Filter management device

Abstract

A filter management device according to the present disclosure comprises: a reception unit that receives concentration information indicating an oil mist concentration from a concentration meter that measures the oil mist concentration in a machining chamber of a machine tool; a rotational speed control unit that, on the basis of the received concentration information, controls the rotational speed of a fan motor of a mist collector that recovers the oil mist in the machining chamber by means of a filter; a determination unit that, on the basis of the controlled rotational speed of the fan motor, determines whether an abnormality has occurred in the filter or replacement of the filter is required; and a warning generation unit that generates a warning when it is determined that an abnormality has occurred in the filter or replacement of the filter is required.

Description

Filter Management Device

[0001] The present disclosure relates to a filter management device that manages a filter of a mist collector.

[0002] Lubricating oil is used during the operation of machine tools, performing various functions such as reducing friction in mechanical components such as ball screws, sealing the machine, cooling, and cleaning. When this lubricating oil disperses and turns into fine particles, it is generally referred to as oil mist. Oil mist is harmful to humans, reduces work efficiency, and can cause electronic device failures. Therefore, mist collectors are known for removing oil mist that fills spaces where lubricating oil is used (see, for example, Patent Document 1). Various methods for removing oil mist using mist collectors are known. For example, a filter method collects oil mist by filtering air containing oil mist sucked in by a fan motor. In filter-type mist collectors, if the filter becomes clogged with oil from the oil mist, the suction power decreases, reducing the oil mist removal effect. Therefore, to prevent a decrease in the oil mist removal effect, clogged filters must be replaced. However, because the timing for filter replacement is not clear, in actual practice, filters are replaced even when they have not yet become clogged, and filters that have already lost most of their effectiveness continue to be used.

[0003] Japanese Patent Application Laid-Open No. 2002-239323

[0004] There is a need to propose a technology that can grasp the condition of the mist collector filter.

[0005] The filter management device according to the present disclosure comprises a receiving unit that receives concentration information indicating oil mist concentration from a concentration meter that measures the oil mist concentration in the machining chamber of a machine tool; a rotation speed control unit that controls the rotation speed of a fan motor of a mist collector that collects oil mist in the machining chamber using a filter based on the received concentration information; a determining unit that determines whether a filter abnormality has occurred or whether the filter needs to be replaced based on the controlled rotation speed of the fan motor; and a warning generating unit that generates a warning when it is determined that a filter abnormality has occurred or the filter needs to be replaced.

[0006] FIG. 1 is a diagram showing a filter management system including a filter management device according to the present embodiment. FIG. 2 is a hardware configuration diagram of the filter management device according to the present embodiment. FIG. 3 is a functional block diagram of the filter management device according to the present embodiment. FIG. 4 is a diagram showing an example of a pattern of fan motor rotation speed control by the rotation speed control unit of FIG. 3. FIG. 5 is a diagram showing another example of a pattern of fan motor rotation speed control by the rotation speed control unit of FIG. 3. FIG. 6 is a diagram showing an example of a threshold information management table stored in the storage unit of FIG. 3. FIG. 7 is a supplementary diagram for explaining an example of a determination process by the determination unit of FIG. 2. FIG. 8 is a supplementary diagram for explaining another example of a determination process by the determination unit of FIG. 2. FIG. 9 is a diagram showing another example of a threshold information management table stored in the storage unit of FIG. 3.

[0007] The filter management device according to the present embodiment will be described with reference to the drawings. In the following description, components having substantially the same functions and configurations are designated by the same reference numerals, and redundant description will be given only when necessary.

[0008] In this embodiment, the terms are defined as follows: Machine tool: A machine tool is a device that produces molded parts or performs predetermined processes such as joining molded parts to supplied workpieces or machining them. In particular, in this embodiment, machine tools refer to various devices that generate oil mist during operation, such as turning machines and cutting machines. Work room: A space that is separated from the outside by a cover that entirely covers the machining tools. Typically, the work room is one element that makes up the machine tool. However, the work room may also be a room in which the machine tool is located. Concentration meter: A device that measures the oil mist concentration within the work room. Typically, the concentration meter is an external device that is independent of the machine tool. However, the concentration meter may also be one element that makes up the machine tool. Mist collector: A device that collects oil mist within the work room. In this embodiment, it is assumed to be a filter-type mist collector.

[0009] The filter management device according to this embodiment has the function of determining whether a filter installed in a mist collector has an abnormality or whether the filter needs to be replaced. The basic principle of this determination process is as follows. Filters with reduced filter performance, such as filters with an abnormality or filters that are clogged to the point of needing replacement, are collectively referred to as abnormal filters.

[0010] That is, when the oil mist generation conditions (e.g., the concentration, amount, and timing of oil mist generated in the machining chamber) and the oil mist collection conditions (e.g., the amount of oil mist collected and the change in the amount over time) are the same, the oil mist concentration in the machining chamber increases more rapidly when a faulty filter is used in the mist collector than when a normal filter is used in the mist collector, and the increased oil mist concentration is difficult to reduce. This is because the amount of air that can be taken into the mist collector decreases when a faulty filter is used, and the oil mist collection efficiency (amount collected) by the filter decreases compared to when a normal filter is used. Therefore, if the change in oil mist concentration over time when a normal filter and the change in oil mist concentration over time when a faulty filter are known, it is possible to determine whether the filter used in the mist collector has an abnormality or whether the filter needs to be replaced from the change in oil mist concentration currently being measured.

[0011] The filter management device of this embodiment controls the rotation speed of the mist collector fan motor according to the oil mist concentration, and uses the basic principles of the above-mentioned determination process to determine whether a filter abnormality has occurred or whether the filter needs to be replaced. Note that in this embodiment, the rotation speed refers to the number of rotations per unit time.

[0012] Typically, the filter management device according to this embodiment is configured as follows: As shown in Fig. 1 , the filter management device 2 according to this embodiment is a device that functions as the core of the filter management system 1. The filter management system 1 includes the filter management device 2, a machine tool 5, a concentration meter 6, and a mist collector 7.

[0013] The machine tool 5 has a machining room 52 and a control panel 55 that controls the entire machine tool 5. Specifically, the control panel 55 has a function of setting machining conditions and a function of controlling the operation of machining tools in the machining room 52 in accordance with the machining conditions. The control panel 55 also has a function of transmitting data related to the machining conditions to the filter management device 2 in response to a request for acquisition of the machining conditions from the filter management device 2. The control panel 55 is realized by a numerical control device, a PC, or the like. The machining conditions here include conditions that can change the concentration, amount, timing, etc. of oil mist generated in the machining room when the machine tool 5 operates in accordance with the machining conditions. Examples of such conditions include machining time, machining speed, type of lubricant, and amount of lubricant supplied.

[0014] The concentration meter 6 measures the oil mist concentration in the work chamber 52 and transmits concentration information indicating the oil mist concentration to the filter management device 2. The mist collector 7 has a housing 72 installed outside the work chamber 52. The work chamber 52 and the housing 72 are connected by a duct 71. Inside the housing 72, there are disposed a fan 75 for sucking air from the work chamber 52 together with the oil mist, a filter 73 for recovering oil mist from the air sucked by the fan 75, and a fan motor 77 for driving the fan 75. Inside or outside the housing 72, there is disposed a driver (not shown) for controlling the rotation speed of the fan motor 77. The driver generates a drive current according to a rotation speed command value (referred to as a rotation speed command value) input from an input device (not shown) provided in the mist collector 7 or from the filter management device 2 connected to the mist collector 7. The drive current generated by the driver is supplied to the fan motor 77. As a result, the fan motor 77 rotates at the rotation speed specified by the command value.

[0015] Fig. 2 is a hardware configuration diagram of the filter management device 2. As shown in Fig. 2, the filter management device 2 is configured such that a RAM 12, a ROM 13, a storage device 14, a mist collector I / F 15, a concentration meter I / F 16, a machine tool I / F 17, an input device 18, a display device 19, a speaker 20, and a signal light 21 are connected to a processor 11 via a data / control bus 10.

[0016] The processor 11 is realized by a CPU, a GPU, etc. The RAM 12 functions as the main memory, work area, etc. of the processor 11. The ROM 13 stores the BIOS, the OS, etc. The storage device 14 stores a filter management program. The various data stored in the storage device 14 may be recorded on removable media and distributed to users, or may be distributed by being downloaded to the filter management device 2 via a network.

[0017] The mist collector 7 is connected to the mist collector I / F 15. A rotation speed command value for the fan motor 77 is input from the filter management device 2 to the mist collector 7 via the mist collector I / F 15. The concentration meter 6 is connected to the concentration meter I / F 16. Concentration information indicating the oil mist concentration is input from the concentration meter 6 to the filter management device 2 via the concentration meter I / F 16. The machine tool 5 is connected to the machine tool I / F 17. A request to acquire machining conditions that are scheduled to be used or are currently being used is input from the filter management device 2 to the machine tool 5 via the machine tool I / F 17, and machining conditions that correspond to the acquisition request are input from the machine tool 5 to the filter management device 2.

[0018] The input device 18 is realized by a keyboard, a mouse, a jog, etc. A user can input various information to the filter management device 2 via the input device 18. The display device 19 is realized by an organic EL display, an LCD, etc. The display device 19 displays various screens under the control of the processor 11. The speaker 20 generates sound to notify the user of a warning or alarm under the control of the processor 11. The signal light 21 lights up under the control of the processor 11 to notify the user of a warning or alarm.

[0019] 3 is a functional block diagram of the filter management device 2. When the processor 11 executes the filter management program loaded from the storage device 14 to the RAM 12, the filter management device 2 functions as an input unit 30, a processing condition receiving unit 31, a concentration information receiving unit 32, a storage unit 33, a screen creating unit 34, a display unit 35, a condition setting unit 36, a rotation speed control unit 37, a determination unit 38, a sound generating unit 39, and a signal generating unit 40.

[0020] The input unit 30 is a function associated with the input device 18 in Fig. 2 and inputs user operations to the filter management device 2. The machining condition receiving unit 31 receives machining conditions from the control panel 55 of the machine tool 5. The concentration information receiving unit 32 receives concentration information indicating the oil mist concentration from the concentration meter 6. The memory unit 33 is a function associated with the storage device 14 in Fig. 2 and stores various information related to the processing of the filter management program. Specifically, the memory unit 33 stores data in a threshold information management table that summarizes threshold information. The threshold information management table will be described in detail later.

[0021] The screen creation unit 34 displays various screens related to the filter management program. Specifically, the screen creation unit 34 creates a condition setting screen, a warning screen, etc. For example, the condition setting screen is configured to allow a pattern for controlling the rotation speed of the fan motor 77 to be set. The warning screen is created when the determination unit 38 determines that an abnormality has occurred in the filter 73 or that replacement of the filter 73 is necessary. The warning screen is configured to allow the user to recognize that an abnormality has occurred in the filter 73 or that replacement of the filter 73 is necessary. For example, the warning screen may be configured to include a mark or text information indicating that an abnormality has occurred in the filter 73 or that replacement of the filter 73 is necessary, or the warning screen may be configured to be entirely or partially displayed in a warning color such as red or yellow.

[0022] 2, and displays the condition setting screen, warning screen, etc. created by the screen creation unit 34. In other words, the display unit 35 functions as a warning generation unit that generates a warning.

[0023] The condition setting unit 36 ​​sets a rotation speed control pattern for the fan motor 77 in accordance with user operations on the condition setting screen. The rotation speed control unit 37 controls the fan motor 77 in accordance with the rotation speed control pattern set by the user. Specifically, the rotation speed control unit 37 uses the set rotation speed control pattern to identify a rotation speed corresponding to the oil mist concentration and creates a rotation speed command value for rotating the fan motor 77 at the identified rotation speed. The rotation speed command value created by the rotation speed control unit 37 is sent to the mist collector 7.

[0024] The determination unit 38 determines whether an abnormality has occurred in the filter 73 or whether replacement of the filter 73 is necessary, based on the rotation speed of the fan motor 77. Details of the determination process by the determination unit 38 will be described later. The rotation speed of the fan motor 77 used in the determination process by the determination unit 38 is the rotation speed represented by a rotation speed command value generated by a rotation speed control unit 37 (described later) and transmitted to the mist collector 7, i.e., the expected value of the rotation speed at which the fan motor 77 will rotate. However, the rotation speed of the fan motor 77 used in the determination process by the determination unit 38 may also be the rotation speed based on the output of an encoder (not shown) provided on the fan motor 77, i.e., the actual rotation speed of the fan motor 77.

[0025] The sound generating unit 39 generates a predetermined sound (alarm sound) to notify the user of an alarm when the determination unit 38 determines that an abnormality has occurred in the filter 73 or that the filter 73 needs to be replaced. The sound generating unit 39 also generates a predetermined sound (warning sound) to notify the user of a warning when the determination unit 38 determines that there is a sign of an abnormality occurring in the filter 73 or that the filter 73 is close to needing replacement. That is, the sound generating unit 39 functions as a warning generating unit that generates a warning. The signal generating unit 40 generates a first signal to turn on the signal light 21 in a first mode when the determination unit 38 determines that there is a sign of an abnormality occurring in the filter 73 or that the filter 73 needs to be replaced. The signal generating unit 40 also generates a second signal to turn on the signal light 21 in a second mode when the determination unit 38 determines that there is a sign of an abnormality occurring in the filter 73 or that the filter 73 is close to needing replacement. For example, the first signal causes the signal light 21 to be lit in red, and the second signal causes the signal light 21 to be lit in yellow. Typically, the first mode is different from the second mode, but may be the same as the second mode. The signal generating unit 40 functions as a warning generating unit that generates a warning.

[0026] Hereinafter, variations of the control of the rotation speed of the fan motor 77 by the rotation speed control unit 37 will be described with reference to FIGS.

[0027] Fig. 4 shows an example of a control pattern for changing the rotation speed of the fan motor 77 in stages in accordance with fluctuations in the oil mist concentration. As shown in Fig. 4, in the first pattern, the fan motor 77 is rotated at the maximum rotation speed when the oil mist concentration is equal to or higher than concentration B1, and the rotation speed of the fan motor 77 is changed in five stages in accordance with fluctuations in the oil mist concentration until the rotation speed of the fan motor 77 reaches the maximum rotation speed.

[0028] FIG. 5 shows an example of a control pattern for continuously changing the rotation speed of the fan motor 77 in accordance with fluctuations in oil mist concentration. As shown in FIG. 5, the second, third, and fourth patterns indicate that the fan motor 77 rotates at the maximum rotation speed when the oil mist concentration is equal to or higher than concentration B1. The second pattern indicates that the rotation speed of the fan motor 77 increases linearly with fluctuations in oil mist concentration until it reaches the maximum rotation speed. The third pattern indicates that the rotation speed of the fan motor 77 increases quadratically with fluctuations in oil mist concentration until it reaches the maximum rotation speed. The fourth pattern indicates that the rotation speed of the fan motor 77 increases linearly and gradually with fluctuations in oil mist concentration while the oil mist concentration is low, and then increases linearly and significantly as the oil mist concentration increases.

[0029] The maximum rotation speed is not the maximum rotation speed in the specifications of the fan motor 77, but the maximum rotation speed controlled by the filter management device 2. Of course, the maximum rotation speed controlled by the filter management device 2 may be the maximum rotation speed in the specifications of the fan motor 77.

[0030] The threshold management table stored in the memory unit 33 will be described below with reference to FIG. 6 . FIG. 6 is a diagram showing an example of the threshold management table stored in the memory unit 33. As shown in FIG. 6 , in the threshold management table, the machining conditions, the rotation speed control pattern, and the duration of the maximum rotation speed are associated with the management number. The duration of the maximum rotation speed is the duration for which the rotation speed of the fan motor 77 remains at the maximum rotation speed, and is a threshold used in the determination process of the determination unit 38. For example, the management number “001” indicates that the threshold for the duration for which the rotation speed of the fan motor 77 remains at the maximum rotation speed when the machine tool 5 operates according to the first machining conditions and the rotation speed of the fan motor 77 of the mist collector 7 is controlled according to the first pattern is T11. The threshold is used to determine whether an abnormality has occurred in the filter 73 or whether replacement of the filter 73 is necessary. Therefore, threshold value T11 corresponds to the time during which the state in which the rotation speed of fan motor 77 indicates the maximum rotation speed continues when machine tool 5 operates in accordance with the first machining condition, the rotation speed of fan motor 77 of mist collector 7 is controlled in accordance with the first pattern, and an abnormal filter 73 is used as filter 73 of mist collector 7. Threshold value T11 may be a value actually measured using filter 73 having an abnormality, or may be a calculated value derived based on a simulation or the like.

[0031] If changes in the machining conditions cause changes in the concentration, amount, timing, and other conditions for generating oil mist in the machining chamber 52, it is desirable to set a threshold value for each machining condition of the machine tool 5. Also, if changes in the pattern of control of the rotation speed of the fan motor 77 cause fluctuations in the collection conditions, such as the amount and speed of oil mist collected, it is desirable to set a threshold value for each control pattern. This is because if either the conditions for generating oil mist in the machining chamber 52 or the conditions for collecting oil mist by the mist collector 7 differ, the change in the oil mist concentration over time will vary; in other words, the duration for which the fan motor 77 continues to rotate at its maximum rotation speed will vary due to factors other than changes in the state of the filter 73.

[0032] On the other hand, if it is not possible to control the rotation speed of the fan motor 77 of the mist collector 7, there is no need to set a threshold value for each control pattern. Similarly, if there is no change in the concentration, amount, timing, etc. of the oil mist generated in the machining chamber 52 depending on the machining conditions, or if the machine tool 5 always operates under the same machining conditions, there is no need to set a threshold value for each machining condition.

[0033] The determination process by the determination unit 38 will be described in detail below with reference to Fig. 7. Fig. 7 is a supplementary diagram for explaining an example of the determination process by the determination unit 38, and is a graph showing the change over time in the oil mist concentration measured by the concentration meter 6. Both of the two graphs 200, 300 show the change over time in the oil mist concentration when the first machining conditions are set for the machine tool 5 and the first pattern of rotation speed control is set for the fan motor 77. As shown in Fig. 4, the threshold value when the first machining conditions are set for the machine tool 5 and the first pattern is set for the fan motor 77 is T11.

[0034] The determination unit 38 compares the duration Tm1, during which the rotation speed of the fan motor 77 remains at the maximum rotation speed, in the first graph 200 with the threshold value T11. Because the duration Tm1 in the first graph 200 is less than the threshold value T11, the determination unit 38 determines that the filter 73 used in the mist collector 7 when the first graph 200 was acquired is a normal filter 73, and that no abnormality has occurred or that replacement of the filter 73 is not required.

[0035] Similarly, the determination unit 38 compares the duration Tm2, ​​during which the rotation speed of the fan motor 77 remains at the maximum rotation speed, in the second graph 300 with the threshold value T11. Because the duration Tm2 in the second graph 300 is equal to or greater than the threshold value T11, the determination unit 38 determines that an abnormality has occurred in the filter 73 used in the mist collector 7 when the second graph 300 was obtained, or that the filter 73 needs to be replaced.

[0036] As described above, the filter management device 2 according to this embodiment can determine whether an abnormality has occurred in the filter 73 or whether replacement of the filter 73 is necessary based on the controlled rotation speed of the fan motor 77. When it is determined that an abnormality has occurred in the filter 73 or that replacement of the filter 73 is necessary, the device can notify the user by sounding an alarm, turning on a signal light, or displaying a warning screen. This allows the user to grasp the condition of the filter 73, and can avoid situations where a filter 73 with low oil mist collection efficiency is used for an extended period of time due to the inability to grasp the condition of the filter 73, or where the filter 73 is replaced even though its performance has not yet deteriorated. In other words, the user can replace the filter at a more appropriate time from the viewpoint of using up the filter 73.

[0037] The above-mentioned determination process by the filter management device 2 according to this embodiment can be realized if the change over time in the oil mist concentration in the workshop 52 and the rotation speed of the fan motor 77 of the mist collector 7 can be acquired. Therefore, there is no need to install a new sensor, etc., and it can be said that the introduction cost of the technology according to this embodiment is very low.

[0038] In this embodiment, the time during which the fan motor 77 maintains its maximum rotational speed is used as a judgment parameter for determining whether an abnormality has occurred in the filter 73 or whether replacement of the filter 73 is necessary based on the rotational speed of the fan motor 77. This is based on the fact that, if the conditions for generating oil mist in the machining chamber 52 and the conditions for collecting the oil mist are the same, the oil mist concentration in the machining chamber 52 when an abnormal filter 73 is used in the mist collector 7 is less likely to decrease than the oil mist concentration in the machining chamber 52 when a normal filter 73 is used in the mist collector 7. Therefore, using the time during which the fan motor 77 maintains its maximum rotational speed as a judgment parameter can clearly differentiate between the use of a normal filter 73 and the use of an abnormal filter 73, thereby improving the accuracy of the judgment. Of course, the judgment parameter is not limited to the time during which the fan motor 77 maintains its maximum rotational speed. For example, it may be the time during which the rotation speed of the fan motor 77 continues to be equal to or greater than a predetermined rotation speed that is lower than the maximum rotation speed.

[0039] The gradient of the change in oil mist concentration over time may also be used as the judgment parameter. FIG. 8 is a supplementary diagram illustrating another example of the judgment process performed by the judgment unit 38, showing a graph representing the change in oil mist concentration over time measured by the concentration meter 6. The first and second graphs 200 and 300 in FIG. 8 are the same as those in FIG. 7. The judgment unit 38 calculates the gradient of the change in oil mist concentration over time, and when the calculated gradient is steeper than a threshold value, judges that an abnormality has occurred in the filter 73 or that replacement of the filter 73 is necessary. For example, the judgment unit 38 calculates gradients Gr2 and Gr3 for the first and second graphs 200 and 300, respectively, based on multiple measured values ​​of oil mist concentration within the range from B2 to B1, and compares these gradients with a threshold value. For example, when the gradient Gr2 is gentler than the threshold value, the judgment unit 38 judges that the filter 73 used in the mist collector 7 when the first graph 200 was acquired was a normal filter 73, that no abnormality has occurred, or that replacement of the filter 73 is not necessary. Similarly, if the gradient Gr3 is steeper than the threshold value, the determination unit 38 determines that the filter 73 used in the mist collector 7 when the second graph 300 was acquired is malfunctioning or needs to be replaced. The range of measurements used to calculate the gradient is not limited to the above. For example, the range may be a range in which the rotation speed of the fan motor 77 is equal to or greater than a predetermined rotation speed and the oil mist concentration reaches its maximum concentration.

[0040] This utilizes the fact that, if the conditions for generating oil mist in the machining chamber 52 and the conditions for collecting the oil mist generated in the machining chamber 52 are the same, the oil mist concentration in the machining chamber 52 when a faulty filter 73 is used in the mist collector 7 will rise more steeply than the oil mist concentration in the machining chamber 52 when a normal filter 73 is used in the mist collector 7. Therefore, using the gradient of the change in oil mist concentration over time as the judgment parameter produces a clear difference between the case where a normal filter 73 is used and the case where a faulty filter 73 is used, and therefore can improve the accuracy of the judgment, just as when the time during which the fan motor 77 continues to rotate at its maximum speed is used as the judgment parameter.

[0041] In the present embodiment, one threshold value is used in the determination process of the determination unit 38. However, multiple threshold values ​​may be used in the determination process of the determination unit 38. FIG. 9 is a diagram showing another example of a threshold value management table stored in the storage unit 33. As shown in FIG. 9, in the threshold value management table 400, a processing condition, a rotation speed control pattern, a first duration of the maximum rotation speed, and a second duration of the maximum rotation speed are associated with a management number. The first duration of the maximum rotation speed (first threshold value) is a threshold value used to determine whether an abnormality has occurred in the filter 73 or whether replacement of the filter 73 is necessary. The second duration of the maximum rotation speed (second threshold value) is a threshold value used to determine whether an abnormality will occur in the filter 73 or whether the replacement time for the filter 73 is approaching. Like the first threshold value, the second threshold value may be obtained by actual measurement or may be a calculated value derived by simulation or the like.

[0042] 7 , the determination unit 38 compares the duration Tm1, during which the rotation speed of the fan motor 77 remains at the maximum rotation speed, in the first graph 200 with a first threshold T11 and a second threshold T12. When the duration Tm1 in the first graph 200 is less than the first threshold T11 and greater than or equal to the second threshold T12, the determination unit 38 determines that there is a sign of an abnormality occurring in the filter 73 used in the mist collector 7 when the first graph 200 was acquired or that the time for replacing the filter 73 is approaching. When the determination unit 38 determines that there is a sign of an abnormality occurring in the filter 73 or that the time for replacing the filter 73 is approaching, the display unit 35 displays a screen to notify the user of this, and the sound generation unit 39 generates a sound different from that generated when the determination unit 38 determines that an abnormality has occurred in the filter 73 or that the filter 73 needs to be replaced.

[0043] In this way, by providing multiple thresholds representing different filter 73 conditions, such as the degree of clogging, the condition of the filter 73 can be determined in more detail. The degree of clogging may also be displayed. This allows the user to grasp the condition of the filter 73 currently in use in more detail, and allows the user to prepare the filter 73 and plan a filter replacement schedule in advance. This contributes to improving the efficiency of the user's filter replacement work.

[0044] The following supplementary notes are further disclosed regarding this embodiment and its modified examples. (Supplementary Note 1) The filter management device 2 includes a receiver 32 that receives concentration information indicating the oil mist concentration from a concentration meter 6 that measures the oil mist concentration in the machining chamber 52 of the machine tool 5, a rotation speed controller 37 that controls the rotation speed of a fan motor 77 of a mist collector 7 that collects the oil mist in the machining chamber 52 using a filter 73 based on the received concentration information, a determiner 38 that determines, based on the controlled rotation speed of the fan motor 77, whether an abnormality has occurred in the filter 73 or whether replacement of the filter 73 is necessary, and warning generators 35, 39 that issue a warning when it is determined that an abnormality has occurred in the filter or that replacement of the filter 73 is necessary. (Supplementary Note 2) In the filter management device 2 described in Supplementary Note 1, the rotation speed controller 37 changes the rotation speed of the fan motor 77 in stages in accordance with fluctuations in the oil mist concentration. (Supplementary Note 3) In the filter management device 2 described in Supplementary Note 1, the rotation speed control unit 37 continuously changes the rotation speed of the fan motor 77 in accordance with fluctuations in the oil mist concentration. (Supplementary Note 4) In the filter management device 2 described in any of Supplements 1 to 3, the determination unit 38 determines that an abnormality has occurred in the filter 73 or that replacement of the filter 73 is necessary when the duration over which the rotation speed of the fan motor 77 remains equal to or greater than a predetermined rotation speed reaches a first threshold. (Supplementary Note 5) In the filter management device 2 described in Supplementary Note 4, the determination unit 38 determines that an abnormality has occurred in the filter 73 or that replacement of the filter 73 is imminent when the duration over which the rotation speed of the fan motor 77 remains equal to or greater than the predetermined rotation speed reaches a second threshold that is shorter than the first threshold. (Supplementary Note 6) In the filter management device 2 described in any of Supplements 1 to 3, the determination unit 38 determines that an abnormality has occurred in the filter 73 or that replacement of the filter 73 is necessary when the gradient of the change in the oil mist concentration over time is steeper than the first threshold. (Appendix 7) In the filter management device 2 described in Appendix 6, the judgment unit 38 judges that there is a sign of an abnormality occurring in the filter 73 or that the time to replace the filter 73 is approaching when the gradient of the change in oil mist concentration over time is between a first threshold value and a second threshold value lower than the first threshold value.(Supplementary Note 8) In the filter management device 2 described in any one of Supplementary Notes 4 to 7, the predetermined rotation speed or higher is the maximum rotation speed at which the rotation speed control unit 37 controls the fan motor 77.

[0045] Although the embodiments of the present disclosure have been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the invention or the concept and spirit of the present invention derived from the content of the claims and their equivalents. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

[0046] 1...filter management system, 2...filter management device, 5...machine tool, 6...concentration meter, 7...mist collector, 10...data / control bus, 11...processor, 12...RAM, 13...ROM, 14...storage device, 15...mist collector I / F, 16...concentration meter I / F, 17...machine tool I / F, 18...input device, 19...display device, 20...speaker, 30...input unit, 31...processing condition receiving unit, 32...concentration information receiving unit, 33...storage unit, 34...screen creation unit, 35...display unit, 36...condition setting unit, 37...rotation speed control unit, 38...determination unit, 39...sound generation unit, 40...signal generation unit, 52...machine room, 55...control panel, 71...duct, 72...housing, 73...filter, 75...fan, 77...fan motor.

Claims

1. A receiving unit that receives concentration information representing the oil mist concentration from a concentration meter that measures the oil mist concentration inside the workshop of a machine tool, Based on the received concentration information, a rotation speed control unit controls the rotation speed of the fan motor of a mist collector that collects oil mist in the workshop using a filter. A determination unit that determines whether a filter malfunction has occurred or whether the filter needs to be replaced, based on the rotational speed of the controlled fan motor, A warning generating unit generates a warning when it is determined that an abnormality has occurred in the filter or that the filter needs to be replaced. A filter management device equipped with the following.

2. The rotation speed control unit changes the rotation speed of the fan motor in steps according to the fluctuations in the oil mist concentration. The filter management device according to claim 1.

3. The rotation speed control unit continuously changes the rotation speed of the fan motor in accordance with the fluctuations in the oil mist concentration. The filter management device according to claim 1.

4. The determination unit determines that a filter malfunction has occurred or that the filter needs to be replaced when the duration for which the fan motor's rotational speed remains above a predetermined rotational speed reaches a first threshold. A filter management device according to any one of claims 1 to 3.

5. The determination unit determines, when the duration for which the fan motor's rotational speed remains above a predetermined rotational speed reaches a second threshold that is shorter than the first threshold, that this indicates an impending malfunction in the filter or that the filter is nearing the time for replacement. The filter management device according to claim 4.

6. The filter management device according to claim 4, wherein the predetermined rotational speed is the maximum rotational speed at which the rotational speed control unit controls the fan motor.

7. The determination unit determines that a filter malfunction has occurred or that the filter needs to be replaced when the gradient of the time change in the oil mist concentration is steeper than a first threshold. A filter management device according to any one of claims 1 to 3.

8. The determination unit determines, when the gradient of the time change in the oil mist concentration is between the first threshold and a second threshold lower than the first threshold, that this indicates an impending malfunction in the filter or that the filter is nearing the time for replacement. The filter management device according to claim 7.