Machining fluid supply system

Abstract

To provide a machining fluid supply system capable of reducing a work burden for setting a threshold for determining a flow rate of a machining fluid.SOLUTION: A machining fluid supply system according to the present disclosure includes a machining fluid supply device configured to supply a machining fluid, a discharge port configured to discharge the machining fluid, a pipe connecting the machining fluid supply device and the discharge port and configured to supply the machining fluid from the machining fluid supply device to the discharge port, a flow rate sensor configured to output a detection value corresponding to a flow rate of the machining fluid flowing through the pipe, and a controller configured to acquire the detection value output from the flow rate sensor and set a threshold value based on the detection value.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a machining fluid supply system for supplying machining fluid in a machine tool. [Background technology]

[0002] Conventionally, various types of machining fluids have been used in machine tools for the purposes of lubrication, cooling, cleaning, etc. For example, the machining fluid supply system disclosed in Patent Document 1 below is equipped with a cyclone filter, and the machining fluid stored in a tank is filtered by the cyclone filter and then discharged from multiple outlets. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-75317 Summary of the Invention [Problem to be solved by the invention]

[0004] In a machining fluid supply system, a flow rate sensor detects the flow rate of the machining fluid being supplied, and in order to judge the detected value output by the flow rate sensor using a threshold, it is necessary to set an appropriate threshold. Conventionally, in setting such a threshold, an operator would check the record of the detected value of the flow rate sensor and set the threshold based on the contents of the record. This has led to the problem of an increased workload for setting the threshold.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a machining fluid supply system that can reduce the workload of setting a threshold value for determining the flow rate of machining fluid. [Means for solving the problem]

[0006] In order to solve the above problems, this specification discloses a machining fluid supply system for supplying machining fluid in a machine tool, comprising: a machining fluid supply device for supplying the machining fluid; a discharge port for discharging the machining fluid; a pipe connecting the machining fluid supply device and the discharge port and for supplying the machining fluid from the machining fluid supply device to the discharge port; a flow sensor for outputting a detection value according to the flow rate of the machining fluid flowing through the pipe; and a control device for acquiring the detection value output by the flow sensor and setting a threshold value based on the detection value. [Effects of the Invention]

[0007] According to the machining fluid supply system of the present disclosure, the control device acquires the detection value output by the flow sensor and sets the threshold value from the acquired detection value. This allows the control device to set the threshold value based on the detection value actually output by the flow sensor, thereby reducing the workload of the user in setting the threshold value. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a block diagram of the machine tool according to the present embodiment. [Figure 2] FIG. 1 is a diagram illustrating a coolant supply system provided in a machine tool. [Figure 3] FIG. 10 is a diagram showing a setting screen for setting a threshold value, the setting screen being a setting screen when an average value mode is set. [Figure 4] FIG. 10 is a diagram showing a setting screen when the minimum value mode is set. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the machining fluid supply system of the present disclosure will be described below with reference to the drawings. As shown in Figures 1 and 2, a machine tool 10 of this embodiment includes a machining device 11, a workpiece holding device 12, a loader 13, a chip conveyor 15, an operation panel 16, a control device 17, a coolant pump 19, a plurality of control valves 21, a flow rate sensor 25, etc.

[0010] The processing device 11 is, for example, a lathe-type processing device, and is a turret equipped with a tool post to which tools (such as a cutting tool or a rotary tool) can be attached. The workpiece holding device 12 is, for example, equipped with a gripping device (such as a chuck jaw) that grips the workpiece and rotates the workpiece around a spindle while gripping the workpiece. The processing device 11 performs processing on the workpiece held by the workpiece holding device 12 using the tool. The machine tool 10 of the present disclosure is not limited to a lathe. For example, the machine tool 10 of the present disclosure may be a milling machine that rotates tools such as drills and end mills, or a machining center equipped with an ATC (automatic tool changer). In this case, the workpiece holding device 12 may be a chuck device that fixes the position of the workpiece relative to the rotary tool of the processing device 11. The number of processing devices 11 included in the machine tool 10 is not limited to one, and may be multiple. Therefore, the machine tool 10 may be equipped with one or more machining chambers. A discharge port 55, which will be described later, may be provided for each of the plurality of processing devices 11 or processing chambers. Also, the machine tool 10 may be a multi-tasking machine equipped with a lathe and a machining center.

[0011] The loader 13 is, for example, a gantry-type workpiece transport device, and includes a head for chucking the workpiece and a slide mechanism for sliding the head in the X-axis and Y-axis directions. The loader 13 transfers the workpiece between the workpiece holding device 12 and other devices. The device for transporting the workpiece is not limited to a loader, and may be another device such as an articulated robot. The chip conveyor 15 is a device for discharging machining debris such as chips outside the machine. The coolant tank 52 shown in FIG. 2, which will be described later, stores machining debris cleaned with coolant 63. The chip conveyor 15 includes a belt conveyor or the like, and separates the machining debris from the coolant 63 stored in the coolant tank 52 and discharges it outside the machine. The device for separating the coolant 63 from the machining debris is not limited to the chip conveyor 15, and may be, for example, a cyclone filter, a filter, or a combination thereof.

[0012] The operation panel 16 is a user interface for the machine tool 10 and includes a touch panel 16A, operation switches 16B, and the like. The operation switches 16B are, for example, push button switches, slide switches, or rotary switches. The operation panel 16 displays information related to the machine tool 10 on the touch panel 16A under the control of the control device 17. The operation panel 16 also accepts operation inputs from the user on the screen displayed on the touch panel 16A, and outputs a signal corresponding to the accepted operation input to the control device 17. The configuration of the user interface described above is one example. For example, the user interface may be configured to include only the touch panel 16A, or may not include the touch panel 16A and may include the operation switches 16B and a monitor.

[0013] As shown in FIG. 1 , the control device 17 includes a numerical control device 31 and a PLC 32. The numerical control device 31 includes a CPU 34 and a storage device 35. The storage device 35 includes, for example, RAM, ROM, flash memory, and HDD. The storage device 35 can store an NC program 36, a control program 38, a detection value 39, a threshold value 40, and a margin 41. The configuration of the storage device 35 that stores the NC program 36 and other data is not limited to the above configuration. It may include an SSD instead of an HDD, or an external storage medium such as a USB memory. The storage device 35 may also be a storage medium such as a DVD-RAM, or a combination of these. The storage device 35 that stores the NC program 36 and other data may also be a server, network storage, or the like.

[0014] The machine tool 10 also includes a control device 17 and a plurality of drive circuits 20 that connect the above-mentioned devices (machining device 11, workpiece holding device 12, loader 13, chip conveyor 15, operation panel 16, coolant pump 19, control valve 21, and flow sensor 25). The numerical control device 31 controls the devices via the drive circuits 20 by executing an NC program 36 and a control program 38 stored in a storage device 35 using a CPU 34. The drive circuits 20 are, for example, a driver circuit (servo amplifier) ​​or an amplifier circuit that amplifies signals. The PLC 32 is a programmable logic controller. For example, the PLC 32 executes a ladder program 33 stored therein and performs sequence processing of various signals using the ladder circuit. These various signals are, for example, signals output by the flow sensor 25. The PLC 32 is connected to the numerical control device 31 via a communication bus 43 and performs signal input / output between the PLC 32 and the numerical control device 31.

[0015] The control program 38 is a program that executes, for example, a process for changing the display content of the touch panel 16A, an input process based on the screen displayed on the touch panel 16A, a process for setting various data, etc. The control program 38 also includes a program that executes a process related to the flow sensor 25, which will be described later. As will be described in detail later, the PLC 32 executes the ladder program 33 to acquire a detection value 39 output by the flow sensor 25 and store it in the storage device 35. The numerical controller 31 executes the control program 38 with the CPU 34 to execute a process for displaying the detection value 39 stored in the storage device 35 on the touch panel 16A, a process for receiving a margin 41 and a threshold value 40 via the touch panel 16A, and a process for setting the threshold value 40 based on the detection value 39. The numerical controller 31 executes the control program 38 with the CPU 34 to execute a process for determining the detection value 39 output by the flow sensor 25 based on the threshold value 40 during machining of a workpiece, etc.

[0016] In this disclosure, "acquire" is used as a concept that does not necessarily require a request. In other words, the concept of "controller 17 acquires detected value 39" also includes the case where flow sensor 25 outputs detected value 39 to controller 17 without controller 17 making a request. Therefore, "acquire" is a concept that includes both a case where controller 17 actively requests flow sensor 25 for detected value 39 and a case where flow sensor 25 actively outputs detected value 39 without being requested.

[0017] Furthermore, machine tool 10 of this embodiment has, for example, two modes for setting threshold value 40: an average value mode and a minimum value mode. The average value mode is a mode in which threshold value 40 is set based on the average value of multiple detection values ​​39 acquired from flow sensor 25. The minimum value mode is a mode in which threshold value 40 is set based on the minimum value of multiple detection values ​​39 acquired from flow sensor 25. Control device 17 receives an instruction to switch between the two modes by executing control program 38 in CPU 34. For example, control device 17 receives an instruction to switch between the two modes based on an operation input to touch panel 16A. Details of each mode will be described later.

[0018] In the following description, the numerical control device 31 of the control device 17 may be described simply by the device name to control each device by executing programs such as the NC program 36 and the control program 38. For example, the description "the control device 17 controls the loader 13 to transfer the workpiece" means "the control device 17 executes the NC program 36 in the CPU 34, controls the loader 13 based on the NC program 36, and transfers the workpiece."

[0019] The control device 17 controls each device using the above-mentioned configuration to perform machining on the workpiece. For example, the control device 17 controls the loader 13 to transfer the workpiece received by the loader 13 from a device in a previous process to the workpiece holding device 12. The workpiece holding device 12 also rotates the gripped workpiece under the control of the control device 17. The control device 17 also controls the machining device 11 to rotate the tool post, identify the desired tool, and machine the workpiece with the identified tool. When machining is completed, the control device 17 transfers the workpiece from the workpiece holding device 12 to the loader 13 and transports the machined workpiece to a device in a subsequent process. The configuration of the machine tool 10 shown in FIGS. 1 and 2 is one example. For example, the machine tool 10 may be equipped with an inverting device that inverts the workpiece, an inspection device that inspects the machined workpiece, and the like. These devices may also dispense the coolant 63, which will be described later.

[0020] (Coolant Supply System 10A) FIG. 2 shows the configuration of a coolant supply system 10A provided in the machine tool 10. The coolant supply system 10A is a system that lubricates, cleans, and cools workpieces and tools, and cleans the chucks of the loader 13 and the workpiece holding device 12. As shown in FIG. 2, the coolant supply system 10A includes, in addition to the control device 17, coolant pump 19, multiple control valves 21, and flow sensor 25, piping 51, a coolant tank 52, a terminal 53, multiple outlets 55, a discharge port 57, a valve 59, and multiple valves 61. The coolant tank 52 stores coolant 63 used in the machine tool 10. The coolant 63 is discharged from the multiple outlets 55 and is used for lubrication, cleaning, cooling, and the like. The outlets 55 are, for example, nozzles that discharge the coolant 63.

[0021] The coolant 63 is an example of a machining fluid according to the present disclosure. The machining fluid according to the present disclosure is not limited to a liquid with a cooling function such as a coolant, but may be a liquid primarily intended for lubrication such as cutting oil. Alternatively, the machining fluid may be a cleaning fluid specialized for cleaning. The machining fluid may also be a liquid with multiple functions, including cooling, cleaning, and lubrication. The machining fluid may also be a liquid obtained by mixing a gas (such as a micro-nano valve) with any of the above-mentioned liquids.

[0022] The coolant tank 52 stores the coolant 63, which has been discharged from the discharge port 55 into the machining chamber and used to wash away chips adhering to the workpiece. The chip conveyor 15 (see FIG. 1) separates the chips contained in the coolant 63 from the coolant tank 52 and discharges them outside the machine. The coolant pump 19 supplies the coolant 63 stored in the coolant tank 52 toward the piping 51. The coolant pump 19 is, for example, a so-called stack pump, and when activated, supplies the coolant 63 toward the piping 51 at a predetermined (constant) flow rate that is set in advance. The coolant pump 19 may be configured to control the flow rate at which the coolant 63 is discharged based on control by the control device 17. The coolant supply system 10A may also include a cyclone filter or a filter upstream or downstream of the coolant pump 19.

[0023] The piping 51 connects the coolant pump 19 to the discharge port 55 and the like, and has a main piping 65, multiple branch piping 66, and a discharge pipe 67. The main piping 65 connects the coolant pump 19 to the terminal 53, and transports the coolant 63 supplied from the coolant pump 19 to the terminal 53. The main piping 65 supplies the coolant 63 to the multiple control valves 21 and the multiple discharge ports 55 via the terminal 53.

[0024] The flow rate sensor 25 is connected between the coolant pump 19 and the terminal 53 in the main pipe 65, and outputs a detection value 39 indicating the flow rate of the coolant 63 flowing from the coolant pump 19 to the main pipe 65 to the control device 17. The control device 17 can detect the flow rate of the coolant based on the detection value 39 obtained from the flow rate sensor 25. The communication method for obtaining the detection value 39 from the flow rate sensor 25 to the control device 17 is not particularly limited, but for example, communication using a communication interface such as IO-Link standardized in IEC 61131-9 can be adopted.

[0025] Furthermore, the valve 59 is connected midway through a discharge pipe 67 that branches off from the main pipe 65. The discharge port 57 is provided at the tip of the discharge pipe 67 and is provided downstream of the valve 59. The valve 59 is, for example, a manual valve, and the flow rate of the coolant 63 that flows from the main pipe 65 through the discharge pipe 67 to the discharge port 57 can be changed by turning a handle (changing the opening degree). The discharge port 57 discharges the coolant 63 that flows from the discharge pipe 67 into the coolant tank 52. For example, the discharge port 57 is provided below the machining chamber and discharges the coolant 63 toward machining chips that have fallen in the machining chamber, washing the machining chips away into the coolant tank 52. For example, an operator closes the valve 59 only when performing maintenance, and keeps the valve 59 open during machining operations, etc.

[0026] As a result, during machining, a portion of the coolant 63 that flows from the coolant pump 19 to the main pipe 65 is discharged from the discharge port 57 via the discharge pipe 67 and returns to the coolant tank 52 while washing away machining debris. In other words, once the coolant pump 19 is started, a portion of the coolant 63 supplied from the coolant pump 19 is constantly discharged from the discharge port 57. For this reason, even if all of the control valves 21 connected to the discharge port 55 (described later) are closed, the coolant 63 can be discharged from the discharge port 57, allowing the coolant pump 19 to continue operating without excessively increasing the load on the coolant pump 19. As a result, there is no need to stop the coolant pump 19 in conjunction with stopping the discharge of the coolant 63 from the discharge port 55, reducing the number of times the coolant pump 19 is stopped and the occurrence of malfunctions.

[0027] The terminal 53 is, for example, a metal distributor, and has a connection port for connecting the main pipe 65, connection ports for connecting the multiple control valves 21, and pipes connecting the connection ports to each other. The terminal 53 is connected to the main pipe 65 downstream of the flow sensor 25. The terminal 53 supplies the coolant 63 supplied from the main pipe 65 to each of the multiple control valves 21. The coolant supply system 10A of this embodiment includes, for example, three combinations of a control valve 21, a valve 61, a branch pipe 66, and an outlet 55. One outlet 55 is connected to one control valve 21 via one branch pipe 66. The coolant 63 discharged from each of the three outlets 55 is collected in the coolant tank 52 together with, for example, machining waste (see the dashed-dotted squares and solid-line arrows in FIG. 2 ).

[0028] Each of the three control valves 21 is connected to the control device 17 and switches the flow rate of the coolant 63 supplied to the branch pipe 66 under the control of the control device 17. For example, the control valve 21 switches between an open state and a stopped state under the control of the control device 17. The open state is a state in which the coolant 63 is discharged from the outlet 55 via the branch pipe 66. The stopped state is a state in which the discharge of the coolant 63 from the outlet 55 is stopped. For example, the control device 17 switches the control valve 21 between an open state and a stopped state for each tool used in machining, thereby switching the outlet 55 from which the coolant 63 is discharged. Note that the control valve 21 is not limited to a configuration that switches between two states, the open state and the stopped state, and may be a configuration that increases or decreases the discharge rate of the coolant 63 discharged from the outlet 55 (changes the opening degree) under the control of the control device 17. That is, the control valve 21 may change the discharge rate of the coolant 63. Furthermore, the control method of the control valve 21 is not particularly limited. For example, the control valve 21 may be an electrically switched control valve using a coil or an electromagnetic motor, an air-type control valve using air, or a hydraulic control valve using oil.

[0029] Each of the three branch pipes 66 is connected to the terminal 53 via a valve 61 and a control valve 21. The valve 61 is connected, for example, downstream of the control valve 21. The valve 61 is, for example, a manual valve, and by turning a handle, the flow rate of the coolant 63 flowing from the control valve 21 to the branch pipe 66, i.e., the discharge amount of the coolant 63 discharged from the discharge port 55, is changed. The three sets of control valves 21, valves 61, branch pipes 66, and discharge ports 55 have the same configuration. For this reason, in the following description, only one set of the control valve 21, valve 61, branch pipe 66, and discharge port 55 will be described, and descriptions of the other sets of the control valve 21, valve 61, branch pipe 66, and discharge port 55 will be omitted.

[0030] The multiple discharge ports 55 can be installed at various locations on the machine tool 10. The locations of the discharge ports 55, i.e., the locations within the machine tool 10 where the coolant 63 is used to clean the workpiece, are not particularly limited. For example, the discharge ports 55 are nozzles that discharge the coolant 63 from the outside of the workpiece chucked in the workpiece holding device 12 toward the cutting edge of the tool in the machining chamber during machining by the machining device 11, thereby lubricating and cooling the workpiece. The discharge ports 55 may also be nozzles that discharge the coolant 63 from within the spindle of a backing or the like of the workpiece holding device 12 toward the cutting edge of the tool, thereby lubricating and cooling the workpiece during boring or other machining. Alternatively, the discharge ports 55 may be nozzles that discharge the coolant 63 toward the workpiece holding device 12 after the workpiece has been removed, thereby cleaning the workpiece. The locations of the discharge ports 55 and the uses of the coolant 63 are not limited to those described above. For example, machine tool 10 may use coolant 63 to clean a workpiece when the workpiece is carried in, before machining, after machining, and before removal. The following explanation will mainly focus on a case where a nozzle that discharges coolant 63 toward the cutting edge of a tool is used as outlet 55. Also, a case where a threshold value 40 is set for each tool regarding the amount of coolant 63 discharged will be explained.

[0031] The configuration of the coolant supply system 10A shown in FIG. 2 is merely an example. For example, the coolant supply system 10A may include combinations of different configurations of the control valve 21, the valve 61, the branch pipe 66, and the discharge port 55. For example, the coolant supply system 10A may include a combination that includes the valve 61 and a combination that does not. Furthermore, the inner diameter of the discharge port 55 or the branch pipe 66 in any combination may be different from the inner diameter of the discharge port 55 or the branch pipe 66 in another combination. Therefore, the size of the flow path for the machining fluid may differ for each combination. Furthermore, the coolant supply system 10A may be configured such that multiple branch pipes 66 and discharge ports 55 are connected to one valve 61.

[0032] The coolant supply system 10A may also be configured to include only one combination of the control valve 21, the valve 61, the branch pipe 66, and the discharge port 55. The coolant supply system 10A may also include a flow rate sensor 25 for each of the three branch pipes 66. In this case, the control device 17 may obtain a detection value 39 from each of the multiple flow rate sensors 25 and set a threshold value 40 for each flow rate sensor 25.

[0033] (Control using detected value 39) Next, the details of control using the detected value 39 will be described. For example, after receiving an instruction to start machining from the operation panel 16, the control device 17 causes coolant 63 to be discharged from the discharge port 55 at a predetermined timing. While the machine tool 10 is machining a workpiece, the control device 17 uses the threshold value 40 to determine the detected value 39 and judges whether the discharge rate (flow rate) of the coolant 63 discharged from the discharge port 55 is appropriate. As described above, the control device 17 switches the opening and closing of the control valve 21 for each tool used in machining, and switches the discharge port 55 that discharges the coolant 63. For this reason, the discharge rate of the coolant 63 varies for each tool. The control device 17 determines the detected value 39 using a threshold value 40 that differs for each tool.

[0034] The control device 17 uses, for example, the threshold value 40 as a value for determining the lower limit of the coolant 63 discharge rate. The control device 17 switches the threshold value 40 for each tool during machining, and when the detection value 39 becomes equal to or less than the threshold value 40, the control device 17 stops the operation of the machining device 11 and the workpiece holding device 12, thereby halting machining of the workpiece. The control device 17 also, for example, issues an alarm sound and displays a message on the touch panel 16A indicating that the discharge rate has decreased. This allows the control device 17 to monitor the discharge rate of the coolant 63 based on the threshold value 40 during machining. If the discharge rate of the coolant 63 decreases and an appropriate amount of coolant 63 cannot be discharged from the discharge port 55, machining can be stopped. If the flow rate of the coolant 63 decreases due to clogging of the branch pipe 66, for example, continuation of machining can be prevented. This can prevent defects such as chipped tool edges from occurring.

[0035] The control using the threshold value 40 described above is merely an example. For example, the control device 17 may use the threshold value 40 as a value for determining the upper limit of the coolant 63 discharge rate. The control device 17 may stop the operation of the machining device 11 and the workpiece holding device 12 and stop machining of the workpiece when the detection value 39 becomes equal to or greater than the threshold value 40 during machining. This allows machining to be stopped if the coolant pump 19 breaks down due to some malfunction and the discharge rate increases. The control device 17 may also stop the coolant pump 19 when the detection value 39 becomes equal to or greater than the threshold value 40. The control device 17 may also perform both control using the upper limit value and control using the lower limit value described above. In this case, the control device 17 may accept the setting of multiple threshold values ​​40. The use of the threshold value 40 is not limited to determining whether to stop machining. For example, the control device 17 may start machining of the workpiece when the detection value 39 becomes equal to or greater than the threshold value 40. Furthermore, the control device 17 may determine the detection value 39 using the same threshold value 40 for each tool, without changing the threshold value 40 for each tool. In this case, the control device 17 may accept the same threshold value 40 for all tools on a setting screen 71, which will be described later.

[0036] The control device 17 receives the value of the threshold 40 via, for example, the touch panel 16A. FIG. 3 shows a setting screen 71 for setting the threshold 40, and shows the setting screen 71 when an average value mode, which will be described later, is set. The control device 17 displays the setting screen 71 on the touch panel 16A in response to a predetermined operation input to the operation panel 16. As shown in FIG. 3, the control device 17 displays a threshold setting section 72 and a tool selection section 73 on the setting screen 71. The control device 17 also displays a threshold input section 75, a history display section 76, a margin acceptance section 77, an automatic setting button 78, and a decision button 79 on the threshold setting section 72.

[0037] Threshold input section 75 is a field that displays threshold 40 set by control device 17 and accepts input of threshold 40 from an operator. For example, when machine tool 10 is shipped from a manufacturing factory, detection value 39 is not stored, and zero values ​​are set as threshold 40 and margin 41 (described later). For this reason, when control device 17 accepts an operation to display setting screen 71 at the time of shipment, it displays zero values ​​in threshold input section 75, detection value display section 84 of history display section 76 (described later), and margin acceptance section 77. Note that FIG. 3 shows setting screen 71 after threshold 40 has been set based on detection value 39. For this reason, numbers are displayed in history display section 76 and the like.

[0038] For example, after machine tool 10 is installed and before machining begins, the operator operates touch panel 16A to set an initial value for threshold 40. The operator touches threshold input unit 75, inputs a desired numerical value (threshold 40), and operates decision button 79. At this stage, detection value 39 has not been stored, so margin 41, which will be described later, is not used. When decision button 79 is operated, control device 17 stores the numerical value input to threshold input unit 75 as threshold 40 in storage device 35. The value input to margin receiving unit 77 (initial value is zero) is stored in storage device 35 as margin 41. When close button 81 displayed in the upper right corner of setting screen 71 is operated, control device 17 closes the display of setting screen 71.

[0039] The operator also sets a threshold value 40 for each tool. The control device 17 displays a tool selection button 85 for selecting a tool in the tool selection unit 73. The machine tool 10 of this embodiment is capable of registering, for example, 24 tools. 24 pieces of identification information, T01 to T24, are set for each tool. The control device 17 displays the tool selection buttons 85 (T01 to T24) displaying the 24 pieces of identification information in the tool selection unit 73. The control device 17 accepts the selection of one of the 24 tool selection buttons 85. The control device 17 displays the selected tool selection button 85 in a more emphasized manner than the other tool selection buttons 85. FIG. 3 shows a state in which the first tool, "T01," has been selected. When the enter button 79 is operated, the control device 17 associates the threshold value 40 input to the threshold input unit 75 and the margin 41 input to the margin receiving unit 77 with the identification information of the tool selected with the tool selection button 85 and stores them in the storage device 35. The operator can set the threshold value 40 for each tool by changing the selection of the tool selection button 85 .

[0040] After setting the threshold value 40, the operator operates the valves 59 and 61 to adjust the amount of coolant 63 discharged from the discharge port 55. After the threshold value 40 is set, the control device 17, upon receiving a command to start machining, switches the threshold value 40 for each tool during machining of the workpiece. The control device 17 determines the detected value 39 based on the set threshold value 40, i.e., the threshold value 40 stored in the memory device 35. If the detected value 39 falls below the threshold value 40, the control device 17 stops the machining operation. The units of each value shown in FIG. 3 are, for example, "L / min." In the example shown in FIG. 3, a value of 393.00 L / min is set as the threshold value 40 for the tool with identification information "T01." In this case, the control device 17 stops the machining operation if the detected value 39 of the flow sensor 25 falls below 393.00 L / min during machining using the tool with identification information "T01." This occurs when the detected value 39 of the flow sensor 25 falls below 393.00 L / min, i.e., when the flow rate of the coolant 63 flowing through the main pipe 65 falls below 393.00 L / min.

[0041] Furthermore, the control device 17 executes the ladder program 33 using the PLC 32, for example, to acquire the detection values ​​39 output by the flow rate sensor 25 during machining and store the acquired detection values ​​39 in the storage device 35. By executing the ladder program 33, the PLC 32 acquires the detection values ​​39 multiple times during a predetermined collection period during machining. This collection period is, for example, a period from when the discharge of the coolant 63 begins until the discharge rate stabilizes at a certain level. In other words, the collection period is a period during which a desired amount of coolant 63 is expected to be discharged during machining. The timing to start and stop acquiring the detection values ​​39 can be set in the ladder program 33. Alternatively, the control device 17 may execute the NC program 36, and the NC program 36 may instruct the ladder program 33 to start and stop acquiring the detection values ​​39.

[0042] Furthermore, the control device 17 acquires the detection values ​​39 at regular time intervals during the collection period, for example, and stores the acquired detection values ​​39 in the storage device 35. The control device 17 also stores the detection values ​​39 for each tool used in machining. The control device 17 stores the acquired detection values ​​39 in association with information about the time at which the values ​​were acquired and identification information of the tool used at the time of acquisition. The control device 17 stores, for example, 30 detection values ​​39 for each tool in the storage device 35. In other words, the storage device 35 stores the most recent 30 detection values ​​39 for each tool.

[0043] The control device 17 does not have to acquire the detection value 39 at regular intervals during the collection period. For example, the control device 17 may acquire the detection value 39 at random times during the collection period. The control device 17 also does not have to automatically acquire the detection value 39 each time machining is performed. For example, the control device 17 may acquire the detection value 39 or update the detection value 39 stored in the storage device 35 when instructed by an operator. Furthermore, when the detection value 39 described above becomes equal to or less than the threshold value 40, the control device 17 may not store the detection value 39 that becomes equal to or less than the threshold value 40 in the storage device 35. Alternatively, the control device 17 may reset (delete) the detection value 39 stored in the storage device 35 when the detection value 39 becomes equal to or less than the threshold value 40.

[0044] For example, when the control device 17 stores the detected values ​​39 in the storage device 35 and receives an operation to display the setting screen 71 after processing is completed, the control device 17 displays the detected values ​​39 on the history display unit 76, as shown in FIG. 3. More specifically, the control device 17 displays a number display unit 83 that displays the history number of the detected values ​​39 and a detected value display unit 84 that displays a list of the detected values ​​39 on the history display unit 76. The control device 17 displays serial numbers from 1 to 30 as history numbers on the number display unit 83. The control device 17 displays each of the 30 detected values ​​39 on the detected value display unit 84 in reverse chronological order of the date and time indicated by the associated time information. Therefore, in FIG. 3, the most recent detected value 39 is displayed as the history number "1." Note that FIG. 3 only shows some of the numbers of the detected values ​​39. Furthermore, the number of detected values ​​39 stored is not limited to 30, and may be one or any other multiple number.

[0045] As described above, the control device 17 acquires and stores the detection values ​​39 for each tool. The storage device 35 stores the most recent 30 detection values ​​39 for each tool. The control device 17 reads out from the storage device 35 the detection values ​​39 associated with the identification information (T01 in FIG. 3 ) of the tool selected by the tool selection unit 73, and displays them on the history display unit 76. Therefore, by selecting a desired tool with the tool selection button 85 of the tool selection unit 73, the operator can check the detection values ​​39 and set the threshold value 40 for the selected tool on the history display unit 76. A different threshold value 40 can be set for each tool.

[0046] Therefore, the control device 17 of this embodiment accepts changes to the threshold value 40 (such as setting an initial value) on the setting screen 71, and determines the detection value 39 output by the flow sensor 25 based on the threshold value 40 that reflects the accepted change. The control device 17 then acquires the detection value 39 during machining while determining the detection value 39 using the threshold value 40, and stores the acquired detection value 39 in the storage device 35. As will be described later, when the automatic setting button 78 is operated, the control device 17 sets a new threshold value 40 based on the acquired multiple detection values ​​39. This allows the operator to set the initial value of the threshold value 40 or change a threshold value 40 that has already been set by operating the threshold value input unit 75 or the decision button 79. The operator can also operate the machine tool 10 with the set threshold value 40 to determine the detection value 39. The control device 17 can then set a new threshold value 40 based on the detection value 39 during the operation.

[0047] (When average mode is set) As described above, machine tool 10 has two modes for setting threshold value 40: average value mode and minimum value mode. First, the case where average value mode is set will be described. Fig. 3 shows setting screen 71 when average value mode is set. For example, when average value mode is set, control device 17 displays the words "average value mode" in the upper left of threshold value setting section 72, and displays average value display section 87 to the right of threshold value setting section 72.

[0048] When the average value mode is set, the control device 17 calculates the average value of the multiple detection values ​​39 and sets the threshold value 40 based on the calculated average value. The control device 17 calculates the average value for the selected tool when displaying the setting screen 71 or when the tool selected in the tool selection unit 73 is changed. The control device 17 reads 30 detection values ​​39 associated with the identification information of the tool selected in the tool selection unit 73 from the storage device 35, calculates the average value of the read 30 detection values ​​39, and displays the calculated average value on the average value display unit 87. For example, when "T01" is selected as the initial state when displaying the setting screen 71, the control device 17 calculates the average value for the tool "T01" and displays it on the average value display unit 87. Furthermore, after displaying the setting screen 71, if a tool other than the tool currently selected in the tool selection unit 73 is selected with the tool selection button 85, the control device 17 calculates the average value for the changed tool and displays it on the average value display unit 87.

[0049] The control device 17 does not have to calculate the average value of all the detected values ​​39 (30 detected values ​​39 in this embodiment). For example, the control device 17 may calculate the average value of the detected values ​​39 selected by the operator from the 30 detected values ​​39 displayed on the history display unit 76, and display the average value on the average value display unit 87.

[0050] Margin acceptance unit 77 is also an input unit for setting margin 41 that is allowed for the average value calculated by control device 17, or for the minimum value in the minimum value mode described below. For example, the operator considers up to what lower limit value machining can be continued without detecting an error, based on past detection values ​​39 displayed on history display unit 76, the operating status of machine tool 10, the planned machining content, etc. The operator inputs the value of margin 41 that corresponds to the lower limit value obtained as a result of the consideration into margin acceptance unit 77 and operates automatic setting button 78.

[0051] When the automatic setting button 78 is operated, the control device 17 subtracts the value of the margin 41 input to the margin receiving unit 77 from the average value displayed in the average value display unit 87, and displays the result as the threshold value 40 in the threshold value input unit 75. This allows the user to set the lower limit value that has the desired margin 41 from the past average value as the threshold value 40 simply by inputting the margin 41 and operating the automatic setting button 78.

[0052] The operator checks the threshold value 40 displayed in the threshold value input unit 75, and if there is no problem, operates the decision button 79. When the decision button 79 is operated, the control device 17 updates the threshold value 40 associated with the tool selected in the tool selection unit 73 with the threshold value 40 displayed in the threshold value input unit 75. Thereafter, when machining begins using the tool for which the threshold value 40 has been set, the control device 17 determines the detection value 39 using the updated threshold value 40.

[0053] (When minimum value mode is set) Next, a case where the minimum value mode is set will be described. When the minimum value mode is set, the control device 17 sets the threshold value 40 based on the minimum value of the plurality of detection values ​​39. Figure 4 shows a setting screen 71A when the minimum value mode is set. In the following explanation, the same content as the explanation of the average value mode using Figure 3 above will be omitted as appropriate.

[0054] For example, when the minimum value mode is set, the control device 17 displays the words "minimum value mode" in the upper left corner of the threshold setting unit 72. Furthermore, when the minimum value mode is set, the control device 17 does not calculate an average value, and therefore does not display the average value display unit 87 that was displayed in the average value mode. Instead, the control device 17 highlights the minimum detected value 39 among the multiple detected values ​​39 displayed in the history display unit 76, i.e., among the detected values ​​39 of the tool selected by the tool selection unit 73, compared to the other detected values ​​39. For example, the control device 17 highlights the text of the minimum detected value 39 in red or yellow. Alternatively, the control device 17 may fill the detected value display unit 84 displaying the minimum detected value 39 in red or yellow. The example shown in FIG. 4 illustrates a case where the detected value 39 with history number "5" is the minimum value. Note that the above-described highlighting method is merely an example. For example, the control device 17 may highlight the number display unit 83 for the minimum value.

[0055] Even when the minimum value mode is set, the control device 17 accepts the margin 41 in the margin acceptance unit 77. When the minimum value mode is set and the setting screen 71A is displayed, and then the automatic setting button 78 is operated, the control device 17 sets the value obtained by subtracting the value of the margin 41 input to the margin acceptance unit 77 from the minimum value detection value 39 (detection value 39 of "5" in the case of FIG. 4) as the threshold value 40 in the threshold value input unit 75. Then, when the enter button 79 is operated, the control device 17 updates the threshold value 40 in the storage device 35 with the threshold value 40 in the threshold value input unit 75, as in the average value mode.

[0056] Therefore, as described above, the control device 17 of this embodiment acquires the detection values ​​39 output by the flow sensor 25 at multiple different times while the machine tool 10 is machining a workpiece, and sets the threshold value 40 based on the average or minimum value of the acquired detection values ​​39. This makes it possible to set the threshold value 40 based on the detection values ​​39 actually detected using the flow sensor 25 during the machining operation. Furthermore, by setting the threshold value 40 based on the average value of the detection values ​​39, it is possible to average out the errors of the multiple detection values ​​39 and set an appropriate threshold value 40. Furthermore, by setting the threshold value 40 based on the minimum value of the detection values ​​39, it is possible to set the threshold value 40 based on the minimum value of all the detected detection values ​​39, and therefore it is possible to easily set the threshold value 40 such that all the detected detection values ​​39 are within the allowable range.

[0057] Furthermore, the control device 17 receives the margin 41 at a margin receiving section 77 displayed on the touch panel 16A, and sets the value obtained by subtracting the margin 41 received at the margin receiving section 77 from the average value or minimum value of the multiple detection values ​​39 output by the flow sensor 25 as the threshold value 40. In this way, the value obtained by subtracting the desired margin 41 from the average value or minimum value can be set as the threshold value 40.

[0058] Furthermore, control device 17 sets threshold value 40 for each of the multiple tools used in machine tool 10. Control device 17 acquires detection values ​​39 output by flow rate sensor 25 at multiple different times during machining for each of the multiple tools. Control device 17 sets threshold value 40 corresponding to each of the multiple tools based on the average or minimum value of the acquired multiple detection values ​​39. This allows threshold value 40 to be set for each of the multiple tools registered in machine tool 10 when using each tool for machining.

[0059] The control device 17 also displays a tool selection unit 73, a detection value display unit 84, a margin acceptance unit 77, and an automatic setting button 78 on the setting screen 71, 71A. The automatic setting button 78 is an operation unit that accepts an instruction to set, as the threshold 40, a value obtained by subtracting a margin 41 accepted by the margin acceptance unit 77 from the average value or minimum value of the multiple detection values ​​39 displayed in the detection value display unit 84. Accordingly, by selecting a tool in the tool selection unit 73, a list of detection values ​​39 detected during machining with the selected tool can be confirmed in the detection value display unit 84. Furthermore, by inputting the margin 41 in the margin acceptance unit 77 and then operating the automatic setting button 78, a value obtained by subtracting the desired margin 41 from the average value or minimum value for the selected tool can be set as the threshold 40.

[0060] Furthermore, when the average value mode is set, the control device 17 displays the average value of the plurality of detection value display units 84 displayed on the detection value display unit 84 on the average value display unit 87 (see FIG. 3). By displaying the average value, the user can easily confirm the average value of the plurality of detection values ​​39. Furthermore, when the minimum value mode is set, the control device 17 highlights the minimum detection value 39 among the plurality of detection values ​​39 displayed on the detection value display unit 84 compared to the other detection values ​​39 (see FIG. 4). By highlighting the minimum detection value 39, the minimum detection value 39 can be displayed in an easy-to-understand manner on the detection value display unit 84. The control device 17 may be configured not to perform the above-mentioned process of displaying the average value or the process of highlighting the minimum value.

[0061] The above-described method for setting the threshold value 40 is merely an example. For example, the control device 17 may provide a radio button on the setting screen 71 for switching between an average value mode and a minimum value mode, and switch the display content (display of the average value or highlighting of the minimum value) according to an operation on the radio button.

[0062] Incidentally, the correspondence between the terms used in this embodiment and those described in the claims will be explained below. The coolant supply system 10A of this embodiment is an example of a machining fluid supply system. The operation panel 16 is an example of a user interface. The coolant pump 19 is an example of a machining fluid supply device. The coolant tank 52 is an example of a machining fluid tank. The coolant 63 is an example of a machining fluid.

[0063] As described above, the present embodiment provides the following effects. In one aspect of this embodiment, the coolant supply system 10A includes a flow rate sensor 25 that outputs a detection value 39 corresponding to the flow rate of the coolant 63 flowing through the pipe 51. The control device 17 of the coolant supply system 10A acquires the detection value 39 output by the flow rate sensor 25 and sets the threshold value 40 based on the acquired detection value 39. This allows the control device 17 to set the threshold value 40 based on the detection value 39 output from the flow rate sensor 25 during actual machining. This reduces the user's workload for setting the threshold value 40. For example, if the operator determines that the detection value 39 has been acquired in a normal machining state, the operator can display a setting screen 71 and set the threshold value 40.

[0064] It goes without saying that the present disclosure is not limited to the above-described embodiments, and various improvements and modifications are possible within the scope of the present disclosure. For example, in the above embodiment, the control device 17 sets the threshold value 40 based on the average value or the minimum value, but this is not limiting. For example, the control device 17 may set the threshold value 40 to a value obtained by subtracting the margin 41 from the maximum value of the multiple detection values ​​39. Furthermore, the control device 17 does not need to receive the value of the margin 41 from the operator. The control device 17 may automatically set and update the threshold value 40, for example, by using a preset fixed value or a value calculated from the detected value 39 and a predetermined calculation formula as the margin 41.

[0065] Furthermore, the control device 17 does not have to accept the threshold value 40 for each tool. For example, the control device 17 may determine the detection value 39 using the same threshold value 40 for all tools. In the above embodiment, the PLC 32 acquires the detection value 39 output by the flow sensor 25, but this is not limiting. For example, the numerical control device 31 may execute the control program 38 to periodically acquire the detection value 39 from the flow sensor 25 and store the acquired detection value 39 in the storage device 35. In the above embodiment, a nozzle that discharges coolant 63 toward the cutting edge of a tool is used as the outlet 55, but this is not limiting. For example, an outlet 55 for cleaning the workpiece holding device 12 after machining, an outlet 55 for cleaning an inspection device that inspects a workpiece, etc. may also be used as the outlet 55. In this case, it is not necessary to set a threshold value 40 for each tool. For example, a threshold value 40 may be set for each installation location of the outlet 55.

[0066] Furthermore, the configuration of the machine tool 10 in the above embodiment is an example. For example, the machine tool 10 may be configured without at least one of the loader 13 and the chip conveyor 15. Furthermore, there is no particular limitation on the number of components such as the control valve 21, the valve 61, the branch pipe 66, and the discharge port 55. For example, the coolant supply system 10A may be configured to include only one set of the control valve 21, the valve 61, the branch pipe 66, and the discharge port 55. The coolant supply system 10A may also include a plurality of flow rate sensors 25. Furthermore, a change in threshold value 40 may be received by a PC or the like connected to machine tool 10.

[0067] The contents of the present disclosure are not limited to the dependent relationships set forth in the claims. For example, this specification also discloses the technical idea of ​​changing "the machining fluid supply system according to claim 3" in claim 5 to "the machining fluid supply system according to claim 3 or claim 4." Furthermore, this specification also discloses the technical idea of ​​changing "the machining fluid supply system according to claim 1 or claim 2" in claim 8 to "the machining fluid supply system according to any one of claims 1 to 7." [Explanation of symbols]

[0068] 10 Machine tool, 10A Coolant supply system (machining fluid supply system), 17 Control device, 16 Operation panel (user interface), 19 Coolant pump (machining fluid supply device), 25 Flow sensor, 39 Detection value, 40 Threshold value, 41 Margin, 51 Piping, 55 Discharge port, 63 Coolant (machining fluid), 73 Tool selection section, 77 Margin reception section, 78 Automatic setting button, 84 Detection value display section.

Claims

1. A machining fluid supply system for supplying machining fluid to a machine tool, a working fluid supply device for supplying the working fluid; a discharge port for discharging the working fluid; a pipe that connects the working fluid supply device and the discharge port and supplies the working fluid from the working fluid supply device to the discharge port; a flow rate sensor that outputs a detection value corresponding to the flow rate of the working fluid flowing through the pipe; a control device that acquires the detection value output by the flow sensor and sets a threshold value based on the detection value; A machining fluid supply system comprising:

2. The control device 2. The machining fluid supply system according to claim 1, further comprising: a processing unit configured to receive a change to the threshold value; a processing unit configured to determine the detected value output by the flow sensor based on the threshold value that reflects the change; and a processing unit configured to set a new threshold value based on a plurality of detected values ​​determined using the threshold value.

3. The control device 3. The machining fluid supply system according to claim 1, wherein the detection values ​​output by the flow rate sensor are acquired at a plurality of different times while the machine tool is machining a workpiece, and the threshold value is set based on an average value or a minimum value of the acquired detection values.

4. a user interface, The control device Accepting a margin via the user interface; 4. The machining fluid supply system according to claim 3, wherein the threshold value is set to a value obtained by subtracting the margin received via the user interface from an average value or a minimum value of the plurality of detection values ​​output by the flow rate sensor.

5. The control device setting the threshold value for each of a plurality of tools used in the machine tool; 4. The machining fluid supply system according to claim 3, wherein the detection values ​​output by the flow rate sensor at a plurality of different timings during machining are acquired for each of the plurality of tools, and the threshold value corresponding to each of the plurality of tools is set based on an average value or a minimum value of the acquired detection values.

6. a user interface, The control device a tool selection unit that accepts selection of an arbitrary tool from among the plurality of tools; a detection value display unit that displays a list of the detection values ​​output by the flow rate sensor at a plurality of different timings for the tool selected by the tool selection unit; a margin receiving unit that receives a margin; an automatic setting button that accepts an instruction to set, as the threshold value, a value obtained by subtracting the margin accepted by the margin accepting unit from an average value or a minimum value of the plurality of detection values ​​displayed on the detection value display unit; The machining fluid supply system according to claim 5 , wherein the user interface displays:

7. The control device an average value mode in which the threshold value is set based on an average value of a plurality of the detection values, and a minimum value mode in which the threshold value is set based on a minimum value of the plurality of the detection values, When the average value mode is set, an average value of the plurality of detection values ​​displayed on the detection value display unit is displayed on the user interface; 7. The machining fluid supply system according to claim 6, wherein when the minimum value mode is set, the minimum detected value among the plurality of detected values ​​displayed on the detected value display unit is displayed in an emphasized manner compared to the other detected values.

8. The control device 3. The machining fluid supply system according to claim 1, wherein when the detected value falls below the threshold value while the machine tool is machining the workpiece, machining of the workpiece is stopped.

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