Monitoring device and monitoring method

Abstract

The present invention provides a monitoring device and a monitoring method capable of capturing the state of a cooling medium in detail. One embodiment of the monitoring device (14) includes: a first detection unit (16) for detecting a first physical quantity; a second detection unit (18) for detecting a second physical quantity; a ratio calculation unit (20) for calculating the ratio of a first value expressed in a predetermined unit to a second value expressed in a predetermined unit for the second physical quantity; and an estimation unit (22) for estimating that either the oil component or the electrolyte contained in the cooling medium is abnormal if the calculated ratio exceeds the upper limit of a management range or falls below the lower limit of a management range.

Description

TECHNICAL FIELD

[0001] The present application relates to a monitoring device and a monitoring method that monitor a cooling medium used in a machine tool. BACKGROUND

[0002] When a tool is used to machine a workpiece, a machine tool sprays a cooling medium to a machined portion. There are cases where the quality of a machined product changes depending on a change in the state of the cooling medium.

[0003] In Japanese Patent Application Publication No. 2017-87403, a control device of a machine tool is disclosed. The control device calculates a change ratio of the hydrogen ion concentration or the like of a cooling medium. Further, the control device causes the machine tool to perform an action to improve the state of the cooling medium in a case where it is determined from the calculated ratio that the state of the cooling medium is deteriorated. SUMMARY

[0004] However, the control device of Japanese Patent Application Publication No. 2017-87403 only monitors the change ratio of the hydrogen ion concentration or the like of the cooling medium. Therefore, it is not possible to grasp which component of the cooling medium is abnormal (deteriorated) in its state. Therefore, there is a case where the state of the cooling medium is not improved despite the control of the state of the cooling medium to improve it.

[0005] Therefore, an object of the present application is to provide a monitoring device and a monitoring method that can capture the state of a cooling medium in detail.

[0006] A first aspect of the present application is a monitoring device that monitors a cooling medium used in a machine tool, the monitoring device comprising:

[0007] a first detection unit that detects a first physical quantity;

[0008] a second detection unit that detects a second physical quantity different from the first physical quantity;

[0009] a ratio calculation unit that calculates a ratio of a first value when the first physical quantity is expressed in a prescribed unit to a second value when the second physical quantity is expressed in the prescribed unit; and

[0010] a presumption unit that presumes that one of an oil component and an electrolyte contained in the cooling medium is abnormal in a case where the ratio calculated by the ratio calculation unit exceeds an upper limit value of a management range of the ratio that is set in advance or is lower than a lower limit value of the management range.

[0011] A second aspect of the present application is a monitoring method that monitors a cooling medium used in a machine tool, the monitoring method comprising:

[0012] a first detection step of detecting a first physical quantity;

[0013] a second detection step of detecting a second physical quantity different from the first physical quantity;

[0014] a ratio calculation step of calculating a ratio of a first value of the first physical quantity expressed in a prescribed unit to a second value of the second physical quantity expressed in the prescribed unit; and

[0015] a presumption step of presuming that one of an oil component and an electrolyte contained in the cooling medium is abnormal in a case where the ratio calculated in the ratio calculation step exceeds an upper limit value of a management range of the ratio set in advance or is lower than a lower limit value of the management range.

[0016] According to the embodiment of the present application, a monitoring device and a monitoring method capable of capturing a change in a state of a cooling medium in detail are provided. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic view showing a monitoring system of the embodiment.

[0018] Figure 2 is a flowchart showing steps of a monitoring process. DETAILED DESCRIPTION

[0019] A preferred embodiment of the present application will be given below and described in detail with reference to the accompanying drawings.

[0020] [EMBODIMENT]

[0021] Figure 1 is a schematic view showing a monitoring system 10 of the embodiment. The monitoring system 10 is provided with a machine tool 12 and a monitoring device 14.

[0022] The machine tool 12 machines a work object by relatively moving a tool with respect to the work object. As a kind of machining, cutting or grinding or the like can be given. The machine tool 12 sprays a cooling medium to a contact portion of the work object and the tool when machining the work object. The machine tool 12 has a tank 12A that stores the cooling medium. The machine tool 12 supplies the cooling medium stored in the tank 12A to the contact portion of the work object and the tool when machining the work object. In addition, an oil component and an electrolyte are contained in the cooling medium.

[0023] The monitoring device 14 monitors the cooling medium used in the machine tool 12. The monitoring device 14 can be a control device that controls the machine tool 12 or can be a device different from the control device. The monitoring device 14 has a first detection section 16, a second detection section 18, a ratio calculation section 20, a presumption section 22, and a notification section 24.

[0024] The first detecting section 16 is a sensor that detects a first physical quantity. The first detecting section 16 is provided on the tank 12A or the cooling medium flow path of the machine tool 12. The first physical quantity is preferably related to an oil component contained in the cooling medium. As such a first physical quantity, for example, a dielectric constant or a hydrogen ion concentration can be cited. In the case where the first physical quantity is the dielectric constant, as a specific example of the first detecting section 16, an electrostatic capacitance sensor can be cited. In addition, in the case where the first physical quantity is the hydrogen ion concentration, as a specific example of the first detecting section 16, a hydrogen ion concentration meter can be cited. In the present embodiment, the first physical quantity is the hydrogen ion concentration.

[0025] The second detecting section 18 is a sensor that detects a second physical quantity different from the first physical quantity. The second detecting section 18 is provided, for example, on the tank 12A or the cooling medium flow path of the machine tool 12. The second physical quantity is preferably related to an electrolyte contained in the cooling medium. As such a second physical quantity, for example, an electric conductivity can be cited. In the case where the second physical quantity is the electric conductivity, as a specific example of the second detecting section 18, an electric conductivity sensor or the like can be cited. In the present embodiment, the second physical quantity is the electric conductivity. In the case where the second physical quantity is the electric conductivity, the electrolyte contained in the cooling medium can be directly acquired, and the behavior of the electrolyte can be accurately grasped as compared with other physical quantities.

[0026] The ratio calculating section 20 calculates a ratio of a first value when the first physical quantity (hydrogen ion concentration) is expressed in a prescribed unit to a second value when the second physical quantity (electric conductivity) is expressed in a prescribed unit. The prescribed unit of the first value and the prescribed unit of the second value can be the same or different. As a specific example of the ratio calculating section 20, a processor represented by a CPU or an MPU or the like can be cited. The ratio calculating section 20 acquires the first physical quantity (hydrogen ion concentration) from the first detecting section 16 and acquires the second physical quantity (electric conductivity) from the second detecting section 18. In the present embodiment, the ratio calculating section 20 calculates a ratio of the second value to the first value. That is, the ratio calculating section 20 calculates a ratio (second value / first value) with the first value as the denominator and with the second value as the numerator.

[0027] The estimating section 22 estimates that one of the oil component and the electrolyte contained in the cooling medium is abnormal. As a specific example of the estimating section 22, a processor represented by a CPU or an MPU or the like can be cited. The estimating section 22 has a memory that holds an upper limit value and a lower limit value of a management range. In addition, the estimating section 22 can also read out the upper limit value and the lower limit value of the management range stored in the memory possessed by the monitoring device 14 and hold the read-out upper limit value and lower limit value.

[0028] In the present embodiment, the ratio calculated by the ratio calculation portion 20 is a ratio of the second value to the first value (second value / first value). The first value is a value related to the oil component contained in the coolant medium, and is a value converted into the first physical quantity. The second value is a value related to the electrolyte contained in the coolant medium, and is a value converted into the second physical quantity. Therefore, the ratio of the second value to the first value indicates the proportion of the oil component to the electrolyte in the coolant medium.

[0029] The more the amount of the oil component in the coolant medium exceeds the amount of the electrolyte, the smaller the ratio of the second value to the first value. Therefore, in a case where the ratio of the second value to the first value is lower than the lower limit value of the management range, it means that the possibility of excessive increase in the amount of the oil component in the coolant medium is high. As a case of excessive increase in the amount of the oil component in the coolant medium, for example, there can be mentioned a case where oil different from the oil component originally contained in the coolant medium is mixed in the coolant medium. In addition, in a case where oil different from the oil component originally contained in the coolant medium is mixed in the coolant medium, the amount of the electrolyte in the coolant medium is substantially not changed.

[0030] On the other hand, the more the amount of the electrolyte in the coolant medium exceeds the amount of the oil component, the larger the ratio of the second value to the first value. Therefore, in a case where the ratio of the second value to the first value exceeds the upper limit value of the management range, it means that the possibility of excessive increase in the amount of the electrolyte in the coolant medium is high. As a case of excessive increase in the amount of the electrolyte in the coolant medium, there can be mentioned a case where the coolant medium is excessively evaporated.

[0031] In addition, in a case where both the amount of the oil component and the amount of the electrolyte in the coolant medium are increased or decreased, the ratio of the second value to the first value is substantially not changed. Therefore, in a case where the ratio of the second value to the first value is within the management range, the coolant medium is normal. On the other hand, in a case where one of the amount of the oil component and the amount of the electrolyte in the coolant medium is increased and the other is decreased, if the ratio of the second value to the first value is outside the range of the management range, the coolant medium is abnormal.

[0032] In a case where the ratio of the second value to the first value is lower than the lower limit value of the management range, the estimation portion 22 estimates that the oil component contained in the coolant medium is abnormal. On the other hand, in a case where the ratio of the second value to the first value exceeds the upper limit value, the estimation portion 22 estimates that the electrolyte contained in the coolant medium is abnormal. In addition, in a case where the ratio of the second value to the first value is within the management range, the estimation portion 22 estimates that the coolant medium is normal.

[0033] The notification section 24 notifies of the result of the estimation by the estimation section 22. As a specific example of the notification section 24, a processor typified by a CPU or an MPU, or the like can be given. The notification section 24 notifies of the result of the estimation by the estimation section 22 by controlling at least one of a speaker, a light emitting section, and a display section. In addition, at least one of the speaker, the light emitting section, and the display section can be provided on the monitoring device 14, or can be provided on a device outside the monitoring device 14.

[0034] In a case where the notification section 24 controls the speaker, the result of the estimation by the estimation section 22 can be notified by generating a sound indicating the result of the estimation by the estimation section 22. In a case where the notification section 24 controls the light emitting section, the result of the estimation by the estimation section 22 can be notified by flickering in a flickering state corresponding to the result of the estimation by the estimation section 22. In a case where the notification section 24 controls the display section, the result of the estimation by the estimation section 22 can be notified by causing the display section to display a character indicating the result of the estimation by the estimation section 22.

[0035] In addition, the notification section 24 can also prompt an improvement strategy for improving the result of the estimation by the estimation section 22. For example, in a case where it is estimated that the oil component contained in the cooling medium is abnormal, the notification section 24 displays a warning message such as "It is likely that oil different from the component of the cooling medium has been mixed in the cooling medium. Please replace the cooling medium." on the display section. On the other hand, in a case where it is estimated that the electrolyte contained in the cooling medium is abnormal, the notification section 24 displays a warning message such as "It is likely that the cooling medium has evaporated excessively. Please replenish water." on the display section.

[0036] Next, the flow of the monitoring process of the monitoring device 14 will be described with respect to the monitoring method of the monitoring device 14. Figure 2 is a flowchart indicating the steps of the monitoring process.

[0037] In step S1, the first detection section 16 detects the hydrogen ion concentration as the first physical quantity related to the oil component contained in the cooling medium. When the first detection section 16 detects the first physical quantity per unit time, the monitoring process proceeds to step S2.

[0038] In step S2, the second detection section 18 detects the electric conductivity as the second physical quantity related to the electrolyte contained in the cooling medium. When the second detection section 18 detects the second physical quantity per unit time, the monitoring process proceeds to step S3.

[0039] In step S3, the ratio calculating section 20 calculates a ratio (second value / first value) based on the first physical quantity (hydrogen ion concentration) detected in step S1 and the second physical quantity (conductivity) detected in step S2. The first value is a value indicating the first physical quantity (hydrogen ion concentration) in a prescribed unit, and the second value is a value indicating the second physical quantity (conductivity) in a prescribed unit. When the ratio calculating section 20 calculates the ratio, the monitoring process shifts to step S4.

[0040] In step S4, the estimation section 22 compares the ratio calculated in step S3 with the upper limit value and the lower limit value of the management range of the ratio set in advance. Here, in a case where the ratio is equal to or lower than the upper limit value of the management range and the ratio is equal to or higher than the lower limit value of the management range (in a case where the ratio is within the management range), the estimation section 22 estimates that the cooling medium is normal. In this case, the monitoring process returns to step S1.

[0041] On the other hand, in a case where the ratio calculated in step S3 is lower than the lower limit value of the management range, the estimation section 22 estimates that the oil component contained in the cooling medium is abnormal. In addition, in a case where the ratio calculated in step S3 exceeds the upper limit value of the management range, it is estimated that the electrolyte contained in the cooling medium is abnormal. In a case where the estimation section 22 estimates that one of the oil component and the electrolyte contained in the cooling medium is abnormal, the monitoring process shifts to step S5.

[0042] In step S5, the notification section 24 notifies the result estimated in step S4. For example, in a case where a setting of desiring to prompt an improvement strategy of the cooling medium is made from the input section of the monitoring device 14, the notification section 24 prompts an improvement strategy for improving the result estimated in step S4. When a prescribed time elapses from the start of notification by the notification section 24, the monitoring process ends.

[0043] Thus, the monitoring device 14 of the present embodiment estimates that one of the oil component and the electrolyte contained in the cooling medium is abnormal based on the ratio of the first value and the second value. Thereby, the monitoring device 14 can capture the state of the cooling medium in detail.

[0044] [Modified Example]

[0045] The ratio calculating section 20 can calculate the ratio of the first value with respect to the second value instead of the ratio of the second value with respect to the first value. That is, the ratio calculating section 20 can calculate a ratio (first value / second value) in which the second value is the denominator and the first value is the numerator.

[0046] In the present modified example, the more the amount of the oil component in the cooling medium than the amount of the electrolyte, the larger the ratio of the first value with respect to the second value. In addition, in the present modified example, the more the amount of the electrolyte in the cooling medium than the amount of the oil component, the smaller the ratio of the first value with respect to the second value.

[0047] Therefore, in the present modification example, in a case where the ratio of the first value to the second value exceeds the upper limit value of the management range, the estimation unit 22 estimates that the oil component contained in the cooling medium is abnormal. In addition, in a case where the ratio of the first value to the second value is lower than the lower limit value of the management range, the estimation unit 22 estimates that the electrolyte is abnormal.

[0048] Thus, the monitoring device 14 can capture the state of the cooling medium in detail, as with the above-described embodiment.

[0049] [INVENTION]

[0050] As the invention that can be grasped from the above-described embodiment and modification example, the first and second inventions are described below.

[0051] (First Invention)

[0052] The first invention is a monitoring device (14) that monitors a cooling medium used in a machine tool (12). The monitoring device (14) includes a first detection unit (16) that detects a first physical quantity, a second detection unit (18) that detects a second physical quantity different from the first physical quantity, a ratio calculation unit (20) that calculates a ratio of a first value when the first physical quantity is expressed in a prescribed unit to a second value when the second physical quantity is expressed in the unit, and an estimation unit (22) that estimates that one of an oil component contained in the cooling medium and an electrolyte is abnormal in a case where the ratio calculated by the ratio calculation unit (20) exceeds an upper limit value of a management range of the ratio that is set in advance or is lower than a lower limit value of the management range. Thus, the state of the cooling medium can be captured in detail.

[0053] In a case where the ratio of the second value to the first value is lower than the lower limit value of the management range or in a case where the ratio of the first value to the second value exceeds the upper limit value of the management range, the estimation unit (22) estimates that the oil component is abnormal. Thus, the state of the cooling medium can be captured in detail.

[0054] In a case where the ratio of the second value to the first value exceeds the upper limit value of the management range or in a case where the ratio of the first value to the second value is lower than the lower limit value of the management range, the estimation unit (22) estimates that the electrolyte is abnormal. Thus, the state of the cooling medium can be captured in detail.

[0055] A notification unit (24) that notifies the result estimated by the estimation unit (22) can be included. Thus, the operator can be alerted to pay attention to the abnormality of the cooling medium component.

[0056] The notification unit (24) can also prompt an improvement measure for improving the result estimated by the improvement estimation unit (22). Thus, it is possible to simplify determination of the cause of the abnormality of the cooling medium composition for the operator and to easily restore the cooling medium to normal.

[0057] (Second Invention)

[0058] The second invention is a monitoring method of monitoring a cooling medium used in a machine tool (12). The monitoring method includes a first detection step (SI) of detecting a first physical quantity, a second detection step (S2) of detecting a second physical quantity different from the first physical quantity, a ratio calculation step (S3) of calculating a ratio of a first value when the first physical quantity is expressed in a prescribed unit to a second value when the second physical quantity is expressed in the unit, and an estimation step (S4) of estimating that one of an oil component and an electrolyte contained in the cooling medium is abnormal in a case where the ratio calculated in the ratio calculation step (S3) exceeds an upper limit value of a management range of the ratio set in advance or is lower than a lower limit value of the management range. Thus, it is possible to capture the state of the cooling medium in detail.

[0059] The estimation step (S4) can estimate that the oil component is abnormal in a case where the ratio of the second value to the first value is lower than the lower limit value of the management range or in a case where the ratio of the first value to the second value exceeds the upper limit value of the management range. Thus, it is possible to capture the state of the cooling medium in detail.

[0060] The estimation step (S4) can estimate that the electrolyte is abnormal in a case where the ratio of the second value to the first value exceeds the upper limit value of the management range or in a case where the ratio of the first value to the second value is lower than the lower limit value of the management range. Thus, it is possible to capture the state of the cooling medium in detail.

[0061] The monitoring method can include a notification step (S5) of notifying a result estimated in the estimation step (S4). Thus, it is possible to make the operator aware of the abnormality of the cooling medium composition.

[0062] The notification step (S5) can prompt an improvement measure for improving the result estimated in the estimation step (S4). Thus, it is possible to simplify determination of the cause of the abnormality of the cooling medium composition for the operator and to easily restore the cooling medium to normal.

Claims

1. A monitoring device (14) for monitoring the cooling medium used in a machine tool (12), characterized in that it comprises: The first detection unit (16) detects the first physical quantity; The second detection unit (18) detects a second physical quantity that is different from the first physical quantity; The ratio calculation unit (20) calculates the ratio of a first value expressed in a specified unit to a second value expressed in the specified unit for the first physical quantity; and The estimation unit (22) estimates that either the oil component or the electrolyte contained in the cooling medium is abnormal if the ratio calculated by the ratio calculation unit exceeds the upper limit of the preset management range of the ratio or is lower than the lower limit of the management range. If the ratio of the second value to the first value is lower than the lower limit of the management range, or if the ratio of the first value to the second value exceeds the upper limit of the management range, the estimation unit presumes that the oil composition is abnormal. If the ratio of the second value to the first value exceeds the upper limit of the management range, or if the ratio of the first value to the second value is lower than the lower limit of the management range, the presumption unit presumes that the electrolyte is abnormal.

2. The monitoring device according to claim 1, characterized in that, It also has a notification unit (24) that notifies the estimation unit of the estimated result.

3. The monitoring device according to claim 2, characterized in that, The notification section suggests improvement strategies for the results estimated by the estimation section.

4. A method for monitoring the cooling medium used in a machine tool, characterized in that it includes: The first detection step (S1) involves detecting the first physical quantity; The second detection step (S2) involves detecting a second physical quantity that is different from the first physical quantity. The ratio calculation step (S3) calculates the ratio of the first value when the first physical quantity is expressed in a specified unit to the second value when the second physical quantity is expressed in the specified unit; as well as In the estimation step (S4), if the ratio calculated in the ratio calculation step exceeds the upper limit of the preset management range of the ratio or falls below the lower limit of the management range, it is estimated that either the oil component or the electrolyte contained in the cooling medium is abnormal. In the presumption step, if the ratio of the second value to the first value is lower than the lower limit of the management range, or if the ratio of the first value to the second value exceeds the upper limit of the management range, the oil composition is presumed to be abnormal. In the presumption step, if the ratio of the second value to the first value exceeds the upper limit of the management range, or if the ratio of the first value to the second value is lower than the lower limit of the management range, the electrolyte abnormality is presumed.

5. The monitoring method according to claim 4, characterized in that, It also includes a notification step (S5) that notifies the result presumed in the presumption step.

6. The monitoring method according to claim 5, characterized in that, The notification step suggests improvement strategies for the results estimated in the estimation step.

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