Attic ventilation structure

Abstract

To provide an attic ventilation structure capable of suppressing scattering of corrosive factors with a simple configuration.SOLUTION: An attic ventilation structure (1) is a ventilation structure for an attic space (91) of a house, and includes an eaves vent (40) provided between an eaves soffit board (21) of a roof eaves portion (20) and an exterior wall (31), and a chamber portion (5). The chamber portion is disposed above the eaves vent, has an inlet opening (51) through which outside air blowing up from the eaves vent flows in, and an outlet opening (52) through which the outside air flowing in from the inlet opening is exhausted to the eaves side, and extends in the width direction of the exterior wall.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an attic ventilation structure of an eaves ventilation type.

Background Art

[0002] As a ventilation structure for the attic of a house, a structure that naturally ventilates the attic space by providing a ventilation opening serving as an inlet for outside air at the eaves part of the roof and an exhaust port at the top is common. The ventilation opening includes a case provided at the eaves base (outer wall side) and a case provided at the eaves tip. In either case, the ventilation opening is generally formed by a plurality of through holes provided at regular intervals in a ventilation member (baffle fitting) extending along the width direction of the outer wall (the roof beam direction).

[0003] For example, Japanese Unexamined Patent Application Publication No. 2004-239001 (Patent Document 1) discloses a ventilation member for an eaves ventilation opening, and this ventilation member has a complicated shape in order to suppress the intrusion of rainwater. However, since it is necessary to make the opening area per unit length of the ventilation opening equal to or more than a certain value in order to make the ventilation volume of the attic space sufficient, even if the shape of the ventilation member is devised, it is difficult to prevent the scattering of sea salt particles (salt content) blown in together with outside air during strong winds.

[0004] As disclosed in Japanese Unexamined Patent Application Publication No. 2010-229632 (Patent Document 2), a technique of arranging a water return sheet in the attic space to prevent the intrusion of rainwater and sea salt particles into the attic space has also been proposed conventionally. One end of the water return sheet is fixed to the outer wall, and the other end is fixed to the rafter.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In an area close to the coastal area, sea salt particles may enter together with outside air from the ventilation opening and scatter inside the soffit space. In this case, damage such as corrosion of the structures inside the soffit space (specifically, rusting occurs on metal structures such as trusses) occurs. Therefore, countermeasures against the scattering of sea salt particles are required, but at present, it only remains at salt damage countermeasures such as setting a certain distance from the coastal area as a construction restriction condition.

[0007] In addition, sodium chloride, calcium chloride, etc. are scattered as snow melting agents on the roadside in heavy snow areas, and the fine particles pulverized from these cause rust. Therefore, similar to sea salt particles, countermeasures against the scattering of fine particles of snow melting agents in the soffit space are also desired.

[0008] In Patent Document 2, a water return sheet is attached to the soffit space to prevent the intrusion of corrosion factors into the soffit space, but the work of attaching the water return sheet to the outer wall and the rafters is troublesome and time-consuming for construction. Therefore, a technology that can improve workability and efficiently prevent the intrusion of corrosion factors has been desired.

[0009] The present invention has been made to solve the above problems, and an object thereof is to provide a soffit ventilation structure that can suppress the scattering of corrosion factors with a simple configuration.

Means for Solving the Problems

[0010] A soffit ventilation structure according to an aspect of the present invention is a ventilation structure for the soffit space of a house, and includes an eaves base ventilation opening provided between the eaves board and the outer wall of the eaves part of the roof, and a chamber part. The chamber part is disposed above the eaves base ventilation opening, has an inlet opening for inflowing the outside air blown up from the eaves base ventilation opening, and an outlet opening for exhausting the outside air flowing in from the inlet opening to the eaves tip side, and extends along the width direction of the outer wall.

[0011] Preferably, the chamber part is installed at the eaves end of the eaves board and is composed of a crosspiece extending along the width direction of the outer wall and a plate material fixed to the upper end of the outer wall and formed in a substantially inverted U shape. An internal space continuous along the width direction of the outer wall is formed between the crosspiece and the plate material.

[0012] Preferably, the plate material has a top surface facing the eaves ventilation opening and the upper surface of the crosspiece. It is desirable that the area per unit length of the top surface is at least twice the opening area per unit length of the eaves ventilation opening.

[0013] More preferably, the plate material has a hanging part extending downward from the eaves-side end of the top surface. It is desirable that the area per unit length of the hanging part is at least twice the opening area per unit length of the eaves ventilation opening.

[0014] Also, it is desirable that the opening area per unit length of the outlet opening is substantially equal to the opening area per unit length of the eaves ventilation opening. Note that "substantially equal" means that the two are approximately equal and is not limited to the example where they are exactly the same.

Advantages of the Invention

[0015] According to the present invention, it is possible to suppress the scattering of corrosion factors with a simple configuration.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0017] Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated.

[0018] (Regarding the outline) With reference to FIG. 1, the outline of the attic ventilation structure 1 of the house in the present embodiment will be described. FIG. 1 is a longitudinal sectional view showing the main part of the attic ventilation structure 1. The arrow A1 in FIG. 1 indicates the eaves direction (underwater side) of the roof 2 of the house. The house has an eaves part (hereinafter referred to as "roof eaves part") 20 that protrudes more than the outer wall 31. In the description of the roof eaves part 20, the side opposite to the eaves tip is referred to as the eaves base.

[0019] The space below the roof 2 integrally includes the attic space 91 and the soffit space 92. The attic space 91 is the space on the back side of the ceiling part 32 located on the indoor side than the position of the outer wall 31. The soffit space 92 is the space on the back side of the soffit board 21 located on the outdoor side than the position of the outer wall 31 and is the internal space of the roof eaves part 20.

[0020] The roof eaves part 20 includes a soffit board 21 that intersects (is orthogonal to) the outer wall 31 and a nose concealer 22 arranged at the eaves tip side end. Further, the roof eaves part 20 includes a crosspiece 23 arranged at the eaves base end of the soffit board 21. The crosspiece 23 is a horizontal crosspiece extending along the width direction (eave girder direction) of the outer wall 31. The crosspiece 23 is typically made of wood.

[0021] The attic ventilation structure 1 in this embodiment is of the so-called eaves ventilation type, and a ventilation member 4 is provided between the eaves board 21 and the outer wall 31. The ventilation member 4 extends along the width direction of the outer wall 31 and has through holes 40 provided at regular intervals. The through holes 40 of the ventilation member 4 function as eaves ventilation openings. That is, the attic ventilation structure 1 takes in outside air from the eaves ventilation opening 40 of the roof eaves portion 20 and naturally ventilates the attic space 91. Note that the exhaust port of the attic ventilation structure 1 is provided, for example, at the top (ridge portion) of the roof 2 (not shown).

[0022] The attic ventilation structure 1 includes a chamber portion 5 that controls the airflow of the outside air flowing in from the eaves ventilation opening 40 (equalizes the wind speed). The chamber portion 5 is disposed above the eaves ventilation opening 40. Hereinafter, a configuration example of the chamber portion 5 will be described in detail.

[0023] (Configuration example of the chamber portion) With reference to FIGS. 2 and 3, a configuration example of the chamber portion 5 will be described. FIG. 2 is an enlarged cross-sectional view schematically showing a configuration example of the chamber portion 5. FIG. 3 is a perspective view schematically showing a configuration example of the chamber portion 5 and is a view seen from the III-III direction in FIG. 1. Note that in FIGS. 2 and 3, the illustration of the ventilation member 4 is omitted. Arrow A2 in FIG. 3 indicates the width direction of the outer wall 31, and arrow A3 indicates the inner-outer direction (the direction in which the roof eaves portion 20 protrudes) perpendicular to the outer wall 31. In the description of the chamber portion 5, the inner-outer direction is also referred to as the depth direction.

[0024] As shown in FIGS. 2 and 3, the chamber portion 5 has an inlet opening 51 through which the outside air blown up from the eaves ventilation opening 40 flows in, and an outlet opening 52 through which the outside air flowing in from the inlet opening 51 is exhausted to the eaves side. As shown in FIG. 3, the chamber portion 5 extends along the width direction of the outer wall 31. The internal space 53 of the chamber portion 5 is continuously connected without partition along the width direction of the outer wall 31 and communicates with the inlet opening 51 and the outlet opening 52.

[0025] The chamber portion 5 is typically composed of the above-described cross member 23 and a plate member 24 fixed to the upper end portion of the outer wall 31. An internal space 53 of the chamber portion 5 is formed by the cross member 23 and the plate member 24. That is, an internal space 53 that is continuous along the width direction of the outer wall 31 is formed between the cross member 23 and the plate member 24.

[0026] The plate member 24 is formed in a substantially inverted U shape. Specifically, the plate member 24 has a rising portion 241 that rises upward along the surface of the outer wall 31, a top surface portion 242 that extends from the upper end of the rising portion 241 toward the eaves tip side, and a hanging portion 243 that extends downward from the eaves tip side end of the top surface portion 242. The plate member 24 is typically formed by bending a thin metal plate.

[0027] The plate member 24 is attached to the upper end portion of the outer wall 31 by fixing the lower end portion of the rising portion 241 to the outer wall 31 with a fixture (not shown) such as a screw. In the drawing, an example is shown in which the lower end height of the rising portion 241 substantially coincides with the lower end position of the cross member 23, but it is not limited to such an example. For example, the lower end height of the rising portion 241 may be within the height range of the cross member 23. Further, the plate member 24 is not limited to an example of being directly fixed to the outer wall 31 and may be fixed via other members.

[0028] None of the rising portion 241, the top surface portion 242, and the hanging portion 243 have ventilation holes and extend in a strip shape along the width direction of the outer wall 31. The top surface portion 242 faces at least a part (the eaves base side end portion) of the eaves base ventilation port 40 and the upper surface 231 of the cross member 23. As shown in FIG. 2, the space (the space directly above the eaves base ventilation port 40) between the rising portion 241 adjacent in the depth direction and the side surface (the eaves base side surface) 232 of the cross member 23 constitutes the inlet opening 51. The space (gap) between the lower end portions of the hanging portions 243 adjacent in the vertical direction and the upper surface 231 of the cross member 23 constitutes the outlet opening 52.

[0029] The opening area per unit length of the inlet opening 51 of the chamber portion 5 (shown as the interval D1 between the side surface 232 of the cross member 23 and the rising portion 241 of the plate member 24 in the longitudinal sectional view of FIG. 2) is equal to or larger than the opening area per unit length of the eaves ventilation opening 40 (hereinafter referred to as "ventilation area"). Note that the interval D1 of the inlet opening 51 is substantially equal to the interval between the cross member 23 and the outer wall 31.

[0030] The opening area per unit length of the outlet opening 52 of the chamber portion 5 (shown as the interval D2 between the upper surface 231 of the cross member 23 and the lower end portion of the hanging portion 243 of the plate member 24 in the longitudinal sectional view of FIG. 2) is equal to or larger than the ventilation area, and desirably substantially equal to the ventilation area. The interval D2 of the outlet opening 52 is equal to or smaller than the interval D1 of the inlet opening 51.

[0031] The area per unit length of the top surface portion 242 of the plate member 24 (shown as the depth dimension L1 of the top surface portion 242 in the longitudinal sectional view of FIG. 2) is desirably at least twice the ventilation area. The depth dimension L1 of the top surface portion 242 corresponds to the depth of the internal space 53 and is desirably at least twice the interval D1 of the inlet opening 51. As an example, the depth dimension L1 of the top surface portion 242 is equal to or larger than the depth dimension of the cross member 23.

[0032] The area per unit length of the hanging portion 243 of the plate member 24 (shown as the height dimension L2 of the hanging portion 243 in the longitudinal sectional view of FIG. 2) is desirably at least twice the ventilation area. The height dimension L2 of the hanging portion 243 corresponds to the depth of the internal space 53 and, for example, is substantially equal to the depth dimension L1 of the top surface portion 242. As an example, the height dimension L2 of the hanging portion 243 is equal to or larger than half of the height dimension of the cross member 23.

[0033] The internal space 53 of the chamber portion 5 is a space surrounded by the upper surface 231 of the cross member 23 and the tunnel-shaped plate member 24 having the dimensions as described above, and has a volume sufficient to disperse the air flow.

[0034] (Function and effect of the attic ventilation structure provided with a chamber portion) The attic ventilation structure 1 according to the present embodiment includes the above-described chamber portion 5 above the eaves ventilation opening 40. First, the proportionality of the attic ventilation structure 1 will be described with reference to FIGS. 7 and 8. FIGS. 7 and 8 are a longitudinal sectional view and a perspective view showing a main part of the attic ventilation structure 100 not including the chamber portion 5.

[0035] The attic ventilation structure 100 does not include the plate member 24 formed in a substantially inverted U shape as compared with the attic ventilation structure 1, and instead includes a plate member 124 formed in a substantially inverted L shape. The plate member 124 is a steel plate (splash prevention steel plate) provided to bounce back rainwater blown in from the eaves ventilation opening 40, and includes a rising portion 1241 that rises upward along the surface of the outer wall 31 and a top surface portion 1242 that extends from the upper end of the rising portion 1241 toward the eaves side (the hanging portion that extends downward from the eaves side end of the top surface portion 1242 is not included).

[0036] According to the attic ventilation structure 100, as shown in FIG. 8, for example, when strong wind blows against a part of the outer wall 31 from the coastal side (along the direction of arrow F11), an upward airflow is generated along the outer wall 31, and the airflow containing sea salt particles blows up into the attic space 92 through the eaves ventilation opening 40 (arrow F12). The airflow that passes through the space between the crosspiece 123 and the rising portion 1241 of the plate member 124 from the eaves ventilation opening 40 (corresponding to the inlet opening 51) is bounced back by the top surface portion 242 of the plate member 124, but flows toward the eaves side while maintaining a high wind speed (arrow F13). The airflow directed toward the eaves side by the plate member 124 rises as it is and flows toward the attic space 91 side along the roof base material as shown in FIG. 7. Then, there is a possibility that sea salt particles will scatter in the attic space 91.

[0037] On the other hand, according to the attic ventilation structure 1 according to the present embodiment, the wind speed of the air flow after entering the gable space 92 can be weakened in the chamber portion 5. Specifically, as shown in FIG. 2, for example, when strong wind blows against a part of the outer wall 31 from the coastal side (along the arrow F1 direction), an upward air flow propagating along the outer wall 31 is generated in the same manner as in the proportional case, and the air flow containing sea salt particles blows up into the gable space 92 through the eaves ventilation port 40 (arrow F2). However, since the chamber portion 5 formed by the crosspiece 23 and the plate member 24 having a substantially inverted U shape (box shape) is provided at the entrance portion of the gable space 92, the air flow passing through the entrance opening 51 of the chamber portion 5 from the eaves ventilation port 40 once diffuses to one side or both sides in the width direction in the internal space 53 of the chamber portion 5 (arrow F3).

[0038] That is, in the internal space 53 that is continuous in the width direction (without a partition), since the air flow flows from a location with a high wind speed (strong location) to a location with a low wind speed (weak location), the wind speed of the air flow is equalized in the internal space 53. As a result, an air flow with a reduced wind speed (substantially uniform speed) is exhausted from the slit-shaped exit opening 52 of the chamber portion 5 (arrow F4). As a result, the scattering of sea salt particles into the attic space 91 can be suppressed.

[0039] In this way, in the present embodiment, by simply making the shape of the plate member 24 disposed in the vicinity of the crosspiece 23 substantially inverted U-shaped, the chamber portion 5 that attenuates the wind speed of the air flow after entering the gable space 92 can be provided at the entrance of the gable space 92. That is, with a simple configuration, the scattering of corrosion factors such as sea salt particles can be suppressed.

[0040] (Modification) The shape of the plate member 24 constituting the chamber portion 5 only needs to be substantially inverted U-shaped, and is not limited to the square box shape as shown in FIG. 2. For example, as shown in FIG. 4, the hanging portion 243 of the plate member 24A constituting the chamber portion 5A may be slightly inclined. That is, the rising portion 241 and the hanging portion 243 do not have to be parallel to each other.

[0041] In addition, in the present embodiment, an example is shown in which the rising portion 241, the top surface portion 242, and the hanging portion 243 constituting the plate material 24 are each flat, but the present invention is not limited to such an example, and for example, a smooth curved surface shape may be used. Further, in that case, each adjacent part of the plate material 24 may be smoothly continuous, and substantially the entire plate material 24 (the portion above the cross member 23) may be formed in an arc shape.

[0042] In addition, in the present embodiment, an example has been described in which the space (gap) between the lower end portion of the hanging portion 243 adjacent in the vertical direction and the upper surface 231 of the cross member 23 constitutes the outlet opening 52, but the present invention is not limited to such an example. For example, as shown in FIGS. 5 and 6, the plate materials 24B and 24C constituting the chamber portions 5B and 5C may be arranged so as to surround the cross member 23, and the outlet opening 52 may be formed on the eaves side with respect to the cross member 23. In this case, the depth dimensions L3 and L4 of the top surface portions 242 of the plate materials 24B and 24C are longer than the depth dimension L1 shown in FIG. 2 by at least the interval D2 (FIG. 2) corresponding to the opening area of the outlet opening 52.

[0043] In the chamber portion 5B shown in FIG. 5, the interval D4 in the gap between the eave board 21 adjacent in the vertical direction and the lower end portion of the hanging portion 243 of the plate material 24B corresponds to the interval D2 in FIG. 2, and the gap constitutes the outlet opening 52. In this case, the interval D3 in the gap between the side surface (the side surface on the eaves side) 233 of the cross member 23 facing in the depth direction and the hanging portion 243 of the plate material 24B may be equal to or greater than the interval D4 of the outlet opening 52.

[0044] In the chamber portion 5C shown in FIG. 6, the interval D5 in the gap between the side surface (the side surface on the eaves side) 233 of the cross member 23 adjacent in the depth direction and the hanging portion 243 of the plate material 24C corresponds to the interval D2 in FIG. 2, and the gap constitutes the outlet opening 52. In this case, the interval D6 in the gap between the eave board 21 facing in the vertical direction and the lower end portion of the hanging portion 243 of the plate material 24C may be equal to or greater than the interval D5 of the outlet opening 52.

[0045] (Other modification examples) In this embodiment, an example in which the chamber portion 5 is configured using the purlin 23 of the roof eaves portion 20 has been described. However, without using the purlin 23, by devising the shape of the plate material, an internal space 53 extending along the width direction of the outer wall 31 may be formed. That is, the chamber portion that attenuates the wind speed of the airflow after entering the soffit space 92 may be formed only by the plate material that forms the outer contour of the chamber portion.

[0046] Further, in this embodiment, the plate material 24 that constitutes the chamber portion 5 is a member different from the ventilation member 4 having the eaves ventilation opening 40. However, the plate material 24 and the ventilation member 4 may be integrally provided.

[0047] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0048] 1 Attic ventilation structure, 2 Roof, 4 Ventilation member, 5, 5A, 5B, 5C Chamber portion, 20 Roof eaves portion, 21 Eaves ceiling board, 23 Purlin, 24, 24A, 24B, 24C Plate material, 31 Outer wall, 40 Eaves ventilation opening, 51 Inlet opening, 52 Outlet opening, 53 Internal space, 91 Attic space, 92 Soffit space, 231 Upper surface, 232, 233 Side surfaces, 241 Upright portion, 242 Top surface, 243 Hanging portion.

Claims

1. A ventilation structure for the attic space of a house, an eaves ventilation opening provided between the eaves board of the eaves part of the roof and the outer wall, an inlet opening that is arranged above the eaves ventilation opening and into which outside air rising from the eaves ventilation opening flows in, and an outlet opening that exhausts the outside air flowing in from the inlet opening to the eaves tip side, and a chamber part extending along the width direction of the outer wall.

2. The chamber part is composed of a crosspiece installed at the eaves end of the eaves board and extending along the width direction of the outer wall, and a plate material fixed to the upper end of the outer wall and formed in a substantially inverted U shape, and an internal space continuous along the width direction of the outer wall is formed between the crosspiece and the plate material. The attic ventilation structure according to claim 1.

3. The plate material has a top surface portion facing the eaves ventilation opening and the upper surface of the crosspiece, and the area per unit length of the top surface portion is 2 times or more the opening area per unit length of the eaves ventilation opening. The attic ventilation structure according to claim 2.

4. The plate material has a hanging portion extending downward from the eaves tip side end of the top surface portion, and the area per unit length of the hanging portion is 2 times or more the opening area per unit length of the eaves ventilation opening. The attic ventilation structure according to claim 3.

5. The opening area per unit length of the outlet opening is substantially equal to the opening area per unit length of the eaves ventilation opening. The attic ventilation structure according to any one of claims 1 to 4.

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