Machine tool, control method, and control program

Abstract

To provide an art for dealing with instability of a value of a concentration sensor.SOLUTION: A machine tool may process a workpiece and includes: a display device; a coolant passage; a concentration sensor which is provided at the passage to detect a concentration of a coolant in the passage; and a control device. The control device performs processing for determining whether or not the coolant flows in the passage and processing for prohibiting the display device from displaying a display item related to the concentration when it is determined that the coolant does not flow in the passage.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2023-35216 (Patent Document 1) discloses a refractive index type concentration sensor used in a machine tool. The concentration sensor detects the concentration of coolant by utilizing the characteristic that the refractive index changes when the concentration of the fluid changes.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When foreign matter adheres to the concentration sensor, the concentration value detected by the concentration sensor tends to become unstable. When such a concentration value is displayed to the user, the reliability of the coolant concentration measurement is impaired. Therefore, a technique for dealing with the instability of the concentration sensor value is required.

Means for Solving the Problems

[0005] In an example of the present disclosure, a machine tool capable of machining a workpiece is provided. The machine tool includes a display device, a coolant flow path, a concentration sensor provided in the flow path for detecting the concentration of the coolant in the flow path, and a control device. The control device executes a process of determining whether the coolant is flowing through the flow path, and a process of prohibiting the display device from displaying display items related to the concentration when it is determined that the coolant is not flowing through the flow path.

[0006] In an example of the present disclosure, when it is determined that the coolant is flowing through the flow path, the control device further executes a process of displaying the display item on the display device.

[0007] In an example of the present disclosure, the display item includes at least one of the concentration and a warning indicating whether the concentration is within a predetermined normal range.

[0008] In an example of the present disclosure, the machine tool further includes a pump for sending the coolant to the flow path. In the determination process, when the pump is driven, it is determined that the coolant is flowing through the flow path, and when the pump is not driven, it is determined that the coolant is not flowing through the flow path.

[0009] In an example of the present disclosure, the machine tool further includes an operation panel for receiving an operation on the machine tool. The display device is provided on the operation panel.

[0010] In an example of the present disclosure, the display device is provided on the concentration sensor.

[0011] In another example of the present disclosure, a control method for a machine tool capable of processing a workpiece is provided. The machine tool includes a display device, a flow path for a coolant, and a concentration sensor provided in the flow path for detecting the concentration of the coolant in the flow path. The control method includes determining whether the coolant is flowing through the flow path, and prohibiting, when it is determined that the coolant is not flowing through the flow path, displaying a display item related to the concentration on the display device.

[0012] In other examples of the present disclosure, a control program for a machine tool capable of machining workpieces is provided. The machine tool includes a display device, a coolant flow path, and a concentration sensor provided in the flow path for detecting the concentration of the coolant in the flow path. The control program causes the machine tool to execute a process of determining whether the coolant is flowing through the flow path, and a process of prohibiting the display device from displaying display items related to the concentration when it is determined that the coolant is not flowing through the flow path.

[0013] 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 connection with the accompanying drawings.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0015] 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 embodiment and each modification described below may be selectively combined as appropriate.

[0016] <A. Appearance of Machine Tool 100> First, with reference to FIG. 1, a machine tool 100 according to an embodiment will be described. FIG. 1 is a view showing the appearance of the machine tool 100.

[0017] 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 may be a vertical machining center. Alternatively, the machine tool 100 may be a lathe, or may be 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 additional machining in addition to removal machining.

[0018] The machine tool 100 includes, for example, a cover body 130, a chip conveyor 150, and an operation panel 200. The cover body 130, also called a splash guard, forms the appearance of the machine tool 100 and partitions and forms a machining area AR for the workpiece.

[0019] The machine tool 100 processes the workpiece while discharging coolant into the machining area AR. The coolant used for machining causes the cuttings of the workpiece to flow from the machining area AR to the chip conveyor 150. The chip conveyor 150 separates the cuttings of the workpiece from the coolant and discharges the cuttings outside the machine tool 100 through the discharge port 27. The coolant from which the cuttings of the workpiece have been removed is reused for machining the workpiece.

[0020] 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.

[0021] <B. Display inhibition process> Next, with reference to FIG. 2, the display inhibition process by the machine tool 100 will be described. FIG. 2 is a diagram for explaining the display inhibition process.

[0022] As shown in FIG. 2, the machine tool 100 includes a control device 50, a concentration sensor 70, and a display device 80 as components related to the display inhibition process.

[0023] The machine tool 100 machines a workpiece while discharging coolant into the machining area AR. The coolant discharged into the machining area AR circulates inside the machine tool 100. In FIG. 2, a flow path R1, which is a part of the coolant circulation path, is shown.

[0024] The flow path R1 is a pipe through which the coolant flows. The concentration sensor 70 is provided in the flow path R1. The concentration sensor 70 is configured to detect the concentration of the coolant in the flow path R1. The coolant concentration detected by the concentration sensor 70 is periodically output to the control device 50.

[0025] The concentration of the coolant changes while circulating inside the machine tool 100 due to evaporation of moisture. Therefore, the control device 50 displays the display items related to the coolant concentration on the display device 80. The operator can determine whether the coolant concentration is within the normal range by checking the display items.

[0026] The coolant contains foreign matter. Examples of such foreign matter include chips of the workpiece, sludge, oil, etc. When foreign matter adheres to the concentration sensor 70, the concentration value detected by the concentration sensor 70 becomes unstable. In particular, when the coolant is not flowing in the flow path R1, foreign matter tends to accumulate on the concentration sensor 70.

[0027] In a state where foreign matter has accumulated on the concentration sensor 70, an abnormality in the coolant concentration may be erroneously notified by the display device 80. When an abnormality in the coolant concentration is notified by the display device 80, the operator will clean the concentration sensor 70 and remove the foreign matter from the concentration sensor 70. However, the foreign matter adhering to the concentration sensor 70 often flows with the coolant when the coolant flows out. Therefore, when an abnormality in the coolant concentration is displayed on the display device 80 when the coolant is not flowing, the operator will perform an operation that is not originally necessary.

[0028] Therefore, the control device 50 determines whether the coolant is flowing through the flow path R1, and when it is determined that the coolant is not flowing through the flow path R1, prohibits the display device 80 from displaying display items related to the coolant concentration. The prohibition process is realized, for example, by the control device 50 discarding the detection value of the concentration sensor 70. Alternatively, the prohibition process may be realized by the control device 50 rewriting the detection value of the concentration sensor 70 to a specific value (for example, a NULL value, etc.). On the other hand, when the control device 50 determines that the coolant is flowing through the flow path R1, the control device 50 causes the display device 80 to display display items related to the coolant concentration. Thereby, the reliability of the coolant concentration measurement is improved. In addition, it is not necessary to trouble the operator with the unnecessary task of cleaning the concentration sensor 70.

[0029] The display items to be prohibited include, for example, at least one of the coolant concentration detected by the concentration sensor 70 and a warning indicating whether the coolant concentration is within a predetermined normal range. In the example of FIG. 2, the display of both the coolant concentration and the warning is prohibited.

[0030] On the other hand, when the control device 50 determines that the coolant is flowing through the flow path R1, the control device 50 releases the prohibition of the display items. That is, in this case, the control device 50 causes the display device 80 to display the coolant concentration detected by the concentration sensor 70 and a warning indicating whether or not the coolant concentration is within a predetermined normal range. The display mode of the warning is arbitrary. As an example, the warning may be displayed as a message indicating normal or abnormal, or may be indicated by a difference in color.

[0031] Note that the display device 80 is an arbitrary display device provided in the machine tool 100. As an example, the display device 80 may be the display 206 (see FIG. 1) provided on the operation panel 200 described above, or may be a display (not shown) provided on the concentration sensor 70.

[0032] <C. Chip discharge mechanism> Next, with reference to FIG. 3, a mechanism for discharging chips generated by machining a workpiece to the outside of the machine tool 100 will be described. FIG. 3 is a diagram schematically showing the state of the machining area AR in the machine tool 100.

[0033] As described above, the machine tool 100 includes a cover body 130. The cover body 130 forms the appearance of the machine tool 100 and partitions and forms a machining area AR for machining a workpiece. In the machining area AR, for example, a spindle 132, coolant discharge mechanisms 134 and 136, and a chip conveyor 150 are provided.

[0034] The spindle 132 is provided inside the housing and is rotatably supported by the housing. A tool T for machining a workpiece, which is the object to be machined, is mounted on 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.

[0035] The discharge mechanism 134 is a mechanism for discharging the clean coolant pumped from the flow path 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.

[0036] The discharge mechanism 136 discharges the clean coolant pumped from the flow path R1 toward the bed BD. By discharging the coolant from the discharge mechanism 136 onto the bed BD, the chips accumulated on the bed BD are discharged to the chip conveyor 150.

[0037] The chip conveyor 150 includes a housing 152, a drum filter 154, and a tank 156.

[0038] The housing 152 forms the exterior of the chip conveyor 150. Also, the housing 152 is configured such that the coolant used for machining the workpiece flows into it.

[0039] The drum filter 154 is rotatably supported with respect to the housing 152 and is configured to be able to collect foreign matters such as chips of the workpiece from the coolant. The coolant that has passed through the drum filter 154 is discharged into the tank 156 of the chip conveyor 150.

[0040] A pump P0 is provided in the tank 156. The pump P0 pumps up the coolant that has passed through the drum filter 154 and accumulated in the tank 156, and pumps the coolant into the flow path RA.

[0041] <D. Sludge separation mechanism> The coolant from which chips have been separated by the drum filter 154 contains sludge. Sludge is fine swarf generated by machining the workpiece.

[0042] Hereinafter, with reference to FIG. 4, the sludge separation mechanism will be described. FIG. 4 is a diagram showing an example of the sludge separation mechanism.

[0043] As shown in FIG. 4, the machine tool 100 includes a tank SU1 and a cyclone filter 400 as a sludge separation mechanism.

[0044] The coolant pumped from the above-described flow path RA (see FIG. 3) is stored in the tank SU1. The coolant stored in the tank SU1 contains sludge.

[0045] The cyclone filter 400 separates the coolant supplied from the tank SU1 into a clean coolant and a dirty coolant by centrifugal force. As a result, the sludge content in the clean coolant becomes less than the sludge content in the dirty coolant.

[0046] More specifically, a flow path R0, a flow path R1, and a flow path R2 are connected to the cyclone filter 400. The flow paths R0 to R2 are pipes.

[0047] One end of the flow path R0 is connected to the tank SU1. On the other hand, the other end of the flow path R0 is connected to the inlet of the cyclone filter 400. Also, a pump P1 is provided on the flow path R0. The pump P1 pumps the coolant in the tank SU1 into the flow path R0 and sends the coolant to the inlet of the cyclone filter 400.

[0048] The coolant sent to the cyclone filter 400 flows spirally inside the cyclone filter 400. 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 400. As a result, the dirty coolant containing a large amount of sludge is discharged into the flow path R2.

[0049] In addition, a throttle mechanism 402 is provided in the cyclone filter 400. The throttle mechanism 402 is a mechanism for restricting the flow rate of the dirty coolant flowing in the flow path R2. The throttle mechanism 402 provides resistance, and as the coolant flows spirally inside the cyclone filter 400, it rises in the direction opposite to the gravitational direction. As a result, the clean coolant free of sludge is discharged into the flow path R1.

[0050] Also, a pump P2 is provided on the flow path R1. The pump P2 pumps the clean coolant from the cyclone filter 400. Thereby, the clean coolant is pumped into the flow path R1 and sent to the above-described discharge mechanisms 134, 136, etc.

[0051] In the example of FIG. 4, an example is shown in which a concentration sensor 70 is provided on the flow path R1 through which the clean coolant flows, but the installation position of the concentration sensor 70 is not limited to the flow path R1. The concentration sensor 70 may be provided, for example, in the flow path RA or in the flow path R0.

[0052] <E. Concentration Sensor 70> Next, with reference to FIG. 5, the concentration sensor 70 shown in FIG. 2 described above will be explained. FIG. 5 is a diagram for explaining the internal configuration of the concentration sensor 70.

[0053] FIG. 5 shows a coolant CL flowing in the flow path R1. The concentration sensor 70 is inserted into the coolant CL.

[0054] When the concentration of the coolant CL changes, the refractive index of the coolant CL changes. The concentration sensor 70 detects the concentration of the coolant CL by utilizing such characteristics.

[0055] More specifically, the concentration sensor 70 includes a light source 71, a light projecting lens 72, a diffusion plate 73, a prism 74, a light receiving lens 75, and an imaging element 76.

[0056] The light source 71 is a light-emitting body such as an LED (Light Emitting Diode). The projection lens 72 is configured to receive the light emitted by the light source 71 and make the incident light received at each location parallel.

[0057] The diffuser plate 73 diffuses the parallel light that has passed through the projection lens 72. The light diffused by the diffuser plate 73 is received by the surface SF1 of the prism 74.

[0058] The surface SF2 of the prism 74 is in contact with the coolant CL. The light diffused by the diffuser plate 73 enters the prism 74 through the surface SF1 and is reflected by the surface SF2, which is the contact surface with the coolant CL. The reflected light exits the prism 74 through the surface SF3.

[0059] The light that has passed through the surface SF3 of the prism 74 is focused by the light-receiving lens 75 and received by the imaging element 76. The imaging element 76 is composed of, for example, CMOS (Complementary Metal-Oxide Semiconductor) sensors arranged in a row. When the concentration of the coolant CL changes, the refractive index changes, and the position of the light incident on the imaging element 76 changes. That is, the amount of light received by each CMOS changes according to the concentration of the coolant CL. Utilizing such characteristics, the concentration sensor 70 detects the coolant concentration.

[0060] When foreign matter adheres to the surface SF2 of the prism 74, the detection value of the concentration sensor 70 becomes unstable. In particular, when the coolant CL is not flowing through the flow path R1, foreign matter is likely to accumulate on the surface SF2 of the prism 74. When the coolant CL is not flowing through the flow path R1 in this way, the machine tool 100 does not display the display items regarding the detection value of the concentration sensor 70 on the display device 80. By prohibiting the display of the detection value of the concentration sensor 70 when the detection value is unstable, the reliability of the coolant concentration measurement is increased.

[0061] Also, when an abnormality in the coolant concentration is indicated on the display device 80, the operator will clean the prism 74. However, foreign matter adhering to the prism 74 often flows together with the coolant CL when the coolant CL flows out. Therefore, when an abnormality in the coolant CL concentration is displayed on the display device 80 when the coolant CL is not flowing, the operator will perform work that is not originally necessary. By not displaying the display items regarding the coolant CL concentration on the display device 80 when the coolant CL is not flowing through the flow path R1, it is possible to prevent the operator from being subjected to the above-mentioned unnecessary trouble.

[0062] In addition, in the above description, the concentration sensor 70 of the type inserted into the coolant CL has been described, but the type of the concentration sensor 70 is not limited to this. As an example, the concentration sensor 70 may be a sensor of a type in which only the surface SF2 of the prism 74 is in contact with the coolant CL. In this case, the surface SF2 of the prism 74 will form a part of the flow path R1, and the part other than the surface SF2 of the prism 74 will be provided outside the flow path R1. Also, in the above description, the optical concentration sensor 70 has been described, but the concentration sensor 70 is not limited to the optical type.

[0063] <F. Drive mechanism> Next, with reference to FIG. 6, various drive mechanisms in the machine tool 100 will be described. FIG. 6 is a diagram showing a configuration example of the drive mechanism in the machine tool 100.

[0064] As shown in FIG. 6, the machine tool 100 includes, as a configuration related to the drive mechanism, a control device 50, motor drivers 111A to 111D, motors MA to M3, the above-mentioned pumps P0 to P2, and the above-mentioned chip conveyor 150.

[0065] As described above, the pump P0 is a device for pumping coolant through the flow path RA (see FIGS. 3 and 4). A motor MA is connected to the pump P0. The motor MA may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0066] The motor MA is driven by a 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 device 50 and outputs an alternating current of a frequency corresponding to the control signal to the motor MA. Thereby, the rotational speed of the motor MA changes, and the flow rate of the coolant pumped through the above-described flow path RA is controlled.

[0067] As described above, the pump P1 is a device for pumping coolant through the flow path R0 (see FIG. 4). A motor MB is connected to the pump P1. The motor MB may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0068] The motor MB is driven by a motor driver 111B. The motor driver 111B is composed of a control circuit, an inverter, etc. The motor driver 111B receives an input of a control signal from the control device 50 and outputs an alternating current of a frequency corresponding to the control signal to the motor MB. Thereby, the rotational speed of the motor MB changes, and the flow rate of the coolant pumped through the above-described flow path R0 is controlled.

[0069] As described above, the pump P2 is a device for pumping coolant through the flow path R1 (see FIGS. 3 and 4). A motor MC is connected to the pump P2. The motor MC may be an AC motor, a stepping motor, a servo motor, or any other type of motor.

[0070] The motor MC 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 device 50 and outputs an alternating current with a frequency corresponding to the control signal to the motor MC. Thereby, the rotational speed of the motor MC changes, and the flow rate of the coolant pumped into the above-described flow path R1 is controlled.

[0071] A motor MD is connected to the above-described chip conveyor 150 (see FIG. 3). The motor MD may be an AC motor, a stepping motor, a servo motor, or other types of motors.

[0072] The motor MD 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 device 50 and outputs an alternating current with a frequency corresponding to the control signal to the motor MD. Thereby, the rotational speed of the motor MD changes, and the rotational speed of the conveyor in the chip conveyor 150 is controlled.

[0073] <Hardware Configuration of the G.CPU Unit 20> Next, with reference to FIG. 7, the hardware configuration of the CPU unit 20, which is an example of the control device 50 shown in FIG. 2 above, will be described. FIG. 7 is a diagram showing an example of the hardware configuration of the CPU unit 20.

[0074] The CPU unit 20 includes a control circuit 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, communication interfaces 104 and 105, and an auxiliary storage device 120. These components are connected to an internal bus 109.

[0075] The control circuit 101 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 (Graphics Processing Unit), at least one ASIC (Application Specific Integrated Circuit), at least one FPGA (Field Programmable Gate Array), or a combination thereof.

[0076] The control circuit 101 controls the operation of the CPU unit 20 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. The control circuit 101 reads the control program 122 from the auxiliary storage device 120 or the ROM 102 into the RAM 103 based on receiving an execution instruction of the control program 122. The RAM 103 functions as a working memory and temporarily stores various data necessary for the execution of the control program 122.

[0077] 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 concentration sensor 70 and the above-described motor drivers 111A to 111D. As the field network, for example, EtherCAT (registered trademark), EtherNet / IP (registered trademark), CC-Link (registered trademark), or CompoNet (registered trademark) is adopted.

[0078] A LAN, an antenna, etc. are connected to the communication interface 105. The CPU unit 20 is connected to a network via the communication interface 105. Thereby, the CPU unit 20 exchanges data with an external device connected to the network. The external device includes, for example, the above-described operation panel 200 and a server (not shown).

[0079] 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 a 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 it 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.

[0080] 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. Furthermore, some or all of the functions provided by the control program 122 may be realized by dedicated hardware. Furthermore, the control device 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.

[0081] <H. Hardware Configuration of the Operation Panel 200> Next, with reference to FIG. 8, the hardware configuration of an operation panel 200, which is an example of the control device 50 shown in FIG. 2 described above, will be described. FIG. 8 is a diagram showing an example of the hardware configuration of the operation panel 200.

[0082] 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.

[0083] The control circuit 201 is constituted by, for example, at least one integrated circuit. The integrated circuit may 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.

[0084] The control circuit 201 controls the operation of the control panel 200 by executing various programs such as the control program 222 and the operating system. Based on receiving the execution instruction of the control program 222, the control circuit 201 reads the control program 222 from the auxiliary storage device 220 or the ROM 202 into the RAM 203. The RAM 203 functions as a working memory and temporarily stores various data necessary for the execution of the control program 222.

[0085] A LAN, an antenna, etc. are connected to the communication interface 204. The control panel 200 is connected to the network via the communication interface 204. Thereby, the control panel 200 exchanges data with external devices connected to the network. The external devices include, for example, the above-mentioned CPU unit 20 and a server (not shown).

[0086] 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 devices. Note that the display 206 may be integrally configured with the control panel 200 or may be configured separately from the control panel 200.

[0087] 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 devices capable of receiving user operations. Note that the input device 208 may be integrally configured with the control panel 200 or may be configured separately from the control panel 200.

[0088] 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 and the like. The storage location of the control program 222 is not limited to the auxiliary storage device 220 and may be stored in the 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).

[0089] Also, the control program 222 may be provided not as a single program but incorporated into a part of an arbitrary 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 222 according to the present embodiment. Furthermore, part or all of the functions provided by the control program 222 may be realized by dedicated hardware. Furthermore, the control device 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 222.

[0090] <J. Flowchart> Next, with reference to FIG. 9, the display processing of the machine tool 100 will be described. FIG. 9 is a flowchart showing the flow of the display processing of the machine tool 100.

[0091] The processing shown in FIG. 9 is executed by the CPU unit 20 which is an example of the control device 50. Alternatively, the processing shown in FIG. 9 is executed by the operation panel 200 which is an example of the control device 50. Alternatively, the processing shown in FIG. 9 is realized by the cooperation of the CPU unit 20 and the operation panel 200 which are examples of the control device 50. In other aspects, part or all of the processing may be executed by a CNC (Computer Numerical Control), a circuit element, or other hardware.

[0092] In step S110, the control device 50 determines whether coolant is flowing in the flow path (for example, flow path R1) where the concentration sensor 70 is provided, based on the control information for controlling the flow of coolant in the machine tool 100. Hereinafter, the description will be made on the premise that the concentration sensor 70 is provided in the flow path R1, but the concentration sensor 70 may be provided in a flow path other than the flow path R1 (for example, flow paths R1, R0, etc.).

[0093] Whether the coolant is flowing in the flow path R1 is determined by various methods. As an example, when the above-described pump P2 for sending the coolant to the flow path R1 is driven, the control device 50 determines that the coolant is flowing in the flow path R1. On the other hand, when the pump P2 is not driven, the control device 50 determines that the coolant is not flowing in the flow path R1.

[0094] Note that the coolant circulates through the flow paths RA, R0, and R1. Therefore, the control device 50 may determine whether the coolant is flowing in the flow path R1 based on the control information of the above-described pump P0 for sending the coolant to the flow path RA, instead of the control information of the pump P2. Alternatively, the control device 50 may determine whether the coolant is flowing in the flow path R1 based on the control information of the above-described pump P1 for sending the coolant to the flow path R0.

[0095] As another example, a flow rate sensor (not shown) is provided in a coolant flow path (for example, any one of the flow paths RA, R0, R1, R2), and the control device 50 determines whether the coolant is flowing in the flow path R1 based on the output value of the flow rate sensor (not shown). In this case, when the output value of the flow rate sensor exceeds a predetermined value, the control device 50 determines that the coolant is flowing in the flow path R1. On the other hand, when the output value of the flow rate sensor is equal to or less than the predetermined value, the control device 50 determines that the coolant is not flowing in the flow path R1.

[0096] When the control device 50 determines that the coolant is flowing in the flow path R1 (YES in step S110), the control is switched to step S120. Otherwise (NO in step S110), the control device 50 switches the control to step S112.

[0097] In step S112, the control device 50 prohibits the display regarding the coolant concentration detected by the above-described concentration sensor 70. Since the prohibition process of the display is as described with reference to FIG. 2, the description thereof will not be repeated.

[0098] In step S120, the control device 50 acquires the coolant concentration detected by the above-described concentration sensor 70.

[0099] In step S130, the control device 50 determines whether or not the coolant concentration acquired in step S120 is within a predetermined normal range. The normal range is defined by at least one of a lower limit and an upper limit. The normal range may be set in advance or may be arbitrarily set by the user. When the control device 50 determines that the coolant concentration acquired in step S120 is within the predetermined normal range (YES in step S130), the control is switched to step S132. Otherwise (NO in step S130), the control device 50 switches the control to step S142.

[0100] In step S132, the control device 50 executes a display process for notifying that the coolant concentration is normal. As an example, the control device 50 displays the value of the coolant concentration and a message indicating that the coolant concentration is normal on the display device 80. Preferably, the value and the message are displayed in a specific color (for example, green) indicating normality.

[0101] In step S142, the control device 50 executes a display process for notifying that the coolant concentration is abnormal. As an example, the control device 50 displays the value of the coolant concentration and a message indicating that the coolant concentration is abnormal on the display device 80. Preferably, the value and the message are displayed in a color different from the display in step S132. As an example, the value and the message are displayed in a specific color indicating abnormality (for example, yellow or red).

[0102] In the above description, an example in which the process of step S120 is executed after the process of step S110 has been described. However, the process of step S120 may be executed before the process of step S110. In this case, the control device 50 acquires the coolant concentration from the concentration sensor 70 regardless of whether the coolant is flowing. Then, when the coolant is not flowing, the control device 50 discards the acquired coolant concentration.

[0103] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. 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 be included.

Explanation of reference numerals

[0104] 20 CPU unit, 27 discharge port, 50 control device, 70 concentration sensor, 71 light source, 72 light projection lens, 73 diffusion plate, 74 prism, 75 light receiving lens, 76 imaging device, 80 display device, 100 machine tool, 101 control circuit, 102 ROM, 103 RAM, 104 communication interface, 105 communication interface, 109 internal bus, 111A motor driver, 111B motor driver, 111C motor driver, 111D motor driver, 120 auxiliary storage device, 122 control program, 130 cover body, 132 spindle, 134 discharge mechanism, 136 discharge mechanism, 150 chip conveyor, 152 housing, 154 drum filter, 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, 400 cyclone filter, 402 throttle mechanism, AR machining area, BD bed, CL coolant, MA motor, MB motor, MC motor, MD motor, P0 pump, P1 pump, P2 pump, R0 flow path, R1 flow path, R2 flow path, RA flow path, SF1 surface, SF2 surface, SF3 surface, SU1 tank, T tool.

Claims

1. A machine tool capable of machining a workpiece, a display device, a coolant flow path, a concentration sensor provided in the flow path for detecting the concentration of the coolant in the flow path, and a control device, wherein the control device performs a process of determining whether or not the coolant is flowing through the flow path, and when it is determined that the coolant is not flowing through the flow path, performs a process of prohibiting the display device from displaying the display items related to the concentration. A machine tool.

2. The machine tool according to claim 1, wherein the control device further performs a process of displaying the display items on the display device when it is determined that the coolant is flowing through the flow path.

3. The display items include at least one of the concentration and a warning indicating whether or not the concentration is within a predetermined normal range. The machine tool according to claim 1 or 2.

4. The machine tool further includes a pump for sending the coolant to the flow path, and in the determining process, when the pump is driven, it is determined that the coolant is flowing through the flow path, and when the pump is not driven, it is determined that the coolant is not flowing through the flow path. The machine tool according to claim 1 or 2.

5. The machine tool further includes an operation panel for receiving an operation on the machine tool, and the display device is provided on the operation panel. The machine tool according to claim 1 or 2.

6. The display device is provided on the concentration sensor. The machine tool according to claim 1 or 2.

7. A control method for a machine tool capable of machining a workpiece, wherein the machine tool includes a display device, a coolant flow path, and a concentration sensor provided in the flow path for detecting the concentration of the coolant in the flow path, and the control method includes determining whether the coolant is flowing through the flow path, and prohibiting the display device from displaying display items related to the concentration when it is determined that the coolant is not flowing through the flow path.

8. A control program for a machine tool capable of machining a workpiece, wherein the machine tool includes a display device, a coolant flow path, and a concentration sensor provided in the flow path for detecting the concentration of the coolant in the flow path, and the control program causes the machine tool to perform a process of determining whether the coolant is flowing through the flow path, and a process of prohibiting the display device from displaying display items related to the concentration when it is determined that the coolant is not flowing through the flow path.

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