control system

Abstract

This technology provides a control system that can reduce the possibility of a discrepancy between the time the coolant reaches its target pressure and the time the machining start state is completed. [Solution] The control system comprises a coolant supply unit, a tool operating unit, and a control device. The control device has a timing adjustment unit that performs an adjustment process to shift the pressurization start timing of the coolant supply unit relative to the operation start timing of the tool operating unit, so that the time difference, which is the difference between the pressure arrival time when the coolant reaches the target pressure and the tool state time when the operation to the machining start state is completed, falls within a first range.

Description

Technical Field

[0001] The present disclosure relates to a control system for a machine tool.

Background Art

[0002] Conventionally, a technique of supplying coolant to a machining point by a center-through coolant system to machine a workpiece has been known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When machining a workpiece by attaching a tool to the spindle of a machine tool, after the coolant supply pressure reaches the target pressure and the tool is operated in a machining start state where the tool can machine the workpiece, the machining of the workpiece is started. The machining start state is, for example, a state where the tool reaches the machining start position and the spindle reaches the target rotational speed. Conventionally, when the drive of the coolant supply unit and the drive of the tool operation unit that operates to the machining start state are started simultaneously after attaching the tool to the spindle, there is a case where the arrival time of the coolant supply pressure at the target pressure and the completion time of the operation in the machining start state deviate. In this case, since one element (coolant supply unit or tool operation unit) for which the operation for machining the workpiece has already been completed needs to maintain the drive, wasted power that is not used for machining the workpiece is consumed.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to a first embodiment of the present disclosure, a control system for a machine tool that supplies coolant to a machining point by a center-through coolant system is provided. The control system comprises a coolant supply unit that pressurizes and supplies the coolant, a tool operating unit that operates a tool attached to the spindle of the machine tool to a machining start state in which a workpiece can be machined, and a control device. The control device has a timing adjustment unit that performs an adjustment process to shift the pressurization start timing of the coolant supply unit relative to the operation start timing of the tool operating unit, so that the time difference, which is the difference between the pressure arrival time when the coolant reaches a target pressure and the tool state time when the operation to the machining start state is completed, falls within a predetermined first range. According to this embodiment, by shifting the pressurization start timing relative to the operation start timing so that the time difference, which is the difference between the pressure arrival time and the operation completion time to the machining start state, falls within a first range, the driving time of the coolant supply unit or tool operating unit that is not used for the actual machining of the workpiece can be reduced. This reduces wasted power that is not used for machining the workpiece. (2) In the above embodiment, the control device further includes a measuring unit that measures the coolant preparation time from the time the coolant supply unit is activated until the coolant pressure reaches the target pressure, and the tool preparation time from the time the tool operating unit is activated until the operation to the machining start state is completed, and the timing adjustment unit may, in the adjustment process, adjust the timing of the pressurization start of the coolant supply unit relative to the operation start timing of the tool operating unit by the difference between the coolant preparation time and the tool preparation time, so that the time difference falls within the first range. In this embodiment, the time difference can be easily made to fall within the first range by shifting the pressurization start timing relative to the operation start timing by the difference between the coolant preparation time and the tool preparation time. (3) In the above configuration, if the coolant preparation time is shorter than the tool preparation time by the difference in the adjustment process, the timing adjustment unit may shift the pressurization start timing to a later timing than the tool operation start timing by the difference. This configuration reduces the operating time of the coolant supply unit that is not used for machining the workpiece. (4) In the above configuration, the measuring unit may measure the coolant preparation time and the tool preparation time for each of the multiple types of tools that can be attached to the spindle, and the timing adjustment unit may perform the adjustment process for each of the multiple types of tools. According to this configuration, it is possible to reduce wasted power that is not used for machining the workpiece for each of the multiple types of tools. (5) In the above configuration, when the measuring unit measures the coolant preparation time and the tool preparation time for the adjustment process, the control device may operate the coolant supply unit and the tool operating unit so that the pressurization start timing of the coolant supply unit and the operation start timing of the tool operating unit are the same. This configuration makes it possible to suppress the complexity of the control system when the adjustment process is not yet complete. (6) In the above configuration, the system may have a storage unit that stores the pressurization start timing adjusted by the adjustment process of the timing adjustment unit in association with the tool. In this configuration, by storing the pressurization start timing adjusted by the adjustment process in the storage unit, it is easy to shift the pressurization start timing relative to the operation start timing of the tool operation unit so that the time difference falls within a first range when using the adjusted tool the next time. (7) In the above configuration, the timing adjustment unit may start the operation of the coolant supply unit at the pressurization start timing stored in the memory unit during the adjustment process. According to this configuration, by operating the coolant supply unit using the pressurization start timing stored in the memory unit, the operating time of the coolant supply unit that is not used for the actual machining of the workpiece can be reduced. (8) In the above configuration, the timing adjustment unit, in the adjustment process, if the pressurization start timing is shifted relative to the operation start timing and the coolant supply unit and the tool operating unit are operated, and the time difference is not within a predetermined second range, executes at least one of the first process and the second process, the first process is a process that executes the adjustment process again so that the time difference is within the first range, and the second process is a process that notifies the outside of the abnormality of the control system. In this configuration, the first process can readjust the time difference so that it is within the first range again, and the second process can notify the user of the abnormality of the control system. (9) In the above embodiment, the machining start state includes a predetermined machining start position of the tool attached to the spindle and a predetermined target rotational speed of the spindle, and setting to the machining start state may be completed when the spindle is moved from the position in which the tool is attached to the spindle so that the tool reaches the machining start position, and the spindle is rotated so that the rotational speed of the spindle reaches the target rotational speed. According to this embodiment, the operation to set to the machining start state can be completed by moving the tool to the machining start position and the rotational speed of the spindle to the target rotational speed. This disclosure can be implemented in various forms, and in addition to the forms described above, it can also be implemented in the form of a control method, a computer program, a non-temporary recording medium on which the computer program is stored, and so on. [Brief explanation of the drawing]

[0007] [Figure 1] A diagram illustrating the control system of an embodiment. [Figure 2] Internal block diagram of the control unit. [Figure 3] A diagram showing the operation table. [Figure 4] A flowchart of the machining preparation process performed by the control system. [Figure 5] A diagram illustrating the processes performed by a control system. [Figure 6]A diagram to explain the post-update configuration process. [Modes for carrying out the invention]

[0008] A. Embodiments: Figure 1 is a diagram illustrating a control system 10 of an embodiment. Figure 1 shows mutually orthogonal X, Y, and Z axes. The XZ plane parallel to the X and Z axes is a horizontal plane, the direction along the Y axis is the up and down direction, and the direction along the +Y axis is the upward direction. The control system 10 is a system that controls a machine tool 11 that supplies coolant to the machining point using a center-through coolant system. The control system 10 comprises the machine tool 11 and a control device 40. The control device 40 controls various operations of the machine tool 11.

[0009] The machine tool 11 is a machine that processes a workpiece W using a tool T, and in this embodiment, it is a machining center. More specifically, the machine tool 11 is a horizontal machining center. The machine tool 11 includes a machine tool body 12, a tool magazine 28 for detachably storing a plurality of tools T, and a coolant supply system 30.

[0010] The machine tool body 12 comprises a bed 17, a column 13, and a spindle 14. The bed 17 is positioned on the floor. Various cables, such as electrical wiring, are arranged in the internal space of the bed 17. The column 13 is positioned on the bed 17. The column 13 supports the headstock 14. The column 13 is positioned on a pair of X-axis guide rails 16 provided on the bed 17.

[0011] Column 13 can move along the X-axis by being guided by the X-axis guide rail 16. A pair of Y-axis guide rails 18 extending along the Y-axis are provided on the wall of column 13 on the +Z-axis side. The headstock 14 can move along the Y-axis by being guided by the Y-axis guide rails 18.

[0012] The spindle 14 is provided with a portion to which a tool T used for machining the workpiece W is detachably attached. This portion is held in the spindle 14 so as to be rotatable around a central axis Rt parallel to the Z axis. The spindle 14 moves in the X axis direction as the column 13 moves, and moves in the Y axis direction as the spindle drive unit M14 is driven. A motor M15 that provides the driving force to rotate the tool T is housed inside the spindle 14. The motor M15 may also be built into the spindle 14.

[0013] The spindle 14 is detachably mounted to the tool T. Inside the spindle 14, a coolant passage 34 is formed that penetrates the spindle 14 along its central axis Rt. The coolant passage 34 is located on the central axis Rt. Pressurized coolant is supplied to the coolant passage 34 from the coolant supply system 30. The coolant that has flowed through the coolant passage 34 is supplied to the machining point, which is the cutting edge of the tool T. The supply of pressurized coolant to the machining point removes chips around the machining point and cools the workpiece W, etc. The coolant may be, for example, a liquid oil or a mist-type oil.

[0014] The machine tool body 12 further includes a column drive unit M13 that moves the column 13 along the X-axis guide rail 16, and a spindle drive unit M14 that moves the headstock 14 along the Y-axis guide rail 18. The column drive unit M13 and the spindle drive unit M14 are ball screw devices each comprising a ball screw and a motor.

[0015] The motor M15 that rotates the spindle 14, the column drive unit M13, and the spindle drive unit M14 together constitute a tool operating unit 19 that moves the tool T attached to the spindle 14 to a state where it can start machining the workpiece W.

[0016] The machine tool body 12 further includes a workpiece table 21, a rotary table 22, and a Z-axis guide rail 23. The workpiece table 21 is guided by the Z-axis guide rail 23 and is movable along the Z-axis. The rotary table 22 is disposed on the workpiece table 21. The rotary table 22 is capable of holding the workpiece W. The rotary table 22 rotates about an axis along the Y-axis. The workpiece table 21 is moved along the Z-axis guide rail 23 by a ball screw device including a ball screw and a motor (not shown). Further, the workpiece table 21 is rotated by a motor (not shown).

[0017] The tool magazine 28 removably stores a plurality of types of tools T. The tool magazine 28 is fixed to the side wall of the bed 17. The tool magazine 28 has tool pods (not shown) for holding each tool T. The tool magazine 28 has an actuator that moves the tool T selected according to a command from the control device 40 to the tool mounting position 29. The tool T moved to the tool mounting position 29 is newly attached to the spindle 14 or exchanged with the tool T already attached to the spindle 14 by a tool changing mechanism (not shown). In this embodiment, the tool T includes tools T1 to Tx.

[0018] The coolant supply system 30 supplies pressurized coolant to the coolant flow path 34 of the spindle 14. The coolant supply system 30 includes a tank 33 that stores the coolant, which is oil, a pump 35, a flow path 31 that communicates with the coolant flow path 34 and the tank 33, and a pressure sensor 32 that measures the pressure of the coolant supplied to the coolant flow path 34. The pressure sensor 32 measures the pressure in the flow path 31 and transmits the measurement result to the control device 40. The flow path 31 is constituted by a flow pipe and a flow path formed in the column 13. The pump 35 rotates at a predetermined rotational speed when the pump motor M35 is driven according to a command from the control device 40, and pressurizes and supplies the coolant in the tank 33 toward the coolant flow path 34. The pump motor M35 of the pump 35 functions as a coolant supply unit that pressurizes the coolant and supplies it to the coolant flow path 34.

[0019] Figure 2 is an internal block diagram of the control device 40. The control device 40 includes a processor 41, a storage unit 47, and a communication interface 49. The communication interface 49 exchanges data with the outside world via wired or wireless communication. The processor 41 functions as a command unit 42, a measurement unit 43, and a notification unit 45 by executing various programs stored in the storage unit 47.

[0020] The command unit 42 transmits commands to each part to control the operation of the control system 10 during the process of starting machining of the workpiece W. For example, the command unit 42 transmits command values ​​to the column drive unit M13, spindle drive unit M14, motor M15, pump motor M35, etc., according to the machining program for the workpiece W predetermined in the memory unit 47. The command unit 42 has a timing adjustment unit 44.

[0021] The timing adjustment unit 44 adjusts the pressurization start timing of the pump motor M35, which is the coolant supply unit, during the machining preparation process that is performed after the tool replacement process of the tool magazine 28 is completed. In this embodiment, the start timing of the operation of the tool operation unit 19 is predetermined. The pressurization start timing is the timing at which the operation of the pump motor M35 begins. Specifically, the timing adjustment unit 44 performs an adjustment process to shift the pressurization start timing relative to the operation start timing so that the time difference, which is the difference between the time at which the coolant reaches the target pressure and the time at which the operation to the pressurization start state (tool preparation process) is completed, falls within a predetermined first range. The absolute values ​​of the upper and lower limits of the first range should be set to values ​​smaller than the time difference (time difference before adjustment) when the pressurization start timing and the operation start timing are set to the same timing. For example, the first range may be -10 msec or more and +10 msec or less, -8 msec or more and +8 msec or less, or 0 msec. In this embodiment, the adjustment process is performed so that the first range becomes 0 msec, that is, so that the time difference becomes zero.

[0022] The measurement unit 43 measures the time used for the adjustment process performed by the timing adjustment unit 44. After the tool magazine 28 completes the process of replacing the tool T on the spindle 14, the measurement unit 43 measures the coolant preparation time from when the pump motor M35, which is the coolant supply unit, starts operating until the coolant pressure reaches the target pressure. The target pressure is a predetermined value. The coolant pressure is the value measured by the pressure sensor 32. The measurement unit 43 also measures the tool preparation time from when the tool operation unit 19 starts operating after the tool T replacement process is complete until the tool T is set to the machining start state. The measurement unit 43 measures the coolant preparation time and the tool preparation time for each of the multiple types of tools T that can be attached to the spindle 14. The machining start state includes a predetermined machining start position of the tool T attached to the spindle 14 and a predetermined target rotational speed of the spindle 14. Furthermore, the operation to initiate machining is completed when the spindle 14 is moved from the tool mounting position 29 so that the tool T reaches the machining start position, and the spindle 14 is rotated until its rotational speed reaches the target rotational speed. The machining start position is determined, for example, by the coordinate position of a predetermined part of the spindle 14 (for example, the tip).

[0023] The notification unit 45 notifies the outside of an abnormality when the pump motor M35 and tool operating unit 19 are operated with the pressurization start timing shifted relative to the operation start timing, and the time difference is not within a predetermined second range. The notification unit 45 may, for example, display information indicating the abnormality on a monitor or output an audio message indicating the abnormality through a speaker. The second range may, for example, be the same as the first range, or the absolute values ​​of the upper and lower limits may be larger than those of the first range. The absolute values ​​of the upper and lower limits of the second range are set to be smaller than the absolute value of the time difference before adjustment.

[0024] The storage unit 47 is composed of RAM, ROM, and a hard disk drive. The storage unit 47 has an operation table 48 that defines at least a part of the processing program.

[0025] Figure 3 shows the operation table 48. The operation table 48 defines the parameters used for adjustment processing for each type of tool T. The operation table 48 stores the tool identifier, a value indicating the machining start state, the target pressure, the start timing of the tool operating unit 19, the amount of deviation as the pressurization start timing, the measurement date and time, the coolant preparation time, and the tool preparation time.

[0026] The tool identifier is an identifier used to identify the type of tool T, and different identifiers are assigned depending on the type of tool T. In this embodiment, the machining start position is defined by the coordinate position of the X, Y, and Z axes. The target rotational speed is the target rotational speed of the spindle 14 when machining of the workpiece W begins. The target pressure is the coolant supply pressure when machining of the workpiece W begins. In the machining preparation process, when the spindle 14 moves to the machining start position, the rotational speed of the spindle 14 reaches the target rotational speed, and the coolant supply pressure reaches the target pressure, the machining process of the workpiece W begins.

[0027] The operation start timing stores the timing tp at which the tool operating unit 19 is started to move to the machining start state. In this embodiment, the operation start timing differs depending on the type of tool T. For example, with a certain type of tool T, the operation start timing tp is a certain time elapsed after the tool T has been replaced on the spindle 14 and the tool T has been attached to the spindle 14. The certain time can be zero or greater. Also in this embodiment, the operation start timing tp is the same before and after the adjustment process is performed by the timing adjustment unit 44.

[0028] The deviation amount is the amount of deviation in the ON timing of the pressure sensor 32 relative to the completion timing of the tool operating unit 19's operation to the machining start state, as determined by the timing adjustment unit 44 performing the adjustment process. The deviation amount is expressed as a deviation time, with the operation start timing time set to zero. For example, for tool T1, the deviation amount is "+t1", and in the machining preparation process, the pump motor M35 of the pump 35 starts driving and the pressurized supply of coolant starts +t1 milliseconds after the operation of the tool operating unit 19 begins. Note that for tool T where the adjustment process has not been performed, and for tool T where the deviation amount has been determined but the machining program has not been updated and therefore the deviation amount has not been updated, the corresponding deviation amount column does not store data indicating the deviation amount.

[0029] The measurement date and time is the date and time when the timing adjustment unit 44 performed the adjustment process. In this embodiment, the measurement date and time is the date and time when the tool preparation time and coolant preparation time were measured by the measurement unit 43 during the adjustment process. The coolant preparation time and tool preparation time are times measured by the measurement unit 43 during the adjustment process.

[0030] Figure 4 is a flowchart of the machining preparation process performed by the control system 10. Figure 5 is a diagram illustrating the process performed by the control system 10. Figure 6 is a diagram illustrating the post-update setting operation.

[0031] As shown in Figure 5, when machining a workpiece W, the control system 10 sequentially performs a tool exchange process, a machining preparation process, and a machining process. The tool exchange process is the process of attaching the tool T from the tool magazine 28 to the spindle 14 according to the machining program. After the tool exchange process is completed, the machining preparation process is executed. The machining preparation process includes a tool preparation process, which consists of moving the spindle 14 to move the tool T to the machining start position and rotating the spindle 14 to a target rotational speed, and a coolant preparation process, which increases the coolant supply pressure to a target pressure. After the tool preparation process is completed, machining of the workpiece W is performed using the tool T. In addition, if multiple types of tools T are used for a single workpiece W, when the machining process with one tool T is completed, a tool exchange process is executed for another tool T, followed by a tool preparation process and a machining process. The tool exchange process, tool preparation process, and machining process are repeatedly executed according to the machining program until the machining process of the workpiece W is completed.

[0032] As shown in Figure 4, in the machining preparation process, in step S10, the command unit 42 determines whether the machining program has been updated for the target tool T that has been attached to the spindle 14 by the replacement process. Specifically, the command unit 42 determines whether the amount of displacement is stored in the operation table 48 shown in Figure 3 for the target tool T. If the amount of displacement is not stored for the target tool T, the command unit 42 performs an initial setup operation in step S12.

[0033] In step S12, as shown in Figure 5, the command unit 42 operates the tool operating unit 19 and the pump 35 so that the start timing Ta of the tool operating unit 19 in the tool preparation process and the start timing Ta of pressurization in the coolant preparation process (the timing at which the pump motor M35 starts driving) are the same. In the tool preparation process, the command unit 42 drives the column drive unit M13 and the spindle drive unit M14 shown in Figure 1 to move the tool T attached to the spindle 14 to the machining start position, and also drives the motor M15 to increase the rotational speed of the spindle 14 to reach the target rotational speed. In the coolant preparation process, the command unit 42 drives the pump motor M35 to pressurize the supply pressure of the coolant supplied to the coolant passage 34 to the target pressure.

[0034] Furthermore, in step S12, the measurement unit 43 measures the tool preparation time A and the coolant preparation time a. The measurement unit 43 stores the tool preparation time A, the coolant preparation time a, and the measurement date and time in the operation table 48.

[0035] As described above, when the measurement unit 43 measures the coolant preparation time a and the tool preparation time A for adjustment processing, the control device 40 operates the pump 35 and the tool operating unit 19 so that the timing of the pump 35 starting to pressurize and the timing of the tool operating unit 19 starting to operate are the same.

[0036] As shown in Figure 4, in step S14, following step S12, the timing adjustment unit 44 calculates the difference between the tool preparation time A and the coolant preparation time a. Specifically, the timing adjustment unit 44 calculates the difference Dt (=Aa) by subtracting the coolant preparation time a from the tool preparation time A. Next, in step S16, the timing adjustment unit 44 updates the pressurization start timing of the pump 35 by storing the calculated difference Dt as the deviation amount in the operation table 48. In subsequent operations, when machining the workpiece W using the tool T whose deviation amount is stored in the operation table 48, the pressurization start timing by the pump motor M35 is shifted relative to the operation start timing of the tool operation unit 19 according to the deviation amount during the machining preparation process. In other words, as shown in Figure 6, the timing adjustment unit 44, in the machining preparation process, shifts the pressurization start timing Tb relative to the operation start timing Tc by the difference Dt between the coolant preparation time a and the tool preparation time A, thereby sending commands to each unit so that the time difference between the time the coolant preparation process is completed and the time the tool is in a state where the tool preparation process is completed falls within a first range. More specifically, in the initial setup operation, as shown in Figure 5, if the coolant preparation time a is shorter than the tool preparation time A by the difference Dt, the timing adjustment unit 44, as shown in Figure 6, sends commands to each unit so that the pressurization start timing Tb is not shifted to a timing later than the operation start timing Tc of the tool operation unit 19 by the difference Dt. For example, in the initial setup operation, if the coolant preparation time a is longer than the tool preparation time A by a difference Dt, the timing adjustment unit 44 sends commands to each unit in the updated setup operation described later, so as not to shift the pressurization start timing Tb to a timing that is earlier than the operation start timing Tc of the tool operation unit 19 by a difference Dt.

[0037] Steps S12 to S16 constitute the adjustment process. Note that if step S12 has been executed and the tool preparation process and coolant preparation process are completed, the machining process may be executed even before steps S14 and S16 are executed.

[0038] If the determination is "Yes" in step S10 shown in Figure 4, that is, if the amount of deviation is stored in the operation table 48 in the operation table 48 in the previous routine when step S16 was executed for the target tool T, the command unit 42 executes the updated setting operation, which is a process of the adjustment process, in step S20.

[0039] In step S20, the timing adjustment unit 44 of the command unit 42 starts the operation of the pump motor M35 at the pressurization start timing stored in the operation table 48. In step S20, the timing adjustment unit 44 also executes the updated setting operation by shifting the pressurization start timing of the pump motor M35 relative to the operation start timing of the tool operation unit 19 by the amount of deviation of the target tool W (i.e., difference Dt) stored in the operation table 48, and starting the operation of the pump motor M35.

[0040] In step S22, the timing adjustment unit 44 calculates a time difference, which is the difference between the completion time of the coolant preparation process, i.e., the pressure arrival time when the coolant reaches the target pressure, and the completion time of the tool preparation process, i.e., the tool state time when the operation to the machining start state is completed. Then, in step S22, the timing adjustment unit 44 determines whether the calculated time difference is within a predetermined second range. If the time difference is within the second range, the timing adjustment unit 44 terminates the processing routine shown in Figure 4. On the other hand, if the time difference is not within the second range, the timing adjustment unit 44 executes at least one of the first process and the second process in step S30.

[0041] The first process is to update the amount of deviation by performing an adjustment process again so that the time difference, which is the difference between the time the pressure is reached and the time the tool is in state, falls within the first range. For example, the first process is explained below using the case where the target tool is tool T1. Suppose that when the updated setting operation in step S20 is performed with a deviation amount "+t1" stored in the operation table 48, the time difference is "ty", which falls outside the second range. Specifically, if the time the pressure is reached is later than the time the tool is in state by time ty, the value obtained by subtracting time "ty" from the deviation amount "+t1" is updated in the operation table 48 as the new deviation amount. Also, for example, if the time the pressure is reached is earlier than the time the tool is in state by time ty, the value obtained by adding time "ty" to the deviation amount "+t1" is updated in the operation table 48 as the new deviation amount. In addition, in the first process, the date and time when step S20, which was the source of the new deviation amount calculation, was performed is updated in the operation table as the measurement date and time.

[0042] The second process involves the notification unit 45 notifying the outside of the abnormality of the control system 10. In the second process, the timing adjustment unit 44 causes the notification unit 45 to notify the abnormality.

[0043] In step S30, the timing adjustment unit 44 may selectively execute either the first process or the second process depending on the magnitude of the time difference. For example, the timing adjustment unit 44 may execute the first process if the time difference ty is within a third threshold range that is greater than the absolute values ​​of the upper and lower limits of the second range, and execute the second process if the time difference ty falls outside the third range. In this way, appropriate measures can be taken according to the level of the time difference ty.

[0044] If the pressurization start timing Ta and the operation start timing Ta are set to the same timing without performing any adjustment processing, and the coolant preparation process and tool preparation process are executed, then, as shown in Figure 5 for example, the time when the pressure is reached will be earlier than the time when the tool is in state. In other words, even after the coolant supply pressure reaches the target pressure, the pump motor M35 must be driven to ensure that the coolant supply pressure does not fall below the target pressure until the time when the operation to the machining start state is completed, i.e., until the tool preparation process is completed. This difference Dt period is the period before the workpiece W is machined. Therefore, the power required to drive the pump motor M35 during this difference Dt period becomes wasted power that is not used for machining the workpiece W.

[0045] On the other hand, according to this embodiment, as shown in Figure 6, the pressurization start timing Tb is shifted relative to the operation start timing Tc so that the time difference, which is the difference between the pressure arrival time and the tool state time, falls within a first range. This reduces the driving time of the pump motor M35 or the tool operating unit 19 that are not used for machining the workpiece W during the machining preparation process, thereby reducing wasted power during the machining preparation process period when the workpiece W is not being machined. Thus, the lifespan of the pump motor M35 and the tool operating unit 19 can be extended.

[0046] Generally, the time from when the pump motor M35 is driven until the coolant supply pressure reaches the target pressure is shorter than the time from when the tool preparation process begins until the tool T attached to the spindle 14 reaches the machining start position and the spindle 14 reaches the target rotational speed. Therefore, as shown in Figure 6, by shifting the pressurization start timing Tb to a timing later than the operation start timing Tc by a difference Dt, the driving time of the pump motor M35 that is not used for machining the workpiece W can be reduced.

[0047] Furthermore, according to the above embodiment, as shown in Figure 6, by shifting the pressurization start timing Tb relative to the operation start timing Tc by the difference Dt between the coolant preparation time and the tool preparation time, the time difference can be easily made to fall within the first range.

[0048] Furthermore, according to the above embodiment, the timing adjustment unit 44 performs adjustment processing for each of the multiple types of tools T. This reduces wasted power that is not used for machining the workpiece W for each of the multiple types of tools T. Therefore, power consumption can be reduced when machining the workpiece W using multiple types of tools T.

[0049] Furthermore, according to the above embodiment, as shown in Figure 4, if the adjustment process has not been performed and a "No" determination is made in step S10, an initial setting operation is performed to drive the pump motor M35 and the tool operating unit 19 so that the pressurization start timing Ta and the operation start timing Ta are the same, as shown in Figure 5. This prevents the control of the control system 10 from becoming complicated when the adjustment process is not completed.

[0050] Furthermore, according to the above embodiment, as shown in Figure 3, the memory unit 47 stores the pressurization start timing adjusted by the adjustment process of the timing adjustment unit 44 as a deviation amount in association with the tool T, and also stores the operation start timing before and after the adjustment process. As a result, by storing the pressurization start timing and operation start timing adjusted by the adjustment process in the memory unit 47, when using the adjusted tool T the next time, the pressurization start timing can be easily shifted relative to the operation start timing of the tool operation unit 19 so that the time difference falls within the first range. Also, in the updated setting operation of step S20 shown in Figure 4, the timing adjustment unit 44 operates the pump motor M35 and the tool operation unit 19 with the pressurization start timing and operation start timing stored in the memory unit 47, which have been shifted by the adjustment process. As a result, the driving time of the pump motor M35 or the tool operation unit 19 in the machining preparation process that is not used for the actual machining of the workpiece W can be reduced for the adjusted tool T.

[0051] Furthermore, according to the above embodiment, when step S30 shown in Figure 4 is executed, the first process can readjust the time difference ty so that it falls within the first range again, and the second process can notify the user of an abnormality in the control system 10.

[0052] B. Other embodiments: B1. Other Embodiments 1: In the above embodiment, as shown in Figure 5, the adjustment process was described using the case where the coolant preparation time is shorter than the tool preparation time. However, in other embodiments, the adjustment process may also be performed when the coolant preparation time is longer than the tool preparation time. In this case, the pressurization start timing before and after the adjustment process is set based on the completion time of the replacement process and stored in the storage unit 47, and the start timing of the operation of the tool operating unit 19 after the adjustment process is expressed as the amount of deviation from the pressurization start timing and stored in the storage unit 47.

[0053] B2. Another Embodiment 2: In the above embodiment, the machine tool 11 was a machining center, but it may be any other machine tool that uses a tool T to work on a workpiece W.

[0054] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features of the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of Symbols]

[0055] 10...Control system, 11...Machine tool, 12...Machine tool body, 13...Column, 14...Spindle, 16...X-axis guide rail, 17...Bed, 18...Y-axis guide rail, 19...Tool operating unit, 21...Workpiece table, 22...Rotary table, 23...Z-axis guide rail, 28...Tool magazine, 29...Tool mounting position, 30...Coolant supply system, 31...Flow path, 32...Pressure sensor, 33...Tank, 34...Coolant flow path, 35...Pump, 40...Control device, 41...Processor, 42...Command unit, 43...Measurement unit, 44...Timing adjustment unit, 45...Notification unit, 47...Memory unit, 48...Operation table, 49...Communication interface, Dt...Difference, M13...Column drive unit, M14...Spindle drive unit, M15...Motor, M35...Pump motor, Rt...Center axis, T...Tool

Claims

1. A control system for a machine tool that supplies coolant to the machining point using a center-through coolant system, A coolant supply unit that pressurizes and supplies the aforementioned coolant, A tool operating unit that moves the tool attached to the spindle of the machine tool to a state where it is ready to process a workpiece, A control device is provided, The control device is A control system having a timing adjustment unit that performs an adjustment process to shift the pressurization start timing of the coolant supply unit relative to the operation start timing of the tool operation unit, such that the time difference, which is the difference between the time at which the coolant reaches a target pressure and the time at which the operation to the machining start state is completed, falls within a predetermined first range.

2. A control system according to claim 1, The control device further, The system includes a measuring unit that measures the coolant preparation time from the time the coolant supply unit is activated until the coolant pressure reaches the target pressure, and the tool preparation time from the time the tool operating unit is activated until the operation to the machining start state is completed. The timing adjustment unit, in the adjustment process, A control system that adjusts the timing of pressurization of the coolant supply unit relative to the start of operation of the tool operating unit by the difference between the coolant preparation time and the tool preparation time, so that the time difference falls within a first range.

3. A control system according to claim 2, The timing adjustment unit, in the adjustment process, A control system that, if the coolant preparation time is shorter than the tool preparation time by the difference, shifts the pressurization start timing to a later timing than the tool operating unit start timing by the difference.

4. A control system according to claim 3, The measuring unit measures the coolant preparation time and the tool preparation time for each of the multiple types of tools that can be attached to the spindle. The timing adjustment unit is a control system that performs the adjustment process for each of the multiple types of tools.

5. A control system according to claim 2, The control device is a control system that, when the measuring unit measures the coolant preparation time and the tool preparation time for the adjustment process, operates the coolant supply unit and the tool operating unit so that the pressurization start timing of the coolant supply unit and the operation start timing of the tool operating unit are the same.

6. A control system according to any one of claims 1 to 5, further comprising: A control system having a storage unit that stores the pressurization start timing adjusted by the adjustment process of the timing adjustment unit in association with the tool.

7. A control system according to claim 6, The timing adjustment unit is a control system that, in the adjustment process, starts the operation of the coolant supply unit at the pressurization start timing stored in the memory unit.

8. A control system according to claim 6, The aforementioned timing adjustment unit is In the adjustment process described above, when the pressurization start timing is shifted relative to the operation start timing and the coolant supply unit and the tool operating unit are operated accordingly, If the aforementioned time difference is not within the predetermined second range, at least one of the first process and the second process is executed. The first process is a process that executes the adjustment process again so that the time difference falls within the first range, The second process is a control system that notifies an external party of an abnormality in the control system.

9. A control system according to claim 1, The machining start state includes a predetermined machining start position of the tool attached to the spindle and a predetermined target rotational speed of the spindle. The control system is configured such that setting to the machining start state is completed when the spindle is moved from the position where the tool is attached to the spindle until the tool reaches the machining start position, and the spindle is rotated until the spindle reaches the target rotation speed.

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