JP2016048618A - Daylighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a daylighting system capable of effectively suppressing variation in daylighting efficiency by variation of incident direction.SOLUTION: A daylighting system 10 takes in light L1, 2 and guides it to a room 2. The daylighting system 10 includes a daylighting part 20 for taking in light, and a light guide part 40 having a cylindrical light guide member 41 connected to the daylighting part 20, and for guiding the light from the daylighting part 20 to the room 2. The daylighting part 20 has a daylighting panel 21 in which light enters, and an opposite panel 31 arranged opposing to the daylighting panel 21. On the surface of the opposite panel 31 that faces the daylighting panel 21 side, a reflection surface 31a is formed. On a cross section which is orthogonal to a panel surface of the daylighting panel 21 and which passes an axis line r of the light guide member 41, the reflection surface 31a is at least partially curved or bent.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a daylighting system that takes in light and guides it to a predetermined space, and more particularly to a daylighting system that can effectively suppress fluctuations in daylighting efficiency due to fluctuations in the incident direction.

For example, as disclosed in Patent Document 1, the development of a daylighting system that collects light and guides the light indoors is underway. The daylighting system is used for indoor lighting, for example, as a system having a daylighting unit having a daylighting panel installed on a roof and a light guide unit that guides sunlight collected by the daylighting unit into the room. . Such a daylighting system is attracting attention as a system that contributes to CO ₂ reduction and that can directly realize energy saving.

JP 58-68701 A JP 2012-189280 A

  In recent years, from the viewpoint of effectively using the installation space, a counter panel is arranged facing the daylighting panel, and a part of the light taken in by the daylighting panel is reflected by the reflecting surface formed on the counter panel. Attempts have been made to guide it to the light guide. However, if the incident direction of sunlight greatly fluctuates, the light taken into the daylighting panel may not be reflected as intended by the reflecting surface of the opposite panel, and fluctuations in daylighting efficiency are sufficiently suppressed. I can't.

  The present invention has been made in consideration of the above points, and an object thereof is to provide a daylighting system capable of effectively suppressing fluctuations in daylighting efficiency due to fluctuations in the incident direction.

  A daylighting system according to the present invention is a daylighting system that takes in light and guides it to a predetermined space, and includes a daylighting unit that takes in light and a cylindrical light guide member connected to the daylighting unit. A light guide unit that guides the light to the predetermined space, and the daylighting unit includes a daylighting panel on which light is incident, and a counter panel disposed to face the daylighting panel, and A reflective surface is formed on a surface of the panel facing the daylighting panel, and the reflective surface is at least partially curved or bent in a cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member. doing.

  In the lighting system according to the present invention, in a cross section that is orthogonal to the panel surface of the lighting panel and passes through the axis of the light guide member, an angle formed by the reflection surface with respect to the axis of the light guide member is The distance from the side away from the light guide member may gradually become smaller toward the side of the reflecting surface that approaches the light guide member.

  In the daylighting system according to the present invention, in a cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member, sunlight incident on a certain position of the daylighting panel at the middle of the winter solstice Reflected by the reflecting surface, passes through a certain position on the connecting surface between the daylighting unit and the light guiding unit, and enters a different position from the certain position of the daylighting panel during the south solstice of the winter solstice. The sunlight to be reflected may be reflected by the reflection surface of the counter panel and pass through the certain position on the connection surface.

  In the daylighting system according to the present invention, in the cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member, the reflecting surface is defined by any of a plurality of straight lines, curved lines, or a combination of straight lines and curved lines. May be.

  In the daylighting system according to the present invention, in the cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member, the reflecting surface is inclined with respect to the axis of the light guide member, It may be prescribed | regulated by the 2nd linear part which is located in the said light guide member side rather than the said 1st linear part, and the angle | corner made with respect to the said axial line of the said light guide member is smaller than the said 1st linear part.

  In the daylighting system according to the present invention, the connection position between the first straight line portion and the second straight line portion is a panel surface of the daylighting panel in a cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member. You may face the center position of the said lighting panel used as the center in the direction in alignment with the normal line direction to the panel surface of the said lighting panel.

  In the daylighting system according to the present invention, in the cross section passing through the axis of the light guide member perpendicular to the panel surface of the daylighting panel, the counter panel side of the daylighting panel along the normal direction to the panel surface of the daylighting panel An interval between the facing surface and the reflecting surface of the counter panel may gradually increase as the light guide member is approached along the panel surface of the daylighting panel.

  According to the present invention, the shape of the reflection surface can be determined so that light incident at the same angle is reflected in different directions between a partial region and another region in the reflection surface. Thereby, it is possible to effectively suppress fluctuations in the daylighting efficiency due to fluctuations in the incident direction.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view which shows typically the building where the lighting system by one embodiment of this invention was attached. Sectional drawing which shows the lighting system shown in FIG. Sectional drawing which shows the principal part of the lighting system shown in FIG. Sectional drawing which expands and shows the lighting panel of the lighting system shown in FIG. FIG. 5 is a cross-sectional view corresponding to FIG. 3 and showing an optical path of light incident on the daylighting panel from an angle different from that in FIG. 4. FIG. 4 is a cross-sectional view corresponding to FIG. 3 and showing a modification of the reflecting surface. FIG. 10 is a cross-sectional view corresponding to FIG. 3 and showing another modification of the reflecting surface. FIG. 4 is a cross-sectional view corresponding to FIG. 3 and showing the result of simulating the daylighting efficiency of the daylighting system according to the first embodiment. FIG. 4 is a cross-sectional view corresponding to FIG. 3 and showing the result of simulating the daylighting efficiency of the daylighting system according to Comparative Example 1; The graph which shows the result of having simulated the lighting efficiency of the lighting system which concerns on Example 1 and Comparative Example 1. FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product. FIGS. 1-10 is a figure for demonstrating one Embodiment by this invention. Among these, FIG. 1 is a longitudinal sectional view schematically showing a building 1 to which a daylighting system 10 is attached.

  In the present specification, terms such as “panel”, “sheet”, and “plate” are not distinguished from each other only based on the difference in designation. Therefore, for example, the “panel” is a concept including a member that can also be called a sheet or a plate. As a specific example, the “lighting panel” includes members called “lighting sheets”, “lighting plates”, and the like.

  The daylighting system 10 is attached to the building 1 for taking in light and guiding it to a predetermined space, for example, the room 2. The daylighting system 10 includes a daylighting unit 20 that captures light, and a light guide unit 40 that is connected to the daylighting unit 20 and guides the light from the daylighting unit 20 to the room 2. In the example described below, as shown in FIG. 1, the light guide 40 extends from the wall 3 of the building 1, and the lighting unit 20 is attached to the extended tip. The light collected by the daylighting unit 20 is guided to the room 2 via the light guide unit 40.

According to such a daylighting system 10, the light collected by the daylighting unit 20 can be used as, for example, indoor illumination light. That is, by using this daylighting system 10, it is possible to directly realize energy saving and contribute to CO ₂ reduction.

  FIG. 2 is a cross-sectional view showing the daylighting system 10. The daylighting unit 20 constituting the daylighting system 10 shown in FIG. 2 is provided in order to stably capture light whose incident direction varies according to the season and time zone. The light taken into the daylighting unit 20 is typically natural light typified by sunlight. The daylighting unit 20 illustrated in FIG. 2 includes a daylighting panel 21 on which light is incident, and a counter panel 31 disposed to face the daylighting panel 21.

  In FIG. 3, the cross section of the lighting part 20 is expanded and shown. The daylighting panel 21 shown in FIG. 3 is configured as a so-called prism panel. As shown in FIG. 3, the daylighting panel 21 has a first surface 22 and a second surface 23 that face each other. The first surface 22 faces outward and functions as a light incident surface of the daylighting system 10. On the other hand, the second surface 23 faces the counter panel 31 side, and the light transmitted through the second surface 23 travels toward the light guide unit 40.

  As shown in FIG. 3, the first surface 22 includes a plurality of inclined surfaces 22a and a rising surface 22b that connects two adjacent inclined surfaces 22a. The inclined surface 22a is a surface expected to adjust the optical path of incident light by exerting an optical action on the incident light. On the other hand, the rising surface 22b is a surface that is not expected to positively adjust the optical path of incident light.

  The plurality of inclined surfaces 22a and the plurality of rising surfaces 22b are alternately arranged in a uniaxial direction d1 extending in a plane parallel to the second surface 23 of the daylighting panel 21. In the present embodiment, the uniaxial direction d1 coincides with the vertical direction. Each inclined surface 22a and each rising surface 22b are within a plane parallel to the second surface 23, in a direction crossing the uniaxial direction d1, more strictly, in the other axial direction perpendicular to the uniaxial direction d1 (in FIG. It extends linearly in the front and back direction. In this embodiment, the other axis direction coincides with the horizontal direction. In the present embodiment, the plurality of inclined surfaces 22a are configured identically, and the plurality of rising surfaces 22b are also configured identically.

  Each inclined surface 22a is inclined with respect to the panel surface of the daylighting panel 21, and is also inclined with respect to the normal direction nd to the panel surface. That is, each inclined surface 22a is not parallel to both the panel surface and the normal direction nd. In the example shown in FIG. 3, the inclined surface 22a is such that one end E1 located on one side in the uniaxial direction d1 is closer to the second surface 23 than the other end E2 located on the other side in the uniaxial direction d1. Inclined.

  In particular, the angle α1 formed by the inclined surface 22a with respect to the surface parallel to the second surface 23 is smaller than the angle α2 formed by the rising surface 22b adjacent to the inclined surface 22a with respect to the surface parallel to the second surface 23. . In the example shown in FIG. 3, the inclined surface 22 a makes an acute angle with respect to the second surface 23 of the daylighting panel 21, while the rising surface 22 b is generally along the normal direction nd to the second surface 23.

  Now, the 2nd surface 23 which comprises the surface of the lighting part 20 with the 1st surface 22 is comprised so that the light taken in by the lighting panel 21 from the inclined surface 22a may be permeate | transmitted. The 2nd surface 23 of this Embodiment is arrange | positioned so that it may become parallel to a perpendicular direction. The second surface 23 is formed as a smooth surface. Note that “smooth” in the present specification means smoothness in an optical sense. That is, here, it means the degree to which a certain percentage of transmitted light in the visible light band is refracted while satisfying Snell's law. Therefore, for example, if the ten-point average roughness Rz (JISB0601) of the second surface 23 is equal to or shorter than the shortest visible light wavelength (0.38 μm), it is sufficiently smooth.

  As an example, such a daylighting panel 21 can be shaped using a mold in which concave portions having shapes corresponding to the inclined surface 22a and the rising surface 22b are formed. In this case, the daylighting panel 21 may be integrally formed, or a prism layer constituting the first surface 22 may be laminated on a base material layer constituting the second surface 23.

  Here, the emission angle at which the light taken from the inclined surface 22a travels from the second surface 23 toward the counter panel 31 will be supplemented with reference to FIG. FIG. 4 is an enlarged sectional view showing the inclined surface 22a. As shown in FIG. 4, the angle formed by the light L0 incident on the inclined surface 22a with respect to the normal direction nd to the panel surface of the daylighting panel 21 is θ, and the incident angle of the light L0 on the inclined surface 22a is β1. The emission angle of the light L0 from the inclined surface 22a is β2. In this case, the incident angle β1 is an angle formed by the light L0 incident on the inclined surface 22a with respect to the normal direction nd1 to the inclined surface 22a, and the emission angle β2 is the light L0 refracted by the inclined surface 22a. This is an angle formed with respect to the normal direction nd1 to the inclined surface 22a. Further, the refractive index of the material forming the inclined surface 22a of the daylighting panel 21 is n.

From the geometric relationship shown in FIG.
β1 = α1-θ (1)
Is obtained. Also, Snell's law
sin β1 = n · sin β2 (2)
Is obtained.

Next, an incident angle when the light L0 transmitted through the inclined surface 22a is incident on the second surface 23 is β3, and an emission angle of the light L0 from the second surface 23 is β4. In this case, the incident angle β3 is an angle formed by the light L0 incident on the second surface 23 with respect to the normal direction nd2 to the second surface 23, and the emission angle β4 is the light refracted by the second surface 23. L 0 is an angle formed with respect to the normal direction nd 2 to the second surface 23. From the geometric relationship shown in FIG.
β3 = α1-β2 (3)
Is obtained. Also, Snell's law
n · sin β3 = sin β4 (4)
Is obtained.

  When satisfying the relations of the equations (1) to (4), θ and β4 are in a monotonically increasing function relation. Therefore, when the solar altitude increases, the angle θ formed by the light L0 incident on the inclined surface 22a with respect to the normal direction nd to the panel surface of the daylighting panel 21 also increases. As a result, the emission angle from the second surface 23 It can be seen that β4 also increases.

  Now, referring back to FIG. 2, the daylighting unit 20 has a counter panel 31 that is disposed to face the second surface 23 of the daylighting panel 21. The counter panel 31 is disposed between the daylighting panel 21 and the wall 3 of the building 1. A reflective surface 31a is formed on the surface of the counter panel 31 facing the daylighting panel 21 side. The reflecting surface 31a has a function of reflecting light, preferably specular reflection of light, that is, a function of specularly reflecting, so that a part of the light transmitted through the lighting panel 21 is reflected by the reflecting surface 31a. Guided toward the light guide 40. Such a reflective surface 31a is obtained, for example, by coating the opposing panel 31 with a high reflectance material such as silver, aluminum, or a dielectric multilayer film. In the illustrated example, the reflection surface 31a is formed as a single layer and covers the entire surface of the counter panel 31 facing the daylighting panel 21 side. The shape of the reflecting surface 31a will be described later.

  The light taken in by the daylighting unit 20 is guided to the room 2 through the light guide unit 40 connected to the daylighting unit 20 from below. As shown in FIG. 2, the light guide unit 40 includes a cylindrical light guide member 41 connected to the daylighting unit 20 from the other side in the uniaxial direction d1. In addition, a cylindrical shape means the shape of an elongate hollow column. The light guide member 41 extends from the daylighting unit 20 to the wall 3 of the building 1 along the axis r, and is partially bent. One end of the light guide member 41 is connected to the lower end of the daylighting panel 21 and the lower end of the opposing panel 31 without a gap, and the other end of the light guide member 41 is connected to the wall 3 of the building 1 without a gap. The axis r of the light guide member 41 coincides with the direction in which the light guide section 40 extends, and typically passes through the center of the light guide member 41 in each cross section orthogonal to the longitudinal direction.

  In the present embodiment, in the cross section orthogonal to the axis r of the light guide member 41, the light guide member 41 has a polygonal contour shape, more specifically, a rectangular contour shape. However, it is not limited to such an example, The light guide member 41 may have a circular outline shape or an elliptical outline shape.

  A reflective surface 42 is formed on the inner surface of the light guide member 41. The reflecting surface 42 has a function of reflecting light, preferably, a function of specularly reflecting light, that is, a function of specularly reflecting light, whereby light passing through the light guide member 41 is reflected and guided by the reflecting surface 42. The Such a reflective surface 42 is obtained, for example, by coating the light guide member 41 with a high reflectivity material such as silver, aluminum, or a dielectric multilayer film.

  In addition, a light guide path 43 that guides the light taken in by the daylighting unit 20 to the room 2 is defined in the space surrounded by the reflection surface 42. One end of the light guide path 43 is connected to the space 25 in the daylighting unit 20, that is, the space 25 surrounded by the daylighting panel 21 and the opposing panel 31. In this specification, a virtual plane that is defined in a boundary or overlapping range between the space 25 in the daylighting unit 20 and the light guide path 43 of the light guide member 41 and is orthogonal to the axis r is referred to as a connection surface SC. As will be described later, the connection surface SC is used to determine the shape of the reflection surface 31a of the counter panel 31.

  The other end of the light guide 43 is connected to the room 2 in the building 1. A diffusion plate 44 is installed so as to close the other end of the light guide path 43. According to the diffusion plate 44, it is possible to uniformly illuminate the interior of the room 2 with the light guided from the light guide unit 40. However, the diffusion plate 44 may not be installed at the end of the light guide member 41, and the light guided through the light guide member 41 may be emitted directly from the end of the light guide member 41. .

  By the way, in the daylighting system 10 shown in FIG. 1, from the viewpoint of effectively using the installation space, it is possible to ensure a sufficient distance between the second surface 23 of the daylighting panel 21 and the reflecting surface 31a of the opposing panel 31. difficult. In the winter solstice where the solar altitude is the lowest when the distance between them becomes short, it has been difficult in the past to guide the light taken in from the daylighting panel 21 to the light guide 40 with high efficiency. In this regard, in the present embodiment, the reflecting surface 31a is at least partially curved or bent in the cross section shown in FIG. According to such a form, the shape of the reflecting surface 31a is determined so that light incident at the same angle is reflected in different directions between a part of the region in the reflecting surface 31a and another region. Can do. Therefore, by determining the shape of the reflection surface 31a so that the daylighting efficiency is increased in the winter solstice, it is possible to guide light to the light guide unit 40 with high stability.

  Here, the cross section shown in FIG. 3 is a cross section orthogonal to the panel surface of the daylighting panel 21 and passing through the axis r of the light guide member 41, and is hereinafter referred to as a main cut surface. In the main cross section shown in FIG. 3, the angle γ formed by the reflective surface 31a with respect to the axis r of the light guide member 41 is determined from the side of the reflective surface 31a away from the light guide member 41. It gradually decreases toward the side approaching the optical member 41. In other words, in the main cross section shown in FIG. 3, the angle γ formed by the tangent TL at each position X on the reflection surface 31 a with respect to the axis r of the light guide member 41 is such that each position X approaches the light guide member 41. As it gets smaller, it gets smaller. Here, “the angle γ gradually decreases” is a concept that includes not only the case where the angle constantly changes so as to always become small, but also the case where the angle does not change at least in some sections. On the other hand, “the angle γ gradually decreases” does not include changing the angle so as to increase in an arbitrary region. Therefore, not only the bent reflecting surface 31a shown in FIG. 3 but also a reflecting surface that is at least partially curved can be expressed as “the angle gradually decreases”.

  Typically, in the main cross section shown in FIG. 3, the reflecting surface 31a is defined by either a plurality of straight lines, curved lines, or a combination of straight lines and curved lines. In the present embodiment, the reflecting surface 31a is defined by the first straight portion 32 and the second straight portion 33 located closer to the light guide member 41 than the first straight portion 32. The first straight portion 32 is inclined at a first angle γ1 with respect to the axis r of the light guide member 41. On the other hand, the second angle γ2 formed by the second straight portion 33 with respect to the axis r of the light guide member 41 is smaller than the first angle γ1. The first angle γ <b> 1 and the second angle γ <b> 2 are determined according to the incident direction of the light that is intended to be guided to the light guide member 41 to the linear portions 32 and 33. Typically, when the light reflected by the reflecting surface 31a is incident on the lighting panel 21 again, there is a risk of stray light or escape from the first surface 22 to the outside. Therefore, the first angle γ1 and the second angle γ2 are determined so as to avoid as much as possible that the light intended to be guided to the light guide member 41 is incident on the lighting panel 21 after being reflected by the reflecting surface 31a. May be.

  As is well known, the position of the sun changes according to the time zone and season. In the winter solstice where the sun is not so strong and the temperature is low, it is most expected to keep the room 2 warm by actively using the light taken into the room 2 from the daylighting system 10. However, in the case of the prior art in which the reflecting surface is a straight line, the daylighting efficiency at the winter solstice, that is, the end of December, was lower than the season away from the winter solstice, for example, October, November, January, and February. The reason is that in the winter solstice, θ is minimum, and therefore the emission angle β4 is also minimum, and the proportion of the light that strikes the daylighting panel 21 out of the reflected light from the reflecting surface 31 increases and escapes to the outside. This situation is shown later in FIG. On the other hand, as the distance from the winter solstice increases, θ increases, and therefore the emission angle β4 also increases, and the proportion of light that strikes the daylighting panel of the reflected light from the reflecting surface decreases, and the proportion of light incident on the light guide section 40 correspondingly decreases. To increase.

  Therefore, it is preferable to determine the first angle γ1 and the second angle γ2 so as to actively guide the light taken in from the daylighting unit 20 to the light guide member 41 at the winter solstice. From such a point of view, in the main cross section shown in FIG. 3, sunlight L1 incident on a certain position of the daylighting panel 21 during the southern middle of the winter solstice is reflected at a certain position on the reflecting surface 31a of the opposing panel 31. Thus, sunlight L2 that passes through a certain position SC1 on the connection surface SC of the daylighting unit 20 and the light guiding unit 40 and is incident on another position different from the certain position of the daylighting panel 21 during the south solstice of the winter solstice. The light is reflected at another position on the reflection surface 31a of the counter panel 31 and passes through the certain position SC1 on the connection surface SC. In this way, by determining the first angle γ1 and the second angle γ2 so that sunlight L1 and L2 passing through at least two different light paths during the winter solstice pass through a certain position SC1 on the connection surface SC. Thus, it becomes possible to guide a large amount of light taken into the daylighting panel 21 to the light guide member 41 with low loss during the winter solstice. In particular, a certain position SC1 on the connection surface SC of the present embodiment is a position that is the center of the connection surface SC in the main cross section. In the example shown in FIG. 3, the axis r passes through a certain position SC <b> 1 that is the center position of the connection surface SC.

  Further, in the main cross section shown in FIG. 3, the connection position between the first straight line portion 32 and the second straight line portion 33 is 34, and the center position of the daylighting panel 21 that is the center in the direction along the panel surface of the daylighting panel 21 is defined. 21a. In the present embodiment, the connection position 34 faces the center position 21 a and the normal direction nd to the panel surface of the daylighting panel 21. In this case, since the region of the reflective surface 31a corresponding to the first straight line portion 32 and the region of the reflective surface 31a corresponding to the second straight line portion 33 are distributed in the reflective surface 31a in a well-balanced manner, fluctuations in daylighting efficiency are caused. Contributes to effective suppression.

  Further, the distance D between the second surface 23 of the daylighting panel 21 and the reflecting surface 31a of the opposing panel 31 changes according to the position along the uniaxial direction d1. In the present embodiment, in the cross section shown in FIG. 2, the distance D between the second surface 23 of the daylighting panel 21 and the reflecting surface 31a of the opposing panel 31 along the normal direction nd to the panel surface of the daylighting panel 21. However, it gradually expands as it approaches the light guide section 40 along the panel surface of the daylighting panel 21. Here, “the interval D gradually increases” is a concept that includes not only the interval constantly changing so as to always increase, but also the case where the interval does not change in at least some sections. On the other hand, “the interval D gradually increases” does not include changing the interval so that the interval decreases in an arbitrary region. Therefore, not only the bent reflecting surface 31a shown in FIG. 3 but also a partially curved reflecting surface can be expressed as “the distance gradually increases”.

  Next, the operation of the present embodiment configured as described above will be described with reference to FIG. FIG. 5 is a cross-sectional view for explaining the operation of the daylighting system 10. In addition, although the following description demonstrates using the example which the daylighting system 10 utilizes sunlight, the light utilized for the daylighting system 10 is not limited to sunlight.

  The sun's altitude is low in the time zone around the middle of the winter solstice. As described above, the panel surface of the daylighting unit 20 is installed in parallel to the vertical direction, and the light guide member 41 is connected to the daylighting unit 20 from below in the vertical direction. For this reason, sunlight L3-L6 injects into the lighting panel 21 from the direction where angle (theta) made with respect to the normal line direction nd to the panel surface of the lighting panel 21 is small. As shown in FIG. 5, when the sunlight L <b> 3 to L <b> 6 enters the inclined surface 22 a from a direction in which the angle θ formed with respect to the normal direction nd to the second surface 23 is relatively small, the equations (1) to (4) ), The emission angle β4 from the second surface 23 is also reduced. Lights L <b> 3 to L <b> 4 having a small emission angle β <b> 4 from the second surface 23 are relatively likely to enter a region of the reflective surface 31 a that is away from the light guide member 41. As understood from FIG. 5, when light L3 to L4 having a relatively small emission angle β4 from the second surface 23 is incident on a region of the reflecting surface 31a that is separated from the light guide member 41, the reflecting surface 31a. After being reflected by the light, the angle formed with respect to the axis r of the light guide member 41 goes from the direction where the angle is relatively small toward the light guide path 43. On the other hand, as can be understood from FIG. 5, the lights L5 to L6 that are emitted from the daylighting panel 21 and enter the region near the light guide member 41 in the reflecting surface 31a are reflected again after being reflected by the reflecting surface 31a. The light enters the light guide 43 mainly without returning to the panel 21.

  In particular, in the present embodiment, the reflecting surface 31a is defined by the first straight portion 32 and the second straight portion 33 located closer to the light guide member 41 than the first straight portion 32. In this case, the light beams L3 to L4 having a small emission angle β4 from the second surface 23 are likely to enter the region of the reflective surface 31a corresponding to the first linear portion 32. Since the first straight portion 32 has a relatively large first angle γ1 with respect to the axis r of the light guide member 41, the light L3 to L4 incident on the region of the reflecting surface 31a corresponding to the first straight portion 32 is Then, after being reflected by the reflecting surface 31 a, the light guide member 41 moves toward the inside of the light guide 43 from a direction in which the angle formed with respect to the axis r of the light guide member 41 is relatively small. On the other hand, the lights L5 to L6 that are emitted from the daylighting panel 21 and enter the region of the reflecting surface 31a corresponding to the second linear portion 33 are mainly reflected by the reflecting surface 31a and then return to the daylighting panel 21 again without being returned to the daylighting panel 21. Enter 43. From the above, as a result, the light L3 to L6 taken into the daylighting panel 21 at the winter solstice greatly contributes to guiding the light into the light guide path 43 with high efficiency.

  The sunlight guided by these light guides 40 is guided through the light guide member 41 toward the room 2 of the building 1 and enters a diffusion plate 44 attached to the end of the light guide member 41. The light incident on the diffuser plate 44 is diffused by the diffuser plate 44 and illuminates the interior of the room 2 evenly.

  As described above, according to the present embodiment, the daylighting unit 20 that captures light and the cylindrical light guide member 41 connected to the daylighting unit 20 are provided to guide the light from the daylighting unit 20 to the room 2. The lighting unit 20 includes a lighting panel 21 on which light is incident, and a counter panel 31 disposed to face the lighting panel 21, and the lighting panel 21 side of the counter panel 31 is A reflective surface 31a is formed on the facing surface, and the reflective surface 31a is at least partially curved or bent in a cross section orthogonal to the panel surface of the daylighting panel 21 and passing through the axis r of the light guide member 41. According to such a form, the shape of the reflecting surface 31a is determined so that light incident at the same angle is reflected in different directions between a part of the region in the reflecting surface 31a and another region. Can do. Therefore, by determining the shape of the reflecting surface 31a so as to maximize the lighting efficiency in the winter solstice, it is possible to effectively suppress fluctuations in the lighting efficiency due to fluctuations in the incident direction.

  Further, according to the present embodiment, in the main cross section shown in FIG. 3, the angle γ formed by the reflective surface 31a with respect to the axis r of the light guide member 41 is separated from the light guide member 41 of the reflective surface 31a. From the side, it gradually becomes smaller toward the side of the reflecting surface 31a that approaches the light guide member 41. According to such a form, as understood from FIG. 5, the light L3 and L4 incident on the daylighting panel 21 is greatly contributed to guiding the light into the light guide path 43 at the winter solstice with low loss.

  Moreover, according to this Embodiment, in the main cross section shown in FIG. 3, the sunlight L1 which injects into a certain position of the lighting panel 21 at the time of the south middle of the winter solstice reflects in the reflective surface 31a of the opposing panel 31. Sunlight L2 that passes through a certain position SC1 on the connection surface SC between the daylighting unit 20 and the light guiding unit 40 and is incident on another position different from the certain position of the daylighting panel 21 during the south solstice of the winter solstice, The light is reflected by the reflection surface 31a of the counter panel 31 and passes through the certain position SC1 on the connection surface SC. In this way, by determining the first angle γ1 and the second angle γ2 so that sunlight L1 and L2 passing through at least two different light paths during the winter solstice pass through a certain position SC1 on the connection surface SC. Thus, it becomes possible to guide a large amount of light taken into the daylighting panel 21 to the light guide member 41 with low loss during the winter solstice. In particular, in the present embodiment, the certain position SC1 on the connection surface SC is a position that is the center of the connection surface SC in the main cross section. In this case, even if the actual optical path of sunlight is slightly deviated from the theoretical optical path due to the effects of manufacturing errors, mounting errors, etc., the lighting function is not greatly affected. For this reason, it contributes greatly to the stable expression of the daylighting function of the daylighting system 10.

  Further, according to the present embodiment, in the main cross section shown in FIG. 3, the reflecting surface 31a is defined by any of a plurality of straight lines, curved lines, or a combination of straight lines and curved lines. In this case, the reflective surface 31a can be easily formed on the counter panel 31, which is advantageous in terms of manufacturing cost.

  Further, according to the present embodiment, in the main cross section shown in FIG. 3, the connection position 34 between the first straight portion 32 and the second straight portion 33 is the center in the direction along the panel surface of the daylighting panel 21. It faces the central position 21 a of the daylighting panel 21 and the normal direction nd to the panel surface of the daylighting panel 21. In this case, since the region of the reflective surface 31a corresponding to the first straight line portion 32 and the region of the reflective surface 31a corresponding to the second straight line portion 33 are distributed in the reflective surface 31a in a well-balanced manner, fluctuations in daylighting efficiency are caused. Contributes to effective suppression.

  Further, according to the present embodiment, in the main cross section shown in FIG. 3, the surface of the daylighting panel 21 facing the opposite panel 31 side along the normal direction nd to the panel surface of the daylighting panel 21 and the reflection of the opposite panel 31. The distance D between the surface 31a gradually increases along the panel surface of the daylighting panel 21 as it approaches the light guide member 41. In this case, compared with the case where the reflective surface 31a is parallel to the panel surface of the daylighting panel 21, the light that is taken from the daylighting panel 21 and is directed toward the reflective surface 31a while being inclined with respect to the axis r of the light guide member 41 is The light is incident on the reflecting surface 31a at a more forward position in the traveling direction, that is, at a position closer to the light guide member 41. For this reason, it becomes easy to guide the light reflected by the reflecting surface 31 a into the light guide path 43. As a result, it contributes to guiding the light taken into the daylighting unit 20 to the light guide unit 40 with stable and high efficiency.

≪Modification≫
Note that various modifications can be made to the above-described embodiment. Hereinafter, an example of modification will be described with reference to the drawings. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as in the above embodiment. A duplicate description is omitted.

  In the above-described embodiment, as shown in FIG. 3, the reflecting surface 31 a is defined by the first straight portion 32 and the second straight portion 33 located closer to the light guide member 41 than the first straight portion 32. An example was given. However, the reflecting surface 31a may be at least partially curved or bent, and is not limited to such an example. 6 and 7 show another example of the reflecting surface 31a.

  In the example shown in FIG. 6, the reflecting surface 31a has a curved shape. In the example shown in FIG. 7, the reflecting surface 31a has a bent shape. In particular, the reflecting surface 31a shown in FIG. 7 includes, in the cross section shown in FIG. 7, a curved portion 35 that is curved in an arc shape, a first linear portion 32 that is located closer to the light guide member 41 than the curved portion 35, and a first The second straight portion 33 is located closer to the light guide member 41 than the straight portion 32. The first straight portion 32 is inclined with respect to the axis r of the light guide member 41, and the second straight portion 33 is smaller in angle with respect to the axis r of the light guide member 41 than the first straight portion 32. Yes. In FIG. 7, the curved portion 35, the first straight portion 32, and the second straight portion 33 have substantially the same length.

  Similar to the configuration shown in FIG. 3, in the main cross section shown in FIGS. 6 and 7, sunlight L <b> 1 incident on a certain position of the daylighting panel 21 during the south solstice of the winter solstice Reflected at the position, passes through a certain position SC1 on the connection surface SC of the daylighting section 20 and the light guide section 40, and enters a different position from the certain position of the daylighting panel 21 during the southern solstice of the winter solstice. The sunlight L2 and L7 to be reflected is reflected at another position on the reflection surface 31a of the opposing panel 31 and passes through the certain position SC1 on the connection surface SC. In the example shown in FIGS. 6 and 7, the certain position SC1 is a position that is the center of the connection surface SC in the main cross section.

  Similarly to the embodiment shown in FIG. 3, in the main cross section shown in FIGS. 6 and 7, the angle γ formed by the reflective surface 31a with respect to the axis r of the light guide member 41 is the light guide member 41 of the reflective surface 31a. It gradually becomes smaller from the side away from the side toward the side closer to the light guide member 41 in the reflecting surface 31a. Further, similarly to the embodiment shown in FIG. 3, in the main cross section shown in FIGS. 6 and 7, the reflection of the second surface 23 of the lighting panel 21 and the opposing panel 31 along the normal direction nd to the panel surface of the lighting panel 21. The distance D between the surface 31a gradually increases as it approaches the light guide 40 along the panel surface of the daylighting panel 21. Therefore, the form shown in FIG. 6 and the form shown in FIG. 7 can achieve the same operational effects as the above-described form shown in FIG.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to this Example. As described below, the daylighting systems according to Examples and Comparative Examples were designed, and it was confirmed by simulation that the daylighting system can effectively suppress fluctuations in daylighting efficiency due to fluctuations in the incident direction.

  The first embodiment corresponds to the daylighting system shown in FIG. The design of each component is as shown in FIG. In particular, as shown in FIG. 8, the length along the uniaxial direction of the daylighting panel was set to 300 mm. The daylighting panel was molded as an integral body, the angle α1 of the inclined surface was 26 °, and the refractive index n was 1.55. The reflectance on the inner surface of the light guide member was 95%.

  Comparative Example 1 corresponds to an example in which the reflecting surface of the opposing panel is configured as a plane in the daylighting system according to Example 1. That is, in the daylighting system according to Comparative Example 1, the outline of the reflecting surface in the main cut surface is a straight line. The design of each component is as shown in FIG.

  Assuming that the lighting system according to Example 1 and Comparative Example 1 was installed at a point of 139 ° east longitude and 39 ° north latitude so that the panel surface of the lighting panel was parallel to the vertical direction, Sunlight was incident on each daylighting system and simulated. 8 and 9 show simulated light rays. The south-central altitude of the winter solstice was 31 °.

  As understood from FIG. 8, in the daylighting system according to the first embodiment, sunlight in the middle of the winter solstice is refracted so that an angle formed with respect to the normal direction to the panel surface in the daylighting panel is increased. Then headed to the reflective surface. The light traveling toward the reflective surface includes light traveling toward the reflective surface region corresponding to the first straight line portion and the reflective surface region corresponding to the second straight line portion. Among these, the light incident on the area of the reflecting surface corresponding to the first straight portion is reflected by the reflecting surface, and enters the light guide path from a direction in which the angle formed with respect to the axis of the light guide member is relatively small. went. For this reason, it was hardly observed that the light reflected by the reflecting surface reenters the daylighting panel and becomes stray light or escapes from the first surface to the outside. On the other hand, most of the light incident on the area of the reflecting surface corresponding to the second straight portion was reflected by the reflecting surface and went toward the light guide without returning to the lighting panel again. Of the light incident on the reflective surface area corresponding to the second linear portion, the light incident on the region relatively close to the first linear portion is reflected by the reflective surface and then returns to the daylighting panel. It escaped from the surface to the outside, but the amount of light was reduced.

  On the other hand, in the daylighting system according to Comparative Example 1, as understood from FIG. 9, the sunlight formed in the middle of the winter solstice has an angle with respect to the normal direction to the panel surface in the daylighting panel. It was refracted to become larger and headed toward the reflecting surface. The light that has entered the region of the reflective surface that is separated from the light guide member is reflected by the reflective surface and then returns to the daylighting panel, escaping from the first surface to the outside. The light incident on the region near the light guide member in the reflection surface was reflected by the reflection surface and went back into the light guide path without returning to the lighting panel, but the amount of light was small.

  From the simulation results shown in FIGS. 8 and 9, in the daylighting system according to Example 1, after the light incident on the reflective surface area corresponding to the first linear portion is reflected by the reflective surface, the axis of the light guide member Therefore, the light at the time of the south solstice of the winter solstice could be guided to the light guide with higher efficiency than the daylighting system according to Comparative Example 1.

  Next, the daylighting function of each daylighting system was evaluated. The evaluation of the daylighting function is the daylighting efficiency at 10, 11, 12 o'clock of the winter solstice, the daylighting efficiency at 10, 11, 12 o'clock on the day after the winter solstice, and the day 10, 11, This was done by evaluating the lighting efficiency at 12:00. Here, the daylighting efficiency refers to the ratio of the amount of light emitted from the lower end of the light guide member to the amount of light incident on the first surface of the daylighting panel. FIG. 10 shows the daylighting efficiency as a graph.

  As understood from FIG. 10, in the daylighting system according to Comparative Example 1, the daylighting efficiency in the time zone around the middle of the winter solstice is the daylighting efficiency in the time zone around the middle of the day after February from the winter solstice. The fluctuation of the daylighting efficiency was large. On the other hand, in the daylighting system according to Example 1, the daylighting efficiency in the time zone around the middle of the winter solstice is larger than that in the daylighting system according to Comparative Example 1, while The daylighting efficiency in the time zone around south-central time was lower than the daylighting system according to Comparative Example 1. From this, it can be seen that the daylighting system according to Example 1 has not only higher daylighting efficiency in the time zone around the middle of the winter solstice but also less fluctuation in daylighting efficiency than the daylighting system according to Comparative Example 1. It was done.

DESCRIPTION OF SYMBOLS 10 Daylighting system 20 Daylighting part 21 Daylighting panel 21a Center position 31 Opposite panel 31a Reflecting surface 32 1st linear part 33 2nd linear part 34 Connection position 40 Light guide part 41 Light guide member r Axis line SC Connection surface

Claims (7)

A daylighting system that takes in light and leads it to a predetermined space,
A daylighting section that captures light;
A cylindrical light guide member connected to the daylighting unit, and guides light from the daylighting unit to the predetermined space;
With
The daylighting unit includes a daylighting panel on which light is incident, and a counter panel arranged to face the daylighting panel,
A reflective surface is formed on the surface of the facing panel facing the daylighting panel,
The daylighting system, wherein the reflecting surface is at least partially curved or bent in a cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member.   In a cross section perpendicular to the panel surface of the daylighting panel and passing through the axis of the light guide member, an angle formed by the reflection surface with respect to the axis of the light guide member is separated from the light guide member of the reflection surface. The daylighting system according to claim 1, wherein the daylighting system gradually decreases from a side to the side closer to the light guide member of the reflecting surface. In a cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member,
Sunlight incident on a certain position of the daylighting panel at the time of the south solstice of the winter solstice is reflected by the reflecting surface of the opposing panel, and a certain position on the connection surface between the daylighting unit and the light guiding unit Street,
Sunlight incident on another position different from the certain position of the daylighting panel during the south solstice of the winter solstice is reflected by the reflecting surface of the opposing panel and passes through the certain position on the connection surface. The daylighting system according to claim 1 or 2.   The cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member, the reflective surface is defined by any of a plurality of straight lines, curved lines, or a combination of straight lines and curved lines. The daylighting system described.   In a cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member, the reflection surface includes at least a first straight portion inclined with respect to the axis of the light guide member, and the first straight portion. Any one of Claims 1 thru | or 4 which are located in the said light guide member side rather than, and the 2nd linear part with which the angle made with respect to the said axial line of the said light guide member is smaller than a said 1st linear part A daylighting system according to claim 1.   In a cross section orthogonal to the panel surface of the daylighting panel and passing through the axis of the light guide member, the connection position of the first straight part and the second straight part is centered in the direction along the panel surface of the daylighting panel. The daylighting system according to claim 5, wherein the daylighting system faces the central position of the daylighting panel and the normal direction to the panel surface of the daylighting panel.   In a cross section perpendicular to the panel surface of the daylighting panel and passing through the axis of the light guide member, a surface facing the opposite panel side of the daylighting panel along a normal direction to the panel surface of the daylighting panel and the opposite panel The daylighting system according to any one of claims 1 to 6, wherein an interval between the reflecting surface and the distance from the reflecting surface gradually increases along the panel surface of the daylighting panel as it approaches the light guide member.

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