Machine tool, control method for machine tool and control program for machine tool

Abstract

To provide a new technique for detecting an abnormality on sludge.SOLUTION: A machine tool capable of machining a workpiece while discharging a coolant includes: a first storage section for storing the coolant containing sludge generated through machining of the workpiece; a cyclone filter for separating the coolant supplied from the first storage section into a clean coolant and a contaminated coolant by using centrifugal force; and a control section for controlling the machine tool. The cyclone filter includes: a first outflow pipe for causing the clean coolant to flow out; a second outflow pipe for causing the contaminated coolant to flow out; a diaphragm mechanism for restricting a flow rate of the contaminated coolant flowing in the second outflow pipe; and a flow sensor for detecting the flow rate of the dirty coolant flowing in the second outflow pipe. On the basis of a situation where the flow rate detected by the flow sensor falls below a predetermined flow rate, the control section executes predetermined abnormality responding processing.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a machine tool, a control method for a machine tool, and a control program for a machine tool.

Background Art

[0002] Japanese Patent Application Laid-Open No. 2020-040186 (Patent Document 1) discloses a coolant supply device used in a machine tool. The coolant supply device includes "a supply pump that supplies the coolant in the clean tank to the machine tool, a recovery path that returns the coolant from the machine tool to the dirty tank, and a cyclone filter that is disposed on a connection path that sends the coolant from the dirty tank to the clean tank and separates the dirty liquid containing sludge and the clean liquid not containing sludge, and discharges the clean liquid through an outlet connected to the clean tank, a container that is connected to the outlet of the dirty liquid in the filter and accumulates sludge, a detection unit that detects the accumulation amount of sludge in the container, and a controller that performs control based on the detection result of the detection unit" (see paragraph

[0008] ).

[0003] The above coolant supply device detects the accumulation amount of sludge in the container by using an image obtained by photographing the container that accumulates sludge with a camera.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the coolant and sludge are suspended in the container, it is practically difficult to detect the height of the sludge in the container with a camera. Therefore, a new technique for detecting an abnormality related to sludge is desired.

Means for Solving the Problem

[0006] In an example of the present disclosure, a machine tool capable of machining a workpiece while discharging a coolant is provided. The machine tool includes a first reservoir for storing a coolant containing sludge generated by machining the workpiece, a cyclone filter for separating the coolant supplied from the first reservoir into a clean coolant and a dirty coolant by centrifugal force, and a control unit for controlling the machine tool. The cyclone filter includes a first outflow pipe for allowing the clean coolant to flow out, a second outflow pipe for allowing the dirty coolant to flow out, a throttle mechanism for restricting the flow rate of the dirty coolant flowing through the second outflow pipe, and a flow rate sensor for detecting the flow rate of the dirty coolant flowing through the second outflow pipe. The control unit executes a predetermined abnormality countermeasure process based on the fact that the flow rate detected by the flow rate sensor is lower than a predetermined amount.

[0007] In an example of the present disclosure, the machine tool further includes a second reservoir for storing the dirty coolant flowing out from the second outflow pipe. The outlet of the second outflow pipe is piped so as to be immersed in the dirty coolant stored in the second reservoir.

[0008] In an example of the present disclosure, the machine tool further includes a recovery mechanism for recovering sludge from the dirty coolant stored in the second reservoir.

[0009] In an example of the present disclosure, the bottom surface of the second reservoir is inclined with respect to the horizontal plane.

[0010] In an example of the present disclosure, the throttle mechanism includes a tapered pipe. The tapered pipe is configured such that the inner diameter decreases along the direction in which the dirty coolant flows.

[0011] In one example of the present disclosure, the throttle mechanism includes a plurality of the tapered pipelines. Each of the plurality of the tapered pipelines is coaxially arranged and connected along the vertical direction.

[0012] In one example of the present disclosure, the predetermined abnormality handling process includes a notification process for notifying that the sludge is clogged in the throttle mechanism.

[0013] In another example of the present disclosure, a control method for a machine tool capable of machining a workpiece while discharging a coolant is provided. The machine tool includes a first reservoir for storing a coolant containing sludge generated by machining the workpiece, and a cyclone filter for separating the coolant supplied from the first reservoir into a clean coolant and a dirty coolant by centrifugal force. The cyclone filter includes a first outflow pipe for allowing the clean coolant to flow out, a second outflow pipe for allowing the dirty coolant to flow out, a throttle mechanism for restricting the flow rate of the dirty coolant flowing through the second outflow pipe, and a flow rate sensor for detecting the flow rate of the dirty coolant flowing through the second outflow pipe. The control method includes a step of obtaining the flow rate from the flow rate sensor, and a step of executing a predetermined abnormality handling process based on the fact that the flow rate obtained in the obtaining step is less than a predetermined amount.

[0014] In other examples of the present disclosure, there is provided a control program for a machine tool capable of machining a workpiece while discharging a coolant. The machine tool includes a first reservoir for storing a coolant containing sludge generated by machining the workpiece, and a cyclone filter for separating the coolant supplied from the first reservoir into a clean coolant and a dirty coolant by centrifugal force. The cyclone filter includes a first outflow pipe for allowing the clean coolant to flow out, a second outflow pipe for allowing the dirty coolant to flow out, a throttle mechanism for restricting the flow rate of the dirty coolant flowing through the second outflow pipe, and a flow rate sensor for detecting the flow rate of the dirty coolant flowing through the second outflow pipe. The control program causes the machine tool to execute a step of acquiring the flow rate from the flow rate sensor, and a step of executing a predetermined abnormality countermeasure process based on the fact that the flow rate acquired in the acquiring step is less than a predetermined amount.

[0015] The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention understood in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0017] Hereinafter, each embodiment according to the present invention will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. Note that each of the embodiments and each modified example described below may be selectively combined as appropriate.

[0018] <A. Appearance of Machine Tool 100> First, with reference to FIG. 1, the machine tool 100 according to the embodiment will be described. FIG. 1 is a diagram showing the appearance of the machine tool 100.

[0019] As used herein, the “machine tool” is a concept encompassing various devices having a function of processing a workpiece. The machine tool 100 may be a horizontal machining center or a vertical machining center. Alternatively, the machine tool 100 may be a lathe, or other cutting machines, grinding machines, composite machining machines, 5-axis machining machines, etc. Further, the machine tool 100 is not limited to performing only removal machining, and may perform addition machining in addition to removal machining.

[0020] The machine tool 100 includes, for example, a cover body 130 and an operation panel 200. The cover body 130, also called a splash guard, forms the appearance of the machine tool 100 and partitions the machining area of the workpiece.

[0021] The operation panel 200 is a general-purpose computer and has a display 206 for displaying various pieces of information related to machining. The display 206 is, for example, a liquid crystal display, an organic EL (Electro Luminescence) display, or other display device. Further, the display 206 is provided with a touch panel and accepts various operations on the machine tool 100 by touch operations.

[0022] The machine tool 100 machines a workpiece while discharging coolant into the machining area inside the machine. The coolant used for machining contains sludge. Sludge is fine swarf generated by machining the workpiece. The machine tool 100 separates sludge from the coolant used for machining and reuses the coolant from which the sludge has been removed for machining the workpiece.

[0023] <B. Sludge Separation Mechanism> Next, with reference to FIG. 2, the sludge separation mechanism will be described. FIG. 2 is a diagram showing an example of the sludge separation mechanism.

[0024] As shown in FIG. 2, the machine tool 100 includes a machining area AR, a storage unit SU1, a cyclone filter 30, and a control unit 50.

[0025] The coolant used for machining the workpiece is discharged from the machining area AR and stored in the storage unit SU1 through the flow path RA. The coolant stored in the storage unit SU1 contains sludge.

[0026] The cyclone filter 30 is a mechanism for separating the coolant supplied from the storage unit SU1 into clean coolant and dirty coolant by centrifugal force. The sludge content in the clean coolant is less than the sludge content in the dirty coolant. Typically, the clean coolant does not contain sludge. The content is represented by, for example, the weight of sludge contained per unit volume.

[0027] More specifically, an inlet pipe R0, an outlet pipe R1 (first outlet pipe), and an outlet pipe R2 (second outlet pipe) are connected to the cyclone filter 30.

[0028] One end of the inlet pipe R0 is connected to the storage unit SU1. On the other hand, the other end of the inlet pipe R0 is connected to the inlet of the cyclone filter 30. Also, a pump P1 is provided on the inlet pipe R0. The pump P1 pumps the coolant in the storage unit SU1 into the inlet pipe R0 and sends the coolant to the inlet of the cyclone filter 30.

[0029] The coolant sent to the cyclone filter 30 flows spirally inside the cyclone filter 30. In this process, the heavy sludge falls in the direction of gravity together with a part of the coolant and is discharged from the lower outlet of the cyclone filter 30. As a result, the dirty coolant containing a lot of sludge is discharged to the outlet pipe R2.

[0030] Also, a throttling mechanism 40 is provided in the cyclone filter 30. The throttling mechanism 40 is a mechanism for restricting the flow rate of the dirty coolant flowing in the outlet pipe R2. The throttling mechanism 40 provides resistance, and the coolant rises in the direction opposite to the direction of gravity while flowing spirally inside the cyclone filter 30. As a result, the clean coolant not containing sludge is discharged to the outlet pipe R2.

[0031] Also, a pump P2 is provided on the outlet pipe R1. The pump P2 pumps the clean coolant from the cyclone filter 30. As a result, the clean coolant is pumped into the outlet pipe R1.

[0032] <C. Clogging Detection Function> Next, with continued reference to FIG. 2, a function for detecting sludge clogging will be described.

[0033] If the cyclone filter 30 continues to be used, sludge will accumulate in the throttle mechanism 40. As a result, the sludge may clog in the throttle mechanism 40. In order to detect such clogging, a flow sensor 45 is provided in the outflow pipe R2.

[0034] The flow sensor 45 is a sensor for detecting the flow rate of the dirty coolant flowing through the outflow pipe R2. Preferably, the flow sensor 45 is arranged on the downstream side of the throttle mechanism 40 in the direction of the coolant flow.

[0035] The type of the flow sensor 45 is arbitrary. As an example, the flow sensor 45 employs a non-contact type sensor capable of detecting the coolant flow rate from the outside of the outflow pipe R2 without contacting the coolant flowing inside the outflow pipe R2. Examples of the non-contact type flow sensor 45 include an ultrasonic type flow sensor and an electromagnetic type flow sensor. The detection result of the flow rate by the flow sensor 45 is output to the control unit 50.

[0036] The control unit 50 is a device for controlling the machine tool 100. The device configuration of the control unit 50 is arbitrary. The control unit 50 may be composed of a single control unit or a plurality of control units. As an example, the control unit 50 includes at least one of a PLC (Programmable Logic Controller) and a CNC (Computer Numerical Control).

[0037] As the amount of sludge accumulating in the throttle mechanism 40 increases, the flow rate of the coolant flowing through the outflow pipe R2 decreases. Focusing on this point, the control unit 50 determines whether sludge clogging has occurred based on the flow rate detected by the flow sensor 45.

[0038] More specifically, when the flow rate detected by the flow rate sensor 45 is equal to or greater than a predetermined amount, the control unit 50 determines that it is in a normal state where no sludge clogging has occurred. On the other hand, when the flow rate detected by the flow rate sensor 45 is less than the predetermined amount, the control unit 50 determines that it is in an abnormal state where sludge clogging has occurred. Thereby, the control unit 50 can detect an abnormality related to sludge clogging.

[0039] When the control unit 50 determines that sludge clogging has occurred, it executes a predetermined abnormality countermeasure process. As an example of the abnormality countermeasure process, the control unit 50 executes a notification process for notifying that sludge is clogged in the throttle mechanism 40. Thereby, the user can grasp that sludge clogging has occurred in the throttle mechanism 40.

[0040] The sludge clogging can be notified in any manner. As an example, the control unit 50 outputs a warning to the display 206 of the operation panel 200 described above. As another example, the control unit 50 outputs a warning to a display (not shown) provided in the flow rate sensor 45. As another example, the control unit 50 lights an indicator (not shown) provided in the flow rate sensor 45. As another example, the control unit 50 outputs an audible warning from a speaker (not shown) provided in the machine tool 100.

[0041] As another example of the abnormality countermeasure process, the control unit 50 executes a process of stopping the coolant discharge mechanism. Thereby, the control unit 50 can prevent the coolant containing sludge from flowing into the outflow pipe R1.

[0042] <D. Sludge Recovery Mechanism> Next, with reference to FIG. 3, an automatic sludge recovery mechanism will be described. FIG. 3 is a diagram for explaining an automatic sludge recovery unit 60 for sludge.

[0043] As an example, the automatic recovery unit 60 includes a storage unit 62, a recovery mechanism 64, and a recovery container 66.

[0044] The storage section 62 (second storage section) is a tank for storing the contaminated coolant discharged from the outflow pipe R2 of the cyclone filter 30. In the example of FIG. 3, the contaminated coolant CL is stored in the storage section 62.

[0045] Preferably, the outlet of the outflow pipe R2 is piped so as to be immersed in the contaminated coolant CL stored in the storage section 62. That is, the outlet of the outflow pipe R2 is arranged to be below the liquid level of the coolant CL. Since the outlet of the outflow pipe R2 is always immersed in the coolant CL, air does not flow backward into the outflow pipe R2. Thereby, the flow rate sensor 45 can accurately detect the flow rate of the coolant flowing through the outflow pipe R2. The recovery mechanism 64 is a transport mechanism for recovering the sludge SL1 from the coolant CL stored in the storage section 62. The recovery mechanism 64 is constituted by, for example, a conveyor or the like. The recovery mechanism 64 transports the sludge SL1 that has settled in the storage section 62 and discharges the sludge SL1 into the recovery container 66. In this way, the recovery mechanism 64 can separate the sludge SL1 from the coolant CL and collect the sludge SL2 that does not contain the coolant in the recovery container 66.

[0046] Preferably, the bottom surface of the storage section 62 is inclined with respect to the horizontal plane. In other words, the bottom surface of the storage section 62 is not parallel to the horizontal plane. Thereby, the sludge SL1 collects at the bottom of the storage section 62, and it becomes easier for the recovery mechanism 64 to recover the sludge SL1.

[0047] The recovery mechanism 64 is arranged along the inclined bottom surface. At this time, the recovery mechanism 64 is arranged in the storage section 62 such that a part of it is immersed in the coolant CL in the storage section 62 and the rest is not immersed in the coolant CL. Thereby, the recovery mechanism 64 can not only recover the sludge SL1 but also recover the oil floating on the liquid surface of the coolant CL.

[0048] In addition, an outflow pipe R3 is connected to the storage section 62. The coolant CL stored in the storage section 62 is returned to the above-described storage section SU1 through, for example, the outflow pipe R3 (see FIG. 2). Thereby, the coolant CL is reused.

[0049] <Coolant mechanism in the machining area AR> Next, with reference to FIG. 4, an example of the coolant mechanism in the machining area AR shown in FIG. 2 described above will be described. FIG. 4 is a diagram schematically showing the state of the machining area AR in the machine tool 100.

[0050] In the machining area AR, for example, a spindle 132 and a chip conveyor 150 are provided.

[0051] The spindle 132 is provided inside the housing and is rotatably supported by the housing. A tool T for machining a workpiece, which is a work piece, is attached to the spindle 132. The spindle 132 machines the workpiece by bringing the tool T into contact with the workpiece while rotating the tool T about its axial direction.

[0052] Inside the spindle 132, a communication passage L1, which is a coolant discharge mechanism, is formed. The communication passage L1 penetrates inside the spindle 132 along the axial direction of the spindle 132. One end of the communication passage L1 is connected to the above-described outflow pipe R1 (see FIG. 2).

[0053] Various types of tools can be attached to the spindle 132. In the example of FIG. 4, a tool T in which a through passage L2 is formed is attached to the spindle 132. The through passage L2 extends from the connection surface between the tool T and the spindle 132 to the tip of the tool T and penetrates the tool T along the axial direction of the spindle 132. Note that the opening of the through passage L2 formed in the tool T is not limited to being formed in the base end surface or the tip end surface of the tool T, and may be formed, for example, in the side surface portion of the tool T.

[0054] The clean coolant sent from the above-mentioned cyclone filter 30 flows in the order of the outflow pipe R1, the communication path L1, and the through-passage L2, and is discharged from the tip of the tool T to the workpiece to be machined. Thereby, the chips generated by machining the workpiece are discharged to the chip conveyor 150.

[0055] The chip conveyor 150 includes a cover body 152, a filtration mechanism 154, and a tank 156. The filtration mechanism 154 is configured to be able to capture foreign matters such as chips from the coolant. The coolant that has passed through the filtration mechanism 154 is discharged from inside the cover body 152 of the chip conveyor 150 to the tank 156.

[0056] A pump P0 is provided in the tank 156. The pump P0 pumps up the coolant that has passed through the filtration mechanism 154 and accumulated in the tank 156, and pressure-feeds the coolant to the flow path RA. The coolant is sent to the above-mentioned storage unit SU1 (see FIG. 2) through the flow path RA.

[0057] In the above description, an example in which the center-through specification in which the coolant is discharged from the cutting edge of the tool T is adopted as the discharge mechanism of the spindle 132 has been described. However, the coolant discharge mechanism adopted for the spindle 132 is not limited to this. As an example, the coolant discharge mechanism adopted for the spindle 132 may be a side-through specification in which the coolant is discharged from the end face of the spindle 132.

[0058] Also, the discharge destination of the clean coolant from the cyclone filter 30 is not limited to the spindle 132. FIG. 5 is a diagram for explaining another example of the discharge destination of the clean coolant. In FIG. 5, discharge mechanisms 134 and 136 are shown as the discharge destinations of the clean coolant.

[0059] The discharge mechanism 134 is a mechanism for discharging the clean coolant pumped from the outflow pipe R1 toward the entire machining area AR. By discharging the coolant from the discharge mechanism 134 into the machining area AR, the chips of the workpiece in the machining area AR are discharged to the chip conveyor 150.

[0060] The discharge mechanism 136 discharges the cleaned coolant pumped from the outflow pipe R1 toward the bed BD. By discharging the coolant onto the bed BD by the discharge mechanism 136, the chips accumulated on the bed BD are discharged to the chip conveyor 150.

[0061] <F. Throttle mechanism 40> Next, with reference to FIG. 6, an example of the throttle mechanism 40 shown in FIG. 2 described above will be described. FIG. 6 is a diagram showing a cross section of the throttle mechanism 40.

[0062] Any mechanism for restricting the flow rate of the coolant in the outflow pipe R2 may be employed in the throttle mechanism 40. In the example of FIG. 6, a tapered pipe 44 whose inner diameter becomes shorter along the direction in which the contaminated coolant flows is employed in the throttle mechanism 40.

[0063] The number of tapered pipes 44 provided in the throttle mechanism 40 may be one or a plurality. In the example of FIG. 6, three tapered pipes 44A to 44C are provided inside the throttle mechanism 40. Hereinafter, when the tapered pipes 44A to 44C are not particularly distinguished, they are also referred to as the tapered pipe 44.

[0064] The sludge is less likely to stay in the tapered pipe 44. Therefore, clogging of the sludge is less likely to occur in the throttle mechanism 40. Further, by employing the tapered pipe in the throttle mechanism 40, the flow path resistance in the outflow pipe R2 can also be increased.

[0065] Each of the tapered pipes 44A to 44C is coaxially arranged and connected along the vertical direction. By employing a plurality of tapered pipes 44A to 44C in the throttle mechanism 40, the flow path resistance in the outflow pipe R2 is further increased.

[0066] Note that, in the above description, the tapered pipe 44 is given as an example of the mechanism employed in the throttle mechanism 40, but the mechanism employed in the throttle mechanism 40 is not limited to this. As an example, a ball valve may be employed in the throttle mechanism 40.

[0067] <G. Driving mechanism> Next, with reference to FIG. 7, various driving mechanisms in the machine tool 100 will be described. FIG. 7 is a diagram showing a configuration example of the driving mechanism in the machine tool 100.

[0068] As shown in FIG. 7, the machine tool 100 includes, as components related to the driving mechanism, a control unit 50, motor drivers 111A to 111E, motors M0 to M3, the above-described pumps P0 to P2, the above-described recovery mechanism 64, and the above-described chip conveyor 150.

[0069] As described above, the pump P0 is a device for pumping coolant into the flow path RA (see FIGS. 2 and 4). A motor M0 is connected to the pump P0. The motor M0 may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0070] The motor M0 is driven by the motor driver 111A. The motor driver 111A is composed of a control circuit, an inverter, etc. The motor driver 111A receives an input of a control signal from the control unit 50 and outputs an alternating current with a frequency corresponding to the control signal to the motor M0. Thereby, the rotational speed of the motor M0 changes, and the flow rate of the coolant pumped into the above-described flow path RA is controlled.

[0071] As described above, the pump P1 is a device for pumping coolant into the inflow pipe R0 (see FIG. 4). A motor M1 is connected to the pump P1. The motor M1 may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0072] The motor M1 is driven by the motor driver 111B. The motor driver 111B is composed of a control circuit, an inverter, and the like. The motor driver 111B receives an input of a control signal from the control unit 50 and outputs an alternating current with a frequency corresponding to the control signal to the motor M1. Thereby, the rotational speed of the motor M1 changes, and the flow rate of the coolant pumped into the above-mentioned inflow pipe R0 is controlled.

[0073] As described above, the pump P2 is a device for pumping the coolant into the outflow pipe R1 (see FIGS. 2 and 4). A motor M2 is connected to the pump P2. The motor M2 may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0074] The motor M2 is driven by the motor driver 111C. The motor driver 111C is composed of a control circuit, an inverter, and the like. The motor driver 111C receives an input of a control signal from the control unit 50 and outputs an alternating current with a frequency corresponding to the control signal to the motor M2. Thereby, the rotational speed of the motor M2 changes, and the flow rate of the coolant pumped into the above-mentioned outflow pipe R1 is controlled.

[0075] A motor M3 is connected to the above-mentioned recovery mechanism 64 (see FIG. 3). The motor M3 may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0076] The motor M3 is driven by the motor driver 111D. The motor driver 111D is composed of a control circuit, an inverter, and the like. The motor driver 111D receives an input of a control signal from the control unit 50 and outputs an alternating current with a frequency corresponding to the control signal to the motor M3. Thereby, the rotational speed of the motor M3 changes, and the rotational speed of the conveyor in the recovery mechanism 64 is controlled.

[0077] The above chip conveyor 150 (see FIG. 4) is connected to a motor M4. The motor M4 may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0078] The motor M4 is driven by a motor driver 111E. The motor driver 111E is composed of a control circuit, an inverter, etc. The motor driver 111E receives an input of a control signal from the control unit 50 and outputs an alternating current with a frequency corresponding to the control signal to the motor M4. Thereby, the rotation speed of the motor M4 changes, and the rotation speed of the conveyor in the chip conveyor 150 is controlled.

[0079] <H. Hardware Configuration of Control Unit 50> Next, with reference to FIG. 8, the hardware configuration of the control unit 50 shown in FIG. 2 above will be described. FIG. 8 is a diagram showing an example of the hardware configuration of the control unit 50.

[0080] The control unit 50 includes a control circuit 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a communication interface 104, and an auxiliary storage device 120. These components are connected to an internal bus 109.

[0081] The control circuit 101 is composed of, for example, at least one integrated circuit. The integrated circuit can be composed of, for example, at least one CPU, at least one GPU (Graphics Processing Unit), at least one ASIC (Application Specific Integrated Circuit), at least one FPGA (Field Programmable Gate Array), or a combination thereof.

[0082] The control circuit 101 controls the operation of the control unit 50 by executing various programs such as the control program 122. The control program 122 is a program for realizing the various processes described in this specification. Based on receiving an execution instruction of the control program 122, the control circuit 101 reads the control program 122 from the auxiliary storage device 120 or the ROM 102 into the RAM 103. The RAM 103 functions as a working memory and temporarily stores various data necessary for the execution of the control program 122.

[0083] The communication interface 104 is an interface for performing periodic communication with an external device using a field network. The external device includes, for example, the above-described flow rate sensor 45 and the above-described motor drivers 111A to 111E. As the field network, for example, EtherCAT (registered trademark), EtherNet / IP (registered trademark), CC-Link (registered trademark), or CompoNet (registered trademark) is adopted.

[0084] The auxiliary storage device 120 is a storage medium such as a hard disk or a flash memory, for example. The auxiliary storage device 120 stores the control program 122 and the like. Note that the storage location of the control program 122 is not limited to the auxiliary storage device 120 and may be stored in a storage area of the control circuit 101 (for example, a cache memory), the ROM 102, the RAM 103, an external device (for example, a server), or the like.

[0085] Further, the control program 122 may be provided by being incorporated into a part of an arbitrary program instead of as a single program. In this case, various processes according to the present embodiment are realized in cooperation with an arbitrary program. Even a program that does not include such a part of the module does not deviate from the gist of the control program 122 according to the present embodiment. Further, some or all of the functions provided by the control program 122 may be realized by dedicated hardware. Further, the control unit 50 may be configured in a form such as a so-called cloud service in which at least one server executes a part of the processing of the control program 122.

[0086] <I. Hardware Configuration of Operation Panel 200> Next, with reference to FIG. 9, the hardware configuration of the operation panel 200 shown in FIG. 1 will be described. FIG. 9 is a diagram showing an example of the hardware configuration of the operation panel 200.

[0087] The operation panel 200 includes a control circuit 201, a ROM 202, a RAM 203, a communication interface 204, a display interface 205, an input interface 207, and an auxiliary storage device 220. These components are connected to a bus 209.

[0088] The control circuit 201 is constituted by, for example, at least one integrated circuit. The integrated circuit can be constituted by, for example, at least one CPU, at least one GPU, at least one ASIC, at least one FPGA, or a combination thereof.

[0089] The control circuit 201 controls the operation of the operation panel 200 by executing various programs such as a control program 222 and an operating system. The control circuit 201 reads the control program 222 from the auxiliary storage device 220 or the ROM 202 into the RAM 203 based on receiving an execution instruction of the control program 222. The RAM 203 functions as a working memory and temporarily stores various data necessary for the execution of the control program 222.

[0090] The communication interface 204 is connected to a LAN, an antenna, etc. The operation panel 200 is connected to a network via the communication interface 204. Thereby, the operation panel 200 exchanges data with external devices connected to the network. The external devices include, for example, the above-described control unit 50 and a server (not shown).

[0091] A display 206 is connected to the display interface 205. The display interface 205 sends an image signal for displaying an image to the display 206 according to a command from the control circuit 201 or the like. The display 206 is, for example, a liquid crystal display, an organic EL display, or other display device. Note that the display 206 may be integrally configured with the operation panel 200 or may be configured separately from the operation panel 200.

[0092] An input device 208 is connected to the input interface 207. The input device 208 is, for example, a mouse, a keyboard, a touch panel, or other device capable of receiving a user's operation. Note that the input device 208 may be integrally configured with the operation panel 200 or may be configured separately from the operation panel 200.

[0093] The auxiliary storage device 220 is a storage medium such as a hard disk or a flash memory, for example. The auxiliary storage device 220 stores a control program 222 or the like. The storage location of the control program 222 is not limited to the auxiliary storage device 220 and may be stored in a storage area of the control circuit 201 (such as a cache memory), the ROM 202, the RAM 203, or an external device (such as a server).

[0094] <J. Flowchart> Next, with reference to FIG. 10, a process of monitoring an abnormality of the cyclone filter 30 will be described. FIG. 10 is a flowchart showing the flow of the process of monitoring an abnormality of the cyclone filter 30.

[0095] The process shown in FIG. 10 is realized by the control unit 50 of the machine tool 100 executing the above-described control program 122. In other aspects, part or all of the process may be executed by a CNC, circuit elements, or other hardware.

[0096] Typically, the process shown in FIG. 10 is executed in a process (such as a machining process) where coolant is used within the machine tool 100.

[0097] More specifically, in step S110, the control unit 50 acquires the coolant flow rate detected by the above-described flow rate sensor 45. The coolant flow rate represents the flow rate of the contaminated coolant discharged from below the cyclone filter 30 (see FIG. 2).

[0098] In step S120, the control unit 50 determines whether the coolant flow rate acquired in step S110 is less than a predetermined amount. The predetermined amount may be set in advance or arbitrarily set by the user. When the control unit 50 determines that the coolant flow rate is less than the predetermined amount (YES in step S120), it determines that sludge clogging has occurred in the cyclone filter 30 and switches the control to step S122. Otherwise (NO in step S120), the control unit 50 determines that sludge clogging has not occurred in the cyclone filter 30 and returns the control to step S110.

[0099] In step S122, the control unit 50 executes a predetermined abnormality handling process. As an example of the abnormality handling process, the control unit 50 executes a notification process for notifying that sludge has clogged the cyclone filter 30. Thereby, the user can grasp that sludge clogging has occurred in the cyclone filter 30.

[0100] <K. Modification Example> Next, referring to FIG. 11, a machine tool 100A according to a modified example will be described. FIG. 11 is a diagram schematically showing a coolant mechanism in the machine tool 100A.

[0101] In the examples of FIGS. 2 and 4 described above, the coolant stored in the tank 156 was sent to the storage section SU1 by the pump P0, and the coolant stored in the storage section SU1 was sent to the cyclone filter 30 by the pump P1. That is, the coolant stored in the tank 156 was indirectly sent to the cyclone filter 30 via the storage section SU1. In contrast, in the machine tool 100A according to this modified example, the coolant stored in the tank 156 is directly sent to the cyclone filter 30 by the pump P0.

[0102] Also, in the examples of FIGS. 2 and 4 described above, the clean coolant discharged from the cyclone filter 30 was directly sent to the machining area AR by the pump P2. In contrast, in the machine tool 100A according to this modified example, the clean coolant discharged from the cyclone filter 30 is once stored in the storage section SU2. Then, the coolant stored in the storage section SU2 is sent to the machining area AR by the pump P2. Thus, in this modified example, the clean coolant discharged from the cyclone filter 30 is indirectly sent to the machining area AR via the storage section SU2.

[0103] It should be considered that all the disclosed embodiments are illustrative and not restrictive in any way. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Description of Reference Numerals

[0104] 30 Cyclone filter, 40 Throttle mechanism, 44 Tapered pipeline, 44A Tapered pipeline, 44B Tapered pipeline, 44C Tapered pipeline, 45 Flow sensor, 50 Control unit, 60 Automatic recovery unit, 62 Storage part, 64 Recovery mechanism, 66 Recovery container, 100 Machine tool, 100A Machine tool, 101 Control circuit, 102 ROM, 103 RAM, 104 Communication interface, 109 Internal bus, 111A Motor driver, 111B Motor driver, 111C Motor driver, 111D Motor driver, 111E Motor driver, 120 Auxiliary storage device, 122 Control program, 130 Cover body, 132 Spindle, 134 Discharge mechanism, 136 Discharge mechanism, 150 Chip conveyor, 152 Cover body, 154 Filtration mechanism, 156 Tank, 200 Operation panel, 201 Control circuit, 202 ROM, 203 RAM, 204 Communication interface, 205 Display interface, 206 Display, 207 Input interface, 208 Input device, 209 Bus, 220 Auxiliary storage device, 222 Control program, AR Machining area, BD Bed, CL Coolant, L1 Connecting passage, L2 Penetrating passage, M0 Motor, M1 Motor, M2 Motor, M3 Motor, M4 Motor, P0 Pump, P1 Pump, P2 Pump, R0 Inflow pipe, R1 Outflow pipe, R2 Outflow pipe, R3 Outflow pipe, RA Flow path, SL1 Sludge, SL2 Sludge, SU1 Storage part, SU2 Storage part, T Tool.

Claims

1. A machine tool capable of machining a workpiece while discharging a coolant, comprising: a first reservoir for storing the coolant containing sludge generated by machining the workpiece; a cyclone filter for separating the coolant supplied from the first reservoir into a clean coolant and a dirty coolant by centrifugal force; a control unit for controlling the machine tool, wherein the cyclone filter has a first outflow pipe for allowing the clean coolant to flow out; a second outflow pipe for allowing the dirty coolant to flow out; a throttling mechanism for restricting the flow rate of the dirty coolant flowing through the second outflow pipe; and a flow rate sensor for detecting the flow rate of the dirty coolant flowing through the second outflow pipe, wherein the control unit executes a predetermined abnormality countermeasure process based on the fact that the flow rate detected by the flow rate sensor is less than a predetermined amount. The machine tool.

2. The machine tool further comprises a second reservoir for storing the dirty coolant flowing out from the second outflow pipe, and the outlet of the second outflow pipe is piped so as to be immersed in the dirty coolant stored in the second reservoir. The machine tool according to claim 1.

3. The machine tool further comprises a recovery mechanism for recovering sludge from the dirty coolant stored in the second reservoir. The machine tool according to claim 2.

4. The bottom surface of the second reservoir is inclined with respect to the horizontal plane. The machine tool according to claim 2 or 3.

5. The throttling mechanism includes a tapered pipe, and the tapered pipe is configured such that the inner diameter decreases along the direction in which the dirty coolant flows. The machine tool according to claim 1 or 2.

6. The throttling mechanism includes a plurality of the tapered pipes, and each of the plurality of tapered pipes is coaxially arranged and connected along the vertical direction. The machine tool according to claim 5.

7. The predetermined abnormality countermeasure process includes a notification process for notifying that the sludge is clogged in the throttling mechanism. The machine tool according to claim 1 or 2.

8. A control method for a machine tool capable of machining a workpiece while discharging a coolant, wherein the machine tool has a first reservoir for storing the coolant containing sludge generated by machining the workpiece, A cyclone filter for separating the coolant supplied from the first storage part into clean coolant and dirty coolant by centrifugal force, The cyclone filter is, A first outflow pipe for allowing the clean coolant to flow out, A second outflow pipe for allowing the dirty coolant to flow out, A throttle mechanism for restricting the flow rate of the dirty coolant flowing through the second outflow pipe, Including a flow rate sensor for detecting the flow rate of the dirty coolant flowing through the second outflow pipe, The control method is, A step of obtaining the flow rate from the flow rate sensor, Based on the fact that the flow rate obtained in the obtaining step is less than a predetermined amount, a step of executing a predetermined abnormality countermeasure process. A control method.

9. A control program for a machine tool capable of machining a workpiece while discharging coolant, The machine tool is, A first storage part for storing coolant containing sludge generated by machining the workpiece, A cyclone filter for separating the coolant supplied from the first storage part into clean coolant and dirty coolant by centrifugal force, The cyclone filter is, A first outflow pipe for allowing the clean coolant to flow out, A second outflow pipe for allowing the dirty coolant to flow out, A throttle mechanism for restricting the flow rate of the dirty coolant flowing through the second outflow pipe, Including a flow rate sensor for detecting the flow rate of the dirty coolant flowing through the second outflow pipe, The control program causes the machine tool to, A step of obtaining the flow rate from the flow rate sensor, Based on the fact that the flow rate obtained in the obtaining step is less than a predetermined amount, a step of executing a predetermined abnormality countermeasure process. A control program.

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