JP2005062785A - Tracking type beam condensing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive tracking type beam condensing unit that is constituted by installing many small-sized condenser lenses with large acceptance angles and combining a simple moving mechanism, and can be installed on the roof of a general Japanese style house. <P>SOLUTION: The tracking type beam condensing unit consists of a compound condenser lens and a moving mechanism. The compound condenser lens includes, in the upper part, a Fresnel lens 1 converging the sunshine incident from above downward, in the inside, an internal condenser lens 2 converging the light beam incident from the upper Fresnel lens 1 and projecting it from its lower end inside, a lens cover 3 having a reflecting film 3a on its internal surface to reflect the light beam transmitted through the internal condenser lens and protecting it outside the internal condenser lens 2, and a lower condenser lens 4 receiving the incident light beam on its top surface, totally reflecting and converging the beam inside, and exiting the beam from its reverse surface below the above condenser lenses. The moving mechanism includes: an x-axial column a5 and an x-axial column b6 in an (x) direction, and a y-axial column a7 and a y-axial column b8 in a (y) direction as axial columns which are attached to the lens cover 3, support the weight of the compound condenser lens and rotate the compound condenser lens toward the sun; and a control rod 9 controlling the quantities of x-axial and y-axial rotations. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention condenses light by changing the direction in accordance with the incident direction of sunlight, and converts the light energy into electric energy or heat energy by a photoelectric converter or a photothermal converter so that it can be used effectively. The present invention relates to a tracking type light collecting device.

Technical background

  There is a light collecting device for collecting sunlight so that the light energy of sunlight is converted into electric energy or heat energy by a photoelectric converter or a photothermal converter. Conventionally, as this condensing device, there are one using a lens and a reflecting mirror, and one using a solar cell panel.

  However, a light collecting device using a lens or a reflecting mirror has a small light receiving angle, and it is necessary to accurately enter sunlight at a certain angle. Therefore, the light beam tracking device requires a complicated and highly accurate moving mechanism. It is expensive. Moreover, this condensing device also has a problem that the condensing efficiency is lowered when the incident direction of sunlight is unclear during cloudy weather. Furthermore, this condensing device has a large shape and a large weight, so it cannot be installed on the roof of a general Japanese house.

  In addition, a solar cell panel is expensive because it can collect solar rays incident from multiple directions and can be installed on the roof, but requires a solar cell equal to the light receiving area.

  The present invention was devised in view of these problems, and can be installed on the roof of a general Japanese house at a low price by installing a large number of small compound condenser lenses having a large light receiving angle and combining simple movement mechanisms. It is an object to provide a tracking type light collecting device.

This will be described with reference to the drawings. The first invention is
A light collecting device that tracks and receives sunlight, which is transparent at the top, a hemispherical surface bulged and curved on the upper surface, and a ring-shaped surface on the lower surface, and incident sunlight from below A fresnel lens (1) that condenses the light, and is transparent and substantially funnel-shaped. Both the inner and outer surfaces bulge and curve inward, and all rays incident from the upper Fresnel lens (1) are contained inside. It has an internal condensing lens (2) that transmits and condenses while reflecting and emits from the lower end. The outer surface of the internal condensing lens (2) has a substantially funnel-shaped inner surface and a reflective film (3a). A lens cover (3) that reflects and protects the light beam that has passed through the internal condenser lens, and further has a transparent, substantially lower end tapered columnar shape at the bottom, and a lower surface. It has a cylindrical groove and the Fresnel lens (1) 'S (2), receiving a light beam incident from the lens cover (3) at the upper surface, a composite condenser lens having a lower condensing lens (4) to be emitted from the total reflection is not condensing and lower surface internally.

The second invention is
A condensing device that tracks and receives sunlight, the compound condensing lens described in the previous section, and a lens cover 3 that supports its weight and allows the direction to be adjusted to the direction of the sun. A metal or other light weight and less flexible support rod that is attached and has an x-axis column a5 and an x-axis column b6 for rotating in the x-axis direction, and connects these x-axis columns A support rod made of light weight or less bent and having a y-axis column a7 and a y-axis column b8 for rotating in the y-axis direction at the center thereof, and the amount of rotation in these x-axis and y-axis directions It consists of a moving mechanism having a control rod 9 made of metal or other light weight and less bent.

  Since the tracking type condensing device according to the first aspect condenses light in two stages by the upper Fresnel lens 1 and the lower condensing lens 4, a large condensing rate can be obtained. In addition, sunlight incident on the optical axis of the Fresnel lens 1 is collected while being reflected and refracted by the internal condenser lens 2 and the reflective film 3 a of the lens cover 3, and further collected by the lower condenser lens 4. A large acceptance angle can be obtained. As a result, the composite condenser lens can efficiently collect not only light rays directly incident from the sun but also light rays reflected by surrounding clouds. Further, most of the light rays incident on the composite condenser lens are transmitted through the space or totally reflected inside the optical medium to be condensed, so that the loss is extremely low. Furthermore, these members can be made of plastic such as polycarbonate so thin that they can be mass-produced by injection molding or the like, and are inexpensive and lightweight.

  Since the tracking type condensing device according to claim 2 has a feature that the composite condensing lens has a large light receiving angle, the tracking device of the condensing device using a conventional lens or reflecting mirror has been required. Therefore, the tracking device can be made inexpensive. Further, as a feature of the substantially funnel shape, since the necessary adjacent interval when the compound condenser lens is inclined can be reduced, a large number of compound condenser lenses are provided on the short x-axis column a5 and the x-axis column b6. They can be supported in a row and the direction of them can be collectively controlled by the control rod 9.

  In addition, a large number of the condensing lenses can be arranged adjacent to each other in a plane, the control rods of those columns can be connected, and the direction of the group of compound condensing lenses can be collectively controlled. A device that collects light while tracking sunlight with a tracking device can be configured. In such a tracking type concentrating device, a concentrating solar cell having higher light conversion efficiency than a general flat solar cell panel can be used. Moreover, since it concentrates, high temperature warm water is obtained and the utilization range of warm water can be expanded.

  An embodiment of a tracking type condensing device according to the present invention is shown in FIGS. This condensing device combines a compound condensing lens with a large light receiving angle and a simple moving mechanism so that it can be installed on the roof of a general Japanese house. It can be configured with members. The shape of the lens cover 3 is changed according to the application so that a solar cell, a water heater or the like can be attached to the lower part of the compound condenser lens. Since the light collecting device is constantly exposed to sunlight and wind and rain, it is composed of a member excellent in light resistance and weather resistance. In addition, the lens of each member is subjected to necessary surface treatment in order to reduce transmission loss and reflection loss. These members include a Fresnel lens 1, an internal condenser lens 2, a lens cover 3, a lower condenser lens 4, an x-axis column a 5, an x-axis column b 6, a y-axis column a 7, a y-axis column b 8, and a control rod 9. .

  The Fresnel lens 1 is made of transparent plastic, has a hemispherical surface bulging and curved on the upper surface, and a ring-stepped surface on the lower surface, and condenses sunlight incident from above by the action of a convex lens. If the focal length is shortened, the light collection rate can be increased, but the light receiving angle is reduced. In cooperation with other members, the focal length is determined so as to maximize the light collecting ability by adjusting the inclination of each surface of the ring staircase. The number of steps is set so that the lens thickness is 5 mm or less.

  The internal condensing lens 2 is made of a substantially funnel-shaped transparent plastic, and both the inner and outer surfaces are bulged and curved inward, and the thickness is increased toward the lower part so that light rays are easily totally reflected inside. The light beam incident from the upper Fresnel lens 1 is transmitted while being totally reflected inside, condensed at the center, and emitted from the lower end. The outer surface is provided with pleats projecting downward to increase the efficiency of the lens so that the change in thickness can be greatly increased. The number of pleats is set so that the lens thickness is 5 mm or less and a necessary light receiving angle is obtained.

  The lens cover 3 is made of plastic, and the inner surface has a substantially funnel-like shape and has a reflective film 3a formed by vapor deposition. The reflected light passes through the internal condenser lens 2 and is again reflected in the composite condenser lens. To collect light. The outer surface protects the inner condenser lens 2 and is a container having a strength capable of supporting the entire compound condenser lens. An x-axis column a5 and an x-axis column b6 are attached to the substantially central portion of the outer surface, respectively, and an R support projection 3b and an L support projection 3c that support the composite condenser lens from the left and right, and a control projection 3d that attaches a control rod 9 to the lower part. have. The position of the support protrusion passes through the center of gravity of the compound condenser lens in order to reduce the force required to control the direction.

  The lower condensing lens 4 is made of transparent plastic, has a substantially cylindrical shape at the lower end, and has a cylindrical groove on the lower surface. Light rays having various directions incident from the Fresnel lens 1, the internal condensing lens 2, and the lens cover 3. The light received from the end surface of the cylindrical lens is confined in the lens by utilizing the property that it does not exit from the side surface, and the lower end tapered side wall of the main body or the cylindrical groove is used inside. The light is totally reflected using the side wall, condensed and emitted from the lower surface. The height of the lower surface is as low as possible, the width of the cylindrical groove is as narrow as machining accuracy allows, and the depth and number of grooves are such that the plastic thickness is 5 mm or less.

  The x-axis column a5 and the x-axis column b6 are metal or other lightweight support rods with little deflection, and are attached to the two support projections of the lens cover 3 to support the weight of the compound condenser lens. To be able to rotate in the x-axis direction to match the direction with the sun. The length and strength of the x-axis strut are determined by the number of composite condenser lenses that are supported.

  The y-axis strut a7 and the y-axis strut b8 are metal or other light weight and less flexible support rods, which connect the x-axis struts so that they can rotate in the y-axis direction at the center. Thereby, the composite condenser lens can be rotated in the y-axis direction while maintaining the inclination with respect to the x-axis, and the direction of the composite condenser lens can be adjusted to the direction with the sun. The strength of the y-axis support is determined by the number of composite condenser lenses to be supported.

  The control rod 9 is made of metal or other light weight and has a small deflection, and is attached to the control projection 3d below the lens cover 3 in order to control the amount of rotation of the compound condenser lens in the x-axis and y-axis directions. By moving the control rod in the x and y directions, the direction of the plurality of compound condenser lenses connected to the control rod can be freely changed. If a control rod that connects a large number of control rods is attached, a larger number of compound condenser lenses can be collectively controlled.

  The action of the compound condensing lens of this tracking type condensing device will be described with reference to FIG. 1 taking light rays A to D incident at various positions and angles as examples.

  In the case of the light beam A incident on the peripheral portion of the Fresnel lens 1 at a small incident angle, it is refracted after passing through the Fresnel lens 1, enters the inner surface of the internal condenser lens 2, and reaches the outer surface after being refracted. Since the incident angle is large on the outer surface, the light is totally reflected, emitted from the surface of the pleat portion, and again incident on the lower part of the inner condenser lens 2. Here, the light reaches the lower end of the lens while being totally reflected in the same manner as described above, and enters the upper surface of the lower condenser lens 4 after being emitted therefrom. The light reaches the lower surface while being refracted in the lower condenser lens 4 and exits from there.

  In the case of the light beam B incident on the central portion of the Fresnel lens 1 at a small incident angle, it hardly refracts after passing through the Fresnel lens 1 and passes through the cavity of the internal condenser lens 2 and enters the upper surface of the lower condenser lens 4. To do. Even in the lower condenser lens 4, it hardly refracts and reaches the lower surface and exits there.

  In the case of the light ray C incident on the central portion of the Fresnel lens 1 at a large incident angle, the light C is refracted after passing through the Fresnel lens 1, enters the inner surface of the internal condenser lens 2, and reaches the outer surface after being refracted. Since the incident angle is large on the outer surface, the light is totally reflected, reaches the lower end of the lens while repeating the total reflection, and enters the upper surface of the lower condenser lens 4 after being emitted therefrom. The light is totally reflected from the side surface of the lower condenser lens 4 and reaches the side surface of the cylindrical groove of the lens. Therefore, the light exits while being refracted.

  In the case of the light beam D incident on the peripheral portion of the Fresnel lens 1 at a large incident angle, the light is refracted after passing through the Fresnel lens 1 and incident on the inner surface of the internal condenser lens 2, and is hardly refracted because the incident angle is small. It passes through the internal condenser lens 2 and reaches the reflection film 3 a of the lens cover 3. Therefore, the light is incident on the outer surface of the internal condenser lens 2 after reflection, reaches the inner surface after being refracted. Since the incident angle is large on the inner surface, the light is totally reflected, emitted from the surface of the fold portion, and reaches the reflection film 3a of the lens cover 3 again. Then, after reflection, it re-enters the outer surface of the internal condenser lens 2, but this time, since the incident angle is small, it passes through the internal condenser lens 2 with almost no refraction, passes through the cavity of the internal condenser lens 2, The light enters the upper surface of the condenser lens 4. The light is refracted in the lower condenser lens 4 and reaches the side surface of the cylindrical groove. Then, it is totally reflected, reaches the lower surface, and exits from there.

    It is front sectional drawing which shows embodiment of the tracking type | mold condensing apparatus which concerns on this invention.     It is a perspective view showing an embodiment at the time of installing two compound condenser lenses of a tracking type condensing device concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fresnel lens 2 Internal condensing lens 3 Lens cover 3a Reflective film 3b R support protrusion 3c L support protrusion 3d Control protrusion 4 Lower condensing lens 5 X-axis support | pillar a
6 x-axis strut b
7 y-axis support a
8 y-axis support b
9 Control lights A to D Sun rays

Claims (2)

A light collecting device that tracks and receives sunlight;
It has a Fresnel lens (1) that is transparent and has a hemispherical surface that is bulged and curved on the upper surface, a ring stepped surface on the lower surface, and condenses sunlight rays that are incident from above. The inside which is transparent and substantially funnel-shaped, bulges inward on both the inner and outer surfaces, and transmits and condenses the light incident from the upper Fresnel lens (1) while totally reflecting inside, and exits from the lower end. A condensing lens (2) is provided. The inner condensing lens (2) has a reflective film (3a) on the outer surface and a substantially funnel-shaped inner surface, and reflects the light beam transmitted through the inner condensing lens. And a lens cover (3) for protecting the same, and further, a transparent groove having a substantially cylindrical shape at the lower end and a cylindrical groove on the lower surface at the lower part thereof, the Fresnel lens (1), Light incident from the condenser lens (2) and the lens cover (3) The light from top, tracking type light collector having a composite condenser lens having a lower condensing lens (4) to be emitted from the total reflection is not condensing and lower surface within the A light collecting device that tracks and receives sunlight;
A composite condenser lens according to claim 1, mounted on a lens cover (3) that supports its weight and allows the direction to be matched to the direction of the sun, and is made of metal or other lightweight It is a support rod with little deflection, and has an x-axis column a (5) and an x-axis column b (6) for rotating in the x-axis direction, and is made of metal or other light weight for connecting these x-axis columns. The support rod has a small deflection, and has a y-axis column a (7) and a y-axis column b (8) for rotating in the y-axis direction at the center, and the amount of rotation in the x-axis and y-axis directions. Tracking type condensing device having a moving mechanism having a control rod (9) made of metal or other light weight and having less deflection

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