JP2013229424A - Terminal box for solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly connect an axial lead type diode 13 to a terminal board 12 by soldering.SOLUTION: Disclosed is a terminal box B for a solar cell module. Inside its box body 11, a plurality of terminal boards 12 to which electrodes a of the solar cell module are connected are disposed, and bypass diodes 13 are also disposed between the terminal boards adjacent to each other. An erected piece 14 is formed by cutting and erecting a part of the terminal board in an L-shape, and holding pieces 14a are erected from the end parts of the erected piece 14. The diode 13 is connected to the terminal board 12 by fitting a lead leg 13b of the diode 13 between the holding pieces 14a, and soldering the leg along a flat surface 12b of the erected piece 14. When soldering, as the erected piece 14 is a small piece, the heat from a soldering iron is not immediately transferred to the whole part of the terminal board 12 to discharge the heat, and the temperature smoothly rises to a solderable level to enable smooth soldering. As the diode 13 gradually heats up, the generated heat is smoothly discharged by being transferred to the whole part of the terminal board 12 via the small erected piece 14.

Description

  The present invention relates to a terminal box for connecting solar cell modules constituting a photovoltaic power generation system that directly converts solar energy into electrical energy, and more particularly to a connection structure between the terminal plate and a bypass diode.

  A solar power generation system arrange | positions a solar cell panel (solar cell module) on the roof of a house, and supplies electric power to various electric devices from the module through a connection box, an inverter, and a distribution board (patent document 1 paragraph 0002, (Refer FIG. 14, patent document 2 paragraph 0002, FIG. 5). The solar cell modules are all arranged to be flush with each other, and are connected in series or in parallel via a terminal box and a connector. The terminal box is fixed to the back surface of the module by adhesion or the like while maintaining the watertightness of the sealing material (see Patent Document 2, paragraph 0002, FIG. 6).

  In the terminal box, generally, terminal plates to which the positive electrode and the negative electrode of the solar cell module are connected are arranged in the box body of the upper surface opening, and for bypassing (for backflow prevention) between the terminal plates. ) A diode is provided, and external connection cables are connected to the terminal plates at both ends (see Patent Document 1 FIGS. 11 and 15).

Japanese Patent No. 3965418 JP 2011-18673 A JP 2003-229592 A

By the way, the solar power generation system has been attracting attention because of today's environmental problems and energy savings, and the performance of solar cell modules has been increasing day by day. Accordingly, the power generation amount of one module has increased. As a result, the amount of current flowing through the terminal box is also increasing. As this amount of current increases, the amount of heat generated by the diode also increases.
For this reason, as disclosed in Patent Document 1, a device for obtaining a high heat dissipation effect is provided by providing a heat radiating plate on the terminal board or a heat transformer plate.
On the other hand, under today's cost reduction pressure (request), this type of solar cell module terminal box is no exception, and further cost reduction is desired.

As one of the cost reductions, use of an inexpensive axial lead type diode and reduction of labor cost for soldering the diode to the terminal board were studied.
In the axial lead type diode, the lead leg protrudes straight from the center of the side of the cylindrical body, and the lead leg is attached to the terminal plate by fitting it into the clamping piece raised from the terminal plate. (See reference 13 in FIG. 4 (d) and reference 13 in FIG. 1 in Patent Document 1), or insert a lead leg into the through hole of the terminal board (see FIG. 8 in Patent Document 3). Accordingly, the lead leg is soldered to the terminal board.

The above-mentioned fitting connection of the lead leg to the holding piece has a problem that the contact area is small, and when trying to increase the connecting area by soldering, the soldering iron is attached to the diode body for soldering to the rising holding piece. There is a risk that the diode may be damaged by touching, and the solder may flow downward to prevent smooth soldering.
In addition, when the lead leg is connected to the terminal board through-hole, when the lead leg is soldered to the surface of the terminal board on the insertion side, the solder iron may touch the diode body and cause damage to the diode. . On the other hand, when soldering the lead leg to the back side of the terminal board with respect to the insertion side, it is necessary to solder the terminal board with the back side of the terminal board as the upper side. . Usually, the diode is attached to the terminal board after the terminal board is attached to the terminal box.

  An object of the present invention is to smoothly connect an axial lead type diode to a terminal board by soldering under such a situation.

In order to achieve the above object, according to the present invention, the lead leg of the axial lead type diode is soldered along the flat surface of the terminal board.
If the lead leg is placed along the flat surface of the terminal board, the connection area between the terminal board and the lead leg becomes larger than the conventional fitting or insertion into the through hole, so that the connection strength can be improved. Further, by setting the soldering portion to the tip end side of the lead leg, there is less possibility that the solder iron touches the diode body, and the workability is improved and the cost can be reduced.

  As a configuration of the present invention, in the box body, a plurality of terminal plates to which the electrodes of the solar cell module are connected are arranged side by side, a bypass diode is provided between the adjacent terminal plates, and the terminal plates at both ends are provided. In the terminal box for a solar cell module to which an external connection cable is connected, the diode is an axial lead type in which a lead leg protrudes sideways straight from the center of the side surface of the cylindrical body, and the lead leg is connected to the terminal plate. The structure soldered along the flat surface can be adopted.

In this configuration, the flat surface can be formed by raising a part of the terminal board and bending the tip of the standing piece in parallel with the terminal board. In this way, if the rising height is equal to or greater than the columnar radius of the diode body, the diode body can be accommodated in the terminal box to the extent that it contacts the terminal plate.
At this time, if the standing piece is a small piece formed by cutting and raising a part of the terminal board, heat will not be transferred instantaneously from the small piece to the entire terminal board during soldering (suppressing heat dissipation locally) ), Since the soldering portion is smoothly raised to a temperature at which soldering can be easily performed, the workability is improved.
Further, if a holding piece is supported by inserting the lead leg into a part of the terminal plate or a side edge of the standing piece facing the lead leg, the lead leg is fitted into the holding piece. Since positioning to a flat surface can be performed, workability is further improved.

  Since the present invention is configured as described above, the axial lead type diode can be smoothly connected to the terminal plate by soldering, and the cost of the terminal box can be reduced.

The perspective view which removed the cover of one Embodiment Main part perspective view of the same embodiment The principal part perspective view of other embodiment (A) is a principal part perspective view of other embodiment, (b) is a principal part cutting front view of the embodiment. The principal part perspective view of other embodiment

  1 to 2 show an embodiment of the present invention. A solar cell module terminal box B according to this embodiment is provided in a polyphenylene ether (PPE) long box body 11 having an upper surface opening. The four terminal plates 12 to which the positive electrode a or the negative electrode a is connected are arranged side by side. The electrode a is introduced into the box body 11 through the through-hole 11a on the back surface, and the end thereof is connected to each terminal board 12 (the connection portion is the shaded portion in FIGS. 1 and 2). A diode 13 is provided between the adjacent terminal plates 12. The number of terminal boards 12 arranged in parallel is arbitrary, such as 2, 3, 5, and so on.

Each terminal board 12 consists of pure copper, and the terminal piece 14 is formed by cutting and raising in the center part. The terminal pieces 14 of the two terminal plates 12 at both ends are cut and raised in an L shape in the left-right direction in FIG. 1, and the terminal pieces 14 of the two terminal plates 12 at the center are formed in the vertical direction in FIG. The tip edge of each terminal piece 14 is a bifurcated sandwiching piece 14a that is further bent upward and rises. The rising height h of the terminal piece 14 from the terminal plate 12 is set to be slightly larger than the radius of the columnar body 13a of the diode 13 (see FIGS. 2 and 4B).
Each terminal plate 12 is fixed to the box body 11 by engaging the cut and raised pieces 12 a with the locking claws 11 b of the box body 11.

  The diode 13 is an axial lead type in which the lead leg 13b protrudes straight from the center of the side surface of the cylindrical main body 13a, and is set in the semicircular arc hole 11d of the rib 11c of the box main body 11. The lead leg 13b is fitted into the holding piece 14a of the terminal plate 12, and is supported and fixed by the terminal plate 12 (holding piece 14a) along the flat surface 12b. In this state, the diode 13 is connected to the terminal plate 12 by soldering. At this time, the holding piece 14a rises from the side edge of the flat surface 12b and the insertion groove of the holding piece 14a reaches the flat surface 12b. Therefore, when the lead leg 13b is fitted into the holding piece 14a, the lead leg 13 is fully It will be in the state which contacted the flat surface 12b over.

At the time of soldering, the terminal piece 14 is a small piece that rises from the terminal board 12, and heat from the soldering iron is not transferred to the entire terminal board 12 and is not dissipated, so the small piece 14 can be soldered smoothly. The temperature rises and smooth soldering is performed.
Crimped terminal portions 12d are formed at the ends of the terminal plates 12 at both ends, and the conductor of the external connection cable P is crimped to the terminal portions 12d.

This terminal box B is provided on the back surface of the solar cell module by an adhesive or the like as in the conventional case.
In this state, the diode 13 generates heat due to a current generated by the power generation of the solar cell module. At this time, since the heat generation of the diode 13 is gradual, the heat generation is transmitted to the entire terminal plate 12 through the terminal piece 14 and is smoothly radiated.

The connection mode between the diode 13 and the terminal plate 12 is not limited to the above, and for example, as shown in FIG. 3, the clamping piece 14 a can be omitted. At this time, as shown in the figure, when the soldering portion (tip portion) of the lead leg 13b is flattened, the installation state (sitting state) of the diode 13 on the flat surface 12b is good and the soldering operation is smooth. . Further, as shown in FIG. 4, in the case where a part of the side edge of the terminal board 12 is raised, the lead leg 13b can be soldered to the raised flat surface 12b. At this time, as shown in FIG. 5, the flat surface 12b can be formed by rising over the entire length of the side edge of the terminal plate 12, and the flat surface 12b is cross-sectionally shown in the cross section of the entire length of the central portion in the width direction of the terminal plate 12. It can also be formed in a letter shape. In any of the embodiments shown in FIGS. 4 and 5, the clamping piece 14a can be provided as shown.
The lead leg 13b is not limited to a round bar having a circular cross section as described above, but may have a square cross section such as a square or a triangle.

11 Terminal box body 12 Terminal board 12b Terminal board flat surface (Lead leg soldering part)
13 Bypass diode 13a Diode body 13b Diode lead leg 14 Diode connection terminal piece (standing piece, small piece)
14a Clamping piece B Terminal box P for solar cell module External connection cable

Claims (3)

In the box main body (11), a plurality of terminal plates (12) to which the electrodes (a) of the solar cell module (M) are connected are arranged side by side, and are used for bypassing between the adjacent terminal plates (12). In the solar cell module terminal box (B) provided with a diode (13) and connected to the terminal plates (12) at both ends with an external connection cable (P),
The diode (13) is an axial lead type in which a lead leg (13b) protrudes sideways straight from the side surface center of the cylindrical body (13a), and the lead leg (13b) is connected to the terminal plate (12). A terminal box for a solar cell module, which is soldered along a flat surface (12b).   The flat surface (12b) is formed by raising a part of the terminal plate (12) and bending the tip of the standing piece (14) in parallel with the terminal plate (12). The terminal box for solar cell modules according to claim 1.   The terminal box for a solar cell module according to claim 2, wherein the upright piece (14) is a small piece formed by cutting and raising a part of the terminal plate (12).

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