Safety management device

Abstract

A safety management device according to the present disclosure has a function of controlling the locking / unlocking of the door of a machine tool such as a lathe or a cutting machine. Specifically, the safety management device is provided with: a reception unit that receives a concentration signal representing an oil mist concentration from a concentration meter that measures the oil mist concentration in a workshop with a lockable / unlockable door; and a lock / unlock control unit that generates a lock signal when triggered by an oil mist concentration exceeding a threshold value for locking, and generates an unlock signal when triggered by the oil mist concentration falling below a threshold value for unlocking.

Description

Safety management device

[0001] The present disclosure relates to a safety management device that controls the locking / unlocking of a workshop door.

[0002] When machine tools are operated, lubricating oil is used to reduce friction in mechanical parts such as ball screws, as well as to seal the machine, cool it, and clean it. When this lubricating oil scatters and turns into fine particles, it is generally called oil mist. Oil mist is harmful to the human body and can cause problems such as reduced workability and electronic device failure. Therefore, a technology has been proposed for reducing the concentration of oil mist by installing a mist collector in a space where lubricating oil is used to collect the oil mist that fills the space (see, for example, Patent Document 1). However, even when a mist collector is used, the concentration of oil mist in the space where the mist collector is installed does not decrease rapidly, so there is still a possibility that workers may work in a space with a high concentration of oil mist.

[0003] Japanese Patent Application Laid-Open No. 2017-091242

[0004] There is a need to propose a technology that can prevent workers from working in a space with a high concentration of oil mist.

[0005] The safety management device according to the present disclosure comprises a receiving unit that receives a concentration signal representing the oil mist concentration from a concentration meter that measures the oil mist concentration in a workshop having a door that can be locked / unlocked, and a locking / unlocking control unit that generates a locking signal when the oil mist concentration exceeds a locking threshold and generates an unlocking signal when the oil mist concentration falls below the unlocking threshold.

[0006] FIG. 1 is a diagram showing a safety management system including a safety management device according to this embodiment. FIG. 2 is a hardware configuration diagram of the safety management device according to this embodiment. FIG. 3 is a functional block diagram of the safety management device according to this embodiment. FIG. 4 is a diagram showing an example of a condition setting screen displayed on the display unit of FIG. 3. FIG. 5 is a supplementary diagram for explaining the measurement value setting process by the measurement value setting unit of FIG. 3. FIG. 6 is a first supplementary diagram for explaining the control procedure for locking / unlocking the workshop door by the safety management device according to this embodiment. FIG. 7 is a second supplementary diagram for explaining the control procedure for locking / unlocking the workshop door by the safety management device according to this embodiment. FIG. 8 is a third supplementary diagram for explaining the control procedure for locking / unlocking the workshop door by the safety management device according to this embodiment. FIG. 9 is a supplementary diagram for explaining the unlock standby process by the lock / unlock control unit of FIG. 3.

[0007] The safety management device 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 performs a predetermined process, such as manufacturing a molded part or joining or machining a molded part to a supplied workpiece. In particular, in this embodiment, the machine tool refers to various devices that generate oil mist during operation, such as a turning machine or a cutting machine. Work room: A space that is separated from the outside space by a cover that completely covers the machining tools. Typically, the work room is one element that makes up a machine tool. However, the work room may also be a room in which the machine tool is located. In this embodiment, the work room has a door.

[0009] Locking device: A device configured to be able to lock / unlock the door of a machine room. Typically, the locking device is one of the components of a machine tool. However, the locking device may also be an external device independent of the machine tool. Control panel: A device that controls the locking / unlocking of the door provided at the entrance / exit of the machine room. Typically, the control panel is one of the components of a machine tool. However, the control panel may also be an external device independent of the machine tool or a higher-level device connected to the machine tool. The control panel is realized by a numerical control device, a PC, etc.

[0010] Concentration meter: A device for measuring the oil mist concentration in a machining chamber. Typically, a concentration meter is an external device independent of the machine tool. However, the concentration meter may be an element that constitutes the machine tool. The concentration meter itself may be located inside the machining chamber, or the main body of the concentration meter may be located outside the machining chamber, with only the sensor part located inside the machining chamber.

[0011] 1 , a safety management device 2 according to this embodiment is a device that functions as the core of a safety management system 1. The safety management system 1 includes the safety management device 2, a machine tool 5, a concentration meter 6, and a mist collector 7.

[0012] Machine tool 5 has a machine room 52, a door 53 installed at the entrance to machine room 52, a locking device 55 for locking door 53, and a control panel 57 for controlling the locking and unlocking operations of locking device 55. Upon receiving a locking signal from safety management device 2, control panel 57 controls locking device 55 to lock door 53, and upon receiving an unlocking signal, controls locking device 55 to unlock door 53. Of course, control panel 57 has the normal door control function of machine tool 5, and, for example, controls locking device 55 to lock door 53 upon start of operation of machine tool 5, and controls locking device 55 to unlock door 53 upon completion of operation.

[0013] The concentration meter 6 measures the oil mist concentration in the machining room 52 and transmits concentration information indicating the oil mist concentration to the safety management device 2. The mist collector 7 is a device that collects oil mist generated in the machining room 52. The mist collector 7 is installed outside the machining room 52 and connected to the machining room 52 via a duct 71. When the fan motor of the mist collector 7 is driven, the oil mist in the machining room 52 is collected into the mist collector 7 together with the air in the machining room 52. As a result, the concentration of oil mist in the machining room 52 gradually decreases.

[0014] 2 is a hardware configuration diagram of the safety management device 2. As shown in Fig. 2, a RAM 12, a ROM 13, a storage device 14, a machine tool I / F 15, a concentration meter I / F 16, an input device 17, a display device 18, and a speaker 19 are connected to a processor 11 via a data / control bus 10.

[0015] 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 safety 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 safety management device 2 via a network.

[0016] The machine tool 5 is connected to the machine tool I / F 15. A locking signal or an unlocking signal is transmitted from the safety management device 2 to the machine tool 5 via the machine tool I / F 15. The concentration meter 6 is connected to the concentration meter I / F 16. The safety management device 2 receives concentration information indicating the oil mist concentration in the machine room 52 from the concentration meter 6 via the concentration meter I / F 16. The input device 17 is realized by a keyboard, a mouse, a jog, etc. A user can input various information to the safety management device 2 via the input device 17. The display device 18 is realized by an organic EL display, an LCD, etc. The display device 18 displays various screens under the control of the processor 11. The speaker 19 generates sounds indicating warnings or alarms under the control of the processor 11.

[0017] 3 is a functional block diagram of the safety management device 2. When the safety management program loaded from the storage device 14 to the RAM 12 is executed by the processor, the safety management device 2 functions as an input unit 30, a receiving unit 31, a storage unit 32, a screen creation unit 33, a display unit 34, a condition setting unit 35, a measurement value setting unit 36, a lock / unlock control unit 37, and a sound generation unit 41.

[0018] The input unit 30 is a function associated with the input device 17 in FIG. 2 and inputs user operations to the safety management device 2. The receiving unit 31 receives a concentration signal (concentration information) indicating the oil mist concentration from the concentration meter 6. The memory unit 32 is a function associated with the storage device 14 in FIG. 2 and stores various information related to the processing of the safety management program. The various information stores various conditions set by the condition setting unit 35. The screen creation unit 33 displays various screens related to the safety management program. Specifically, the screen creation unit 33 creates a condition setting screen, an oil mist concentration screen, a warning screen, etc. The warning screen is created when display notification is set on the condition setting screen. The warning screen includes marks, symbols, and text information to notify the user that the oil mist concentration has exceeded the locking threshold. The warning screen may be displayed superimposed on the oil mist concentration screen. The display unit 34 is a function associated with the display device 18 in FIG. 2 and displays the condition setting screen, oil mist concentration screen, warning screen, etc. created by the screen creation unit 33. The oil mist concentration screen displays, as information representing the oil mist concentration, for example, a graph showing the change in oil mist concentration over time. The condition setting unit 35 sets various conditions in accordance with user operations on the condition setting screen. Details of the condition setting screen and the condition setting process performed by the condition setting unit 35 will be described later.

[0019] The measurement value setting unit 36 ​​sets a measurement value of the oil mist concentration to be used in the determination process by the determination unit 38, which will be described later. Specifically, among the measurement values ​​measured by the concentration meter 6, erroneous measurement values ​​are excluded from the measurement values ​​of the oil mist concentration to be used in the determination process. The measurement value setting process by the measurement value setting unit 36 ​​will be described in detail later.

[0020] The locking / unlocking control unit 37 generates a locking signal for locking the door 53 or an unlocking signal for unlocking the door 53 based on the measured value of the oil mist concentration set by the measurement value setting unit 36. If a minimum interval for switching between locking and unlocking is set on the condition setting screen, the locking / unlocking control unit 37 restricts generation of an unlocking signal until the time (second time) specified by the minimum interval has elapsed since the locking signal was generated. In other words, the locking / unlocking control unit 37 does not generate an unlocking signal until the time (second time) specified by the minimum interval has elapsed since the locking signal was generated. After the restriction is lifted, the locking / unlocking control unit 37 executes normal processing. As a result, locking / unlocking is not switched at intervals shorter than the minimum interval, thereby preventing a decrease in worker operability.

[0021] The locking / unlocking control unit 37 has a determination unit 38, a signal generation unit 39, and a transmission unit 40. The determination unit 38 determines whether the door 53 is locked or unlocked based on the measured value of the oil mist concentration set by the measurement value setting unit 36. The signal generation unit 39 generates a locking signal for locking the door 53 or an unlocking signal for unlocking the door 53 according to the determination result of the determination unit 38. The transmission unit 40 transmits the locking signal or the unlocking signal generated by the signal generation unit 39 to the machine tool 5.

[0022] The sound generating unit 41 has a function related to the speaker 19 in Fig. 2 and functions when sound notification is set on the condition setting screen. When the determination unit 38 determines that the door 53 is locked, the sound generating unit 41 generates a sound (alarm sound) to notify the user as a warning or alarm that the oil mist concentration in the work chamber 52 is high and the door 53 has been locked. When the determination unit 38 determines that the door 53 is unlocked, the sound generating unit 41 also generates a sound to notify the user that the oil mist concentration in the work chamber 52 has decreased and the door 53 has been unlocked.

[0023] The condition setting process performed by the condition setting unit 35 will be described below with reference to FIG. 4 . FIG. 4 is a diagram illustrating an example of a condition setting screen displayed on the safety management device 2 according to this embodiment. The condition setting screen 100 is configured to allow various conditions related to the control of locking / unlocking of the door 53 to be set. As shown in FIG. 4 , the condition setting screen 100 includes multiple items. The “Threshold Setting” item includes an input field for a locking threshold, an input field for an unlocking threshold, and a selection box for setting the unlocking threshold to the same value as the locking threshold. The condition setting unit 35 sets the locking threshold and the unlocking threshold based on a user operation on the input form included in the “Threshold Setting” item. The “Notification Setting” item includes radio buttons for selecting whether or not to notify the user of a high oil mist concentration, and a selection box for the notification method (audio, display) when notified. The condition setting unit 35 sets the notification method based on a user operation on the input form included in the “Notification Setting” item. The “Other Settings” item includes a selection box for setting an unlock standby process and a selection box for setting a lock / unlock switching restriction process. The setting information also includes an input field for the standby time (first time) when the unlock standby process is set, an input field for the standby threshold, and an input field for the shortest interval when the lock / unlock switching restriction process is set. The standby threshold is set to a value greater than the unlock threshold and less than or equal to the lock threshold. The condition setting unit 35 sets the unlock standby process and the lock / unlock switching restriction process by operating the input form included in the item "Other Settings."

[0024] The measurement value setting process by the measurement value setting unit 36 ​​will be described below with reference to FIG. 5 . FIG. 5 is a supplementary diagram supplementing the description of the measurement value setting process by the measurement value setting unit 36, and is a graph showing the change in oil mist concentration over time. In FIG. 5 , measurement values ​​M1 to M7 represent the oil mist concentrations measured by the concentration meter 6 at times t1 to t7, respectively. If the concentration meter 6 had measured correctly, the oil mist concentration would be higher than the unlocking threshold. However, if the concentration meter 6 did not measure correctly due to a measurement error, malfunction, or other factor, the oil mist concentration measurement value M7 may fall below the unlocking threshold, resulting in the door 53 being erroneously unlocked. To prevent this from happening, the measurement value setting unit 36 ​​excludes any oil mist concentration measurement values ​​measured by the concentration meter 6 that have been erroneously measured due to an error, malfunction, or the like from the measurement values ​​used in the determination process by the determination unit 38.

[0025] Specifically, the measurement value setting unit 36 ​​calculates an approximated line 200 using a plurality of measurement values ​​M1 to M6 measured immediately before, and when the deviation of a current measurement value M7 from a predicted value M7' calculated using the approximated line 200 is greater than a threshold, the measurement value setting unit 36 ​​excludes the current measurement value M7 from the objects of the determination process by the determination unit 38. Of course, as long as it is possible to determine whether or not a measurement value has been measured correctly, the determination method is not limited to the above. For example, when the absolute value of the deviation of the current measurement value from the measurement value measured immediately before is greater than a threshold, the measurement value setting unit 36 ​​may exclude the current measurement value from the objects of the determination process.

[0026] The measurement value setting process by the measurement value setting unit 36 ​​allows, for example, multiple measurement values ​​M1 to M6 and M8 excluding measurement value M7 shown in FIG. 5 to be set as targets for the judgment process by the judgment unit 38, thereby preventing the door 53 from being erroneously unlocked at time t7 and then relocked at time t8. This contributes to ensuring the safety of the worker. Furthermore, the frequency of locking / unlocking can be reduced, which also contributes to preventing a decrease in the worker's work efficiency.

[0027] 6 to 8, a control procedure for locking / unlocking the door 53 of the workshop 52 by the safety management device 2 according to this embodiment will be described below. Referring to Fig. 6, the control of locking / unlocking the door 53 when the unlocking threshold is set to the same value as the locking threshold will be described below. Fig. 6 is a graph showing an example of the change over time in the oil mist concentration in the workshop 52 measured by the concentration meter 6. The locking threshold and the unlocking threshold are set to the same value (referred to as a common threshold).

[0028] When the operation of the machine tool 5 begins (time t10), the door 53 is locked and the mist collector 7 is driven under control of the machine tool 5. The machine tool 5 generates oil mist in the machine room 52. If the amount of oil mist generated is greater than the amount of oil mist collected by the mist collector 7, the oil mist concentration in the machine room 52 increases. The safety management device 2 generates a locking signal when the oil mist concentration in the machine room 52 exceeds the common threshold (time t11). The generated locking signal is sent to the machine tool 5. Since the door 53 of the machine tool 5 is already locked, this state is maintained. Even if the machine tool 5 is operating, if the amount of oil mist generated is less than the amount of oil mist collected by the mist collector 7, the oil mist concentration in the machine room 52 decreases. Furthermore, when the operation of the machine tool 5 ends, the generation of oil mist ends, while the collection of oil mist by the mist collector 7 continues, so the oil mist concentration in the machine room 52 gradually decreases. The safety management device 2 generates an unlock signal when the oil mist concentration in the machine room 52 falls below the common threshold (time t12). The generated unlock signal is sent to the machine tool 5. The control panel 57 of the machine tool 5, upon receiving the unlock signal from the safety management device 2, controls the locking device 55 to unlock the door 53. As a result, the door 53 of the machine room 52 is unlocked.

[0029] Even after the door 53 of the machine room 52 is unlocked, the oil mist concentration in the machine room 52 may increase due to some factors, such as a measurement error by the concentration meter 6, uneven distribution of oil mist in the machine room 52, or a deterioration in the function of the mist collector 7. For this reason, while the machine tool 5 is running, the safety management device 2 continues to control the locking / unlocking of the door 53 of the machine room 52. The safety management device 2 generates a lock signal when the oil mist concentration in the machine room 52 again exceeds the common threshold (time t13). The generated lock signal is sent to the machine tool 5. The control panel 57 of the machine tool 5, upon receiving the lock signal from the safety management device 2, controls the locking device 55 to lock the door 53. As a result, the door 53 of the machine room 52 is locked again. Thereafter, the safety management device 2 generates an unlock signal when the oil mist concentration in the machine room 52 falls below the common threshold (time t14). The generated unlock signal is transmitted to the machine tool 5. Upon receiving the unlock signal from the safety management device 2, the control panel 57 of the machine tool 5 controls the locking device 55 to unlock the door 53. As a result, the door 53 of the machine room 52 is unlocked again.

[0030] According to the control of unlocking / locking of the door 53 of the work room 52 by the safety management device 2 according to the present embodiment described with reference to FIG. 6 , the door 53 of the work room 52 can be kept locked even after the operation of the machine tool 5 has been terminated, as long as the oil mist concentration in the work room 52 is high. This prevents workers from entering the work room 52 even if they are unaware that the oil mist concentration in the work room 52 is high, thereby preventing a situation in which the oil mist causes health damage to the workers. Furthermore, the door 53 of the work room 52 can be unlocked when the oil mist concentration drops to a safe concentration (unlocking threshold) that does not cause health damage to the workers. This allows the workers to enter the work room 52 once the oil mist concentration has dropped to a safe level. This eliminates the need for workers to wait an unnecessarily long time to enter the work room 52 because they are unable to determine whether the oil mist concentration in the work room 52 has dropped to a safe level, thereby preventing a decrease in work efficiency.

[0031] 7 and 8, the control of locking / unlocking the door 53 when the unlocking threshold is set to a value lower than the locking threshold will be described. Figures 7 and 8 are graphs showing another first example of the change over time in the oil mist concentration in the workshop 52 measured by the concentration meter 6. Figure 7 shows the period from time t20 to time t27, and Figure 8 shows the period from time t27 to time t33. The unlocking threshold is set to a value lower than the locking threshold.

[0032] When the operation of the machine tool 5 begins (time t20), the door 53 is locked by control on the machine tool 5 side, and the oil mist concentration in the machine room 52 rises. The safety management device 2 generates a lock signal when the oil mist concentration in the machine room 52 exceeds the locking threshold (time t21). Since the door 53 of the machine tool 5 is already locked, this state is maintained. When the operation of the machine tool 5 ends, the generation of oil mist stops, but on the other hand, the collection of oil mist by the mist collector 7 continues, so the oil mist concentration in the machine room 52 gradually decreases. The safety management device 2 generates an unlock signal when the oil mist concentration in the machine room 52 falls below the unlocking threshold (time t27). As a result, the door 53 of the machine room 52 is unlocked. Even after the door 53 of the machine tool room 52 is unlocked, if the oil mist concentration in the machine tool room 52 exceeds the locking threshold value for some reason (time t31), this triggers the safety management device 2 to generate a locking signal, which causes the door 53 of the machine tool 5 to be locked again.

[0033] Between time t21 and time t27, when the oil mist concentration in the workshop 52 exceeds the locking threshold and falls below the unlocking threshold, the oil mist concentration in the workshop 52 may fluctuate above and below the locking threshold due to some factor. If the locking threshold and the unlocking threshold are the same, the door 53 of the workshop 52 will be repeatedly locked and unlocked at times 22, 23, 24, 25, and 26, when the oil mist concentration crosses the locking threshold.

[0034] Similarly, between time t27 when the oil mist concentration in the workshop 52 falls below the unlocking threshold and time t31 when it exceeds the locking threshold, the oil mist concentration in the workshop 52 may fluctuate above and below the unlocking threshold due to some factor. If the locking threshold and the unlocking threshold are the same, the door 53 of the workshop 52 will be repeatedly locked and unlocked at time t28, time 29, and time 30 when the oil mist concentration crosses the unlocking threshold.

[0035] If a worker confirms that the door 53 is unlocked and is preparing to start work when the door 53 is locked, the worker must wait until the door 53 is unlocked again. Also, if the door 53 to the workroom 52 is repeatedly locked and unlocked in a short period of time, it is unclear when a block of time can be secured, so the worker must ultimately wait until the oil mist concentration falls significantly below the unlocking threshold. In this way, if the locking threshold and the unlocking threshold are the same, the worker's work efficiency may be reduced due to the door being locked and unlocked so frequently.

[0036] As shown in Figures 7 and 8, by setting the unlocking threshold to a value lower than the locking threshold, it is possible to prevent the door 53 from being locked or unlocked in a short period of time due to the oil mist concentration fluctuating across the unlocking threshold. Furthermore, by setting the unlocking threshold lower than the locking threshold, the door 53 can be unlocked when the oil mist concentration has dropped to a safer level, further preventing health damage to workers caused by oil mist. Furthermore, once the oil mist concentration falls below the unlocking threshold, it is unlikely to again exceed the locking threshold, which is higher than the unlocking threshold. This prevents the door 53 from being locked again in a short period of time after being unlocked. This contributes to preventing a decrease in worker operability.

[0037] The unlocking standby process performed by the safety management device 2 according to this embodiment will now be described with reference to FIG. 9 . FIG. 9 is a supplementary diagram for explaining the unlocking standby process performed by the lock / unlock control unit 37. FIG. 9 shows a graph representing the change over time in the oil mist concentration in the machine room 52 measured by the concentration meter 6. When the unlocking standby process is set on the condition setting screen 100, as shown in FIG. 9 , the safety management device 2 generates an unlocking signal not at time t41 when the oil mist concentration falls below the unlocking threshold, but at time t42 when a standby time has elapsed since time t41. Generally, when the mist collector 7 is operating and the machine tool 5 is not operating, the oil mist concentration in the machine room 52 decreases over time. Therefore, by unlocking the door 53 of the machine room 52 not at time t41 when the oil mist concentration falls below the unlocking threshold, but at time t42 when a standby time has elapsed since time t41, the worker can work in a safer environment where the oil mist concentration is lower than the unlocking threshold. In addition, since the time from the time when the door 53 was locked, before time t41, can be secured, it is possible to avoid the door 53 being locked / unlocked in a short period of time, thereby suppressing a decrease in the workability of the workers.

[0038] It is possible that the oil mist concentration may become much higher than the unlocking threshold at time t42, when the standby time has elapsed since time t41, when the oil mist concentration fell below the unlocking threshold. To reliably avoid such a situation, the safety management device 2 may continue to monitor the oil mist concentration from time t41, when the oil mist concentration fell below the unlocking threshold, until time t42, when the standby time has elapsed, and generate an unlock signal at time t42, when the oil mist concentration remains lower than the standby threshold (higher than the unlocking threshold and lower than the locking threshold). If the oil mist concentration exceeds the standby threshold between time t41 and time t42, the unlocking standby process is terminated. Thereafter, the unlocking standby process is restarted when the oil mist concentration falls below the unlocking threshold again. This makes it possible to avoid the unlikely event that the oil mist concentration becomes much higher than the unlocking threshold value once the waiting time has elapsed since the oil mist concentration fell below the unlocking threshold value.

[0039] The following supplementary notes are further disclosed regarding this embodiment and its modified examples. (Supplementary Note 1) The safety management device 2 includes a receiver 31 that receives a concentration signal indicating an oil mist concentration from a concentration meter 6 that measures the oil mist concentration in a workshop 52 having a lockable / unlockable door 53, and a lock / unlock control unit 37 that generates a lock signal when the oil mist concentration exceeds a locking threshold and generates an unlock signal when the oil mist concentration falls below the unlocking threshold. (Supplementary Note 2) In the safety management device 2 described in Supplementary Note 1, the unlocking threshold is the same as the locking threshold. (Supplementary Note 3) In the safety management device 2 described in Supplementary Note 1, the unlocking threshold is lower than the locking threshold. (Supplementary Note 4) In the safety management device 2 described in any of Supplements 1 to 3, the lock / unlock control unit 37 generates an unlock signal when a predetermined first time has elapsed since the oil mist concentration fell below the unlocking threshold. (Supplementary Note 5) In the safety management device 2 described in Supplementary Note 4, the locking / unlocking control unit 37 generates an unlocking signal if the oil mist concentration remains below a threshold value set higher than the unlocking threshold but lower than the locking threshold during the first hour period after the oil mist concentration falls below the unlocking threshold. (Supplementary Note 6) In the safety management device 2 described in any of Supplements 1 to 5, the locking / unlocking control unit 37 restricts generation of the unlocking signal until a predetermined second hour period has elapsed after generation of the locking signal. (Supplementary Note 7) The safety management device 2 described in any of Supplements 1 to 6 further includes a display unit 34 that displays information related to the oil mist concentration. (Supplementary Note 8) In the safety management device 2 described in Supplementary Note 7, the display unit 34 displays a graph showing the change in oil mist concentration over time. (Supplementary Note 9) The safety management device 2 described in any one of Supplementary Notes 1 to 8 further includes a sound generating unit 41 that generates a sound representing a warning or an alarm when the oil mist concentration exceeds the locking threshold.

[0040] 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.

[0041] 1...Safety management system, 2...Safety 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...Machine tool I / F, 16...Concentration meter I / F, 17...Input device, 18...Display device, 19...Speaker, 30...Input section, 31...Receiving section, 32...Storage section, 33...Screen creation section, 34...Display section, 35...Condition setting section, 36...Measurement value setting section, 37...Locking / unlocking control section, 38...Determination section, 39...Signal generating section, 40...Transmitting section, 41...Sound generating section, 52...Workroom, 53...Door, 55...Locking device, 57...Control panel, 71...Duct.

Claims

1. A receiving unit that receives a concentration signal representing the oil mist concentration from a concentration meter that measures the oil mist concentration in a workshop having a lockable / unlockable door, A locking / unlocking control unit that generates a locking signal when the oil mist concentration exceeds a locking threshold, and generates an unlocking signal when the oil mist concentration falls below an unlocking threshold, A safety management device equipped with the following features.

2. The unlocking threshold is the same as the locking threshold. The safety management device according to claim 1.

3. The unlocking threshold is lower than the locking threshold. The safety management device according to claim 1.

4. The locking / unlocking control unit generates the unlocking signal when a predetermined first time has elapsed since the oil mist concentration fell below the unlocking threshold. A safety management device according to any one of claims 1 to 3.

5. The locking / unlocking control unit generates the unlocking signal if, during the period from when the oil mist concentration falls below the unlocking threshold until the first time has elapsed, the oil mist concentration is maintained at or below a threshold set to be higher than the unlocking threshold and lower than or equal to the locking threshold. The safety management device according to claim 4.

6. The locking / unlocking control unit restricts the generation of the unlocking signal until a predetermined second time has elapsed since the generation of the locking signal. A safety management device according to any one of claims 1 to 3.

7. The system further includes a display unit that displays information regarding the oil mist concentration. A safety management device according to any one of claims 1 to 3.

8. The safety management device according to claim 7, wherein the display unit displays a graph showing the time change of the oil mist concentration.

9. The system further includes a sound generating unit that generates a sound indicating a warning or alarm when the oil mist concentration exceeds a locking threshold. A safety management device according to any one of claims 1 to 3.