determination step of determining whether a specific time before a first predetermined time from the end of the machining program has been reached based on the machining time from the start to the end of the machining program according to the machining program; and The first pump driving step drives the pump for the first predetermined time from the specific time to the end of the machining program when the first determining step determines that the specific time has arrived.

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