Disk device and method for suppressing pressure change

Abstract

To provide a panel device and a pressure change suppression method capable of reducing the pressure difference between the outside and the inside of a housing and suppressing the enlargement of the device.SOLUTION: A panel device 100 includes electromagnetic valves 30a and 30b that adjust the opening areas of openings 13a and 13b provided in a housing 10 so as to adjust the flow rate of air between the outside and the inside of the housing 10. In addition, the panel device 100 includes a control unit configured to adjust the opening areas of the electromagnetic valves 30a and 30b so as to suppress the pressure change inside the housing 10 caused by the pressure change outside the housing 10 on the basis of the pressure change detected by pressure sensors 40a and 40b.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a panel device and a method for suppressing pressure changes, and more particularly to a panel device provided with a housing for accommodating equipment therein and a method for suppressing pressure changes.

Background Art

[0002] Conventionally, a panel device provided with a housing for accommodating electrical equipment therein has been known (see, for example, Patent Document 1).

[0003] The panel device described in Patent Document 1 includes a housing and a pressure difference relief device. The housing accommodates electrical equipment therein. An opening is provided in this housing. The pressure difference relief device includes a blocking member having a telescopic bellows structure. The pressure difference relief device also includes a filter mounting member to which a filter is attached. This pressure difference relief device is attached to the outer surface of the housing so that the blocking member surrounds the opening of the housing together with the filter mounting member. When the pressure outside the housing drops from the normal atmospheric pressure (1 atm) during normal times, the volume inside the housing increases due to the blocking member being fully extended. Thus, in the panel device described in Patent Document 1, the pressure difference between the outside and inside of the housing caused by a micro-pressure wave is relieved by the pressure difference relief device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the board device described in Patent Document 1 is configured such that when the pressure outside the housing decreases from the normal pressure (atmospheric pressure), the shielding member extends outward to increase the volume inside the housing. Therefore, in the board device described in Patent Document 1, when the pressure outside the housing increases, the pressure difference between the outside and inside of the housing cannot be alleviated. Further, although not described in Patent Document 1, when configured to alleviate the pressure difference when the pressure outside the housing increases due to the deformation of the bellows-shaped shielding member toward the inside of the housing, it is necessary to provide a space inside the housing for the deformed shielding member to enter. Therefore, in order to alleviate the pressure difference between the outside and inside of the housing when the pressure outside the housing increases, the device becomes larger. Therefore, it is desired to suppress the pressure difference between the outside and inside of the housing and to suppress the increase in the size of the device.

[0006] The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a board device and a pressure change suppression method capable of alleviating the pressure difference between the outside and inside of a housing and suppressing an increase in the size of the device.

Means for Solving the Problems

[0007] To achieve the above object, a board device according to a first aspect of the present invention includes a housing that houses equipment therein, an area adjustment valve that adjusts the opening area so as to adjust the air flow rate between the outside and inside of the housing at an opening provided in the housing, a detection unit that detects a pressure change outside the housing, and a control unit configured to adjust the opening area of the area adjustment valve so as to suppress a pressure change inside the housing caused by a pressure change outside the housing based on the pressure change detected by the detection unit.

[0008] In the board device according to the first aspect of the present invention, as described above, an area adjustment valve is provided to adjust the opening area so as to adjust the air flow rate between the outside and the inside of the housing. Then, based on the detected pressure change, the opening area of the area adjustment valve is adjusted so as to suppress the pressure change inside the housing caused by the pressure change outside the housing. Thereby, when the pressure outside the housing changes, the pressure change inside the housing can be suppressed by adjusting the opening area of the area adjustment valve. Therefore, it is possible to suppress the pressure difference between the outside and the inside of the housing without providing a member that expands and contracts toward the inside or outside of the housing in order to change the volume inside the housing. As a result, the pressure difference between the outside and the inside of the housing can be alleviated, and the increase in the size of the device can be suppressed. Further, when the pressure does not change outside the housing, by setting the opening area of the area adjustment valve to 0, it is possible to suppress the intrusion of foreign matter such as dust into the housing.

[0009] In the board device according to the first aspect, preferably, when the control unit detects a pressure change such that the pressure outside the housing increases by the detection unit, the control unit is configured to increase the opening area of the area adjustment valve, and when a pressure change such that the pressure outside the housing decreases is detected, the control unit is configured to decrease the opening area of the area adjustment valve. Here, when a pressure change such that the pressure outside the housing decreases is detected and the decrease in the internal pressure of the housing is suppressed by decreasing the opening area of the area adjustment valve, the housing is loaded so as to bulge outward due to the decrease in the external pressure of the housing. In this case, unlike the case where the housing is loaded so as to shrink inward, the housing does not interfere (contact) with the internal devices or the like due to the deformation of the housing. In consideration of this point, in the present invention, when a pressure change such that the pressure outside the housing decreases is detected, the decrease in the internal pressure of the housing can be suppressed by decreasing the opening area of the area adjustment valve. Therefore, since the internal pressure of the housing can be maintained at a state higher than the normal pressure (atmospheric pressure), it is possible to suppress a decrease in the insulation breakdown voltage inside the housing. Further, when a pressure change such that the pressure outside the housing increases is detected, the internal pressure of the housing can be increased in accordance with the external pressure change of the housing by increasing the opening area of the area adjustment valve. Therefore, when a pressure change such that the pressure outside the housing increases is detected, the pressure difference between the outside and the inside of the housing can be alleviated, so that it is possible to suppress the housing from deforming so as to shrink.

[0010] In this case, preferably, the detection unit is configured to detect a pressure change outside the housing by detecting a pressure difference between the outside and the inside of the housing, and when the pressure difference detected by the detection unit is greater than a predetermined reference value, the control unit Assuming that a pressure change is detected such that the pressure outside the housing increases, increases the opening area of the area adjustment valve and, when the pressure difference is equal to or less than the reference value, Assuming that a pressure change is detected such that the pressure outside the housing decreases,It is configured to reduce the opening area of the area adjustment valve. As a result, based on the pressure difference detected by detecting the pressure difference between the outside and the inside of the housing, it is possible to easily detect a change in pressure outside the housing. Also, compared to the case where only the pressure outside the housing is detected, by detecting the pressure difference between the outside and the inside of the housing, it is possible to easily determine the direction (outward or inward) of the load applied to the housing due to the pressure difference. Therefore, it is possible to easily determine whether a load that causes the housing to expand or a load that causes the housing to contract is acting. As a result, by detecting the pressure difference, it is possible to easily keep the pressure inside the housing higher than the normal pressure (atmospheric pressure), so that it is possible to more effectively suppress a decrease in the dielectric withstand voltage inside the housing.

[0011] In this case, preferably, when the control unit increases the opening area of the area adjustment valve, it is configured to adjust the size of the opening area of the area adjustment valve according to the magnitude of the pressure difference. As a result, when the difference between the pressure outside and the pressure inside the housing is large, the opening area of the area adjustment valve can be increased, so that the pressure difference between the outside and the inside of the housing can be eliminated more quickly. Therefore, it is possible to more effectively suppress the deformation of the housing toward the inside due to the pressure outside the housing being greater than the pressure inside.

[0012] In a panel device that increases the opening area of an area adjustment valve when a pressure change that causes the pressure outside the housing to rise is detected, preferably, after the control unit detects a pressure change that causes the pressure outside the housing to rise, when the pressure change per unit time detected by the detection unit becomes smaller than a predetermined magnitude, the opening area of the area adjustment valve is configured to be a constant magnitude or to gradually decrease. As a result, when the pressure change per unit time becomes smaller than a predetermined magnitude in a state where the pressure inside the housing is increased in accordance with the pressure change outside the housing, the increased pressure inside the housing can be gradually decreased and returned to the normal magnitude. Therefore, it is possible to suppress a rapid decrease in the increased pressure inside the housing, and thus it is possible to suppress the occurrence of condensation inside the housing due to a rapid decrease in pressure. As a result, it is possible to suppress the abnormal operation of the devices housed inside the housing due to the condensation generated inside the housing.

[0013] In a panel device that increases the opening area of an area adjustment valve when a pressure change that causes the pressure outside the housing to rise is detected, preferably, the housing, separately from the opening, is deformed so as to increase the volume of the internal space of the housing when the pressure outside the housing is smaller than the internal pressure, thereby further including a pressure difference relaxation portion that relaxes the pressure difference between the outside and the inside of the housing. Here, when suppressing a decrease in the pressure inside the housing by reducing the opening area of the area adjustment valve, if the pressure outside the housing changes so as to greatly decrease, the load in the direction in which the housing expands increases. On the other hand, in the present invention, the housing, separately from the opening, is deformed so as to increase the volume of the internal space of the housing when the pressure outside the housing is smaller than the internal pressure, thereby further including a pressure difference relaxation portion that relaxes the pressure difference between the outside and the inside of the housing. Thereby, the pressure difference between the outside and the inside of the housing can be easily relaxed by the pressure difference relaxation portion without adjusting the opening area of the area adjustment valve, so that the magnitude of the load received by the housing so as to expand outward can be easily reduced. As a result, while keeping the pressure inside the housing larger than the normal pressure (atmospheric pressure), it is possible to easily suppress the load for the housing to expand outward from becoming larger than necessary.

[0014] In a panel device that increases the opening area of an area adjustment valve when a pressure change that causes the pressure outside the housing to rise is detected, preferably, the housing further includes a pump that pressurizes the inside of the housing, and the control unit is configured to suppress a pressure change inside the housing in a state pressurized by the pump based on the pressure change detected by the detection unit. Thereby, the pressure inside the housing can always be kept higher than the atmospheric pressure by the pump. And, in a state where the pressure inside the housing is kept higher than the atmospheric pressure by the pump, the opening area of the area adjustment valve can be adjusted so as to suppress a pressure change inside the housing caused by a pressure change outside the housing. Therefore, since the pressure inside the housing can be kept higher than the atmospheric pressure by the pump, it is possible to more effectively suppress a decrease in the dielectric withstand voltage inside the housing.

[0015] In the panel device according to the first aspect, preferably, a filter is further provided which is arranged to cover an opening provided in the housing and suppresses the intrusion of foreign matter from the outside of the housing. Thereby, when taking in air into the housing by increasing the opening area of the area adjustment valve, it is possible to suppress foreign matter such as dust contained in the outside air from entering the housing. Further, when discharging the air inside the housing to the outside through the opening, since the foreign matter attached to the filter can be discharged to the outside of the housing together with the air, it is possible to suppress the foreign matter from remaining attached to the filter. Therefore, the replacement frequency of the filter can be reduced, and the work load required for the filter replacement work can be reduced.

[0016] In the panel device according to the first aspect, preferably, the area adjustment valve includes a solenoid valve that can be adjusted to at least a plurality of different opening areas in an open state based on the control by the control unit, and the control unit is configured to adjust the opening area of the solenoid valve to at least a plurality of different opening areas in an open state based on the pressure change detected by the detection unit. Thereby, since the solenoid valve is configured to be adjustable to at least a plurality of different opening areas in an open state, the air flow rate at the opening can be easily adjusted to a plurality of magnitudes. As a result, by using the solenoid valve, the pressure difference between the outside and the inside of the housing can be easily alleviated, and the enlargement of the device can be easily suppressed.

[0017] Further, the pressure change suppression method according to the second aspect of the present invention includes a step of detecting a pressure change outside a housing that houses equipment inside, and based on the detected pressure change, adjusting the opening area of an area adjustment valve that adjusts the opening area so as to adjust the air flow rate between the outside and the inside of the housing at an opening provided in the housing so as to suppress the pressure change inside the housing caused by the pressure change outside the housing.

[0018] In the method for suppressing pressure changes according to the second aspect of the present invention, as described above, based on the detected pressure changes, the opening area of an area adjustment valve that adjusts the opening area so as to adjust the air flow rate between the outside and inside of the housing is adjusted at the opening provided in the housing, so as to suppress the pressure change inside the housing caused by the pressure change outside the housing. Thereby, when the pressure outside the housing changes, the pressure change inside the housing can be suppressed by adjusting the opening area of the area adjustment valve. Therefore, it is possible to suppress the pressure difference between the outside and inside of the housing without providing a member that expands and contracts toward the inside or outside of the housing to change the volume inside the housing. As a result, it is possible to provide a method for suppressing pressure changes that can alleviate the pressure difference between the outside and inside of the housing and suppress the enlargement of the device. Further, when the pressure does not change outside the housing, it is possible to provide a method for suppressing pressure changes that can suppress the intrusion of foreign matter such as dust into the housing by setting the opening area of the area adjustment valve to 0.

Advantages of the Invention

[0019] According to the present invention, as described above, it is possible to provide a board device and a method for suppressing pressure changes that can alleviate the pressure difference between the outside and inside of the housing and suppress the enlargement of the device.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0021] Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

[0022] [First Embodiment] Referring to FIGS. 1 to 5, the configuration of the panel device 100 according to the first embodiment will be described. The panel device 100 is installed, for example, in a tunnel through which a railway vehicle passes. The panel device 100 is, for example, a distribution board or a switchboard.

[0023] (Configuration of the panel device) As shown in FIG. 1, the panel device 100 includes a housing 10. Inside the housing 10, devices 20 (electrical devices) such as breakers are accommodated. The housing 10 is a rectangular parallelepiped box extending in the front-rear direction (X direction), left-right direction (Y direction), and up-down direction (Z direction). And, the housing 10 is provided with a door portion 11 that can open the inside of the housing 10 on the front side (X1 direction side). Further, on the side surface portion 12 on the Y2 direction side (right side) of the housing 10, openings 13a and 13b for allowing air to flow between the outside and inside of the housing 10 are provided. Further, the housing 10 is configured to suppress the flow of air in portions such as gaps excluding the openings 13a and 13b by a sealing material or the like.

[0024] Further, an attachment member 12a is provided on the side portion 12 of the housing 10. The attachment member 12a is a plate-like member for arranging electromagnetic valves 30a and 30b described later. Further, the attachment member 12a is provided with hole portions corresponding to the opening portions 13a and 13b. The attachment member 12a is fastened to the side portion 12 on the inner side (Y1 direction side) of the housing 10 by a fastening member such as a screw.

[0025] As shown in FIG. 2, the panel device 100 includes electromagnetic valves 30a and 30b, pressure sensors 40a and 40b, and control units 50a and 50b. The electromagnetic valves 30a and 30b are an example of the "area adjustment valve" in the claims. The pressure sensors 40a and 40b are an example of the "detection unit" in the claims.

[0026] The electromagnetic valve 30b, the pressure sensor 40b, and the control unit 50b have the same configurations as the electromagnetic valve 30a, the pressure sensor 40a, and the control unit 50a, respectively. In the following description, only the electromagnetic valve 30a, the pressure sensor 40a, and the control unit 50a will be described, and the description of the electromagnetic valve 30b, the pressure sensor 40b, and the control unit 50b will be omitted.

[0027] In the first embodiment, the electromagnetic valve 30a adjusts the air flow rate between the outside and the inside of the housing 10 at the opening portion 13a. Specifically, the electromagnetic valve 30a is arranged inside the side portion 12 of the housing 10 so as to cover the opening portion 13a. The electromagnetic valve 30a is fixed to the attachment member 12a by a fastening member such as a screw, for example. Then, the electromagnetic valve 30a adjusts the air flow rate at the opening portion 13a by adjusting the opening area. The electromagnetic valve 30a is configured to be adjustable to at least a plurality of different opening areas in an open state based on the control by the control unit 50a described later.

[0028] As shown in FIG. 3, specifically, the solenoid valve 30a is a proportional control valve capable of continuously adjusting the opening area (flow rate) between 0% (closed state) and 100% in proportion to the control signal from the control unit 50a. Further, the solenoid valve 30a is, for example, a butterfly-type proportional control valve. The solenoid valve 30a is driven by power such as a solenoid coil or a motor. Also, the switching time of the opening area of the solenoid valve 30a is, for example, in the range of 0.01 seconds or more and 0.1 seconds or less. The switching time varies according to the magnitude of the opening area to be changed.

[0029] As shown in FIG. 2, the pressure sensor 40a detects a change in pressure outside the housing 10. Specifically, the pressure sensor 40a is configured to indirectly detect a change in pressure outside the housing 10 by detecting the pressure difference between the outside and inside of the housing 10. Further, the pressure sensor 40a is installed on the side portion 12 provided with the opening 13a.

[0030] And the pressure sensor 40a includes a strain gauge. The pressure sensor 40a is configured to detect the pressure difference between the outside and inside of the housing 10 by detecting the displacement (strain) in the Y direction of the side portion 12. Also, the detected value a (see FIG. 5) detected by the pressure sensor 40a is output to the control unit 50a described later. For example, the pressure sensor 40a is configured to output a positive detected value a as the pressure difference when the pressure outside the housing 10 is greater than the pressure inside the housing 10. Also, the pressure sensor 40a is configured to output a negative detected value a as the pressure difference when the pressure outside the housing 10 is less than the pressure inside the housing 10.

[0031] The control unit 50a controls the opening area of the solenoid valve 30a based on the detected value a from the pressure sensor 40a. Specifically, the control unit 50a outputs, as a control signal to the solenoid valve 30a, a command value b (see FIG. 5) for controlling the opening area to be 0% or more and 100% or less. The control unit 50a includes, for example, a microcomputer (microcontroller) having an arithmetic device (processor) such as a CPU (Central Processing Unit) and a storage device (memory) such as a ROM (Read Only Memory). Details of the control of the opening area of the solenoid valve 30a by the control unit 50a will be described later.

[0032] Also, as shown in FIG. 4, the panel device 100 includes a filter 60. The filter 60 is disposed so as to cover the openings 13a and 13b provided in the side portion 12 of the housing 10. And the filter 60 suppresses the intrusion of foreign matter from the outside of the housing 10. Specifically, the filter 60 includes a dust collecting filter that allows air to pass through while suppressing the passage of foreign matter such as sand and dust. Also, the filter 60 includes, for example, a rectangular nonwoven fabric. And the filter 60 is held by the filter holding member 61.

[0033] The filter holding member 61 has a rectangular parallelepiped box shape. Also, the filter holding member 61 is attached to the attachment member 12a so as to cover the solenoid valves 30a and 30b and the control units 50a and 50b. The surface of the filter holding member 61 on the side of the attachment member 12a (Y2 direction side) is open so that air can flow through the openings 13a and 13b (solenoid valves 30a and 30b). Also, the filter 60 is disposed on the surface of the filter holding member 61 on the Y1 direction side. That is, the panel device 100 is configured to allow air to flow from the openings 13a and 13b through the filter 60.

[0034] (Pressure change suppression control by the control unit) As shown in FIG. 5, in the first embodiment, the control unit 50a is configured to adjust the opening area of the solenoid valve 30a so as to suppress the pressure change inside the housing 10 caused by the pressure change outside the housing 10 based on the pressure change detected by the pressure sensor 40a. Specifically, the panel device 100 according to the first embodiment is configured to adjust the opening area of the solenoid valve 30a so as to suppress the oscillating change in the pressure inside the housing 10 when the pressure outside the housing 10 changes oscillatingly due to the micro-pressure wave generated when the railway vehicle passes through the tunnel.

[0035] Specifically, when no pressure change outside the housing 10 is detected, the control unit 50a sets the opening area of the solenoid valve 30a to 0% (closed state). That is, when the pressure outside the housing 10 is at the normal pressure P0, the solenoid valve 30a is in a closed state. For example, in the period before the time point T1 in FIG. 5, the pressure outside the housing 10 is maintained at the normal pressure P0. When the pressure outside the housing 10 is maintained at the normal pressure P0, since the detected value a obtained from the pressure sensor 40a is substantially 0 and constant, the control unit 50a sets the opening area of the solenoid valve 30a to 0%. Here, the "normal pressure P0" means a state where the pressure is substantially constant without change outside the housing 10 (atmospheric pressure state).

[0036] In the first embodiment, when the control unit 50a detects a pressure change such that the pressure outside the housing 10 increases by the pressure sensor 40a, the control unit 50a is configured to increase the opening area of the solenoid valve 30a (open the solenoid valve 30a). Specifically, the control unit 50a increases the opening area of the solenoid valve 30a when the pressure difference detected by the pressure sensor 40a is greater than a predetermined reference value. In the first embodiment, the predetermined reference value is 0. That is, the control unit 50a increases the opening area of the solenoid valve 30a when the detected value a detected by the pressure sensor 40a is a positive value.

[0037] In addition, when a pressure change is detected such that the pressure outside the housing 10 decreases from the state of the normal pressure P0, the control unit 50a is configured to keep the opening area of the solenoid valve 30a at 0% (keep the solenoid valve 30a closed). That is, when the detected value a detected by the pressure sensor 40a is a negative value, the control unit 50a keeps the opening area of the solenoid valve 30a at 0%.

[0038] For example, during the period from time point T1 to time point T2 in FIG. 5, the pressure outside the housing 10 changes so as to increase. Due to the pressure change outside the housing 10, the control unit 50a obtains a positive detected value a from the pressure sensor 40a. Then, based on the fact that the positive detected value a has been obtained, the control unit 50a outputs a command value b so as to set the opening area of the solenoid valve 30a to 100%. That is, when the control unit 50a first obtains a positive detected value a from a state where no pressure change outside the housing 10 is detected (state of the normal pressure P0), the opening area of the solenoid valve 30a is set to 100%.

[0039] And when a pressure change is detected such that the pressure outside the housing 10 decreases, the control unit 50a is configured to reduce the opening area of the solenoid valve 30a. Specifically, when a pressure change is detected such that the pressure outside the housing 10 decreases, the control unit 50a is configured to change the opening area of the solenoid valve 30a to 0% (close the solenoid valve 30a). That is, when the detected pressure difference (detected value a) is less than or equal to the reference value (negative value or 0), the control unit 50a is configured to set the opening area of the solenoid valve 30a to 0% (close the solenoid valve 30a).

[0040] For example, at time point T2 in FIG. 5, it is detected that the pressure outside the housing 10 has become lower than the pressure inside the housing 10. That is, the detected value a obtained by the pressure sensor 40a at time point T2 changes from a positive value to a negative value. Based on the fact that the detected value a has changed from a positive value to a negative value, the control unit 50a changes (adjusts) the opening area to 0. During the period from time point T2 to time point T3 in FIG. 5, based on the fact that the detected value a of a negative value is detected, the control unit 50a sets the opening area of the solenoid valve 30a to the state of 0. Then, at time point T3 in FIG. 5, a positive detected value a is detected again. Based on the fact that the detected value a has changed from a negative value to a positive value, the control unit 50a increases the opening area of the solenoid valve 30a again.

[0041] Here, in the first embodiment, when the control unit 50a increases the opening area of the solenoid valve 30a, it is configured to adjust the size of the opening area of the solenoid valve 30a according to the magnitude of the pressure difference. Specifically, when the detected value a changes from a negative value to a positive value, the control unit 50a adjusts the size of the opening area based on, for example, the amount of change (change rate) of the detected value a per unit time. In detail, when the pressure outside the housing 10 is higher than the pressure inside the housing 10, the control unit 50a is configured to make the opening area relatively large when the amount of change of the detected value a is relatively large, and make the opening area relatively small when the amount of change of the detected value a is relatively small.

[0042] For example, during the period from time point T3 to time point T4 in FIG. 5, the control unit 50a sets the opening area to 50% based on the obtained detected value a. Note that the control unit 50a may calculate a command value b for adjusting the opening area of the solenoid valve 30a by executing a prestored arithmetic process (program) from the obtained detected value a. Further, the control unit 50a may obtain a command value b for adjusting the opening area based on a table prestored so that the amount of change of the detected value a and the command value b are associated with each other.

[0043] Then, at time point T4 in FIG. 5, the detected value a changes from a positive value to a negative value again. At time point T4, the control unit 50a sets the opening area of the solenoid valve 30a to 0% in the same manner as at time point T2. Then, at time point T5 in FIG. 5, the detected value a changes from a negative value to a positive value. At time point T5, the control unit 50a sets the opening area of the solenoid valve 30a to 50% in the same manner as at time point T3. Thus, also at time points T5 and T6, the control unit 50a changes (adjusts) the opening area based on the detected detected value a.

[0044] In the first embodiment, after a pressure change in which the pressure outside the housing 10 increases is detected, when the pressure change per unit time detected by the pressure sensor 40a becomes smaller than a predetermined magnitude, the control unit 50a is configured to set the opening area of the solenoid valve 30a to a certain magnitude. Specifically, the control unit 50a is configured to acquire the amount of change in the detected value a per unit time. Then, the control unit 50a determines whether the amount of change in the detected value a per unit time is smaller than a predetermined magnitude (predetermined determination value) stored in advance. When the control unit 50a determines that the acquired amount of change in the detected value a per unit time is smaller than the predetermined determination value, it determines that the pressure change outside the housing 10 has ended. Then, when the control unit 50a determines that the pressure change outside the housing 10 has ended, in order to gradually make the pressure inside the housing 10 equal to the external pressure, it is configured to set the opening area of the solenoid valve 30a to a relatively small constant magnitude (20%).

[0045] For example, at time point T7 in FIG. 5, the control unit 50a determines that the amount of change in the detected value a per unit time has become smaller than the predetermined determination value. The predetermined determination value is set in advance in consideration of the pressure change in the environment where the panel device 100 is installed.

[0046] As described above, when a pressure change that causes vibration is detected outside the housing 10, the control unit 50a is configured to suppress the change in the pressure inside the housing 10 so as to vibrate. That is, when the control unit 50a first detects a pressure change that rises from the state of the normal pressure P0, the opening area of the solenoid valve 30a is set to 100%. Then, when the detected value a becomes a negative value, the control unit 50a sets the opening area of the solenoid valve 30a to 0%. And when the detected value a becomes a positive value for the second time and subsequent times, the control unit 50a changes (adjusts) the opening area according to the magnitude of the change amount of the detected value a. Further, when the pressure outside the housing 10 returns to the normal pressure P0 after the pressure change outside the housing 10, the control unit 50a is configured to gradually return the pressure inside the housing 10 to the normal pressure P0 while suppressing a sudden change in the pressure change inside the housing 10.

[0047] Note that the control of the opening area by the control unit 50b of the solenoid valve 30b provided in the opening 13b is the same as the control of the opening area of the solenoid valve 30a by the control unit 50a.

[0048] (Control Process of Pressure Change Suppression Method) Next, with reference to FIG. 6, the control process flow regarding the pressure change suppression method by the panel device 100 of the first embodiment will be described. Further, the control regarding this pressure change suppression method is executed by the control unit 50a and the control unit 50b. In the following description, the control of the solenoid valve 30a by the control unit 50a will be described.

[0049] First, in step S101, the opening area of the solenoid valve 30a is set to 0%. That is, when the pressure outside the housing 10 is in the normal state (the state of the normal pressure P0), a command value b is output so that the opening area of the solenoid valve 30a becomes 0% (the state where the solenoid valve 30a is closed).

[0050] Next, in step S102, a detected value a is acquired so as to detect a pressure change outside the housing 10. Specifically, the pressure difference between the outside and the inside of the housing 10 detected by the pressure sensor 40a is acquired as the detected value a.

[0051] Next, in step S103, it is determined whether the detected detection value a is a positive value (greater than 0). That is, it is determined whether a pressure change is detected such that the pressure outside the housing 10 becomes greater than the pressure inside. If it is determined that the detection value a is a positive value, the process proceeds to step S104. If it is not determined that the detection value a is a positive value, the process returns to step S102.

[0052] In step S104, the opening area of the solenoid valve 30a is set to 100%. That is, when it is first determined that the detection value a is a positive value from the state where the solenoid valve 30a is closed, the opening area of the solenoid valve 30a is controlled to 100%.

[0053] Next, in step S105, it is determined whether the pressure change per unit time is smaller than a predetermined magnitude. Specifically, it is determined whether the change amount of the detection value a per unit time is smaller than a determination value stored in advance. If it is determined that the change amount of the detection value a per unit time is smaller than the determination value, the process proceeds to step S107. If it is not determined that the change amount of the detection value a per unit time is smaller than the determination value, the process proceeds to step S106.

[0054] In step S106, based on the determination that the pressure change per unit time is not smaller than a predetermined magnitude, it is determined that the pressure change outside the housing 10 continues. Then, based on the detected pressure change (detection value a), the opening area of the solenoid valve 30a is adjusted at the opening 13a provided in the housing 10 so as to suppress the pressure change inside the housing 10 caused by the pressure change outside the housing 10. Specifically, when the detection value a is a negative value, the opening area is set to 0%, and when the detection value a is a positive value, the opening area is adjusted according to the magnitude of the change amount of the detection value a. Then, the process returns to step S105.

[0055] In step S107, based on the determination that the pressure change per unit time is smaller than a predetermined magnitude, it is determined that the pressure change outside the housing 10 has ended. Then, in order to gradually make the pressure inside the housing 10 equal to the pressure outside the housing 10, the opening area of the solenoid valve 30a is set to a constant magnitude (20%).

[0056] Next, in step S108, it is determined whether the detected value a has become 0. Specifically, based on the determination that the pressure change outside the housing 10 has ended, it is determined whether the detected value a has become 0 in a state where the opening area of the solenoid valve 30a is controlled to 20%. That is, it is determined whether the pressure difference between the outside and the inside of the housing 10 has disappeared. If it is determined that the detected value a has become 0, the process proceeds to step S109. If it is not determined that the detected value a has become 0, the process returns to step S107 and the opening area remains 20%.

[0057] In step S109, based on the determination that the detected value a has become 0, the opening area of the solenoid valve 30a is set to 0. That is, based on the determination that no pressure change is detected outside the housing 10 and the pressure difference between the outside and the inside of the housing 10 has become 0, the opening area of the solenoid valve 30a is set to 0 (closed state).

[0058] Note that the control of the solenoid valve 30b by the control unit 50b is the same as the above-described control of the solenoid valve 30a by the control unit 50a.

[0059] (Effect of the First Embodiment) In the first embodiment, the following effects can be obtained.

[0060] In the first embodiment, as described above, solenoid valves 30a and 30b (area adjustment valves) are provided to adjust the opening area so as to adjust the air flow rate between the outside and the inside of the housing 10. Then, based on the detected pressure change, the opening areas of the solenoid valves 30a and 30b are adjusted so as to suppress the pressure change inside the housing 10 caused by the pressure change outside the housing 10. Thereby, when the pressure outside the housing 10 changes, the pressure change inside the housing 10 can be suppressed by adjusting the opening areas of the solenoid valves 30a and 30b. Therefore, without providing a member that expands and contracts toward the inside or the outside of the housing 10 to change the volume inside the housing 10, the pressure difference between the outside and the inside of the housing 10 can be suppressed. As a result, the pressure difference between the outside and the inside of the housing 10 can be alleviated, and an increase in the size of the apparatus can be suppressed. Further, when the pressure does not change outside the housing 10, by setting the opening areas of the solenoid valves 30a and 30b to 0, it is possible to suppress the intrusion of foreign matters such as dust into the inside of the housing 10.

[0061] Also, in the first embodiment, as described above, when the control units 50a and 50b detect a pressure change such that the pressure outside the housing 10 increases by the pressure sensors 40a and 40b (detection units), the opening areas of the electromagnetic valves 30a and 30b (area adjustment valves) are configured to increase. When a pressure change such that the pressure outside the housing 10 decreases is detected, the opening areas of the electromagnetic valves 30a and 30b are configured to decrease. Here, when a pressure change such that the pressure outside the housing 10 decreases is detected and the decrease in the pressure inside the housing 10 is suppressed by decreasing the opening areas of the electromagnetic valves 30a and 30b, the housing 10 receives a load so as to expand outward due to the decrease in the pressure outside the housing 10. In this case, unlike the case where the housing 10 receives a load so as to contract inward, the housing 10 does not interfere (contact) with the internal device 20 or the like due to the deformation of the housing 10. Considering this point, in the first embodiment, when a pressure change such that the pressure outside the housing 10 decreases is detected, the decrease in the pressure inside the housing 10 can be suppressed by decreasing the opening areas of the electromagnetic valves 30a and 30b. Therefore, the pressure inside the housing 10 can be maintained at a state higher than the normal pressure (atmospheric pressure), so that the decrease in the insulation breakdown voltage inside the housing 10 can be suppressed. Also, when a pressure change such that the pressure outside the housing 10 increases is detected, the pressure inside the housing 10 can be increased in accordance with the pressure change outside the housing 10 by increasing the opening areas of the electromagnetic valves 30a and 30b. Therefore, when a pressure change such that the pressure outside the housing 10 increases is detected, the pressure difference between the outside and inside of the housing 10 can be relaxed, so that the deformation of the housing 10 so as to contract can be suppressed.

[0062] Also, in the first embodiment, as described above, the pressure sensors 40a and 40b (detection units) are configured to detect a change in the external pressure of the housing 10 by detecting the pressure difference between the outside and inside of the housing 10. The control units 50a and 50b are configured to increase the opening areas of the electromagnetic valves 30a and 30b (area adjustment valves) when the pressure difference (detection value a) detected by the pressure sensors 40a and 40b is greater than a predetermined reference value, and to decrease the opening areas of the electromagnetic valves 30a and 30b when the pressure difference is equal to or less than the reference value. Thereby, based on the pressure difference detected by detecting the pressure difference between the outside and inside of the housing 10, a change in the external pressure of the housing 10 can be easily detected. Also, compared to the case of detecting only the external pressure of the housing 10, by detecting the pressure difference between the outside and inside of the housing 10, the direction (outward or inward) of the load received by the housing 10 due to the pressure difference can be easily determined. Therefore, it is possible to easily determine whether a load that causes the housing 10 to expand or a load that causes it to contract is acting. As a result, by detecting the pressure difference, the internal pressure of the housing 10 can be easily maintained at a state higher than the normal pressure (atmospheric pressure), so that a decrease in the dielectric withstand voltage inside the housing 10 can be more effectively suppressed.

[0063] Also, in the first embodiment, as described above, the control units 50a and 50b are configured to adjust the opening areas of the electromagnetic valves 30a and 30b (area adjustment valves) according to the magnitude of the pressure difference when increasing the opening areas of the electromagnetic valves 30a and 30b. Thereby, when the difference between the external pressure and the internal pressure of the housing 10 is large, the opening areas of the electromagnetic valves 30a and 30b can be increased, so that the pressure difference between the outside and inside of the housing 10 can be eliminated more quickly. Therefore, it is possible to more effectively suppress the deformation of the housing 10 toward the inside due to the external pressure of the housing 10 being greater than the internal pressure.

[0064] Also, in the first embodiment, as described above, after a pressure change such that the pressure outside the housing 10 increases is detected, when the pressure change per unit time detected by the pressure sensors 40a and 40b (detection units) becomes smaller than a predetermined magnitude (determination value), the opening areas of the electromagnetic valves 30a and 30b are configured to be a constant magnitude (20%). Thereby, in a state where the pressure inside the housing 10 is increased in accordance with the pressure change outside the housing 10, when the pressure change per unit time becomes smaller than a predetermined magnitude (determination value), the increased pressure inside the housing 10 can be gradually reduced and returned to the normal magnitude. Therefore, it is possible to suppress a rapid decrease in the increased pressure inside the housing 10, and thus it is possible to suppress the occurrence of condensation inside the housing 10 due to a rapid decrease in pressure. As a result, it is possible to suppress the operation of the device 20 housed inside the housing 10 from being abnormally performed due to the condensation generated inside the housing 10.

[0065] Also, in the first embodiment, as described above, a filter 60 is provided which is arranged so as to cover the openings 13a and 13b provided in the housing 10 and suppresses the intrusion of foreign matter from outside the housing 10. Thereby, when air is taken into the housing 10 by increasing the opening areas of the electromagnetic valves 30a and 30b (area adjustment valves), it is possible to suppress foreign matter such as dust contained in the outside air from entering the housing 10. Further, when discharging the air inside the housing 10 to the outside through the openings 13a and 13b, since the foreign matter attached to the filter 60 can be discharged to the outside of the housing 10 together with the air, it is possible to suppress the foreign matter from remaining attached to the filter 60. Therefore, the replacement frequency of the filter 60 can be reduced, and thus the work load required for the replacement work of the filter 60 can be reduced.

[0066] Also, in the first embodiment, as described above, the solenoid valves 30a and 30b (area adjustment valves) can be adjusted to at least a plurality of different opening areas while being open, based on the control by the control units 50a and 50b. The control units 50a and 50b are configured to adjust the opening areas of the solenoid valves 30a and 30b to at least a plurality of different opening areas while being open, based on the pressure changes detected by the pressure sensors 40a and 40b (detection units). As a result, since the solenoid valves 30a and 30b are configured to be adjustable to at least a plurality of different opening areas while being open, the air flow rates at the openings 13a and 13b can be easily adjusted to a plurality of magnitudes. Consequently, by using the solenoid valves 30a and 30b, the pressure difference between the outside and the inside of the housing 10 can be easily alleviated, and the enlargement of the device can be easily suppressed.

[0067] (Effect of the pressure change suppression method) In the pressure change suppression method by the panel device 100 of the first embodiment, the following effects can be obtained.

[0068] In the method for suppressing pressure changes by the board device 100 of the first embodiment, as described above, based on the detected pressure changes, the opening areas of the electromagnetic valves 30a and 30b (area adjustment valves) that adjust the air flow rate between the outside and inside of the housing 10 are adjusted so as to suppress the pressure change inside the housing 10 caused by the pressure change outside the housing 10 at the openings 13a and 13b provided in the housing 10. Thereby, when the pressure outside the housing 10 changes, the pressure change inside the housing 10 can be suppressed by adjusting the opening areas of the electromagnetic valves 30a and 30b. Therefore, it is possible to suppress the pressure difference between the outside and inside of the housing 10 without providing a member that expands and contracts toward the inside or outside of the housing 10 to change the volume inside the housing 10. As a result, it is possible to provide a method for suppressing pressure changes that can relax the pressure difference between the outside and inside of the housing 10 and suppress the increase in the size of the device. Further, when the pressure is not changing outside the housing 10, it is possible to provide a method for suppressing pressure changes that can suppress the intrusion of foreign matter such as dust into the housing 10 by setting the opening areas of the electromagnetic valves 30a and 30b to 0.

[0069] [Second Embodiment] Next, with reference to FIGS. 7 to 9, the configuration of the board device 200 according to the second embodiment will be described. In the second embodiment, in addition to the housing 10 of the board device 100 according to the first embodiment, a pressure difference relaxation portion 270 that deforms so as to increase the volume inside the housing 210 is provided. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0070] (Configuration of the board device according to the second embodiment) As shown in FIG. 7, the board device 200 according to the second embodiment includes a housing 210. The housing 210 houses the device 20 inside, similarly to the housing 10 according to the first embodiment. The housing 210 is provided with a door portion 211 that can open the inside of the housing 210 on the front side (X1 direction side).

[0071] In the second embodiment, the housing 210 includes a pressure difference relaxation portion 270. The pressure difference relaxation portion 270 is provided separately from the openings 13a and 13b. Specifically, the pressure difference relaxation portion 270 is provided on the door portion 211 of the housing 210. When the pressure outside the housing 210 is smaller than the pressure inside, the pressure difference relaxation portion 270 deforms to increase the volume of the internal space of the housing 210, thereby relaxing the pressure difference between the outside and the inside of the housing 210.

[0072] As shown in FIG. 8, the pressure difference relaxation portion 270 includes a movable portion 270a having a bellows structure. As shown in FIG. 8(A), when the pressures inside and outside the housing 210 are substantially equal and when the pressure outside the housing 210 is greater than the pressure inside, the movable portion 270a of the pressure difference relaxation portion 270 is in a closed state (contracted state). Then, as shown in FIG. 8(B), when the pressure outside the housing 210 is smaller than the pressure inside, the movable portion 270a of the pressure difference relaxation portion 270 is in an open state (extended state). The pressure difference relaxation portion 270 increases the volume inside the housing 210 by the outward deformation of the movable portion 270a.

[0073] Note that the pressure difference relaxation portion 270 is in a sealed state so as not to allow air to flow between the outside and the inside of the housing 210. That is, the housing 210 is configured not to allow air to flow except at the openings 13a and 13b, and to allow air to flow only at the openings 13a and 13b.

[0074] As shown in FIG. 9, the control of the solenoid valves 30a and 30b by the control units 50a and 50b according to the second embodiment is the same as the control in the first embodiment. Specifically, when the detected value a detected by the pressure sensor 40a is a positive value, the control unit 50a increases the opening areas of the solenoid valves 30a and 30b. When the detected value a is a negative value, the control unit 50a sets the opening area of the solenoid valve 30a to 0%.

[0075] For example, in the period before time point T201 in FIG. 9, since no pressure change outside the housing 210 is detected, the control unit 50a keeps the opening area of the solenoid valve 30a at 0%. Then, in the period from time point T201 to time point T202 in FIG. 9, based on the detected value a being a positive value, the control unit 50a increases the opening area of the solenoid valve 30a. In the period from time point T201 to time point T202, for example, the control unit 50a sets the opening area to 100%.

[0076] Then, in the period from time point T202 to time point T203 in FIG. 9, based on the detected value a being a negative value, the control unit 50a sets the opening area of the solenoid valve 30a to 0%. Here, in the second embodiment, the pressure outside the housing 210 drops significantly to a value lower than the normal pressure P0 in the period from time point T202 to time point T203. The pressure difference relaxation unit 270 according to the second embodiment suppresses (relaxes) the pressure difference between the outside and inside of the housing 210 by increasing the volume inside the housing 210 when the pressure outside the housing 210 drops, as in the period from time point T202 to time point T203.

[0077] Then, in the period from time point T203 to time point T204 in FIG. 9, the opening area of the solenoid valve 30a is increased in the same manner as in the period from time point T201 to time point T202. And in the period from time point T204 to time point T205 in FIG. 9, the opening area of the solenoid valve 30a is set to 0% in the same manner as in the period from time point T202 to time point T203. At this time, the pressure difference relaxation unit 270 increases the volume of the internal space of the housing 210, and thus the pressure difference between the outside and inside of the housing 210 is similarly relaxed. Then, in the period after time point T205, similar to the first embodiment, it is determined that the pressure change outside the housing 210 has ended, and the pressure inside the housing 210 is gradually made equal to the outside pressure.

[0078] Also, other configurations according to the second embodiment are the same as those of the first embodiment.

[0079] [Effects of the Second Embodiment] In the second embodiment, the following effects can be obtained.

[0080] In the second embodiment, as described above, when the pressure outside the housing 210 is lower than the pressure inside, the housing 210 is deformed so as to increase the volume of the internal space of the housing 210 separately from the openings 13a and 13b, thereby providing a pressure difference relaxation portion 270 that relaxes the pressure difference between the outside and inside of the housing 210. Here, when suppressing a decrease in the pressure inside the housing 210 by reducing the opening areas of the solenoid valves 30a and 30b (area adjustment valves), if the pressure outside the housing 210 changes so as to greatly decrease, the load in the direction in which the housing 210 expands increases. On the other hand, in the second embodiment, the housing 210 is deformed so as to increase the volume of the internal space of the housing 210 separately from the openings 13a and 13b when the pressure outside the housing 210 is lower than the pressure inside, thereby providing a pressure difference relaxation portion 270 that relaxes the pressure difference between the outside and inside of the housing 210. Thereby, the pressure difference relaxation portion 270 can easily relax the pressure difference between the outside and inside of the housing 210 without adjusting the opening areas of the solenoid valves 30a and 30b, so that the magnitude of the load received by the housing 210 so as to expand outward can be easily reduced. As a result, while keeping the pressure inside the housing 210 higher than the normal pressure (atmospheric pressure), it is possible to easily suppress the load causing the housing 210 to expand outward from becoming excessively large.

[0081] Also, other effects according to the second embodiment are the same as those of the first embodiment.

[0082] [Third Embodiment] Next, with reference to FIG. 10, the configuration of the panel device 300 according to the third embodiment will be described. In the third embodiment, a pump 380 for pressurizing the inside of the housing 310 is provided. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[0083] (Configuration of Panel Device According to Third Embodiment) As shown in FIG. 10, the board device 300 according to the third embodiment includes a housing 310 and a pump 380. The housing 310 houses the device 20 inside, similar to the housing 10 according to the first embodiment. Also, the pump 380 is connected to the housing 310. The pump 380 pressurizes the inside of the housing 310. Specifically, the pump 380 pressurizes the inside of the housing 310 with a constant pressure regardless of the pressure change outside the housing 310.

[0084] And in the third embodiment, the control units 50a and 50b are configured to suppress the pressure change inside the housing 310 in the pressurized state by the pump 380 based on the pressure changes detected by the pressure sensors 40a and 40b. That is, the control units 50a and 50b acquire the pressure difference between the pressure inside the housing 310 in the pressurized state by the pump 380 and the pressure outside the housing 310 as the detected value a. The control of the solenoid valves 30a and 30b by the control units 50a and 50b based on the detected value a is the same as in the first embodiment.

[0085] That is, in the third embodiment, since the inside of the housing 310 is to be constantly pressurized, when no pressure change outside the housing 310 is detected, the detected value a is always a negative value. Since the detected value a is a negative value, the control units 50a and 50b control the opening areas of the solenoid valves 30a and 30b to 0%. And when the detected detected value a becomes greater than 0 due to the pressure change outside the housing 310, the control units 50a and 50b increase the opening areas of the solenoid valves 30a and 30b. The control based on the detected value a from the pressure sensors 40a and 40b is the same as in the first embodiment.

[0086] Also, other configurations according to the third embodiment are the same as those in the first embodiment.

[0087] [Effect of the Third Embodiment] In the third embodiment, the following effects can be obtained.

[0088] In the third embodiment, as described above, a pump 380 for pressurizing the inside of the housing 310 is provided, and the control units 50a and 50b are configured to suppress the pressure change inside the housing 310 in a pressurized state by the pump 380 based on the pressure changes detected by the pressure sensors 40a and 40b (detection units). Thereby, the pressure inside the housing 310 can always be kept higher than the atmospheric pressure by the pump 380. Then, with the pressure inside the housing 310 kept higher than the atmospheric pressure by the pump 380, the opening areas of the solenoid valves 30a and 30b can be adjusted so as to suppress the pressure change inside the housing 310 due to the pressure change outside the housing 310. Therefore, since the pressure inside the housing 310 can be kept higher than the atmospheric pressure by the pump 380, it is possible to more effectively suppress the decrease in the dielectric withstand voltage inside the housing 310.

[0089] Also, other effects according to the third embodiment are the same as those of the first and second embodiments.

[0090] [Modification Example] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is shown not by the description of the above embodiments but by the claims, and further includes all changes (modification examples) within the meaning and scope equivalent to the claims.

[0091] For example, in the above first to third embodiments, when a pressure change such that the pressure outside the housing 10 (210, 310) decreases is detected (when the detected value a is a negative value), an example is shown in which the opening areas of the solenoid valves 30a and 30b (area adjustment valves) are configured to be 0%. However, the present invention is not limited to this. In the present invention, when the detected value a is a negative value, the opening areas of the solenoid valves 30a and 30b may be made small instead of 0%. For example, when the detected value a is a positive value, the opening area may be controlled to 100%, and when the detected value a is a negative value, the opening area may be controlled to be reduced to 10%.

[0092] In addition, in the first to third embodiments described above, the control units 50a and 50b are configured to increase the opening areas of the electromagnetic valves 30a and 30b (area adjustment valves) when a pressure change that causes the pressure outside the housing 10 (210, 310) to rise is detected by the pressure sensors 40a and 40b (detection units) (when the detected value a is a positive value). However, the present invention is not limited to this. For example, when a pressure change that causes the pressure outside the housing 10 (210, 310) to decrease is detected, the opening areas of the electromagnetic valves 30a and 30b (area adjustment valves) may be increased (the electromagnetic valves 30a and 30b may be opened). That is, when a pressure change that vibrates so as to decrease compared to the normal pressure P0 (pressure during normal times) is detected, the opening areas of the electromagnetic valves 30a and 30b may be adjusted so as to suppress the vibration of the pressure change.

[0093] In addition, in the first to third embodiments described above, an example is shown in which the control units 50a and 50b are configured to detect a pressure change outside the housing 10 (210, 310) by detecting the pressure difference (detected value a) between the outside and inside of the housing 10 (210, 310). However, the present invention is not limited to this. For example, instead of the pressure difference, the pressure outside and the pressure inside the housing 10 (210, 310) may be detected separately. Also, only the pressure outside the housing 10 (210, 310) may be detected without detecting the pressure inside the housing 10 (210, 310). In that case, for example, when the detected pressure outside the housing 10 (210, 310) (the magnitude of the pressure change from the atmospheric pressure) is greater than a predetermined reference value, the electromagnetic valves 30a and 30b (area adjustment valves) may be controlled to open. In this case, the magnitude of the opening area and the timing (time) may be adjusted according to the magnitude of the detected pressure.

[0094] Also, in the above-described first to third embodiments, an example is shown in which when the detected detection value a is greater than the reference value of 0 (in the case of a positive value), the opening areas of the solenoid valves 30a and 30b (area adjustment valves) are increased, and when the detected detection value a is less than or equal to the reference value of 0 (in the case of 0 and negative values), the opening areas of the solenoid valves 30a and 30b are decreased (to 0%). However, the present invention is not limited to this. For example, the reference value of the detection value a may be a value other than 0. For example, a value that is larger than the normal pressure P0 (pressure during normal operation) by a predetermined value (for example, several tens of Pa or several hundreds of Pa) may be used as the reference value, or a value that is smaller than the normal pressure P0 by a predetermined value may be used as the reference value.

[0095] Also, in the above-described first to third embodiments, an example is shown in which the opening areas of the solenoid valves 30a and 30b (area adjustment valves) are adjusted according to the magnitude of the detected detection value a (pressure difference). However, the present invention is not limited to this. For example, the opening area may be adjusted regardless of the magnitude of the detection value a. Specifically, when the detection value a is a positive value, the opening area may be adjusted to a constant size (for example, 100%). Also, in cases where the mode of pressure change outside the housing 10 (210, 310) is substantially constant, etc., the adjustment of the opening areas of the solenoid valves 30a and 30b may be preset. That is, when a pressure change outside the housing 10 (210, 310) is detected, the opening areas of the solenoid valves 30a and 30b may be set based on the preset timing and magnitude.

[0096] In addition, in the first to third embodiments described above, when a positive detected value a is first detected from the normal pressure P0, the opening area is controlled to 100%, and when a positive detected value a is detected for the second time and subsequent times, an example is shown in which the opening area is controlled according to the magnitude of the detected value a. However, the present invention is not limited to this. For example, the adjustment of the opening area may be changed according to the mode of pressure change in the environment where the disk device 100 (200, 300) is installed. Specifically, in an environment where a pressure change such as a vibrating pressure change such as a micro-pressure wave occurs, when a pressure change as a wave in which the second pressure increase is larger than the first is detected, the opening area may be set to 100% at the timing when a positive detected value a is detected for the second time from the normal pressure P0.

[0097] In addition, in the first to third embodiments described above, an example is shown in which the control units 50a and 50b are configured to set the opening areas of the electromagnetic valves 30a and 30b (area adjustment valves) to a constant size (20%) when the pressure change per unit time (change amount of the detected value a) detected by the pressure sensors 40a and 40b (detection units) becomes smaller than a predetermined size (determination value). However, the present invention is not limited to this. For example, when the magnitude of the change amount of the detected value a per unit time becomes smaller than a predetermined determination value, the opening areas of the electromagnetic valves 30a and 30b may be gradually reduced. Specifically, when the change amount of the detected value a per unit time is smaller than a predetermined determination value, the opening areas of the electromagnetic valves 30a and 30b may be adjusted to change gradually from 20% by 1% per second.

[0098] In addition, in the second embodiment described above, an example is shown in which the volume of the internal space of the housing 210 is increased by the pressure difference relaxation portion 270 having a bellows structure. However, the present invention is not limited to this. For example, the volume of the internal space of the housing 210 may be increased by using an elastic member such as rubber.

[0099] In addition, in the above-described first to third embodiments, an example in which the filter 60 disposed so as to cover the openings 13a and 13b is provided has been shown, but the present invention is not limited thereto. For example, the filter 60 may not be provided. Further, one filter may be provided for each of the plurality (two) of the openings 13a and 13b.

[0100] In addition, in the above-described first to third embodiments, an example in which the butterfly-type solenoid valves 30a and 30b for adjusting the air flow rate between the outside and the inside of the housing 10 (210, 310) are provided has been shown, but the present invention is not limited thereto. For example, depending on the installation environment of the board device 100 (200, 300) or the flow rate, solenoid valves other than the butterfly type (for example, shutter type, ball type, etc.) may be provided. Further, a check valve for suppressing the pressure drop inside the housing 10 (210, 310) may be provided.

[0101] In addition, in the above-described first to third embodiments, an example in which the solenoid valves 30a and 30b (area adjustment valves) are proportional control valves capable of continuously adjusting the opening area has been shown, but the present invention is not limited thereto. For example, the solenoid valves 30a and 30b may be configured to be adjustable to a plurality of opening areas stepwise, such as 0%, 25%, 50%, 75%, and 100%. Further, a solenoid valve that can be controlled to only two types of opening areas of 0% and 100% may be used. In that case, a plurality of solenoid valves may be provided, and the opening area may be adjusted (the air flow rate may be adjusted) by changing the number of solenoid valves to be opened based on the detected pressure change.

[0102] In the above first to third embodiments, the panel device 100 (200, 300) is shown as an example installed in a tunnel through which a railway vehicle passes, but the present invention is not limited to this. For example, the panel device 100 (200, 300) may be installed near the entrance or exit of the tunnel. Also, the panel device 100 (200, 300) may be configured to be mounted on a vehicle such as a railway vehicle. Further, the panel device 100 (200, 300) may be mounted on an aircraft or a ship other than a vehicle. Additionally, the panel device 100 (200, 300) may be installed in a place where a pressure change occurs, such as a mountainous area.

[0103] In the above first to third embodiments, the panel device 100 (200, 300) is shown as an example of a distribution board or a switchboard, but the present invention is not limited to this. For example, the panel device 100 (200, 300) may include a power conversion device such as an inverter device or a control panel.

[0104] In the above first to third embodiments, an example is shown in which two openings 13a and 13b are provided in the housing 10 (210, 310), but the present invention is not limited to this. For example, the number of openings provided in the housing 10 (210, 310) may be one, or may be three or more. Similarly, one or three or more electromagnetic valves (area adjustment valves) may be provided. Also, by providing a flow path such as a duct, the number of openings and the number of electromagnetic valves may be made different.

[0105] In the above first to third embodiments, an example is shown in which a plurality (two) of control units 50a and 50b and a plurality (two) of pressure sensors 40a and 40b (detection units) are provided corresponding to each of the plurality (two) of electromagnetic valves 30a and 30b, but the present invention is not limited to this. For example, a plurality of electromagnetic valves may be controlled by a common (one) control unit. Also, a common (one) pressure sensor may be used to detect a pressure change outside the housing 10 (210, 310).

[0106] In addition, in the above-described first to third embodiments, an example in which the pressure sensors 40a and 40b (detection units) include strain gauges has been shown, but the present invention is not limited thereto. For example, as long as the pressure difference between the outside and the inside of the housing 10 (210, 310) can be detected, the pressure sensor may not include a strain gauge. For example, the pressure sensor may measure the pressure using a change in capacitance.

Explanation of Signs

[0107] 10, 210, 310 Housing 13a, 13b Opening 20 Equipment 30a, 30b Electromagnetic valve (area adjustment valve) 40a, 40b Pressure sensor (detection unit) 50a, 50b Control unit 60 Filter 100, 200, 300 Disk device 270 Pressure difference relaxation unit 380 Pump

Claims

1. A housing for accommodating equipment therein, An area adjustment valve provided at an opening of the housing for adjusting an opening area so as to adjust a flow rate of air between the outside and the inside of the housing, A detection unit for detecting a pressure change outside the housing, A control unit configured to adjust the opening area of the area adjustment valve so as to suppress a pressure change inside the housing caused by a pressure change outside the housing based on the pressure change detected by the detection unit. A panel device comprising the above components.

2. The control unit is configured to increase the opening area of the area adjustment valve when a pressure change in which the pressure outside the housing increases is detected by the detection unit, and to decrease the opening area of the area adjustment valve when a pressure change in which the pressure outside the housing decreases is detected. The panel device according to Claim 1.

3. The detection unit is configured to detect a pressure change outside the housing by detecting a pressure difference between the outside and the inside of the housing, When the pressure difference detected by the detection unit is greater than a predetermined reference value, the control unit increases the opening area of the area adjustment valve as if a pressure change in which the pressure outside the housing increases is detected, and when the pressure difference is less than or equal to the reference value, the control unit decreases the opening area of the area adjustment valve as if a pressure change in which the pressure outside the housing decreases is detected. The panel device according to Claim 2.

4. The control unit is configured to adjust the size of the opening area of the area adjustment valve according to the magnitude of the pressure difference when increasing the opening area of the area adjustment valve. The panel device according to Claim 3.

5. After a pressure change such that the pressure outside the housing increases is detected, when the pressure change per unit time detected by the detection unit becomes smaller than a predetermined magnitude, the control unit is configured to set the opening area of the area adjustment valve to a constant magnitude or to gradually decrease it. The panel device according to any one of claims 2 to 4.

6. The housing further includes a pressure difference alleviation unit that, separately from the opening, deforms so as to increase the volume of the internal space of the housing when the pressure outside the housing is smaller than the pressure inside the housing, thereby alleviating the pressure difference between the outside and inside of the housing. The panel device according to any one of claims 2 to 5.

7. The housing further includes a pump for pressurizing the inside of the housing, Based on the pressure change detected by the detection unit, the control unit is configured to suppress the pressure change inside the housing in the state pressurized by the pump. The panel device according to any one of claims 2 to 6.

8. The panel device according to any one of claims 1 to 7 further includes a filter that is disposed so as to cover the opening provided in the housing and suppresses the intrusion of foreign matter from outside the housing.

9. The area adjustment valve includes a solenoid valve that can be adjusted to at least a plurality of different opening areas while in an open state based on control by the control unit, Based on the pressure change detected by the detection unit, the control unit is configured to adjust the opening area of the solenoid valve to at least a plurality of different opening areas while in an open state. The panel device according to any one of claims 1 to 8.

10. A step of detecting a pressure change outside a housing that houses equipment inside, Based on the detected pressure change, adjusting the opening area of an area adjustment valve that adjusts the air flow rate between the outside and inside of the housing at an opening provided in the housing so as to suppress the pressure change inside the housing caused by the pressure change outside the housing. A pressure change suppression method comprising the step of adjusting the opening area of the area adjustment valve.

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