JP6062819B2 - Terminal box - Google Patents

Description

  The present invention relates to a terminal box that constitutes an output part of a solar cell module that constitutes a photovoltaic power generation system.

  The terminal box that constitutes the output part of the solar cell module has a charging part (circuit part) of a circuit constituent part constituted by a terminal block, a bypass diode, an output cable, etc. in a box that is open on one side. The charging part of the circuit constituent part is embedded by filling a potting material (filler).

  Patent Document 1 discloses a technique of covering an open portion of a box structure with a double structure box cover having an inner cover made of a metal material and an outer cover made of a weather resistant resin.

Japanese Unexamined Patent Publication No. 2005-19833

  In the above conventional technique, even if the charging part of the circuit component part generates heat, the charging part is isolated from the outer wall of the box, so that the outer shell of the box is hardly thermally deformed, and the box cover is also made of a metal material. Although it has a double structure consisting of an inner cover and an outer cover made of weather-resistant resin, it is a structure that is difficult to thermally deform, but the output current of the solar cell is proportional to its area, so the solar cell is enlarged Then, the temperature rise of the bypass diode becomes larger. In order to prevent this, techniques such as increasing the surface area and volume of the filler and the terminal block and increasing the heat radiation efficiency are taken. However, taking such a method involves problems such as an increase in the size and cost of the terminal box.

  The present invention has been made in view of the above, and is a terminal box for a solar cell module that does not easily cause thermal deformation due to heat generation of circuit components and does not reduce the manufacturing cost of the solar cell module or impair mass productivity. The purpose is to obtain.

  In order to solve the above-described problems and achieve the object, the present invention is a terminal box that constitutes an output unit of a solar cell module having a solar cell panel, and outputs the electric power generated by the solar cell panel to the outside. And a circuit portion including a plurality of terminal blocks having a connection portion with an output lead wire, a bypass diode connecting the plurality of terminal blocks, and a box shape in which a surface facing a mounting surface to the solar cell panel is opened A box body that houses the circuit part, a filler that fills the box body so as to cover the circuit part, a flat outer cover, and a metal that has irregularities and has a larger surface area than the outer cover. A box cover that is attached to the box body so that the outer cover covers the open surface of the box body from above the inner cover, and the inner cover is in close contact with the filler. And location, is characterized in that so as to dissipate heat generated in the circuit portion from the portion of the irregularity.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that generation | occurrence | production of the thermal deformation by the heat_generation | fever of a circuit structure part can be prevented, the manufacturing cost of a solar cell module can be reduced, and mass productivity can be improved.

FIG. 1 is an exploded perspective view of a terminal box according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of a terminal box attached to the solar cell panel. FIG. 3 is a plan view of the terminal box. FIG. 4 is a cross-sectional view of the terminal box. FIG. 5 is a diagram showing a procedure for attaching the inner cover. FIG. 6 is a cross-sectional view of the terminal box. FIG. 7 is a longitudinal sectional view of the terminal box.

  Embodiments of a terminal box according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is an exploded perspective view of a terminal box according to an embodiment of the present invention, showing a state before potting a charging part of a circuit component. FIG. 2 is a longitudinal sectional view of the terminal box attached to the solar cell panel, showing a state in which the box cover is removed. FIG. 3 is a plan view of the terminal box, showing a state in which the box cover is removed. FIG. 4 is a cross-sectional view of the terminal box, showing a state where the outer cover is removed. FIG. 5 is a diagram showing a procedure for attaching the inner cover. FIG. 5 (a) shows a state in which the flat portion of the inner cover is hooked on the protrusion and the small protrusion is fitted into the small hole formed in the flat portion of the inner cover. FIG. 5B shows a state in which the inner cover is attached to the box body.

  The terminal box 40 constitutes an output part of the solar cell module 50. As illustrated in FIG. 1, the terminal box 40 includes a box body 2 and a box cover 3. As shown in FIG. 2, the box body 2 accommodates circuit components and is attached to the back surface of the solar cell panel 1 by adhesion or the like. The box body 2 is integrally formed into a rectangular box structure with a side facing the mounting surface 4 opened using a resin having high flame resistance and weather resistance such as ABS resin and m-PPE resin. The box cover 3 is rich in flame resistance and weather resistance such as an inner cover 15 made of a stainless steel having a thickness of about 0.5 mm or a steel plate subjected to rust prevention treatment, and ABS resin or m-PPE resin. It has a double structure having an outer cover 16 formed of resin. The inner cover 15 has a shape in which the flat plate portion 15a and the corrugated plate portion 15b are combined, and the outer shape is almost the same size as the outer cover 16, but the corrugated plate portion 15b is uneven so that the surface area is outside. It is larger than the cover 16. A small hole 20 is formed in the flat plate portion 15 a of the inner cover 15.

  In the box main body 2, a charging portion storage portion 6 is defined in four rounds inside a space that is separated from the outer wall structure 5 in the four rounds with a space around. That is, as for the box main body 2, the side surface surrounding the attachment surface to a solar cell panel has a double wall structure. The charging unit storage unit 6 is formed so that the standing dimension is lower than that of the outer wall structure 5, and the charging unit storage unit 6 and the inner wall of the outer wall structure 5 are connected by a plurality of vertical and horizontal ribs 7. . Two outlets 9 for the output lead wires 8 are provided side by side on one of the longer surfaces of the outer wall structure 5. The output lead wire 8 is a cable for outputting the electric power generated in the solar cell module 50 to the outside. Two engaging recesses 10 are provided on the shorter surface of the outer wall structure 5 at intervals from the inner wall surface. Holes through which the output lead wires 8 are inserted are provided at positions corresponding to the respective outlets 9 of the charging unit storage unit 6.

  As shown in FIG. 5, a projection 21 is formed on one of the longer surfaces of the outer wall structure 5, and a small projection 19 is formed on the top of the charging unit storage unit 6 on the opposite side. The tops of the four circumferences of the charging unit storage unit 6 are formed to have the same height except for the small protrusions 19. Resin members 17 that can be fitted into the engaging recesses 10 of the box body 2 are formed on both short sides of the outer cover 16. Further, a step portion 18 is formed near the tip of the outer wall structure 5. That is, the inner surface 18b of the outer wall structure 5 is lower than the outer surface 18c with the step 18a as a boundary.

  Terminal blocks 12 a and 12 c connected to the lead wires of the solar cell panel 1 and terminal blocks 12 b connected to the horizontal tab wires of the solar cell panel 1 are installed on the bottom surface of the charging unit storage unit 6. The bypass diode 13a that prevents the reverse current from flowing through the solar cells (solar cell strings) in the solar cell panel 1 is mounted across the terminal block 12a and the terminal block 12b. On the other hand, the bypass diode 13b is mounted across the terminal block 12b and the terminal block 12c. An output lead wire 8 is connected to the terminal blocks 12a and 12c.

  As described above, the circuit component includes the terminal blocks 12a to 12c, the bypass diodes 13a and 13b, and the output lead wire 8, and the connection between the terminal blocks 12a to 12c and the bypass diodes 13a and 13b and the output lead wire 8 A charging unit 11 (circuit unit) such as a connection portion with the terminal blocks 12 a and 12 c is stored in the charging unit storage unit 6.

  After storing the charging unit 11 in the charging unit storage unit 6, the charging unit storage unit 6 is filled with a filler 14 so as to completely cover the charging unit 11. As the filler 14, it is preferable to use a flame retardant material, for example, a UL94 standard V0 grade material. UL94 standard V0 grade two-component mixed silicon potting material is suitable in terms of flame retardancy, heat dissipation, and filling properties.

  The inner cover 15 is put on the opening of the charging unit storage unit 6 before the filler 14 is cured. At this time, the end of the flat plate portion 15a of the inner cover 15 is hooked on the protrusion 21 (FIG. 5A), and the small protrusion 19 is fitted into the small hole 20 formed in the flat plate portion 15a of the inner cover 15 (FIG. 5). 5 (b)). In addition, in order to make an understanding of a structure easy, illustration of the filler 14 is abbreviate | omitted in FIG. With this configuration, the inner cover 15 can be fixed on the charging unit storage unit 6 without using screws.

  FIG. 6 is a cross-sectional view of the terminal box. FIG. 7 is a longitudinal sectional view of the terminal box. 6 shows a cross section taken along the line VI-VI in FIG. 7, and FIG. 7 shows a cross section taken along the line VII-VII in FIG. In order to facilitate understanding of the structure, although not shown in FIGS. 6 and 7, a filler 14 is filled inside the charging unit storage unit 6. As shown in FIG. 6, the flat plate portion 15a of the inner cover 15 and the bottom surface side of the corrugated plate portion 15b are formed to have the same height. By covering the inner cover 15 on the tops of the four circumferences of the charging unit storage unit 6, the charging unit is surrounded by the bottom surface of the main body 2, the four cycles of the charging unit storage unit 6, and the inner cover 15. .

  From the viewpoint of FIG. 6, the interval between the charging storage portions 6 and the width of the inner cover 15 are substantially equal. From the viewpoint of FIG. 7, the width of the inner cover 15 is wider than the interval between the charge storage units 6, and the inner cover 15 is placed on the top of the charge storage unit 6.

  Here, since the position in the vertical direction is determined by providing the flat plate portion 15a near the center of the inner cover 15, the inner cover 15 is fixed in the vertical direction without looseness by the charging storage portion 6, the small protrusion 19, and the protrusion 21. be able to. Moreover, the surface area of the inner cover 15 can be increased by forming a corrugated plate shape such as the corrugated plate portion 15 b other than the fixed portion of the inner cover 15.

  The inner cover 15 is fixed in the vertical direction by the charging portion storage portion 6, the small protrusion 19 and the protrusion 21 at the flat plate portion 15 a, and fixed in the lateral direction by the inner surface of the outer wall structure 5, the charging portion storage portion 6 and the small protrusion 19. Has been. The inner surface of the flat plate portion of the filler 14 and the inner cover 15 is in close contact, and the inner cover 15 is restrained and fixed to the box body 2 by fitting the small protrusions 19 and the small holes 20. Here, by providing the small hole 20 in the flat plate portion 15a, the drilling process is facilitated, and the small protrusion 19 and the small hole 20 can be easily fixed.

  The outer cover 16 is placed on the open portion of the box body 2 so as to cover the inner cover 15 after the filler 14 is cured. The outer cover 16 is attached to the box body 2 with one long side resin member 17 fitted into the engagement recess 10 and the other long side resin member 17 fitted into the engagement recess 10. By fitting the peripheral portion of the outer cover 16 into the step portion 18, the water tightness of the charging portion storage portion 6 is maintained. That is, the gap between the outer cover 16 and the outer wall structure 5 is bent along the step 18a and the outer surface 18c, so that the terminal box 40 is provided with watertightness. The outer cover 16 and the inner cover 15 are not in close contact with each other, and a gap of about 1 mm is formed between them.

  Since the terminal box 40 is insulated from the outer wall structure 5 of the box body 2 and the charging unit housing 6 even if heat is generated by the bypass diodes 13a and 13b in the charging unit 11, the box is insulated. Thermal deformation does not occur in the outer wall structure 5 of the main body 2. Since the box cover 3 has a double structure of the inner cover 15 made of a metal material and the outer cover 16 made of a flame-retardant resin, it is virtually free from thermal deformation. Therefore, by using multiple diodes connected in series and in parallel as bypass diodes, the current flowing through the bypass diodes can be reduced, the surface area and volume of fillers and terminal blocks can be increased, and the area of solar cells can be reduced. Even if not, the solar cell module 50 can be configured, and problems such as an increase in size and cost of the terminal box 40 and a decrease in mass productivity can be prevented. Moreover, selection of the bypass diodes 13a and 13b is facilitated, and the diameter of the solar battery cell can be increased.

  Further, the heat generated by the charging unit 11 is transferred to the filler 14, transferred to the inner cover 15 that is in close contact with the filler 14, and radiated by the radiating fin function of the inner cover 15. Since a gap is secured between the outer cover 16 and the inner cover 15, the influence of heat on the outer cover 16 is small. Since the inner cover 15 is inside the outer cover 16 and is formed of a stainless steel plate or a steel plate (for example, galvanized steel plate) that has been subjected to rust prevention treatment, it functions as a terminal box for a long time even in an actual use environment. Can be maintained. Since the box cover 3 has a double structure, the waterproofness and dustproofness of the charging unit 11 can be secured over a long period of time.

  In the terminal box 40 according to the embodiment, since the inner cover 15 is made of metal, heat dissipation from the lid surface is good, and the temperature rise of the entire terminal box due to heat generation from the bypass diodes 13a and 13b can be reduced.

  Further, since the corrugated plate portion 15b is provided in the metal inner cover 15, the heat radiation area is widened, so that the heat of the bypass diodes 13a and 13b can be efficiently radiated, and the temperature rise of the bypass diodes 13a and 13b is suppressed to a small level. And reliability is improved. Note that the same effect can be obtained by increasing the surface area of the inner cover 15 by providing a plurality of protrusions on the surface of the inner cover 15 instead of providing the corrugated plate portion 15b.

  Further, by attaching the metal inner cover 15 before the filler 14 is cured, the filler 14 and the inner cover 15 are in close contact with each other, and the heat of the bypass diodes 13a and 13b can be efficiently radiated, and the bypass diodes 13a and 13b. The temperature rise of the capacitor can be kept small, the reliability is improved, and since the surface area is small, it is possible to use a relatively small-capacity diode that easily traps heat as the bypass diodes 13a and 13b. Is possible.

  Further, a part of the inner cover 15 is formed into a flat plate portion 15a, and the small hole 20 is provided in the flat plate portion 15a, so that the inner cover 15 can be fixed to the box body 2 by fitting with the small protrusion 19 and screwed. Is not required, the structure is simple, and manufacture is easy.

  As described above, the terminal box according to the present invention is useful in that it can efficiently dissipate heat generated in the charging unit.

  DESCRIPTION OF SYMBOLS 1 Solar cell panel, 2 box main body, 3 box cover, 4 mounting surface, 5 outer wall structure, 6 charging part accommodating part, 7 rib, 8 output lead wire, 9 outlet, 10 engaging recessed part, 11 charging part, 12a, 12b, 12c Terminal block, 13a, 13b Bypass diode, 14 Filler, 15 Inner cover, 15a Flat plate portion, 15b Corrugated plate portion, 16 Outer cover, 17 Resin member, 18 steps, 18a Step, 18b Inner surface, 18c Outer surface Side, 19 small protrusions, 20 small holes, 21 protrusions.

Claims (6)

A terminal box constituting an output part of a solar cell module having a solar cell panel,
A circuit unit including a plurality of terminal blocks having a connection portion with an output lead for outputting the electric power generated by the solar cell panel to the outside, and a bypass diode connecting the plurality of terminal blocks;
The box facing the mounting surface to the solar cell panel is an open box, and the box body that houses the circuit unit;
A filler filled in the box body so as to cover the circuit portion;
A flat outer cover, located on both sides of the flat portion and the flat plate portion has the small hole provided having a corrugated portion that covers the bypass diode, made of metal have large surface area than the outer cover An inner cover, and a structure for fixing the inner cover to the terminal box body by fitting the small hole and a small protrusion provided on the box body;
A box cover attached to the box body so that the outer cover covers an open surface of the box body from above the inner cover;
The terminal box, wherein the entire inner cover is disposed in close contact with the filler to dissipate heat generated in the circuit portion from the inner cover . The terminal box according to claim 1, wherein the box body and the outer cover are made of resin. The box body has a terminal box according to claim 1 or 2, characterized in that the side surface surrounding the mounting surface there is a double wall structure. The terminal box according to any one of claims 1 to 3 , wherein the box cover has a gap between the entire inner cover and the outer cover. The terminal box according to any one of claims 1 to 4 , wherein the filler is formed of a flame retardant material. The terminal box according to any one of claims 1 to 5 , wherein the inner cover is formed of a stainless steel or a steel plate that has been subjected to a rust prevention treatment.

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