Tunnel board

Abstract

To provide a tunnel board capable of reducing the pressure difference between the inside and outside of a housing without changing the volume inside the housing even when a pressure difference occurs between the inside and outside of the housing.SOLUTION: A tunnel board 100 is installed inside a tunnel, and includes a housing 1, a first ventilation opening 2 and a second ventilation opening 3 leading to the inside of the housing 1, a filter 4 covering the first ventilation opening 2, and a door body 5 that closes the second ventilation opening 3 in an openable and closable manner, and the door body 5 is configured to open the second ventilation opening 3 when the pressure inside the housing 1 becomes positive compared to the pressure outside the housing 1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a panel for a tunnel.

Background Art

[0002] Patent Document 1 discloses a conventional panel device. The panel device described in Patent Document 1 is installed in a tunnel through which a vehicle passes. When a vehicle passes through the tunnel, the surrounding of the outside of the housing of the panel device becomes a negative pressure due to the air pressure wave generated, and the inside of the housing becomes a relatively positive pressure, resulting in a pressure difference between the inside and the outside of the housing.

[0003] Therefore, the panel device of Patent Document 1 includes a filter mounting member equipped with a filter and a blocking member having a telescopic bellows structure. When the pressure inside the housing becomes positive with respect to the outside of the housing, the bellows structure extends to increase the volume inside the housing and reduce the pressure inside the housing.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the pressure inside the housing of the panel device of Patent Document 1 becomes positive with respect to the outside of the housing, it deforms to increase the volume of the housing. Therefore, there is a problem in that it is necessary to consider the installation space in consideration of the shape after the deformation of the bellows structure.

[0006] In view of the above circumstances, the present invention is made, and an object thereof is to provide a tunnel panel that can relieve the pressure difference between the inside and the outside of the housing without changing the volume inside the housing even when a pressure difference occurs between the inside and the outside of the housing.

Means for Solving the Problems

[0007] The tunnel panel according to one aspect of the present invention is a tunnel panel installed in a tunnel, and includes a housing, a first ventilation port and a second ventilation port communicating with the inside of the housing, a filter covering the first ventilation port, and a door body that can open and close the second ventilation port. The door body is configured to open the second ventilation port when the pressure inside the housing becomes positive pressure compared to the outside of the housing.

Advantages of the Invention

[0008] The tunnel panel according to the above aspect of the present invention has the advantage that even when a pressure difference occurs between the inside and outside of the housing, the pressure difference between the inside and outside of the housing can be alleviated without changing the volume inside the housing.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] <Embodiment> The tunnel panel 100 is a panel installed in a tunnel. As shown in Fig. 1, the tunnel panel 100 includes a housing 1, a first ventilation port 2 and a second ventilation port 3 communicating with the inside of the housing 1, a filter 4 covering the first ventilation port 2, and a door body 5 that can open and close the second ventilation port 3. The door body 5 is configured to open the second ventilation port 3 when the pressure inside the housing 1 becomes positive pressure compared to the outside of the housing 1.

[0011] With this configuration, when a vehicle moves in the tunnel, for example, when the vehicle passes near the tunnel panel 100, a temporary pressure fluctuation occurs around the tunnel panel 100, and the atmospheric pressure outside the housing 1 temporarily drops. At this time, since the second ventilation port 3 of the tunnel panel 100 is opened, air flows from the inside of the housing 1 to the outside of the housing 1, and the pressure difference between the inside and outside of the housing 1 can be reduced. After the vehicle passes near the tunnel panel 100, the atmospheric pressure around the tunnel panel 100 rapidly recovers from the depressurized state to the original pressure. At this time, since the inside of the housing 1 becomes negative pressure compared to the outside of the housing 1, the second ventilation port 3 is closed. Then, the air outside the housing 1 passes through the filter 4 and flows into the housing 1, and the pressure difference between the inside and outside of the housing 1 can be reduced.

[0012] Thus, in the tunnel panel 100 according to this embodiment, when the pressure inside the housing 1 becomes positive relative to the outside of the housing 1, the second vent 3 opens to reduce the pressure difference between the inside and outside of the housing 1. Even when the second vent 3 is open, the inflow of dust from the second vent 3 can be reduced by the airflow from the inside of the housing 1 to the outside of the housing 1. Further, when the pressure inside the housing 1 becomes negative relative to the outside of the housing 1, air flows in through the filter 4, so that the intrusion of dust can be reduced. As a result, according to the tunnel panel 100 according to this embodiment, even when pressure fluctuations occur in the tunnel, while reducing the entry of dust into the housing 1, the pressure difference between the inside and outside of the housing 1 can be reduced without changing the volume of the housing 1.

[0013] Examples of the tunnel panel 100 include, for example, a distribution board 10 included in a switchgear, a switchboard, a circuit breaker panel, a disaster prevention receiving panel, a control panel, a relay amplifier panel, and the like. In this embodiment, as the tunnel panel 100, a distribution board 10 in which electrical equipment is housed inside the housing 1 will be described.

[0014] Hereinafter, for convenience of explanation, the direction along the horizontal plane and from the inside to the outside of the housing 1 is referred to as the "outer direction", the opposite direction is referred to as the "inner direction", and the direction parallel to the outer direction and the inner direction may be referred to as the "inner-outer direction".

[0015] In addition, in this specification, "parallel" includes not only the case where two straight lines, planes, etc. (hereinafter, straight lines, etc.) do not intersect even when extended, but also the case where the angle formed by two straight lines, etc. intersects within a range of 10° or less. Further, "orthogonal" means the case where two straight lines, etc. intersect within a range of 90° ± 10°. However, even if two straight lines, etc. do not directly intersect, if they intersect when extended, they are included in "orthogonal".

[0016] (Electrical equipment) Electrical equipment is equipment that is driven by receiving power supply. There is no particular limitation on the electrical equipment, and examples include, for example, a circuit breaker, a switch, a circuit breaker, an earthing switch, an instrument transformer, a transformer, and the like.

[0017] (Housing 1) FIG. 1(A) is a schematic perspective view of the switchboard 10 as seen from the front side. The housing 1 is a box body having a front panel 14, a rear panel 15, a pair of side plates 11, a top plate 12, and a bottom plate 13. Examples of the material of the housing 1 include metals.

[0018] A first ventilation opening 2 and a second ventilation opening 3 are formed in the housing 1. The first ventilation opening 2 is a through-hole in which a filter 4 is installed, and the second ventilation opening 3 is a through-hole in which a door body 5 is installed. The first ventilation opening 2 and the second ventilation opening 3 are preferably formed in the front panel 14. However, the first ventilation opening 2 and the second ventilation opening 3 may be formed in the side plate 11 or the rear panel 15 as long as they are not on the surface facing the surrounding obstacles such as the wall surface.

[0019] The first ventilation opening 2 and the second ventilation opening 3 are preferably formed in the lower part of the housing 1. The lower part of the housing 1 means the part below the center in the height direction of the housing 1. By forming the first ventilation opening 2 and the second ventilation opening 3 in the lower part of the housing 1, even if dust enters from the first ventilation opening 2 or the second ventilation opening 3, it is easy to drop the dust to the bottom of the housing 1, and the possibility that the electrical equipment in the housing 1 is soiled by the dust can be reduced.

[0020] The second ventilation opening 3 is preferably formed below the first ventilation opening 2. Thereby, it is easy to drop the dust that has entered from the second ventilation opening 3 where no filter is provided to the bottom of the housing 1. However, the second ventilation opening 3 may be formed above the first ventilation opening 2. Also, the first ventilation opening 2 and the second ventilation opening 3 do not have to be formed on the same plate. For example, the first ventilation opening 2 may be formed in the front panel 14 and the second ventilation opening 3 may be formed in the side plate. Also, the first ventilation opening 2 and the second ventilation opening 3 may be formed side by side.

[0021] The first vent 2 and the second vent 3 are preferably formed in an elongated rectangular shape extending along a horizontal plane. However, the shapes of the first vent 2 and the second vent 3 may be, for example, circular, elliptical, square, semi-circular, rhombus, etc. Also, the first vent 2 and the second vent 3 may be composed of a plurality of holes. The shapes of the vents 2 and 3 may be selected according to the strength required for the housing 1.

[0022] Further, the first vent 2 and the second vent 3 may be covered, for example, with a cover member having a large number of through holes such as wire mesh, perforated metal, expanded metal, wire netting, etc. Examples of the shape of the through holes include round, slot, polygonal, slit, etc. The maximum value of the inner diameter of the through holes is larger than the maximum value of the hole diameter of the filter 4. When wire mesh is used as the cover member, the wire mesh may be, for example, H-shaped, V-shaped, punching type, mesh type, single flow type, corrugated, etc.

[0023] (Filter 4) The filter 4 is arranged so as to cover the first vent 2. The filter 4 is a dust filter that can capture fine particles (dust) contained in the air. The filter 4 preferably can capture fine particles having a particle size of 5 μm or more, for example. The fine particles captured by the filter 4 include relatively large-sized dust, dirt, powder, etc. (hereinafter referred to as dust. In this specification, "dust" also includes "dust and dirt"). Examples of the form of the filter 4 include flat plate shape, pleated shape, etc. The filter 4 may be a single layer or a multi-layer.

[0024] As shown in FIG. 1(B), the filter 4 is attached along the inner surface of the front panel 14 of the housing 1. The filter 4 is preferably removably held by an attachment portion 41 provided on the inner surface of the housing 1. The attachment portion 41 is formed in a substantially rectangular frame shape in front view and holds the outer peripheral portion of the filter 4. Note that the attachment of the filter 4 is not limited to the attachment portion 41 and may be realized, for example, by adhesion, screwing, clamping, etc. The filter 4 may be attached along the outer surface of the housing 1.

[0025] (Door body 5) The door body 5 is attached to the housing 1 so as to be able to close the second vent 3. The door body 5 can be switched between an open position (see Fig. 2(A)) where the second vent 3 is opened and a closed position (see Fig. 2(B)) where the second vent 3 is closed. Although the basic position of the door body 5 is the closed position, when the pressure inside the housing 1 becomes positive relative to the outside of the housing 1, the door body 5 is switched to the open position.

[0026] In this embodiment, the door body 5 is provided with a rotating shaft 51 at its upper end. The rotating shaft 51 extends along the horizontal plane. The door body 5 is attached to the front panel 14 via a hinge having, for example, the rotating shaft 51. When an external force is applied along the outward direction to the door body 5, the lower end rotates in a direction away from the housing 1 about the rotating shaft 51, and is switched from the closed position to the open position. When the external force is released, it is switched back to the closed position.

[0027] The tunnel panel 100 may have a spring that applies a force to the door body 5 from the open position toward the closed position. Thereby, when no force is applied to the door body 5 toward the open position, it is easy to position the door body 5 at the closed position. Examples of the spring include a torsion spring and the like. However, when the door body 5 can be sufficiently positioned at the closed position by its own weight, the spring may not be provided.

[0028] The door body 5 is, for example, plate-shaped. There is no particular limitation on the material of the door body 5, and examples thereof include metal, synthetic resin, glass, carbon, wood, pulp, and the like.

[0029] As shown in Fig. 2(A), when the pressure inside the housing 1 becomes positive relative to the pressure outside the housing 1, air pressure is evenly applied to the filter 4 and the door body 5. However, due to the air resistance of the filter 4, the door body 5 is more likely to open before air passes through the filter 4. Therefore, when the door body 5 is switched to the open position, the second vent 3 allows the flow of air from the inside to the outside of the housing 1, and thus the air inside the housing 1 is discharged to the outside of the housing 1 through the second vent 3.

[0030] As shown in FIG. 2(B), when the pressure inside the housing 1 becomes negative pressure compared to the external pressure, the air outside the housing 1 enters the housing 1 through the first ventilation port 2 and through the filter 4. At this time, the door body 5 in the closed position blocks the air attempting to pass through the second ventilation port 3.

[0031] Thus, in the tunnel panel 100 according to the present embodiment, when the pressure inside the housing 1 becomes positive pressure compared to the outside of the housing 1, the second ventilation port 3 opens to reduce the pressure difference between the inside and outside of the housing 1. However, even when the second ventilation port 3 is open, the inflow of dust from the second ventilation port 3 can be reduced by the air flow from the inside of the housing 1 to the outside of the housing 1. Further, when the pressure inside the housing 1 becomes negative pressure compared to the outside of the housing 1, air flows in through the filter 4, so that the intrusion of dust can be reduced. As a result, according to the tunnel panel 100 according to the present embodiment, even when pressure fluctuations occur in the tunnel, while reducing the entry of dust into the housing 1, the pressure difference between the inside and outside of the housing 1 can be reduced.

[0032] It is preferable to design the opening areas of the first ventilation port 2 and the second ventilation port 3 so that the pressure difference between the inside and outside of the housing 1 can always be suppressed below a predetermined pressure. The "predetermined pressure or less" referred to here is preferably 5 kPa or less, and more preferably 2 kPa or less. Thereby, it is possible to design with a lower estimated strength of the housing 1. For example, the reinforcement structure of the housing 1 can be simplified.

[0033] <Modification Example> The above embodiment is merely one of various embodiments of the present invention. The embodiment can be variously modified according to design and the like as long as the object of the present invention can be achieved. Hereinafter, modification examples of the embodiment will be listed. The modification examples described below can be applied in appropriate combination.

[0034] (First Modification Example) In the above embodiment, the first vent 2 is formed in the housing 1. However, as shown in FIG. 3, the first vent 2 may be formed in the door body 5. As shown in FIG. 3, the first vent 2 is formed so as to penetrate the door body 5. A filter 4 is held so as to cover the first vent 2. The filter 4 is removably held on the door body 5 by a mounting portion 41 provided at the opening peripheral edge of the door body 5.

[0035] As shown in FIG. 3(B), when the pressure inside the housing 1 becomes a positive pressure higher than the pressure outside the housing 1, the air pressure is evenly applied to the filter 4 and the door body 5. However, due to the air resistance of the filter 4, the air opens the door body 5 before passing through the filter 4. Therefore, when the door body 5 is switched to the open position, the second vent 3 allows the air flow from the inside to the outside of the housing 1, so the air inside the housing 1 passes through the second vent 3 and is discharged to the outside of the housing 1.

[0036] As shown in FIG. 3(C), when the pressure inside the housing 1 becomes a negative pressure lower than the external pressure, the air outside the housing 1 enters the housing 1 through the first vent 2 and through the filter 4. At this time, the door body 5 in the closed position blocks the air trying to pass through the second vent 3 other than the air passing through the first vent 2.

[0037] According to this configuration, only one opening (the second vent 3) is required for the opening to be processed on the housing 1. According to this, for example, since the door body 5 having the first vent 2 can be prefabricated at the factory, it is easy to perform additional processing on the existing tunnel panel 100.

[0038] (Second Modification Example) In the above embodiment and the first modification example, when the door body 5 is opened, if the door body 5 moves vigorously, there is a possibility that it may open too much and not return to the closed position. However, in the second modification example, by having a stopper 6 that regulates the opening degree of the door body 5, it is possible to prevent the door body 5 from opening too much.

[0039] In this modified example, the stopper 6 is an elastic body 61 that connects the housing 1 and the door body 5. The housing 1 has a support member 31 disposed at a position overlapping the second vent 3 in a front view. The support member 31 is fixed to the opening peripheral edge of the second vent 3 and protrudes into the second vent 3 in a front view. The elastic body 61 connects the support member 31 and the door body 5 and regulates the opening degree of the door body 5. Examples of the elastic body 61 include a torsion coil spring, rubber, and the like.

[0040] The maximum opening degree of the door body 5 is preferably 60° or less, more preferably 45° or less, and even more preferably less than 30° with respect to the vertical plane.

[0041] Thereby, since the door body 5 is prevented from opening too much, when the door body 5 is opened, even if the door body 5 moves vigorously, it is reduced that the door body 5 opens too much and does not return to the closed position.

[0042] (Third Modified Example) As the stopper 6, as shown in FIG. 5(A), it may be a rotation restricting portion 62 that contacts a part of the door body 5 when the door body 5 is opened. The rotation restricting portion 62 includes a horizontal piece 621 protruding from the housing 1 and a vertical piece 622 protruding downward from the horizontal piece 621. The vertical piece 622 overlaps the door body 5 in a front view. The horizontal piece 621 and the vertical piece 622 are made of, for example, metal.

[0043] When the door body 5 opens, the door body 5 contacts the vertical piece 622, and further opening of the door body 5 is restricted. That is, the position where the door body 5 contacts the vertical piece 622 becomes the open position of the door body 5. The position of the lower end of the vertical piece 622 is set according to the maximum opening degree of the door body 5.

[0044] The rotation restricting portion 62 is composed of the horizontal piece 621 and the vertical piece 622, but may be composed of, for example, a string, a belt, a chain, a wire, etc. attached so as to connect the door body 5 and the housing 1.

[0045] (Fourth Modified Example) When the inside of the housing 1 becomes negative pressure compared to the outside of the housing 1, the door body 5 is switched to the closed position. At this time, in order to enhance the responsiveness of the movement of the door body 5, like in this modified example, the housing 1 may have a flow path guide 7. The flow path guide 7 can guide the airflow flowing from outside the housing 1 into the housing 1 to the outer surface of the door body 5. As shown in FIG. 6, the flow path guide 7 includes a horizontal plate portion 71 protruding from the outer surface of the housing 1 and a vertical plate portion 72 protruding upward from the horizontal plate portion 71. The upper end of the vertical plate portion 72 is preferably located above the upper end of the second ventilation port 3.

[0046] The air flowing from outside the housing 1 toward the second ventilation port 3 is guided by the flow path guide 7 and hits the outer surface of the door body 5. Then, pressure is applied to the door body 5 from the air in addition to its own weight, and it rotates faster than when it rotates by its own weight.

[0047] The vertical plate portion 72 is preferably formed at a position where the door body 5 hits when the door body 5 is switched to the open position. Thereby, the function of the stopper 6 described in the second and third modified examples can also be served.

[0048] (Other Modified Examples) In the above embodiment, the rotation axis 51 of the door body 5 is provided at the upper end of the door body 5, but it may be provided at the lower end or may be located at the center in the vertical direction. Also, it may have a rotation axis 51 extending in the vertical direction at the end of the door body 5 in the left - right direction. Further, a structure in which two door bodies 5 are opened and closed like a double - leaf door may also be possible.

[0049] In the above embodiment, the door body 5 is switched between the open position and the closed position by rotating around the rotation axis 51, but the open position and the closed position may be switched by translating the door body 5 in a direction parallel to the opening surface of the second ventilation port 3.

[0050] In the above embodiment, a part of the front plate 14 is interposed between the first ventilation port 2 and the second ventilation port 3, but the first ventilation port 2 and the second ventilation port 3 may be connected. That is, the first ventilation port 2 and the second ventilation port 3 may be formed by one opening.

[0051] As the switchboard 10, for example, any of a secondary transformer board, a bus tie board, a receiving board, a distribution line board, a primary transformer board, an in-station transformer board, a VCT board, etc. may be used.

[0052] The vehicle passing through the tunnel may be a railway vehicle (train, maglev railway) or an automobile as long as it is a vehicle that causes a pressure fluctuation exceeding several kPa in the tunnel.

[0053] <Summary> As described above, the tunnel panel 100 according to the first aspect is a tunnel panel 100 installed in a tunnel, and includes a housing 1, a first ventilation port 2 and a second ventilation port 3 communicating with the inside of the housing 1, a filter 4 covering the first ventilation port 2, and a door body 5 that closably closes the second ventilation port 3. The door body 5 is configured to open the second ventilation port 3 when the pressure inside the housing 1 becomes positive pressure compared to the outside of the housing 1.

[0054] According to this aspect, when a vehicle moves inside the tunnel, for example, when the vehicle passes near the tunnel panel 100, a temporary pressure fluctuation occurs around the tunnel panel 100, and the air pressure outside the housing 1 temporarily drops. At this time, since the second vent 3 of the tunnel panel 100 is opened, air flows from inside the housing 1 to outside the housing 1, and the pressure difference between the inside and outside of the housing 1 can be reduced. After the vehicle passes near the tunnel panel 100, the air pressure around the tunnel panel 100 rapidly recovers from the depressurized state to the original pressure. At this time, since the inside of the housing 1 becomes negative pressure compared to the outside of the housing 1, the second vent 3 is closed. Then, the air outside the housing 1 passes through the filter 4 and flows into the housing 1, and the pressure difference between the inside and outside of the housing 1 can be reduced. In this way, in the tunnel panel 100, when the inside of the housing 1 becomes positive pressure compared to the outside of the housing 1, the second vent 3 is opened to reduce the pressure difference between the inside and outside of the housing 1. However, even when the second vent 3 is opened, the inflow of dust from the second vent 3 can be reduced by the air flow from inside the housing 1 to outside the housing 1. Also, when the inside of the housing 1 becomes negative pressure compared to the outside of the housing 1, air flows in through the filter 4, so the intrusion of dust can be reduced. As a result, according to the tunnel panel 100 according to the present embodiment, even when a pressure fluctuation occurs inside the tunnel, while reducing the entry of dust into the housing 1, the pressure difference between the inside and outside of the housing 1 can be reduced without changing the volume of the housing 1.

[0055] In the tunnel panel 100 according to the second aspect, in the first aspect, the first vent 2 is formed above the second vent 3. According to this aspect, this makes it easier to drop the dust that has entered from the second vent 3 where the filter 4 is not provided to the bottom of the housing 1.

[0056] In the tunnel panel 100 according to the third aspect, in the first aspect, the first vent 2 and the filter 4 are formed on the door body 5. According to this aspect, the opening to be processed in the housing 1 only needs to be one opening (the second vent 3), and the manufacturability is good.

[0057] In the tunnel panel 100 according to the fourth aspect, in any one of the first to third aspects, the door body 5 is rotatably attached to the housing 1 by a rotation axis 51 whose upper end portion extends along the horizontal direction, and the lower end portion of the door body 5 moves away from the housing 1 so that the door body 5 opens. The housing 1 has a stopper 6 that regulates the opening degree of the door body 5. According to this aspect, since the door body 5 is prevented from opening too much, when the door body 5 is opened, even if the door body 5 moves vigorously, it is reduced that the door body 5 opens too much and does not return to the closed position.

[0058] In the tunnel panel 100 according to the fifth aspect, in the fourth aspect, the stopper 6 is an elastic body 61 that connects the housing 1 and the door body 5. According to this aspect, when the door body 5 is opened, the generation of a collision sound is suppressed.

[0059] In the tunnel panel 100 according to the sixth aspect, in the fourth aspect, the stopper 6 is a rotation restricting portion 62 that hits the door when the door body 5 is opened. According to this aspect, when the door body 5 is opened, the rotation of the door body 5 can be reliably restricted.

[0060] In the tunnel panel 100 according to the seventh aspect, in any one of the first to sixth aspects, the housing 1 has a flow path guide 7 that guides the airflow flowing from the outside to the inside of the housing 1 to the outer surface of the door body 5. According to this aspect, the air flowing from outside the housing 1 toward the second ventilation port 3 is guided by the flow path guide 7 and hits the outer surface of the door body 5. Then, the door body 5 is subjected to the force from the air in addition to its own weight, and rotates faster than when rotating by its own weight. Thereby, the responsiveness of the movement of the door body 5 from the open position toward the closed position can be enhanced.

Explanation of Reference Numerals

[0061] 100 Tunnel panel 10 Distribution board 1 Housing 2 First ventilation port 3 Second ventilation port 4 Filter 5 Door body 51 Rotation axis 6 Stopper 61 Elastic body 62 Rotation restricting section 7 Flow path guide

Claims

1. A tunnel panel installed in a tunnel, comprising: a housing; a first vent and a second vent communicating with the inside of the housing; a filter covering the first vent; a door body that closably opens and closes the second vent; and is configured such that when the pressure inside the housing becomes positive relative to the outside of the housing, the door body opens the second vent. Tunnel panel.

2. The second vent is formed below the first vent. The tunnel panel according to claim 1.

3. The first vent and the filter are formed on the door body. The tunnel panel according to claim 1.

4. The door body is rotatably attached to the housing by a horizontal rotation axis at the upper end, and is configured to open when the lower end of the door body moves away from the housing. The housing has a stopper for regulating the opening degree of the door body. The tunnel panel according to any one of claims 1 to 3.

5. The stopper is an elastic body connecting the housing and the door body. The tunnel panel according to claim 4.

6. The stopper is a rotation restricting portion that contacts the door body when the door body opens. The tunnel panel according to claim 4.

7. The housing has a flow path guide for guiding the airflow flowing from the outside to the inside of the housing to the outer surface of the door body. The tunnel panel according to any one of claims 1 to 3.

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