Solar cooker

Abstract

To provide a solar cooker which can be carried easily, does not need a lot of labor for assembly when used, and has high light collection efficiency on a reflection surface.SOLUTION: A solar cooker 1 includes: a reflection plate 2; and a frame 3 which holds a periphery of the reflection plate 2. The reflection plate 2 includes: an elastic sheet 4 whose periphery is held by the frame 3; and a reflection surface 5 formed on one surface of the elastic sheet 4. The reflection surface 5 is formed by an aggregation of glass mirror pieces 6, and a gap 7 is provided between the adjacent glass mirror pieces 6.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a solar cooker that can cook food by utilizing thermal energy from sunlight. [Background technology]

[0002] Conventionally, solar cookers are known that convert sunlight collected by a parabolic reflecting surface into thermal energy and cook food on a cooking counter set up in front of the reflecting surface (e.g., Patent Documents 1 and 2). The solar cooker described in Patent Document 1 is provided with a framework in which a number of rod-shaped bodies with curved cross sections are rotatably arranged to form the reflecting surface, a number of fan-shaped reflective sheets detachably attached to the rod-shaped bodies, a cooking counter, and a support base, all of which are detachably provided. In addition, the light-collecting cooking utensil described in Patent Document 2 is provided with a circular reflecting plate with a concave curved center and legs extending from the reflecting back surface of the reflecting plate that bulges out in a convex shape, and the reflecting plate is provided with a reflective surface coated with a light-absorbing material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3143682 [Patent Document 2] JP 2005-114190 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the solar cooker described in Patent Document 1, when it is used, it is necessary to attach a fan-shaped reflective sheet to each of the multiple rod-shaped bodies with curved cross sections that extend radially from a disk-shaped base to form a circular reflective surface, which makes assembly time-consuming and cumbersome.In addition, in the light-collecting cooking device described in Patent Document 2, a circular reflector with a concave curved center is used, which makes the reflector bulky and increases the overall weight, making it difficult to carry.

[0005] Therefore, an object of the present invention is to provide a solar cooker that is easy to carry, does not require the effort of assembling when used, and has good light collecting efficiency on the reflective surface. [Means for solving the problem]

[0006] The solar cooker of the present invention comprises a reflector and a frame that holds the periphery of the reflector, and the reflector comprises an elastic sheet whose periphery is held by the frame and a reflective surface formed on one side of the elastic sheet, and the reflective surface is formed by an assembly of a plurality of reflective pieces, with gaps provided between adjacent reflective pieces.

[0007] In the solar cooker of the present invention, the plurality of reflective pieces are glass mirror pieces, and the back surface of each glass mirror piece is bonded to one surface of the elastic sheet.

[0008] In addition, in the solar cooker of the present invention, the reflecting surface curves under its own weight by maintaining the reflecting plate and the frame in a backward tilted position. Effect of the Invention

[0009] According to the solar cooker of the present invention, a flexible reflective surface is formed by an assembly of multiple reflective pieces arranged on one side of an elastic sheet, so that the reflective surface can be kept flat when carrying the solar cooker, making it easy to carry. In addition, when using the solar cooker, the reflective surface is formed into a curved shape simply by tilting the reflector and frame backwards, making it easy to assemble. Furthermore, since gaps are provided between the multiple reflective pieces that form the reflective surface, it can also accommodate changes in the shape of the flexible reflective surface.

[0010] In addition, according to the solar cooker of the present invention, the reflective surface is formed by multiple glass mirror pieces, so there is little distortion of the reflective surface due to aging, and an excellent reflective effect is obtained. In addition, the weight of the glass is used to cause an appropriate deflection in the elastic sheet during use.

[0011] Furthermore, according to the solar cooker of the present invention, by maintaining the reflector and the frame in a backward tilted position, the reflecting surface bends moderately under its own weight, forming a curved reflecting surface. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a front view of a solar cooker according to a first embodiment. [Diagram 2] FIG. 2 is a rear view of the solar cooker according to the first embodiment. [Diagram 3] FIG. 1 is an exploded perspective view of a solar cooker according to a first embodiment. [Figure 4] FIG. 4(a) is an explanatory diagram of the use state of the solar cooker according to the first embodiment, and FIG. 4(b) is an enlarged view of part A in FIG. 4(a). [Diagram 5] FIG. 10(a) is a front view of a solar cooker according to a second embodiment, (b) is an exploded view of the frame, and (c) is a view of the reflector plate folded up. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The solar cooker of the present invention will be described below based on an embodiment with reference to the drawings. Note that the drawings are schematic representations of the solar cooker, and the dimensions and dimensional ratios of the actual product do not necessarily match those in the drawings. Also, duplicated descriptions will be omitted as appropriate, and the same reference numerals may be used to designate the same components.

[0014] 1 to 3 show a solar cooker according to a first embodiment of the present invention. The solar cooker 1 comprises a reflector 2 and a frame 3 that holds the periphery of the reflector 2. The reflector 2 comprises an elastic sheet 4 whose periphery is held by the frame 3, and a reflecting surface 5 formed on one side of the elastic sheet 4. The elastic sheet 4 is made of a thin rectangular rubber sheet, for example, having a length and width of about 1000×1000 mm and a thickness of about 1.2 mm, and is flexible. The reflecting surface 5 is formed by an assembly of a plurality of reflecting pieces. Each of the plurality of reflecting pieces is made of a glass mirror piece 6, for example. Each glass mirror piece 6 is made of a rectangular thin piece, for example, having a length and width of 50×50 mm and a thickness of 1.2 mm. Then, a plurality of glass mirror pieces 6 are arranged lengthwise and widthwise on the elastic sheet 4, thereby forming a reflecting surface 5 in which a plurality of glass mirror pieces 6 are assembled. Each glass mirror piece 6 is attached to one side of the elastic sheet 4 by a silicone-based adhesive applied to the back surface. The glass mirror pieces 6 are made by applying a thin layer of silver to transparent glass. Because the material is glass, there is little distortion of the surface due to aging, and the reflection efficiency is excellent.

[0015] Since the elastic sheet 4 has flexibility, it can bend to a certain extent under its own weight, but when the load of the multiple glass mirror pieces 6 is applied, the bending width of the elastic sheet 4 increases, and a curved reflective surface 5 is formed. The reflective surface 5 maintains a flat shape when the reflector 2 is upright, and the curved surface is formed by tilting the reflector 2 backward and tilting the reflection 5 upward. The upward angle of the reflective surface 5 is not particularly limited as long as it is an angle at which a curved surface is formed on the reflective surface 5. The magnitude of the curvature of the curved surface is also not particularly limited. As the reflective pieces, not only the glass mirror pieces 6 but also film mirror pieces made of high-precision transparent polyester film can be used.

[0016] A characteristic feature of this embodiment is that slit-shaped gaps 7 are provided between the multiple glass mirror pieces 6 arranged on the elastic sheet 4. The width of these gaps 7 is not particularly limited, but as shown in FIG. 4, it is necessary that the width is such that the ends of adjacent glass mirror pieces 6 do not overlap each other when the solar cooker 1 is tilted backward to curve the reflective surface 5. The gaps 7 are provided continuously around the entire circumference of each glass mirror piece 6, and one surface of the underlying elastic sheet 4 can be seen through the gaps 7 under normal conditions. The formation of these gaps 7 makes it possible to accommodate changes in the shape of the reflective surface 5 between its flat shape and its curved shape.

[0017] The frame 3 that holds the periphery of the reflector 2 includes a pair of plate-like members 8a, 8b that sandwich the elastic sheet 4 from both sides, and a frame member 9 that is arranged along the periphery of the plate-like members 8a, 8b, as shown in FIG. 3. The pair of plate-like members 8a, 8b are made of rectangular aluminum plates, for example, with a length and width of about 1000×1000 mm and a thickness of about 2.0 mm, and have an opening 10 in the center that largely exposes the reflector 2. The reflecting surface 5 is formed by arranging a large number of glass mirror pieces 6 on the elastic sheet 4 exposed from the opening 10. In addition, a clamping portion 11 that clamps the elastic sheet 4 is provided around the opening 10. In this embodiment, the entire plate-like members 8a, 8b except for the opening 10 are the clamping portion 11, so that the elastic sheet 4 can be clamped more reliably. The double-sided tape 21 is applied to each of the clamping portions 11 of both plate-like members 8a and 8b in advance, and the elastic sheet 4 is placed on the plate-like member 8b on the back side, and one side of the elastic sheet 4 is adhered to the plate-like member 8b. Next, the plate-like member 8a on the front side is placed on top of the elastic sheet 4, and the other side of the elastic sheet 4 is adhered to the plate-like member 8a. In this way, the elastic sheet 4 is fixed to the plate-like members 8a and 8b by adhering the periphery of the elastic sheet 4 to the pair of plate-like members 8a and 8b. When the elastic sheet 4 is placed on the plate-like member 8b on the back side and adhered, it is not necessary to adhere the elastic sheet 4 while pulling it. By simply placing the elastic sheet 4 on the plate-like member 8b, it is possible to provide the elastic sheet 4 with an appropriate amount of flexure. The plate-like members 8a and 8b are not limited to aluminum plates. Weight reduction can be achieved by using plywood or the like.

[0018] In this embodiment, a reflecting surface 5 is formed on one surface of the elastic sheet 4 held by the pair of plate-like members 8a and 8b. The reflecting surface 5 is formed by adhering a plurality of glass mirror pieces 6 one by one to the circular elastic sheet 4 exposed from the opening 10 of the plate-like member 8a on the front side. At this time, a grid of vertical and horizontal lines corresponding to the shape of the glass mirror pieces 6 and the width of the gaps 7 is provided on one surface of the elastic sheet 4. In this way, a large number of glass mirror pieces 6 can be easily adhered to predetermined positions. Also, gaps 7 of a predetermined width can be reliably provided around the glass mirror pieces 6. As a result, a reflecting surface 5 consisting of a collection of a large number of glass mirror pieces 6 arranged evenly vertically and horizontally is formed in the opening 10.

[0019] As shown in FIG. 1, glass mirror pieces 6 processed into triangles, trapezoids, or the like according to the circumferential shape are arranged on the circumferential part of the opening 10. On the other hand, glass mirror pieces 6 processed into rectangular shapes are arranged in the central part excluding the circumferential part, so that the entire opening 10 is filled with glass mirror pieces 6. In this embodiment, a plurality of glass mirror pieces 6 are arranged vertically and horizontally in the circular opening 10, and in the vertical arrangement, the glass mirror pieces 6 are arranged with a shift of 1 / 2, but as in the horizontal arrangement, there is no problem if they are arranged in a straight line with joints. In addition, it is possible to arrange the glass mirror pieces 6 radially from the center of the opening 10, or to arrange the glass mirror pieces 6 in a spiral shape, without being limited to the vertical and horizontal arrangement.

[0020] The frame member 9 is disposed along the periphery of a pair of plate-like members 8a, 8b that sandwich the reflector 2. The frame member 9 is formed by, for example, arranging four aluminum square pipes 12a-12d, two on each of the top, bottom, left and right, and connecting the ends of each square pipe 12a-12d with corner joints 13 to form a square frame. The size of the frame member 9 corresponds to the overall shape of the plate-like members 8a, 8b. Therefore, by adhesively fixing the outer peripheries of the plate-like members 8a, 8b to the frame member 9, the independence of the plate-like members 8a, 8b is ensured, and at the same time, the flatness of the reflector 2 is maintained.

[0021] In this embodiment, the frame member 9 has a rectangular storage space 14 surrounded by four square pipes 12a to 12d. As shown in Figs. 2 and 3, a support 15 for supporting the reflector 2 and the frame 3 in a backward tilted position is stored in the center of this storage space 14, and tripods 17 for installing a cooking appliance are stored on both the left and right sides. The support 15 has an upper end rotatably attached to the square pipe 12a at the upper side, and a lower end abuts against the square pipe 12b at the lower side. It also has a pair of nuts 22 at the top and a joint 23 at the middle. When using the solar cooker 1, the abutment at the lower end of the support 15 is removed to make it rotatable, and as shown in Fig. 4, the length of the support 15 is adjusted with the nuts 22 and the joint 23 to support the reflector 2 and the frame 3 in a backward tilted position at an appropriate angle. The tripod 17 also consists of six legs 18 stored on each side, three on each side. When using the tripod 17, the left and right legs 18 are connected one by one to assemble the tripod 17. At this time, the tripod 17 is erected by connecting the round rings 24 attached to the tops of the three legs 18 with shackles (not shown). The support legs 19 are stored inside the square pipe 12b at the lower side. When using the solar cooker 1, the support legs 19 are attached to the outside of the square pipe 12b at the lower side to support the frame member 9. In this embodiment, the support posts 15 and legs 18 are made of fully threaded shafts.

[0022] Next, a method of using the solar cooker 1 having the above-mentioned configuration will be described. When the reflector 2 and the frame 3 are in an upright position, the reflecting surface 5 does not bend and maintains a flat shape, so the solar cooker 1 has a thin overall shape and can be carried by holding both sides of the frame 3. In addition, since the entire unit is not bulky, it is easy to carry in a car. Accessories such as the support 15, tripod 17, and support legs 14 can also be carried without forgetting. As shown in FIG. 4, by tilting the reflector 2 and the upper part of the frame 3 backward and maintaining a backward tilted position, a curved reflecting surface 5 is formed at the opening 10 of the frame 3. The curved shape of the reflecting surface 5 varies depending on the upward angle α of the reflecting surface 5 with respect to the vertical axis ax when the frame 3 is in an upright position, as shown in FIG. 4. By reducing the upward angle α, the curved shape of the reflecting surface 5 becomes shallower, and conversely, by increasing the upward angle α, the curved shape of the reflecting surface 5 becomes deeper. This is because when the upward angle α of the reflecting surface 5 is small, the elastic sheet 4 is less deflected, and conversely, when the upward angle α of the reflecting surface 5 is large, the elastic sheet is more deflected. The weight of the glass mirror pieces 6 further deflects the elastic sheet 4, forming a curved reflective surface 5. The closer the sun is to directly overhead, the greater the backward tilt angle of the reflector 2 and frame 3. As a result, the upward angle α of the reflective surface 5 becomes larger and the curved shape becomes deeper, thereby improving the light collection efficiency. The orientation of the frame 3 is adjusted to face the sun, and the backward tilt of the reflector 2 and frame 3 is adjusted by the support 15 so that the sunlight reflected by the reflective surface 5 is efficiently collected on the cooking appliance 16 installed in front of the solar cooker 1.

[0023] The cooking device 16 is preferably one that can easily transfer heat energy from sunlight to the cooking ingredients inside, such as a pot or rice cooker. The cooking device 16 is hung, for example, from a chain 20 hanging from the top of a tripod 17. The chain 20 can also be stored in the storage space 14 of the frame member 9.

[0024] 5(a), (b), and (c) show a solar cooker 31 according to a second embodiment of the present invention. This solar cooker 31 is designed to be more convenient to carry, and the reflector 32 and the frame 33 that holds the periphery of the reflector 32 can be removed. As in the first embodiment, the reflector 32 is composed of an elastic sheet 4 and a reflecting surface 5 formed by an assembly of a plurality of glass mirror pieces 6 arranged on one surface of the elastic sheet 4, and a slit-shaped gap 7 is provided around each glass mirror piece 6. The reflector 32 is formed in an octagonal planar shape, and eight vertices are fixed to the frame 33. The fixing means may be a tie string 34 as in this embodiment, or a hook-shaped means that is hooked and fixed to the frame 33. The arrangement shape of the glass mirror pieces 6 that form the reflecting surface 5 corresponds to the octagonal shape of the elastic sheet 4, but is not limited to this shape and may be formed, for example, in a circular shape.

[0025] On the other hand, the frame 33 is formed in a circular shape so as to surround the periphery of the reflector 32. The entire frame is made of aluminum pipes, which reduces weight. The frame 33 is formed in a circular shape by connecting eight divided pipe members 35 with connecting pieces 36.

[0026] In the solar cooker 31 according to this embodiment, the reflector 32 and the frame 33 are separated when transporting, and are assembled and integrated when in use. Also, as shown in Fig. 5(b), the frame 33 is divided into eight pipes 35, which further improves the convenience of transporting. Furthermore, the reflector 32 is formed of a flexible elastic sheet 4 and an assembly of glass mirror pieces 6 arranged on one surface of the sheet with gaps 7 between them, so that it can be folded and carried as shown in Fig. 5(c).

[0027] In the solar cooker 31 of this embodiment, the backward tilted position of the reflector 32 and frame 33 is supported by pillars similar to those in the first embodiment, so that the central portion of the octagonal reflector 32 bends and the reflecting surface 5 is formed into a curved shape as shown by the dashed line. [Explanation of symbols]

[0028] 1. Solar Cooker 2 Reflector 3 Frame 4 Elastic sheet 5 Reflective surface 6 Glass mirror pieces 7. Gap 8a, 8b Plate-shaped members 9 Frame members 10 Opening 11 Clamping part 12a~12d Square pipe 13 Corner joint 14 Storage space 15 Posts 16 Cooker 17 Tripod 18 Connecting legs 19 Support legs 20 Chain 21 Double-sided tape 22 Nut 23 Joint 24 Round Ring 31 Solar Cooker 32 Reflector 33 Frame 34 Tie 35 Pipe material 36 Linked Pieces

Claims

1. A reflector and A frame that holds a periphery of the reflector, The reflector includes an elastic sheet whose periphery is held by the frame, and a reflecting surface formed on one side of the elastic sheet, In this solar cooker, the reflective surface is formed by an assembly of a plurality of reflective pieces, and gaps are provided between adjacent reflective pieces.

2. 2. The solar cooker according to claim 1, wherein each of the plurality of reflective pieces is a glass mirror piece, the back surface of each glass mirror piece being adhered to one surface of the elastic sheet.

3. 3. The solar cooker according to claim 2, wherein the glass mirror pieces are made of thin rectangular pieces, and the reflective surface is formed by an assembly of a plurality of glass mirror pieces arranged lengthwise and widthwise.

4. 2. The solar cooker according to claim 1, wherein the gaps are formed in the shape of slits along the periphery of each reflective piece.

5. The solar cooker according to claim 1 , wherein the reflecting surface is curved by its own weight by maintaining the reflecting plate and the frame in a backward tilted position.

6. 2. The solar cooker according to claim 1, further comprising a support for maintaining the reflector and the frame in a rearward tilted position.

7. The solar cooker described in claim 1, wherein the frame comprises a pair of plate-shaped members having an opening in the center to expose the reflective surface and having clamping portions around the periphery to sandwich the elastic sheet, and a frame member arranged along the periphery of the plate-shaped members.

8. The solar cooker according to claim 7, wherein the opening of the plate member is circular.

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