JP2016111192A - Solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress breakdown of a power generation element when receiving a shock from the outside.SOLUTION: In a solar cell module 1 including a lamination structure where a sealing layer L2, sealing a plurality of power generation elements 2, is laminated between a surface layer L1 and a back layer L3, and the power generation elements 2 are arranged in the sealing layer L2, the lamination structure consists of a first lamination 11 consisting of a part laminating the power generation elements 2, and a second lamination 12 consisting of a part not laminating the power generation elements 2, and a hollow part 50 is provided in the back layer L3 of the second lamination 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to the structure of a solar cell module.

  Conventionally, a solar cell module having a multilayer structure in which a surface layer, a sealing layer, and a back layer are laminated is well known. In this structure, the power generation element is laminated between the surface layer and the back layer, and the power generation element is sealed by the sealing layer.

  In general, since the solar cell module is installed in an environment where sunlight can be directly received, there is a case where a hail falls and hits the surface layer directly. Therefore, in order to improve the durability of the solar cell module, in addition to being excellent in weather resistance, it is desired that the solar cell module is not easily damaged by an impact caused by falling objects. Therefore, a solar cell module configured to mitigate an impact received from the outside is disclosed in the following patent document.

  Patent Document 1 describes that the sealing material constituting the sealing layer reduces the impact acting on the power generation element by having flexibility. Patent Document 2 describes that an adhesive layer and an insulating layer constituting a sealing layer are elastic and have shock absorption.

  Patent Document 3 describes that the adhesive between the solar cell panel and the roof rail serves as a buffer material that absorbs external impact applied to the solar cell panel. Patent Document 4 describes that a member that rotatably supports a solar cell panel includes an elastic body in a portion that contacts the back surface of the solar cell panel. Patent Document 5 describes that a spacer made of a resin body absorbs an external impact on the lower surface of the solar cell main body.

JP 2004-79823 A JP 2014-011270 A JP 2012-033573 A JP 2004-165556 A Japanese Utility Model Publication No. 04-63655

  However, in the configuration of each patent document, when a bag or the like hits the surface layer directly, a portion of the solar cell module where the power generating elements are stacked may be greatly bent or greatly deformed. Therefore, an excessive bending stress may act on the power generation element.

  Moreover, when mounting in a vehicle like patent document 3, in order to improve a fuel consumption in addition to durability, it is also desired that a solar cell module is lightweight. If a dedicated impact absorbing member is provided separately from the solar cell module as in Patent Documents 4 and 5, the number of parts increases and the weight increases.

  Furthermore, it may be desirable not to provide a power generation element near the periphery of the solar cell module in order to improve durability such as corrosion and erosion prevention and to realize long-term guarantee of power generation efficiency. Are known.

  The present invention has been made in view of the above circumstances, and has an object to provide a solar cell module that is light in weight and capable of suppressing damage to a power generating element when subjected to an external force such as an impact. To do.

  In order to achieve the above object, the invention according to claim 1 is configured in a laminated structure in which a sealing layer is laminated between a surface layer and a back surface layer, and the sealing layer has a sealing structure. In the solar cell module in which a plurality of the generated power generation elements are arranged, the stacked structure includes a first stacked portion including a portion where the power generation elements are stacked and a second stack including a portion where the power generation elements are not stacked. The back surface layer of the second stacked portion is provided with a hollow portion.

  According to a second aspect of the present invention, in the first aspect of the invention, the hollow portion is provided inside a connection portion that contacts a member that supports the laminated structure in the back surface layer. It is a battery module.

  According to a third aspect of the present invention, in the second aspect of the invention, the connecting portion is formed in a protruding portion in which a part of the back layer protrudes toward the opposite side of the surface layer, and the hollow The part is a solar cell module characterized in that the part is provided inside the protrusion.

  According to a fourth aspect of the present invention, in the invention of the third aspect, the protruding portion includes a side wall extending toward the opposite side of the surface layer as a wall portion defining the hollow portion, It is a solar cell module characterized by being formed in a flexible structure.

  The invention according to claim 5 is the solar cell module according to claim 4, wherein the flexible structure is a structure in which the thickness of the side wall is thinner than the base end portion of the side wall. .

  The invention according to claim 6 is the solar cell module according to claim 4, wherein the flexible structure is a bellows structure extending in a direction in which the protruding portion protrudes.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the surface layer is constituted by a resin plate, the back layer is constituted by a fiber reinforced resin plate, and the surface layer is externally provided. The solar cell module is configured such that the back layer is deformed so that the shape of the hollow portion changes when subjected to an impact.

  The invention according to an eighth aspect is the invention according to any one of the first to seventh aspects, wherein the outer plate member of the vehicle is configured when mounted on a vehicle, and the hollow portion is an interior of a connection portion attached to the vehicle body structure. It is provided in the solar cell module characterized by the above-mentioned.

  According to the first aspect of the present invention, when the surface layer receives an impact from the outside, the portion of the back layer that forms the hollow portion bends, so that the bending caused by the impact in the second laminated portion having the hollow portion. Can receive stress such as moment. Thereby, the bending moment which acts on a 1st laminated part can be reduced, and it can suppress that an excessive bending stress acts on a power generating element by an impact. Moreover, since a part of back layer is a hollow structure, a solar cell module can be reduced in weight.

  According to the invention of claim 2, in addition to the effect of the above invention, since the hollow portion is located inside the connecting portion of the back surface layer, deformation occurs in the supported portion and the shock absorption is improved. Can do.

  According to the invention of claim 3, in addition to the effects of the invention described above, the connecting portion is formed in the protruding portion and the hollow portion is provided inside the protruding portion, so that the rigidity of the back layer can be ensured and the impact can be ensured. Absorbability can be improved. Moreover, since parts other than a connection part can be made thin in a back surface layer, a solar cell module is weight reduction.

  According to the invention of claim 4, in addition to the effects of the above invention, since the side wall of the protruding portion has a flexible structure, when the surface layer receives an impact from the outside, the side wall is easily deformed, and the hollow protruding portion is stressed. Can concentrate. Thereby, stress, such as the bending moment at the time of an impact, can be received in a 2nd laminated part, and it can suppress that an excessive bending stress acts on the electric power generating element in a 1st laminated part.

  According to the invention of claim 5, in addition to the effects of the above invention, since the bending structure is a structure in which the thickness of the side wall is thinner than the base end portion of the side wall, when the surface layer receives an impact from the outside, Deformation due to the shape of the side wall occurs, and stress can be concentrated on the hollow protrusion.

  According to the invention of claim 6, in addition to the effect of the invention described above, since the flexible structure is a bellows structure, when the surface layer receives an impact from the outside, the deformation due to the shape of the side wall occurs, and the hollow protruding portion Stress can be concentrated on the surface. Furthermore, since the bellows structure extends in the direction in which the protruding portion protrudes, the protruding portion is easily bent.

  According to invention of Claim 7, in addition to the effect of the said invention, a solar cell module can be reduced in weight rather than the case where the surface layer made from glass is provided. Further, when the surface layer receives an impact from the outside, the back surface layer is elastically deformed, and thereafter, the shape of the hollow portion can be elastically restored. Thereby, since it can suppress that the deformation amount of a hollow part reduces when receiving the impact in multiple times, an impact can be absorbed effectively.

  According to the invention of claim 8, in addition to the effects of the invention, when the surface layer forming the outer surface of the vehicle body receives an impact from the outside, the power generation element is excessive in the solar cell module as the outer plate member of the vehicle body. It is possible to suppress a large bending stress from acting.

It is sectional drawing which shows the laminated structure of a solar cell module. (A) is an expanded sectional view for demonstrating a protrusion part and a hollow part. (B) is sectional drawing which shows the part by which the solar cell module is attached to the vehicle body structure as a roof panel. (A) is a perspective view which shows an example of a vehicle body structure. (B) is a rear view of a solar cell module. It is a top view of the vehicle carrying a solar cell module as a roof panel. (A) is sectional drawing which shows the AA cross section of FIG. (B) is sectional drawing which shows the BB cross section of FIG. (C) is sectional drawing which shows CC cross section of FIG. (D) is sectional drawing which shows the DD cross section of FIG. It is sectional drawing which shows the side wall comprised by the bellows structure. It is sectional drawing which shows the modification of a solar cell module. (A) is explanatory drawing which shows a cantilever multilayer beam model. (B) is explanatory drawing which shows the case where the multilayer beam model shown to (a) bends with a temperature change.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the structure of the solar cell module in this specific example. In the following description, the thickness direction of the solar cell module may be described using the upper side and the lower side shown in FIG.

  The solar cell module 1 is formed in a plate-like multilayer structure in which a surface layer L1, a sealing layer L2, and a back layer L3 are laminated. The sealing layer L2 is laminated between a surface layer L1 that forms the surface 1a and a back surface layer L3 that forms the back surface 1b, and a plurality of power generation elements 2 are provided therein. The solar cell module 1 of this specific example is mounted on a vehicle and constitutes a roof panel, and the back surface 1b side is a portion (hereinafter referred to as “connecting portion”) 10 attached to the vehicle body structure, and the surface 1a is the surface of the vehicle. Forming the outer surface. The vehicle inner side and the vehicle outer side shown in FIG. 1 represent the width direction of the vehicle or the front-rear direction of the vehicle.

  The surface layer L1 is constituted by the resin plate 3. The resin plate 3 is formed into a film by a resin material that is transparent and excellent in weather resistance, and is made of a resin material such as polycarbonate (PC), polyethylene terephthalate (PET), or polytetrafluoroethylene (PTFE). Has been. Since the resin plate 3 (PC plate) made of polycarbonate is excellent in weather resistance and lightweight, it is suitable as the surface layer L1 in the solar cell module 1 mounted on a vehicle. Further, the thickness of the surface layer L1 is uniform as a whole.

  The sealing layer L <b> 2 includes a plurality of power generation elements 2 and a sealing material 4. In the sealing layer L <b> 2, the plurality of power generation elements 2 are regularly arranged and sealed with the sealing material 4. The power generation element 2 is a known power generation element such as a silicon-based cell. The sealing material 4 is formed into a film by a transparent resin material having elasticity and adhesiveness, and is made of a well-known resin as a cell sealing material such as ethylene vinyl acetate copolymer (EVA) or polyolefin. . Further, the thickness of the sealing layer L2 is uniform as a whole.

  For example, the power generating element 2 is sealed by laminating the power generating element 2 from above and below both sides by two sealing materials 4 formed in a film shape. In this case, since the sealing material 4 is in contact with the power generation element 2, the impact acting on the power generation element 2 can be reduced by the elasticity of the sealing material 4. Moreover, since the back surface of the resin plate 3 and the surface of the sealing material 4 are joined by the adhesiveness of the sealing material 4, the interface between the surface layer L1 and the sealing layer L2 is formed on the joint surface. Similarly, since the back surface of the sealing material 4 and the surface of the back sheet 5 are joined, the interface between the sealing layer L2 and the back layer L3 is formed on the joining surface.

  In addition, in the sealing layer L2, the adjacent power generation elements 2 are electrically connected to each other by a conductive wire (not shown), and as a whole of the solar cell module 1, a group of power generation elements 2 are electrically connected in series or in parallel. It is connected.

  In the solar cell module 1, in order to improve durability and realize long-term guarantee, the power generation element 2 is not provided in the vicinity of the peripheral edge portion 1c in the sealing layer L2. Therefore, the sealing layer L2 includes a single-layer structure portion composed only of the sealing material 4 as in the vicinity of the peripheral portion 1c, and a three-layer structure composed of the power generating element 2 and the sealing material 4 as in the center side. It consists of a structural part. Furthermore, since the power generating elements 2 are arranged at a predetermined interval in the sealing layer L2, there is a single-layer structure portion composed only of the sealing material 4 even in the vicinity of the peripheral portion 1c.

  In addition, a predetermined range from the peripheral portion 1c toward the center side may be described as a peripheral area. It can be said that the peripheral area is an area where it is desirable not to install the power generation element 2. An area other than the peripheral area is an area where the power generating element 2 can be installed. The area is a range defined by the width direction and the front-rear direction of the vehicle when the solar cell module 1 is a roof panel.

  Therefore, of all the areas of the solar cell module 1, the portion where the power generation element 2 is laminated in the laminated structure from the front surface 1a to the back surface 1b is defined as the first laminated portion 11, and the portions other than the first laminated portion 11 are designated. Let it be the second laminated portion 12. That is, the 2nd lamination | stacking part 12 is a part which is the lamination | stacking structure from the surface 1a to the back surface 1b, and the electric power generation element 2 is not laminated | stacked. The second stacked unit 12 constitutes at least the peripheral area of the solar electronic module 1.

  Specifically, the first stacked portion 11 is formed in a five-layer structure, and the portion of the surface layer L1 facing the surface of the power generating element 2 and the power generating element 2 of the sealing layer L2 are stacked. And a portion of the back layer L3 facing the back surface of the power generating element 2. On the other hand, the second laminated portion 12 is formed in a three-layer structure, and has a single-layer structure including only a portion of the surface layer L1 that does not face the power generating element 2 and a sealing material 4 of the sealing layer L2. And a portion of the back layer L3 not facing the power generating element 2.

  The back layer L3 is constituted by the back sheet 5. The back sheet 5 is formed in a plate shape by a material that can be elastically deformed or plastically deformed. For example, the backsheet 5 is made of a fiber that is rigid and lightweight, such as fiber reinforced resin (FRP), carbon fiber reinforced resin (CFRP), or aluminum. It is composed of materials. Since the back sheet 5 (FRP plate) made of fiber reinforced resin is lightweight and elastically deformable, and has the rigidity necessary for the outer plate member of the vehicle body, the back surface of the solar cell module 1 mounted on the vehicle. Suitable as the layer L3.

  The back sheet 5 is provided with a hollow portion 50 in which a part on the back surface 1b side is formed in a hollow structure. Since the backsheet 5 can be elastically deformed or plastically deformed, when the surface layer L1 receives an impact from the outside, the back surface layer L3 can be deformed so that the shape of the hollow portion 50 changes. That is, the hollow part 50 is a structure for absorbing an impact by the back surface layer L3.

  Furthermore, the back sheet 5 is provided with a protruding portion 52 that protrudes downward from the flat plate portion 51. The flat plate portion 51 forms a bonding surface with the sealing material 4 over the entire surface, and the surface of the flat plate portion 51 (the bonding surface with the sealing material 4) is a flat surface. The back surface 1 b of the solar cell module 1 is formed in a concavo-convex surface by a concave surface 51 a formed from the back surface of the flat plate portion 51 and a convex surface 52 a formed from the back surface of the protruding portion 52. That is, the thickness of the back surface layer L3 is formed so that the portion where the protruding portion 52 is provided is thicker than the portion consisting only of the flat plate portion 51. The hollow portion 50 is provided inside the protruding portion 52. That is, the back sheet 5 has a relatively thick portion formed in a hollow structure, and the hollow portion 50 is provided in a portion constituting the second laminated portion 12 in the back layer L3.

  As shown in FIG. 2A, the protruding portion 52 includes a pair of side walls 52b extending downward from the flat plate portion 51 and a bottom wall 52c forming a convex surface 52a. Each side wall 52b is connected via the bottom wall 52c, and the hollow part 50 is divided by the inner wall surface of each side wall 52b and the inner wall surface of the bottom wall 52c.

  The side wall 52b is formed in a flexible structure. The bending structure is a structure for easily causing the protrusion 52 to bend due to the shape of the side wall 52b when the surface layer L1 receives an impact from the outside. The bending structure of this specific example is formed in a thin structure by the cut portion 52d as compared to the thickness of the side wall 52b and the base end portion of the side wall 52b. The base end portion is a side wall portion corresponding to the position on the most surface side of the hollow portion 50. The cut portion 52d is formed so that the wall surface of the side wall 52b has a valley shape with respect to the vertical direction. That is, the thickness of the side wall 52b is configured to gradually change by the cut portion 52b. Moreover, the notch part 52d is provided in the outer wall surface and inner wall surface of the side wall 52b. In addition, the dotted line shown to Fig.2 (a) is an auxiliary line parallel to an up-down direction.

  Thus, since the side wall 52b has a bending structure, the stress generated in the solar cell module 1 due to the external impact of the surface layer L1 can be concentrated on the hollow protrusion 52. Therefore, the second laminated portion 12 having the protruding portion 52 functions as a structure for receiving (absorbing) stress such as a bending moment generated by impact. Therefore, since the second laminated portion 12 receives a bending moment at the time of impact, the bending moment acting on the power generating element 2 in the first laminated portion 11 can be reduced. That is, it is possible to prevent the power generating element 2 from being damaged by the bending moment at the time of impact.

  For example, when the back sheet 5 is made of an elastic fiber reinforced resin plate (FRP plate), the protruding portion 52 is bent and elastically deformed by a bending moment generated by an impact load. Since the protrusion 52 can return elastically, the shape of the hollow portion 50 deformed at the time of impact returns to the shape before the impact thereafter. Thereby, even when the surface layer L1 receives impacts a plurality of times, it is possible to suppress the reduction of the deformable amount of the hollow portion 50, so that the impacts can be effectively absorbed.

  Moreover, since the hollow part 50 is provided in the inside of the protrusion part 52, the hollow part 50 is located in the lower side of the back surface layer L3 relatively. As shown in FIG. 2A, when the hollow portion 50 is positioned below the concave surface 51a, the portion of the protruding portion 52 extending from the concave surface 51a to the hollow portion 50 in the vertical direction has a predetermined thickness. The thickness Δd is thicker than the flat plate portion 51. In addition, the thickness of the protruding portion 52 including the hollow portion 50 (the length from the concave surface 51a of the flat plate portion 51 to the convex surface 52a of the protruding portion 52 in the vertical direction) is a predetermined thickness D (> Δd) from the flat plate portion 51. Also thick.

  And when the solar cell module 1 comprises a roof panel as shown in FIG.2 (b), in the 2nd lamination | stacking part 12 in a peripheral area, the part (connection part 10) where the back surface layer L3 is connected to a vehicle body structure. ) The connecting portion 10 in the peripheral area is attached to the roof side rail 21 via the molding 6, and the convex surface 52a of the protruding portion 52 is bonded to the upper surface of the molding 6 with an adhesive. In short, the contact area between the convex surface 52a and the molding 6 becomes the connection portion 10, and the hollow portion 50 is provided inside the portion of the back layer L3 that becomes the connection portion 10. Note that the molding 6 is not essential, and when the molding 6 is not used, a contact area between the convex surface 52a and the roof side rail 21 is a connecting portion.

  As shown to Fig.3 (a), in the vehicle body structure 20 to which the solar cell module 1 is attached, as a member which supports the solar cell module 1 used as a roof panel, the roof side rail 21, the front header 22, and the rear header 23 are shown. And a roof center reinforcement (hereinafter referred to as “center R / F”) 24 and a roof dental reinforcement (hereinafter referred to as “dent R / F”) 25.

  The roof side rail 21 constitutes a side member integrated with the front pillar, the center pillar, and the rear pillar. The front header 22 is attached to the front pillar, and the rear header 23 is attached to the rear pillar. The center R / F 24 and the dent R / F 25 are attached to the roof side rail 21. Further, one dent R / F 25 is provided between the front header 22 and the center R / F 24 and two between the rear header 23 and the center R / F 24 in the longitudinal direction of the vehicle.

  As shown in FIG. 3B, the solar cell module 1 is provided with a connecting portion 10 at a position corresponding to the vehicle structure 20. As the connection part 10 in the peripheral area, a first connection part 10 a attached to the roof side rail 21, a second connection part 10 b attached to the front header 22, and a third connection part 10 c attached to the rear header 23 are provided. ing. Furthermore, as the connection part 10 other than the peripheral area, a fourth connection part 10d attached to the center R / F 24 and a fifth connection part 10e attached to the dent R / F 25 are provided. And the hollow parts 50 in each connection part 10a-10e are communicating. In short, the hollow part 50 is provided in the position corresponding to the vehicle body structure 20 in the solar cell module 1, and the back layer L3 is formed in a series of hollow structures.

  And as shown in FIG. 4, when the solar cell module 1 is attached to the vehicle body structure 20, the one solar cell module 1 comprises the whole roof panel as an outer plate member of a vehicle. An attachment structure between the connecting portion 10 and the vehicle body structure 20 in this case is shown in FIG. In FIG. 5, the vehicle body structure 20 and the connection portion 10 are illustrated separately.

  As shown in FIG. 5A, at the front end portion of the solar cell module 1, the convex surface 52 a of the second connection portion 10 b is bonded to the upper surface of the front header 22 by an adhesive 41. The second connection portion 10 b is supported by the front header 22.

  As shown in FIG. 5B, the convex surface 52a of the fourth connecting portion 10d is in contact with the upper surface of the center R / F 24 in the vicinity of the middle portion of the solar cell module 1 in the front-rear direction. That is, the fourth connecting portion 10d is supported by the center R / F 24.

  As shown in FIG. 5C, the convex surface 52a of the fifth connecting portion 10e is in contact with the upper surface of the dent R / F 25, and the fifth connecting portion 10e is supported by the dent R / F 25. In this case, the dent R / F 25 is configured to have a lower rigidity than the other vehicle body structures 20 such as the front header 22 in order to prevent the roof panel from being dented by falling objects. Therefore, the dent R / F 25 can be bent more than the front header 22 by an impact load. Therefore, the fifth connection portion 10e supported by the dent R / F 25 may be configured to have a smaller amount of deflection (deformation amount) than the other connection portions 10a to 10d. For example, the fifth connecting portion 10e is formed so that the volume of the hollow portion 50 is smaller than that of the other connecting portions 10a to 10d, and the deformation amount of the fifth connecting portion 10e is smaller than that of the other connecting portions 10a to 10d. May be configured. In other words, when the rigidity of the vehicle body structure 20 is high, the connection portion 10 having a large deflection amount can be formed. On the contrary, when the rigidity of the vehicle body structure 20 is low, the connection portion 10 having a small deflection amount can be formed.

  As shown in FIG. 5D, at the rear end of the solar cell module 1, the convex surface 52 a of the third connection portion 10 c is bonded to the upper surface of the rear header 23 by the adhesive 41. The third connection portion 10 c is supported by the rear header 23.

  Thus, since the vehicle body structure 20 is a member that supports the solar cell module 1, when a bag or the like directly hits the surface layer L 1, the hollow protrusion 52 is deformed by the impact load, and the vehicle body structure 20 Is receiving.

  As described above, according to the solar cell module of this specific example, when the surface layer receives an impact from the outside, the portion of the back layer that forms the hollow portion is deformed, and thus may have a hollow portion. The second laminated part can absorb the impact. That is, at the time of impact, the back layer of the second laminated portion is bent and the bending moment is applied to the second laminated portion, so that the bending moment acting on the first laminated portion can be reduced. Therefore, damage to the power generation element due to impact can be suppressed. Moreover, since the side wall which divides the hollow part is a bending structure, stress can be concentrated on the back layer side of a 2nd laminated part. Furthermore, since a part of back layer is formed in the hollow structure, a solar cell module can be reduced in weight.

  The solar cell module according to the present invention is not limited to the specific examples described above, and can be appropriately changed without departing from the object of the present invention.

  For example, the flexure structure of the present invention is not limited to the structure in which the cut portions 52d are provided on the inner wall surface and the outer wall surface of the side wall 52b as in the specific examples described above, and at least of the inner wall surface and the outer wall surface. The structure provided in either one may be sufficient. As a modification, as shown in FIG. 6A, a side wall 52b in which a notch 52d is provided only on the outer wall surface may be used.

  As another modification, as shown in FIG. 6B, the bending structure of the side wall 52b may be formed in a bellows structure 52e extending in a direction in which the protruding portion 52 protrudes. The bellows structure 52e is a structure in which the thickness of the side wall 52b is constant and the cross-sectional area of the hollow portion 50 increases or decreases along the thickness direction of the back layer L3. In the case of the bellows structure 52e, when the surface layer L1 receives an impact, the amount of deformation (the amount of expansion / contraction in the vertical direction) due to the shape of the side wall 52c increases more than in the case of the cut portion 52d. Absorption performance is improved. Furthermore, in this invention, the shape of the hollow part 50 is not specifically limited. Note that the dotted lines shown in FIGS. 6A and 6B are auxiliary lines parallel to the vertical direction. Moreover, the hollow part 50 is formed in the flat plate part 51, and the protrusion part 52 does not need to be provided. In this case, the contact area between the flat plate portion 51 and the vehicle body structure is the connection portion.

  Moreover, in the solar cell module of this invention, the hollow part 50 should just be provided in the 2nd lamination | stacking part 12 in the peripheral area at least among the solar cell modules 1. FIG. As a modification thereof, as shown in FIG. 7, a configuration in which the hollow portion 50 is provided only in the peripheral area may be employed. That is, even if it is the 2nd lamination | stacking part 12, if it is outside a peripheral area, it becomes the structure by which the hollow part 50 and the protrusion part 52 are not provided in the back surface layer L3.

  In particular, when the solar cell module is mounted on a vehicle, an outer plate member such as a bonnet or a trunk can be configured without being limited to the roof panel. Furthermore, the solar cell module may constitute an outer plate member such as a door panel or a side panel.

  In addition, at least the second laminated portion 12 in the peripheral area is provided with the protruding portion 52 on the back layer L3, so that the second laminated portion 12 can be formed thicker than the first laminated portion 11. Thereby, when the solar cell module 1 receives a temperature change, it is possible to suppress a deformation amount (thermal deformation amount) caused by a difference in linear expansion coefficient among members constituting each layer of the multilayer structure. Therefore, according to the specific example and the modification described above, it is possible to suppress the amount of thermal deformation due to the multilayer structure and to absorb an external impact. In the following, with reference to FIG. 8, a supplementary description will be given of thermal deformation that occurs in the multilayer structure.

(Supplementary explanation)
In the multilayer structure in which the interface of each layer is joined as in the solar cell module 1, the magnitude of the axial force generated in each layer and the direction of action differ when the temperature changes due to the difference in linear expansion coefficient among the constituent members of each layer. Therefore, thermal deformation occurs. FIG. 8A shows a multilayer beam model of a cantilevered n-layer beam. FIG. 8B shows a multilayer beam model deformed by a temperature change.

As shown in FIG. 8A, when the multi-layer beam model of the n-layer beam is subjected to a temperature change, the strain due to thermal expansion (hereinafter referred to as “thermal strain”) ε ^′ _i and the axial force Pi in the _i-layer . strain (hereinafter "axial strain" hereinafter) ε ^'' _i, bending moment M _i by strain (hereinafter "bending strain" as) ε ^''_'i occurs.

The strain ε _i generated in each layer can be represented by the sum of the thermal strain ε ^′ _i , the axial strain ε ^″ _i, and the bending strain ε ^{″ ″} _i, and therefore can be represented by the following formula 1.

In equation (1), α _i is a linear expansion coefficient, ΔT is a temperature change, A _i is a cross-sectional area, E _i is a Young's modulus, P _i is an axial force, and R is a radius of curvature at the neutral plane of each layer. , T _i represent the thickness of each layer. Since the thickness t _{i of} each layer is smaller than the radius of curvature R _i , and it can be assumed that the radius of curvature R _i is almost equal in any layer, the same radius of curvature R can be used for all layers. Δ shown in FIG. 8B represents the deflection.

  Since the strain at the joint surface becomes equal from the continuity of the strain at the joint surface between the two layers, it can be expressed by the following formula 2.

  Further, the following formula 3 can be obtained from the balance of the axial force.

  The relationship among the bending moment, bending stiffness, and radius of curvature in all layers can be expressed by the following equation 4 from the elastic curve equation.

In the above formula 4, M _i represents a bending moment generated in each layer, E _i I _i represents a bending rigidity, and I _i represents a cross-sectional secondary moment. The bending moment in all layers shown in the above formula 4 can be expressed by the following formula 5 from the balance of the bending moment.

Y in the above formula 5 represents the distance from the neutral plane to the surface of the entire n-layer beam. Further, the stress σ _i generated in each layer is obtained by multiplying the strain generated in each layer, that is, the Young's modulus E _{i of} each layer by the above formula 1, but the thermal strain ε ^′ _i does not cause a stress. Can be expressed as:

  As described above, the solar cell module 1 has a multilayer structure and thus undergoes thermal deformation. However, since the second laminated portion 12 in the peripheral area is thicker than the first laminated portion 11 as described above, the amount of thermal deformation. Can be suppressed.

  Specifically, since the portion constituting the second laminated portion 12 in the back layer L3 is thicker than the portion constituting the first laminated portion 11, the stresses generated in the laminated portions 11 and 12 obtained from the above formula 6 are A close value. Therefore, when the curvature radii of the stacked portions 11 and 12 are obtained using the above formula 4, the curvature radii are close to each other. In this case, the curvature radius of the second laminated portion is increased by forming the second laminated portion 12 thick. The close value includes a case where the radii of curvature coincide with each other in each of the stacked portions 11 and 12 or a case where stresses coincide. That is, it represents that the difference in the radius of curvature R or the difference in stress between the stacked portions 11 and 12 becomes a value within a predetermined range including zero.

More specifically, the first laminated portion 11 includes the first layer L ₁₁ (α ₁₁ , E ₁₁ , A ₁₁ ) made of the resin plate 3 and the second layer L ₁₂ (α made of the surface side sealing material 4. ₁₂ , E ₁₂ , A ₁₂ ), the third layer L ₁₃ (α ₁₃ , E ₁₃ , A ₁₃ ) made of the power generating element 2, and the fourth layer L ₁₄ (α ₁₄ , made of the sealing material 4 on the back side. E ₁₄ , A ₁₄ ) and a fifth layer L ₁₅ (α ₁₅ , E ₁₅ , A ₁₅ ) composed of the backsheet 5. Sectional area A ₁₁ to A ₁₅ is determined by the thickness t ₁₁ ~t ₁₅ of each layer.

The second laminated portion 12 includes a first layer L ₂₁ (α ₂₁ , E ₂₁ , A ₂₁ ) made of the resin plate 3 and a second layer L ₂₂ (α ₂₂ , E ₂₂ , A ₂₂ ) made only of the sealing material 4. ) And a third layer L ₂₃ (α ₂₃ , E ₂₃ , A ₂₄ ) made of the backsheet 5. Sectional area A ₂₁ to A ₂₃ is determined by the thickness t ₂₁ ~t ₂₃ of each layer.

Each laminate section 11 and 12, the thickness t ₂₁ = t ₁₁ for the surface layer L1, the thickness of the sealing layer _{L2 t 22 = t 12 + t} 13 + t 14, relationship between the thickness t _23> t ₁₅ for the rear layer L3 Holds. The linear expansion coefficient α and Young's modulus E are specific to the material. Therefore, in each of the first layers L ₁₁ and L _{21 made of} the resin plate 3, the linear expansion coefficient α ₁₁ = α ₂₁ and the Young's modulus E ₁₁ = E ₂₁ are obtained. Similarly, in each of the second layers L ₁₂ and L ₂₂ and the fourth layer L ₁₄ made of the sealing material 4, the linear expansion coefficient α ₁₂ = α ₁₄ = α ₂₂ and the Young's modulus E ₁₂ = E ₁₄ = E ₂₂ Become. In the fifth layer L ₁₅ and the third layer L _{23 made of the} backsheet 5, the linear expansion coefficient α ₁₅ = α ₂₃ and the Young's modulus E ₁₅ = E ₂₃ are obtained.

For example, in the solar cell module 1, the resin plate 3 is composed of a PC plate, the power generating element 2 is composed of crystalline silicon, the sealing material 4 is composed of an ethylene vinyl acetate copolymer, and the back sheet 5 is composed of an FRP plate. In this case, the first laminated portion 11 has a linear expansion coefficient α ₁₅ <α ₁₂ << α ₁₁ <α ₁₂ = α ₁₄ .

And when the solar cell module 1 receives a temperature change, each lamination | stacking part 11 and 12 will generate | occur | produce the distortion | strain by thermal expansion, the axial force P will arise in each layer, and a bending moment will arise. In this case, in the first laminated portion 11, the axial forces P ₁₁ , P ₁₂ and P ₁₄ generated in the first, second and fourth layers L ₁₁ , L ₁₂ and L ₁₄ become tensile loads, and the third and fifth layers Axial forces P ₁₃ and P ₁₅ generated at L ₁₃ and L ₁₅ are compression loads. Further, in the second laminate section 12, first, it is the second layer L _21, the axial force P ₂₁ occurring L _22, P ₂₂ is tensile load, axial force P ₂₃ is the compressive load occurring in the third layer L ₂₃ . Thereby, a bending moment is generated in each of the stacked portions 11 and 12 as a whole.

  DESCRIPTION OF SYMBOLS 1 ... Solar cell module, 2 ... Electric power generation element, 3 ... Resin board, 4 ... Sealing material, 5 ... Back sheet, 10 ... Connection part, 11 ... 1st laminated part, 12 ... 2nd laminated part, 20 ... Vehicle structure 50 ... hollow part, 52 ... projecting part, 52b ... side wall, L1 ... surface layer, L2 ... sealing layer, L3 ... back layer.

Claims (8)

In a solar cell module that is configured in a stacked structure in which a sealing layer is stacked between a surface layer and a back layer, and a plurality of sealed power generation elements are arranged in the sealing layer,
The laminated structure is
A first laminated portion comprising a portion where the power generating elements are laminated;
It consists of a second laminated part consisting of a part where the power generating element is not laminated,
A hollow part is provided in the back layer of the second lamination part, The solar cell module characterized by things.   The solar cell module according to claim 1, wherein the hollow portion is provided in a connection portion that contacts a member that supports the laminated structure in the back surface layer. The connecting portion is formed in a protruding portion in which a part of the back layer protrudes toward the side opposite to the surface layer,
The solar cell module according to claim 2, wherein the hollow portion is provided inside the protruding portion. The protruding portion includes a side wall extending toward the opposite side of the surface layer as a wall portion defining the hollow portion,
The solar cell module according to claim 3, wherein the side wall is formed in a flexible structure.   The solar cell module according to claim 4, wherein the flexible structure is a structure in which a thickness of the side wall is thinner than a base end portion of the side wall.   The solar cell module according to claim 4, wherein the flexible structure is a bellows structure extending in a direction in which the protruding portion protrudes. The surface layer is composed of a resin plate,
The back layer is composed of a fiber reinforced resin plate,
The said back surface layer is comprised so that the shape of the said hollow part may change, when the said surface layer receives the impact from the outside, It is comprised in any one of Claim 1 to 6 characterized by the above-mentioned. Solar cell module. When mounted on a vehicle, it constitutes a vehicle outer plate member,
The solar cell module according to claim 1, wherein the hollow portion is provided inside a connection portion attached to the vehicle body structure.

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