JP2008243374A - Solar azimuth tracking device, solar light condensing device, and solar light illumination system using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To materialize a solar azimuth tracking device having a simple mechanism, a solar light condensing device, and a solar light illumination system using it. <P>SOLUTION: This solar azimuth tracking device 3 has a thermally expanding body 5 which expands and contracts based on heat by solar light 7, a movement conversion part 6 to convert reciprocation attendant on expansion and contraction of the thermally expanding body 5 to a movement corresponding to the diurnal movement of the sun, and a tracking device body 4 to track a solar azimuth by interlocking with movement by the movement conversion part 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solar azimuth tracking device, a solar light collecting device, and a solar lighting system using the same.

  There are many cases in the building and underground / semi-underground facilities where sufficient sunlight does not enter the window during the day, even though it is fine, and the lighting is turned on and off. Therefore, if the sunlight radiated outside the building during sunny weather can be effectively used as the light source inside the building, the power for lighting can be reduced, contributing to energy saving.

  There is a solar lighting system that uses sunlight as a light source inside a building. That is, the solar light collection system is a system including a light collecting unit that changes the direction according to the solar direction by the solar direction tracking device in order to collect sunlight with high efficiency. This system is composed of a condensing unit, a solar azimuth tracking device, an optical transmission unit, and an irradiation unit.

The condensing unit consists of a parabolic reflector formed into a parabolic shape and a plurality of lenses, and has a structure for condensing as much of the sunlight as possible on the light receiving surface to the light entrance of the light transmission unit. It has become.
The solar azimuth tracking device directs the condensing unit toward the sun in order to condense the light received by the condensing unit onto the optical transmission unit with high efficiency. Since the sun always changes its direction due to the diurnal motion, the condensing part tracks the direction to match the direction of the sun.

The light transmission unit transmits the sunlight collected by the light collecting unit to the inside using an optical duct or an optical fiber cable that reflects light inside.
The irradiating unit diffuses the transmitted light throughout the room by irradiating the lens and the light diffuser.

In the daylighting system described in Patent Document 1, the diurnal motion of the sun is calculated in advance by a computer, and control is performed so that the direction of the light collecting parabola coincides with the solar direction based on the calculation result. . An electric drive motor is used as the driving force for changing the direction of the condensing parabola.
In addition, the same document proposes a method of monitoring the amount of sunlight incident on an optical fiber that is an optical transmission unit and controlling the direction of the condensing parabola so that the amount of incident light is maximized.

JP-A-11-232915

The method of determining the optimal light receiving unit direction while calculating changes in the sun's azimuth and monitoring the amount of transmitted light with a computer requires a computer, a clock, or a light amount detector to be built into the system. It becomes a factor. Moreover, the electric power for operating these apparatuses will be consumed constantly, and it will be contrary to the purpose of the energy saving of a sunlight condensing system. Furthermore, there is a possibility that they may break down or the time of the clock may be shifted, and regular maintenance is also required.
Similarly, the drive motor that changes the direction of the light condensing unit also has problems of cost increase and power consumption.

  In addition, the sunlight collected at the condensing part of the sunlight collecting system includes not only the visible light component necessary for indoor lighting but also the near infrared component, and this component is guided indoors. The temperature rises more than necessary indoors. This is a big problem especially in summer when the temperature is high.

  The problem to be solved by the present invention is to provide a solar azimuth tracking device with a simple mechanism. Moreover, it is providing the sunlight condensing device which has a solar azimuth | direction tracking device with a simple mechanism. In addition, a solar azimuth tracking device, a solar concentrating device, and a solar lighting system using the solar azimuth tracking device that do not require regular maintenance, are inexpensive, and can realize energy saving.

  The present invention includes a thermal expansion body that expands and contracts based on heat from sunlight, a motion conversion unit that converts a reciprocating motion accompanying expansion and contraction of the thermal expansion body into a motion corresponding to the diurnal motion of the sun, and the motion conversion It is a solar azimuth | direction tracking apparatus which has a tracking apparatus main body which tracks a solar azimuth | direction by synchronizing with the motion by a part.

  Specifically, the motion conversion unit is configured such that the connection shaft of the tracking device main body having a connection portion with the thermal expansion body and a lower end shaft tip, and the shaft tip of the support shaft are traced. A plate having a guide groove carved on a fixed substrate, a circular ring or perforation through which the support shaft passes, and converting the movement of the support shaft based on the above to correspond to the diurnal motion of the sun, and And a support member including a connection portion with the fixed substrate.

  In addition, although a thermal expansion body is used for the drive mechanism of the support shaft tip, when the displacement amount is insufficient with only the displacement amount of the thermal expansion body, the displacement amount due to the thermal expansion can be amplified using an enlarged lever. Further, as a technique that does not use an enlarged lever, a mechanism may be used in which the displacement amount of the thermal expansion body is detected by a displacement sensor, and the support shaft tip is displaced by an electric motor in accordance with the displacement amount. In this case, the thermal expansion body is provided with a driving force applied to the support shaft tip by displacing the support shaft tip with an electric motor provided separately, and the motion of the support shaft tip is driven by the driving force of the electric motor. Can be controlled. Thus, the reason why the electric motor is provided separately is that the amount of displacement can be increased by directly providing the displacement of the thermal expansion body by providing the electric motor separately from the thermal expansion body. .

  Preferably, the guide groove has a change in depth at a predetermined portion or prevents the thermal expansion at noon in order to prevent the support shaft tip from running backward in a time zone in which the amount of sunshine before sunset decreases. The solar azimuth tracking device has a closed curve shape that faces the south side in a state where the body is most inflated, and a step is provided at a predetermined location to prevent the shaft tip from running backward.

  Here, when the guide groove is provided on the movable substrate, the function of responding to the change of the diurnal motion of the sun accompanying the change of the season can be provided by displacing the position of the substrate.

  Moreover, this invention is a sunlight condensing apparatus which has a condensing part which condenses sunlight, and the said solar direction tracking apparatus.

  The sunlight condensing device includes a light guiding mechanism that guides a part of sunlight condensed by the light collecting unit to the thermal expansion body.

  Preferably, the light guiding mechanism includes a spectroscopic device that separates a near-infrared component of sunlight collected by the light collecting unit, and separates and induces the separated near-infrared component to the thermal expansion body. Have the device.

  Specifically, the spectroscopic device includes a reflecting mirror made of a dielectric multilayer film that selectively reflects the near-infrared component of the collected sunlight and a reflecting mirror having a wavelength-independent reflection characteristic. Has been.

  Preferably, the auxiliary condensing unit is different from the condensing unit, and the auxiliary condensing unit condenses when the sunshine recovers after the solar azimuth tracking of the solar azimuth tracking device stops due to the interruption of sunshine. The solar expansion device has a function of resuming the solar direction tracking of the solar direction tracking device by irradiating the thermal expansion body with the sunlight.

  Furthermore, the present invention provides a solar lighting system including an optical transmission unit that transmits sunlight collected by a solar concentrator to an illumination unit, and an irradiation unit that irradiates the transmitted sunlight indoors. It is.

  The mechanism of the solar azimuth tracking device, the solar light collecting device, and the solar lighting system using the same according to the present invention is simple.

  FIG. 1 is a diagram illustrating a configuration of a solar azimuth tracking device according to an embodiment of the present invention and a solar light collecting device using the solar azimuth tracking device.

The solar light collecting device 1 shown in FIG. 1 has a light collecting unit 2 and a solar azimuth tracking device 3, and the sun including a light collecting unit, a solar azimuth tracking device, a light transmission unit, and an irradiation unit. It is part of the daylighting system.
The solar azimuth tracking device 3 is further configured by a tracking device main body 4 (light condensing unit 2), a thermal expansion body 5, and a motion conversion unit 6.

  The condensing part 2 condenses the sunlight 7 irradiated from the sun. In addition, the specific structure of the condensing part 2 consists of the parabolic reflecting mirror shape | molded in the parabolic shape as shown in FIG. 1, and a some lens, Of sunlight 7 irradiated to a light-receiving surface Thus, as much as possible can be collected at the light entrance of the light transmission section.

  The thermal expansion body 5 constituting the solar azimuth tracking device 3 expands and contracts in the direction of the double-headed arrow AR1 shown in FIG. Here, based on the heat from the sunlight 7 means that it is mainly based on the heating action on the object of the near-infrared component contained in the sunlight 7 collected by the light collecting unit 2 as described below. In order for the thermal expansion body 5 to perform such expansion and contraction, the thermal expansion body 5 has a cylinder piston sealed with a medium such as liquid or gas as shown in FIG. It is also possible to use a metal rod having a large thermal expansion coefficient.

  The motion conversion unit 6 has a function of converting the expansion / contraction of the thermal expansion body 5 into a motion corresponding to the diurnal motion of the sun. That is, in FIG. 1, the motion conversion unit 6 converts the reciprocating motion of the double arrow AR1 due to the expansion and contraction of the thermal expansion body 5 into the motion indicated by the arrow AR2. In conjunction with this movement, the tracking device main body 4 (light condensing unit 2) performs a movement corresponding to the solar path 8 performing the daily movement as indicated by the arrow AR3, and the tracking device main body 4 (light collecting unit 2). ) Will track the sun.

A more specific mechanism of the motion conversion unit 6 for causing the tracking device main body 4 (the light collecting unit 2) to perform the motion indicated by the arrow AR3 will be further described with reference to FIG.
That is, as shown in FIG. 1, the support shaft 9 is attached to the lower part of the tracking device main body 4 (light collecting unit 2). A connecting portion 10 that moves in conjunction with expansion and contraction of the thermal expansion body 5 is provided at a location P <b> 1 of the support shaft 9. The light collection efficiency of the sunlight 7 is maximized in the direction of the tracking device main body 4 (light collecting unit 2) such that the sun is positioned on the extended line of the central axis of the support shaft 9. At this time, in order to increase the light collection efficiency of the sunlight 7, the orientation of the support shaft 9 may be adjusted so that the sun is positioned on the extended line of the central axis of the support shaft 9.

  A guide groove having a predetermined plane pattern is provided on the surface Q on which the solar light collecting device 1 is installed, and the support shaft tip 11 is made to trace the guide groove. When the support shaft 9 moves in conjunction with the expansion and contraction of the thermal expansion body 5, the support shaft tip 11 performs the movement indicated by the arrow AR2 by tracing the guide groove. The upper part of the support shaft 9 passes through a support member 12 made of a plate material having a circular ring or a perforation connected to a fixed substrate by a connection portion, and has a structure in which movement is restricted at this part. When the support shaft tip 11 moves in a state where the movement of the upper portion of the support shaft 9 is restricted, the direction of the support shaft 9 changes accordingly, and the direction of the tracking device main body 4 (light collecting unit 2) is changed to the arrow AR3. It will change as shown in.

  FIG. 2 is a plan view showing one specific example of the guide groove. That is, an arcuate guide groove 13a as shown in FIG. 2 is provided on the surface Q on the fixed substrate. Point F is a projection point onto the surface Q from the center of the ring or perforation attached to the support member 12. When the guide groove 13a is traced on the support shaft tip 11, the support shaft tip 11 performs the movement shown in the direction of the arrow AR5 by the expansion and contraction of the thermal expansion body 5, and the tracking device main body 4 (the light collecting portion 2) is moved. The direction can be changed as indicated by the arrow AR3.

Such movement will be further described with reference to FIG.
First, the guide groove 13a has two end points Pe and Pw in the east-west direction and draws a convex arc in the north direction. The expansion and contraction of the thermal expansion body 5 basically causes a reciprocating motion in the direction indicated by the arrow AR1. However, since the tip of the thermal expansion body 5 is connected to the support shaft 9 at the connection portion 10, the movement of the support shaft tip 11 is restricted by the guide groove 13a, so that the orientation of the thermal expansion body 5 matches that. Will receive a lot of corrections.

As the movement of the tracking device body 4 (condenser 2) corresponding to the diurnal movement of the sun, first, the support shaft tip 11 is located in the vicinity of the west end point Pw of the guide groove 13a in the early morning before sunrise. The tracking device main body 4 (light condensing unit 2) faces the east side. At this time, the thermal expansion body 5 is in a contracted state because the near infrared component contained in the sunlight 7 is not irradiated.
After the sunrise, when the tracking device main body 4 (the light collecting unit 2) receives the sunlight 7, the thermal expansion body 5 is heated by the near-infrared component contained in the sunlight 7 and starts expanding, and the force is connected to the connection portion. 10 is transmitted to the support shaft 9 and the support shaft tip 11 moves in the northeast direction while being guided by the guide groove 13a. Along with this, the direction of the tracking device main body 4 (light condensing unit 2) changes in the southwest direction.

  This mechanism will be described in more detail. The thermal expansion body 5 heated by the irradiation of the near-infrared component contained in the sunlight 7 expands, moves the support shaft 11 in the northeast direction, and changes the direction of the tracking device body 4. When the expansion of the thermal expansion body 5 further proceeds, the orientation of the tracking device body 4 further changes, and the light collection efficiency of the sunlight 7 decreases. Then, the intensity | strength of the near-infrared component of the sunlight 7 irradiated to the thermal expansion body 5 becomes weak, and expansion | swelling stops. Thus, the expansion amount of the thermal expansion body 5 is determined at a point where the heating amount of the near-infrared component contained in the sunlight 7 and the heat amount released to the external atmosphere coincide. When the solar direction changes, the point at which this amount of heat changes also changes, and the expansion amount of the thermal expansion body 5 changes accordingly. As a result, the tracking device main body 4 (condenser 2) becomes the solar diurnal. The condensing part 2 can continue condensing the received sunlight 7 to a predetermined position with high efficiency by performing an exercise corresponding to the exercise.

From the afternoon to the evening, the intensity of the sunlight 7 is weakened, and the heat supplied to the thermal expansion body 5 is reduced. If the amount of heat sufficient to maintain the expanded state of the thermal expansion body 5 cannot be obtained even if the position of the support shaft 11 is at the point where the light collection efficiency of the sunlight 7 is maximized, the thermal expansion body 5 Thereafter, the support shaft 11 continues to contract and returns to the same west end point Pw as in the early morning before sunrise, and thereafter, the solar azimuth tracking cannot be continued.
Moreover, even if it is the situation where the amount of heat sufficient to maintain the expanded state of the thermal expansion body 5 is obtained, the support shaft tip 11 moves to the west side with respect to maximizing the light collection efficiency of the sunlight 7 by some means. As a result, similarly, the thermal expansion body 5 continues to contract thereafter, and the solar azimuth tracking cannot be continued thereafter.

  Therefore, in order to alleviate this problem, it is desirable that the depth of the guide groove 13a becomes deeper as it approaches the east end point Pe. Thereby, the weight of the tracking device main body 4 assists the movement of the support shaft tip 11 in the Pe direction due to the expansion of the thermal expansion body 5. With the assistance of such exercise, even if the intensity of the sunlight 7 decreases from noon to the evening, it is possible to prevent the support shaft 11 from running backward to the Pw side by any moment.

  Since the sunshine is interrupted during the night from sunset to before sunrise, the thermal expansion body 5 heated and expanded by the near-infrared component of the sunlight 7 during the day is cooled and contracted by the outside air temperature. The tip 11 returns to the vicinity of the end point Pw on the west side of the guide groove 13a. Thus, the above motion is repeated again after the next day's sunrise.

As the distance between the point located most north in the guide groove 13a and the point F increases, the tracking device main body 4 tilts more southward when the support shaft tip 11 reaches the northmost point. Become. Since the inclination of the sun toward the south at noon changes depending on the season, if the distance between the northernmost point and the point F can be adjusted according to the season, the light collecting unit 2 has the highest efficiency in each season. It is possible to collect the sunlight 7 received in step 1 at a predetermined position, which is more preferable. Specifically, another planar substrate that can be slid by manual operation or the operation of an electric motor is placed on the fixed substrate Q, and the guide groove 13a is provided on the upper surface thereof.
In the southern hemisphere of the earth, the sun rises from the east and sinks west through the north sky. Therefore, when used in the southern hemisphere, the guide groove 13a must be a convex arc on the south side.

FIG. 3 is a plan view showing a specific example of another guide groove. That is, the closed curve has a shape close to a semicircle facing north as shown in FIG.
If the support shaft tip 11 is traced in the guide grooves 13b and 13c, the expansion and contraction of the thermal expansion body 5 is converted into the movement indicated by the arrows AR7 and AR8 of the support shaft tip 11, so that the main body of the tracking device 4 (light collecting unit 2) can be changed as indicated by an arrow AR3.
At this time, the solar azimuth tracking device faces the south side in a state where the thermal expansion body 5 is most expanded at noon. Therefore, even when the thermal insulation of the thermal expansion body 5 is not so high, or without changing the depth of the guide groove and without the help of the weight of the tracking device body 4, the tracking device body 4 can be used until sunset. The sun direction can be tracked continuously.

Such movement will be further described with reference to FIG.
First, the guide groove 13b has two end points Pwb and Pnb in the north-west direction, and draws a convex arc in the northwest direction. The guide groove 13c in contact with the guide groove 13b has two end points Pnc and Pwc and draws a convex arc in the east direction. Although the end point Pnb of the guide groove 13b is in contact with the guide groove 13c, a step is formed at the contact portion. At the point Pnb, the guide groove 13c is slightly deeper than the guide groove 13b. Similarly, although the end point Pwc of the guide groove 13c is in contact with the guide groove 13b, a step is formed at the contact portion. At the point Pwc, the guide groove 13b is slightly deeper than the guide groove 13c.

  The expansion and contraction of the thermal expansion body 5 basically causes a reciprocating motion in the direction indicated by the arrow AR1. However, since the tip of the thermal expansion body 5 is connected to the support shaft 9 by the connecting portion 10, the movement of the support shaft tip 11 is restricted by the guide groove 13 b or the guide groove 13 c. Will be modified to fit.

  As the movement of the tracking device main body 4 (condensing part 2) corresponding to the diurnal movement of the sun, first, the support shaft tip 11 is located in the vicinity of the end point Pwb on the west side of the guide groove 13b in the early morning before sunrise. The tracking device main body 4 (light condensing unit 2) faces the east side. At this time, the thermal expansion body 5 is in a contracted state because the near infrared component contained in the sunlight 7 is not irradiated.

  After the sunrise, when the tracking device main body 4 (the light collecting unit 2) receives the sunlight 7, the thermal expansion body 5 is heated by the near-infrared component contained in the sunlight 7 and starts expanding, and the force is connected to the connection portion. 10 is transmitted to the support shaft 9, and the support shaft tip 11 moves in the northeast direction while being guided by the guide groove 13b. Along with this, the direction of the tracking device main body 4 (light condensing unit 2) changes in the southwest direction. When it is near noon, the support shaft tip 11 moves from the guide groove 13b to the guide groove 13c at the point Pnb, and at noon the support shaft tip 11 further moves to the vicinity of the point Pnc.

  When the sun azimuth moves west past noon, the direction of the tracking device main body 4 (condenser 2) deviates from the sun azimuth with the support shaft tip 11 in the vicinity of the point Pnc. The intensity | strength of the near-infrared component of the sunlight 7 irradiated to the expansion body 5 falls. Then, the thermal expansion body 5 starts to contract this time, and the support shaft tip 11 moves away from the point Pnc. At this time, since there is a step at the point Pnb, the support shaft 11 does not run backward to the guide groove 13b, but moves in the southeast direction along the guide groove 13c. Then, the direction of the tracking device main body 4 (condensing part 2) changes to the northwest according to it, and approaches the solar direction. Along with this, the intensity of the near-infrared component of the sunlight 7 irradiated to the thermal expansion body increases, and the amount of heat generated by the near-infrared component of the sunlight 7 matches the amount of heat released to the external atmosphere. The expansion amount of the thermal expansion body 5 is determined. When the solar direction changes, the point at which this amount of heat changes also changes, and the amount of expansion of the thermal expansion body 5 changes accordingly. As a result, the tracking device main body 4 (condenser 2) also becomes solar in the afternoon. Continuing the movement corresponding to the diurnal movement, the condensing unit 2 can continue to collect the sunlight 7 received with high efficiency at a predetermined position.

  Since the sunshine is interrupted during the night from sunset to before sunrise, the thermal expansion body 5 heated and expanded by the near-infrared component of the sunlight 7 during the day is cooled and contracted by the outside air temperature, and most of the guide groove 13c. It passes through a point located east and reaches a point Pwc. Further, it passes through the step and moves to the vicinity of the point Pwb, and the next morning sunrise is reached at that point. The thermal expansion body 5 starts to expand again with the next morning sunrise, but the support shaft 11 does not run backward to the guide groove 13c because there is a step at the point Pwc, and again in the northwest direction along the guide groove 13b. Move to.

  As described above, when the support shaft tip 11 traces any of the guide groove 13a, the guide groove 13b, or the guide groove 13c, the position slightly deviated from the direction in which the heat flowing into the thermal expansion body 5 becomes maximum. Thus, the support shaft tip 11 is determined. Therefore, the amount of heat flowing into the thermal expansion body 5 does not become more than a predetermined amount, and even if the solar light collecting device provided with the solar azimuth tracking device shown in the present application is used in an area with strong sunlight, the heat due to overheating. Deterioration of the expansion body 5 can be suppressed.

  The motion conversion unit 6 has a function of converting the reciprocating motion due to the expansion and contraction of the thermal expansion body 5 into a motion corresponding to the diurnal motion of the sun. Here, when the thermal expansion amount of the thermal expansion body 5 is small and the displacement amount in the direction of the double-headed arrow AR1 is insufficient, as shown in FIG. This motion may be expanded to the motion indicated by the double arrow AR9. Alternatively, instead of using the enlarged lever 14, the displacement amount of the thermal expansion body can be detected by a displacement sensor, and the support shaft tip can be displaced by an electric motor in accordance with the displacement amount. A mechanism for detecting the amount of displacement with a displacement sensor and displacing the support shaft tip with an electric motor is not specifically described, but a known method may be used.

  As described above, in the solar azimuth tracking device 3 shown in FIG. 1, the tracking of the solar azimuth by the tracking device main body 4 is realized only by a mechanical mechanism. Therefore, a device such as a computer or a drive motor is unnecessary, and not only the cost of the solar azimuth tracking device 3 can be kept low, but also no power is required, leading to energy saving. In addition, there is little possibility of failure, and maintenance such as time correction of the built-in clock becomes unnecessary. The above merits are the same also about the sunlight condensing device 1 which has this solar azimuth | direction tracking device 3. FIG.

  As a heat source for expanding the thermal expansion body 5 of the solar azimuth tracking device 3, it is preferable to extract and use only the near-infrared component of the sunlight 7 collected by the light collecting unit 2. In order to realize this, a light guiding mechanism that separates the near-infrared component from the sunlight 7 received by the sunlight collecting device 1 and guides it to the thermal expansion body 5 is required.

  FIG. 5 is a cross-sectional view of the light collecting unit 2 constituting the solar light collecting device 1. The light collecting unit 2 shown in FIG. 5 is configured by a parabolic reflector 15 covered with a transparent protective cover 16. In the vicinity of the focal point of the parabolic reflector 15, a spectroscopic device 17 is provided as a light guiding mechanism. The near-infrared component separated by the spectroscopic device 17 may be guided to the thermal expansion body 5 and the remaining sunlight from which the near-infrared component has been removed may be transmitted to an indoor illumination unit.

Specifically, the spectroscopic device 17 is provided with a concave mirror 18a having the same wavelength-independent reflection characteristics as a normal mirror in the vicinity of the focal point, and in front of this, the wavelength selectivity that selectively reflects only the near-infrared component. The concave mirror 18b is provided. An example of the wavelength-selective reflector that selectively reflects only the near-infrared component is a dielectric multilayer film.
FIG. 6 shows an enlarged cross-sectional view of the spectroscopic device 17 composed of a combination of two concave mirrors 18 having different reflection characteristics. As shown in FIG. 6, the near-infrared component of the sunlight 7 reflected by the parabolic reflector 15 is separated by the combination of the two concave mirrors 18a and 18b. The separated near infrared component is reflected to the lens 19b. On the other hand, components other than near-infrared components of sunlight 7 including visible light components are reflected to the lens 19a.

  The near-infrared component reflected by the near-infrared component condensing lens 19b is guided to the thermal expansion body 5 through an optical duct or an optical fiber. On the other hand, the other components mainly composed of visible light reflected on the lens 19a are transmitted separately to the illuminating unit of the solar lighting system by transmitting an optical transmission unit composed of an optical duct and an optical fiber, and are used for indoor illumination light. Used as. By transmitting the remaining solar light component from which the near-infrared component has been removed to the indoor lighting equipment, an unnecessary increase in indoor temperature due to the near-infrared component can be suppressed.

  Note that a wavelength selective reflector using a dielectric multilayer film requires highly accurate film thickness control in order to obtain a uniform high reflectivity over a wide wavelength band. Even if there is, there is only a problem that the heating efficiency of the thermal expansion body 5 is somewhat lowered. Conversely, if the reflectance in the visible light band is non-uniform, an unnatural color occurs in the illumination light transmitted indoors, but it is difficult to obtain a uniform low reflectance over a wide wavelength band. Absent. Therefore, the spectroscopic device 17 is easier to manufacture by combining a near-infrared component selective reflecting mirror and a wavelength non-selective reflecting mirror.

  The spectroscopic device 17 as the sunlight guiding mechanism can use not only a wavelength selective reflecting mirror made of a dielectric multilayer film but also a spectroscopic optical element such as a diffraction grating or a hologram sheet.

  In the solar azimuth tracking device 3 and the solar light collecting device 1 using the solar azimuth tracking device 3 according to the embodiment of the present invention shown in FIG. The tracking device main body 4 (light collecting unit 2) tracks the sunlight 7 in response to the movement. However, when the weather temporarily deteriorates and the sunshine stops, the thermal expansion body 5 that expands in accordance with the sun direction contracts, and accordingly, the direction of the tracking device main body 4 (light condensing unit 2) is before sunrise. It will return to the state. Once the tracking device body 4 (condenser 2) returns to the pre-sunrise direction, the solar azimuth tracking mechanism described above resumes solar azimuth tracking until the next day's sunrise even if sunshine recovers later. Can not do it. The thermal insulation around the thermal expansion body 5 can be improved to prevent the thermal expansion body 5 from contracting due to a short interruption of sunshine. Is not valid.

  In order to solve this problem, an auxiliary condensing unit is provided separately from the main condensing unit 2, and the sunlight 7 collected there is guided to the thermal expansion body 5 to heat the thermal expansion body 5. What is necessary is just a mechanism. In this case, since the sun azimuth cannot be tracked in the auxiliary condensing unit, it is necessary to condense wide-angle light, and conversely, not only the near-infrared component but also all the light is used for heating the thermal expansion body 5. Therefore, the light collection efficiency is not so high. Therefore, it is desirable that the structure of the auxiliary condensing unit is a combination of the concave lens integrated body 20a, the convex lens 20b, and the light guide 21 as shown in FIG.

  In addition, the condensing direction is slightly tilted to the southwest side and fixed to make it difficult to collect sunlight from the east side. Further, a light amount adjusting mechanism interlocking with the movement of the support shaft 11 is provided to provide the main condensing unit 2. If the light guide rate of the collected light to the thermal expansion body 5 decreases as the direction of the light is directed to the west side, the influence when the tracking device body 4 is normally tracking the solar direction is reduced, On the contrary, when the tracking function of the tracking device main body 4 is stopped despite the sunshine, it can have a great influence.

  Specifically, as shown in FIG. 8, the optical fiber 23 for guiding light or the optical coupling lens 22 is fixed with a play by a spring 25 or the like, and according to the expansion degree of the thermal expansion body 5. What is necessary is just to adjust the optical coupling efficiency to the optical fiber 23 by transmitting displacement.

It is a figure which shows the structure of the solar concentrating device provided with the solar azimuth | direction tracking apparatus which concerns on embodiment of this invention, and the solar azimuth | direction tracking apparatus. It is one example of the top view of the guide groove used by the motion conversion part of the solar azimuth | direction tracking device which concerns on embodiment of this invention. It is another example of the top view of the guide groove used by the motion conversion part of the solar azimuth | direction tracking device which concerns on embodiment of this invention. It is a figure which shows the mechanism which expands the displacement amount by expansion / contraction of a thermal expansion body. It is sectional drawing of the condensing part used with the sunlight condensing device which concerns on embodiment of this invention. It is sectional drawing of the spectroscopic device provided in the condensing part used with the sunlight condensing device which concerns on embodiment of this invention. It is sectional drawing of the auxiliary | assistant condensing part which consists of the combination of the accumulation body of a concave lens and a light guide used with the sunlight condensing apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the mechanism which changes the optical coupling efficiency from a condensing lens to an optical fiber according to the displacement amount transmitted from the outside.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sunlight condensing device 2 ... Condensing part 3 ... Solar direction tracking device 4 ... Tracking apparatus main body 5 ... Thermal expansion body 6 ... Motion conversion part 7 ... Sunlight 8 ... Path | route 9 ... Support shaft 10 ... Connection part 11 ... Support shaft tip 12 ... Support member 13 ... Guide groove 14 ... Enlarged lever 15 ... Parabolic reflector 16 ... Protective cover 17 ... Spectroscopic device 18 ... Concave mirror 19 ... Lens 20a ... Concave lens assembly 20b ... Convex lens 21 ... Light guide 22 ... Optical coupling Lens 23 ... Optical fiber 24 ... Optical fiber fixing member 25 ... Spring

Claims (12)

A thermal expansion body that expands and contracts based on heat from sunlight;
A motion converter for converting the reciprocating motion associated with the expansion and contraction of the thermal expansion body into a motion corresponding to the diurnal motion of the sun;
A tracking device main body that tracks the sun's azimuth by interlocking with the motion by the motion conversion unit;
A solar azimuth tracking device. The motion converter is
A support shaft of the tracking device main body having a connection portion with the thermal expansion body and a lower end shaft;
A guide groove carved on a fixed substrate for converting the movement of the support shaft based on the movement of the connecting portion by tracing the support shaft tip so as to correspond to the diurnal motion of the sun;
The solar azimuth tracking device according to claim 1, further comprising: a plate member having a circular ring or perforation through which the support shaft passes, and a support member including a connection portion with a fixed substrate. The displacement amount of the thermal expansion body is detected by a displacement sensor, and according to the displacement amount, a support shaft tip provided separately from the thermal expansion body is displaced by an electric motor, whereby a driving force is applied to the support shaft tip. The solar azimuth tracking device according to claim 2, wherein the movement of the support shaft tip is controlled by a driving force of an electric motor.   4. The solar azimuth tracking device according to claim 2, wherein the guide groove has an open arcuate curved shape having end points and has the guide groove having a change in depth at a predetermined portion. 5.   It is a closed curve shape, and the solar azimuth tracking device is facing the south side in the state where the thermal expansion body is most expanded at noon, and has a step to prevent the shaft tip from running backward at a predetermined location. The solar azimuth | direction tracking apparatus of Claim 2 or Claim 3 which has the said guide groove provided. The guide groove according to any one of claims 2 to 5 is provided on a movable substrate, and has a function of responding to a change in the diurnal motion of the sun accompanying a seasonal change by displacing the position of the substrate. The solar azimuth | direction tracking device of Claim 1 or Claim 2.   Sunlight comprising the solar azimuth tracking device according to any one of claims 1 to 3 and claim 6, and having a sunlight condensing unit that tracks the solar azimuth in conjunction with the solar azimuth tracking device. Concentrator.   The solar light collecting device according to claim 7, further comprising a light guide mechanism that guides a part of the sunlight collected by the light collecting unit to the thermal expansion body.   Separation induction having a spectroscopic device for separating the near-infrared component of sunlight collected by the condensing unit, and guiding the near-infrared component separated by the spectroscopic device to the thermal expansion body by the light guiding mechanism The solar light collecting device according to claim 8, comprising the device.   The spectroscopic device includes a reflecting mirror made of a dielectric multilayer film that selectively reflects near-infrared components of sunlight collected by the light collecting unit, and a reflecting mirror having a wavelength-independent reflection characteristic. The solar light collecting device according to claim 9.   Sunlight collected by the auxiliary light-collecting unit when the sunshine recovers after the sun-directional tracking of the solar azimuth tracking device stops due to the disruption of sunshine. The solar light collecting device according to any one of claims 7 to 10, which has a function of resuming solar azimuth tracking of the solar azimuth tracking device by being irradiated on the thermal expansion body. The solar light collecting device according to any one of claims 7 to 11, and an optical transmission unit that transmits sunlight collected by the solar light collecting device to an illumination unit, and has been transmitted. A solar lighting system including an irradiation unit that irradiates sunlight indoors.

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