Fan monitoring system

Abstract

To suppress the number of devices required for monitoring fans.SOLUTION: A fan monitoring system includes a fan 11 that can be used to blow air, a board 11b capable of communicating signals related to the fan's rotation speed, a monitoring unit capable of receiving the signals related to the fan's rotation speed communicated from the board, a fan power line 21 connecting a common power line 71 and the fan's drive unit 11a, and a monitoring unit power line 22 connecting the common power line and the monitoring unit 12. The fan monitoring system is capable of determining that the fan's rotation speed has decreased but is not zero, and that the fan's rotation speed has become zero.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fan monitoring system.

Background Art

[0002] An overcurrent flowing through a device such as a fan can cause a fire or failure of the device. To prevent this, a fuse is provided on the wiring path. When an overcurrent flows through the fuse, the fusible part in the fuse melts and the wiring path can be disconnected, so that the overcurrent does not flow through the device. In such a configuration, as described in Patent Document 1, it is necessary to use a fuse blow detector for detecting that the fuse has blown. On the other hand, the rotation speed (rotational speed) of the fan may decrease due to clogging of a filter or the like on the ventilation path of the fan or deterioration of the fan. In order to detect this, a determination unit as in Patent Document 2 is provided.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

[0004] By the way, in the case of the above examples, it is necessary to provide respective detection units, determination units, and their dedicated circuits for each event, and there is a concern about an increase in the size of the device and an increase in cost.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inventor of the present case has tried to solve this problem by earnestly studying this point. The problem to be solved by the present invention is to suppress the number of device points required for fan monitoring.

Means for Solving the Problems

[0006] In order to solve the above problems, a fan that can be used to send air, a substrate capable of communicating a signal related to the rotation speed of the fan, a monitoring unit capable of receiving a signal related to the rotation speed of the fan communicated from the substrate, a common power line, a power line for the fan connecting the power unit of the fan, and a power line for the monitoring unit connecting the common power line and the monitoring unit are provided, and a fan monitoring system capable of determining that the rotation speed of the fan has decreased and is not zero, and that the rotation speed of the fan has become zero is provided.

[0007] Also, it is preferable to have a configuration in which a fuse is provided on the power line for the fan.

[0008] Also, it is preferable to have a configuration in which the presence or absence of a signal from the fan is determined when the rotation speed of the fan becomes zero.

[0009] Also, when the rotation speed of the fan decreases and is not zero, it is preferable to have a configuration in which a signal is transmitted to increase the output of the fan, and then it is determined whether the rotation speed has become equal to or higher than a predetermined value.

[0010] In addition, a fan that can be used to send air, a substrate capable of communicating a signal related to the rotation speed of the fan, a monitoring unit capable of receiving a signal related to the rotation speed of the fan communicated from the substrate, a common power line, a power line for the fan connecting the power unit of the fan, and a power line for the monitoring unit connecting the common power line and the monitoring unit are provided, and it is preferable to provide a fan monitoring system capable of determining whether the rotation speed of the fan is equal to or higher than a first threshold value and less than a second threshold value, and whether the rotation speed of the fan is less than the first threshold value.

Effects of the Invention

[0011] In the present invention, it is possible to suppress the number of equipment points required for monitoring the fan.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0013] Embodiments for carrying out the invention are shown below. The fan monitoring system 1 in the example shown in FIG. 1 includes a fan 11 that can be used to send air, a board 11b that can communicate a signal regarding the rotation speed of the fan 11, a monitoring unit 12 that can receive a signal regarding the rotation speed of the fan 11 communicated from the board 11b, a common power line 71, a fan power line 21 that connects the power unit 11a of the fan 11, and a monitoring unit power line 22 that connects the common power line 71 and the monitoring unit 12. It is possible to determine that the rotation speed of the fan 11 has decreased and is not zero, and that the rotation speed of the fan 11 has become zero. For this reason, it is possible to suppress the number of device points required for monitoring the fan 11.

[0014] The fan monitoring system 1 is preferably used for temperature adjustment of a box for housing electrical and electronic devices. The fan monitoring system 1 is preferably provided in the device 10. For example, it is preferably provided in a heat exchange device using a Peltier element or the like. Further, it may be provided in a device used for replacing the air in a box for housing electrical and electronic devices, such as a ventilation device.

[0015] The power supply connected to the fan monitoring system 1 may be a DC power supply 81 or an AC power supply 82. First, the case of the DC power supply 81 will be described as an example. In the example shown in FIG. 1, DC electricity is supplied from the DC power supply 81 to the fan monitoring system 1. Therefore, DC electricity is supplied to both the power unit 11a of the fan 11 and the monitoring unit 12. Further, DC electricity is supplied to the substrate 11b of the fan 11. In the example shown in FIG. 1, a branch line 27 extending from the fan power supply line 21 is connected to the substrate 11b.

[0016] Further, the substrate 11b of the fan 11 operates using DC electricity, and this substrate 11b can detect the rotation of the fan 11. Further, the substrate 11b can output a signal regarding the rotation speed of the fan 11 to the monitoring unit 12. Therefore, information regarding the rotation speed of the fan 11 can be collected by the monitoring unit 12.

[0017] The monitoring unit 12 is configured to be able to determine that the rotation speed of the fan 11 has decreased and is not zero, and that the rotation speed of the fan 11 has become zero. For this reason, it is possible to distinguish whether the rotation speed of the fan 11 is in a state of being zero or in a state where the rotation speed of the fan 11 has decreased and is not zero. For example, when electricity or information does not flow through the wiring path, or when the fan 11 stops due to a failure of the power unit 11a of the fan 11, the rotation speed of the fan 11 becomes zero. Further, for example, due to clogging in the ventilation path or deterioration of the fan 11, the rotation speed of the fan 11 may decrease and not be zero. Therefore, if the above determination can be made, the cause of the abnormality can be distinguished (see FIG. 2). Note that the failure of the power unit 11a of the fan 11 includes failures due to defects of the fan 11 and failures due to the lifespan of the fan 11.

[0018] Also, in the embodiment, when the rotation speed of the fan 11 decreases and is determined to be non-zero, and when the substrate 11b receives a signal from the control unit 13 to increase the output of the fan 11, the substrate 11b can instruct the power unit 11a of the fan 11 to increase the output.

[0019] By instructing the power unit 11a of the fan 11 to increase the output, if the rotation speed of the fan 11 exceeds a predetermined value, it can be determined that there is no problem with the operation of the fan 11. In this case, it may be determined that there is a blockage in the ventilation path (see FIG. 3).

[0020] On the other hand, if the rotation speed of the fan 11 does not reach the predetermined value even when instructed to increase the output of the power unit 11a of the fan 11, it may be determined that the fan 11 is deteriorated.

[0021] As can be understood from these descriptions, when the rotation speed of the fan 11 decreases and is non-zero, it is preferable to configure to transmit a signal to increase the output of the fan 11 and then determine whether the rotation speed becomes equal to or higher than a preset value.

[0022] When it is determined that the rotation speed of the fan 11 is 0, it may be determined whether there is a signal from the substrate 11b to the monitoring unit 12. When the rotation speed of the fan 11 becomes 0, it is conceivable that the wiring path does not function or the fan 11 stops due to a failure of the power unit 11a of the fan 11. However, when the wiring path does not function, no signal is sent from the substrate 11b to the monitoring unit 12. Examples of the case where the wiring path does not function include, for example, the fuse 28 blowing, the wiring cable (the fan power supply line 21 and the communication line 23 connecting between the substrate 11b and the monitoring unit 12) breaking, and the connection at the terminal part coming off. If there is no power supply to the substrate 11b, no signal is supplied from the substrate 11b to the monitoring unit 12. Also, if the communication line 23 for sending a signal from the substrate 11b to the monitoring unit 12 does not function, no signal is supplied from the substrate 11b to the monitoring unit 12 either. Therefore, if it is determined by the monitoring unit 12 or the like that the rotation speed of the fan 11 is 0 and there is no signal from the substrate 11b to the monitoring unit 12, it can be considered that there is a problem in the wiring path.

[0023] On the other hand, even if there is no problem in the wiring path, if there is a problem in the power unit 11a of the fan 11, the fan 11 does not move. In this case, since there is no problem in the wiring path, a signal is sent from the substrate 11b to the monitoring unit 12. Therefore, if it is determined by the monitoring unit 12 or the like that the rotation speed of the fan 11 is 0 and there is a signal from the substrate 11b to the monitoring unit 12, it can be considered that there is a problem in the power unit 11a of the fan 11.

[0024] As can be understood from these descriptions, when the rotation speed of the fan 11 becomes 0, it is preferable to have a configuration for determining whether there is a signal from the fan 11.

[0025] Note that since the fuse 28 melts when an overcurrent flows, it is preferably used to stop the supply of electricity to the power unit 11a of the fan 11. Even when the fuse 28 melts, in order to make the monitoring unit 12 function, the fuse 28 may be provided on the fan power supply line 21. If the fuse 28 is provided on the common power supply line 71, the monitoring unit 12 will be located downstream of the fuse 28, and electricity cannot flow through the common power supply line 71 to the monitoring unit 12. However, if the fuse 28 is provided on the fan power supply line 21, electricity can flow through the common power supply line 71 to the monitoring unit 12 even when the fuse 28 melts.

[0026] As can be understood from these descriptions, it is preferable to adopt a configuration in which the fuse 28 is provided on the fan power supply line 21.

[0027] Here, the rotation of the fan 11 and the behavior of the signal of the fan 11 will be described. As can be understood from FIG. 4, in a normal state, signals frequently reach the monitoring unit 12, and thus changes in the signal values are frequently repeated. On the contrary, when the wiring path does not function, signals will not reach the monitoring unit 12 after the rotation of the fan 11 stops.

[0028] When the power of the fan 11 fails, it is assumed that the fan 11 may not move at all or may move slightly. When the fan 11 does not move at all, signals are continuously sent to the monitoring unit 12 (see the first form of the fan signal in FIG. 4). On the other hand, when the fan 11 may move slightly, there are changes in the signal values reaching the monitoring unit 12, but they are not as frequent as in the normal case (see the second form of the fan signal in FIG. 4).

[0029] When the fan 11 may move slightly, the rotation speed of the fan 11 is not zero. Therefore, instead of using whether the rotation speed of the fan 11 is zero as a criterion, it is conceivable to use whether the rotation speed of the fan 11 is less than a first threshold as a criterion. In this case, the first threshold is set to a value smaller than the rotation speed observed during normal operation. On the other hand, whether it is operating normally or not can be determined by using whether the rotation speed of the fan 11 is less than a second threshold as a criterion. The second threshold is set such that if the rotation speed of the fan 11 is equal to or greater than the second threshold, it is normal operation, and if it is less than the second threshold, some abnormality is assumed.

[0030] If it is determined in this way, the determination corresponding to FIG. 3 can be expressed as shown in FIG. 5. Of course, even when determining based on a threshold, it may be determined as corresponding to FIG. 2, or other determinations may be made.

[0031] As can be understood from these descriptions, a fan 11 that can be used to send air, a substrate 11b that can communicate a signal regarding the rotation speed of the fan 11, a monitoring unit 12 that can receive a signal regarding the rotation speed of the fan 11 communicated from the substrate 11b, a common power line 71, a fan power line 21 that connects the power unit 11a of the fan 11, and a monitoring unit power line 22 that connects the common power line 71 and the monitoring unit 12 are provided. It is preferable that the fan monitoring system 1 can determine whether the rotation speed of the fan 11 is equal to or greater than the first threshold and less than the second threshold, and can determine whether the rotation speed of the fan 11 is less than the first threshold.

[0032] Next, an example in which the power supply connected to the fan monitoring system 1 is an AC power supply 82 will be described. In the example shown in FIG. 6, AC electricity is supplied from the AC power supply 82 to the fan monitoring system 1. Therefore, AC electricity is supplied to the power unit 11a of the fan 11. On the other hand, DC electricity is used for the monitoring unit 12 and the substrate 11b respectively. For this reason, it is necessary to convert the AC electricity sent through the common power line 71 into DC electricity.

[0033] In the example shown in FIG. 6, the electricity sent from the power supply line 22 for the monitoring unit is converted from alternating current to direct current by the AC / DC converter 14 and sent to the monitoring unit 12 and the control unit 13 located downstream. Since the substrate 11b of the fan 11 also requires a supply of direct current electricity, the electricity converted by the AC / DC converter 14 is sent to the substrate 11b. In the example shown in FIG. 6, the monitoring unit 12 and the substrate 11b are connected by wiring. Signals can also be sent through this wiring (power and communication line 24). With this configuration, simplification of the wiring can be expected. However, the wiring for sending electricity to the substrate 11b (power line) and the wiring for sending signals (communication line 23) may be provided separately.

[0034] When the monitoring unit 12 and the substrate 11b are connected by a line for sending electricity, a line for sending signals, or a line for sending both electricity and signals, if there is no signal to the monitoring unit 12, it can be seen that there is a problem with the line connecting the monitoring unit 12 and the substrate 11b (see FIG. 7).

[0035] Note that in the example shown in FIG. 6, since the AC power supply 82 is connected to the fan monitoring system 1, a breaker 29 is provided on the upstream side of the device 10 equipped with the fan monitoring system 1, more specifically, on the common power supply line 71. This is to trip the breaker 29 when an overcurrent flows and stop the supply of electricity to the fan 11.

[0036] Incidentally, when an overcurrent flows through the fan 11, the heat generated by the overcurrent reduces the insulation performance between the conductive parts of different phases, and a short circuit occurs between different phases. As a result, the resistance becomes extremely small, and a larger overcurrent flows not on the monitoring unit 12 side but on the fan 11 side, which may cause the fan 11 to malfunction. This phenomenon occurs in a short time and is a phenomenon that occurs before the breaker 29 trips due to the overcurrent. Even in such a case where this can happen, a determination can be made. Since the determination can derive the result before the trip condition is met, it is also possible to determine the failure of the power unit 11a at the moment when the breaker 29 cannot handle it. This determination result can be recorded, and it is also possible to cause some operation to be performed using the determination result. For example, the data may be transferred to somewhere other than the device 10. Also, the supply of electricity to the fan 11 may be stopped before the breaker 29 trips.

[0037] As described above, the present invention has been described by taking the embodiments as examples, but the present invention is not limited to the above embodiments and can be in various forms. For example, it is also conceivable to wirelessly send a signal between the substrate and the monitoring unit.

Explanation of Reference Numerals

[0038] 1 Fan monitoring system 11 Fan 11a Power unit 11b Substrate 12 Monitoring unit 21 Power supply line for fan 22 Power supply line for monitoring unit 28 Fuse 71 Common power supply line

Claims

1. A fan that can be used to send air, A substrate capable of communicating a signal related to the rotational speed of the fan, A monitoring unit capable of receiving a signal related to the rotational speed of the fan communicated from the substrate, A power supply line for the fan connecting the common power supply line and the power unit of the fan, A power supply line for the monitoring unit connecting the common power supply line and the monitoring unit, Comprising A fan monitoring system capable of determining that the rotational speed of the fan has decreased and is not zero, and that the rotational speed of the fan has become zero.

2. The fan monitoring system according to claim 1, comprising a fuse on the power supply line for the fan.

3. The fan monitoring system according to claim 1, which determines the presence or absence of a signal from the fan when the rotational speed of the fan becomes zero.

4. When the rotational speed of the fan decreases and is not zero, a signal is transmitted to increase the output of the fan, Thereafter, it is determined whether the rotational speed has become equal to or greater than a preset value The fan monitoring system according to claim 1.

5. A fan that can be used to send air, A substrate capable of communicating a signal related to the rotational speed of the fan, A monitoring unit capable of receiving a signal related to the rotational speed of the fan communicated from the substrate, A power supply line for the fan connecting the common power supply line and the power unit of the fan, A power supply line for the monitoring unit connecting the common power supply line and the monitoring unit, Comprising A fan monitoring system capable of determining whether the rotational speed of the fan is equal to or greater than a first threshold value and less than a second threshold value, and determining whether the rotational speed of the fan is less than the first threshold value.

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