JP2018074071A - Cable fixing structure and connection box for solar power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable fixing structure which reduces temporal damage of a coating of a cable without needing processing of a housing.SOLUTION: A cable fixing structure has: a housing 1 having a bottom surface 1a provided with wiring holes 10; switches 7 and a terminal block 4 disposed within the housing 1; and multiple cable fixing tools 5 respectively inserted into the housing 1 through the wiring holes 10 to fix multiple cables 3 connected with the switches 7 or the terminal block 4. The multiple cable fixing tools 5 fix the cables 3 while inclining relative to the bottom surface 1a.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a cable fixing structure for fixing a cable connected to a wiring connection component in a housing, and a connection box for a photovoltaic power generation system using the cable fixing structure.

  A conventional connection box for a photovoltaic power generation system connects a cable from a solar cell module to a switch installed inside the casing, and similarly connects a cable to the power converter to a terminal block installed inside the casing. Is connected.

  When wiring the cable, open the wiring hole in the bottom of the connection box, pass the cable, and connect it to the switch or terminal block. This may be caused by the cable being pulled during construction or by stress on the connection due to the weight of the cable. Terminal looseness or damage may occur. In order to prevent loosening or damage of the terminal, a structure in which a tension stopper for fixing the cable is provided in the vicinity of the connection portion between the switch or the terminal block and the cable is generally used.

  Equipment related to photovoltaic power generation is often required to have a product life of about 15 years, and the junction box may be used outdoors under conditions where it is exposed to wind and rain and sudden temperature changes. It is desirable to fix the cable so that the stress applied to the cable becomes as small as possible.

  Patent Document 1 includes a cover having a case having a convex portion and a concave portion installed in parallel with the convex portion, and has a tension stopper structure that sandwiches a cable between the convex portion and the concave portion when the cover is attached. It is disclosed.

JP 2012-119071 A

  However, in the structure disclosed in Patent Document 1, since it is necessary to process the protrusions on the case, the processing range is widened in a connection box having a large number of cables to be wired, and an increase in cost due to processing costs is assumed. Further, in the structure disclosed in Patent Document 1, since a load is concentrated on the fixed portion of the cable due to the unevenness, the cable sheath may be damaged over time, resulting in insulation failure.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a cable fixing structure that does not require processing of the casing and reduces damage with time of the covering of the cable.

  In order to solve the above-described problems and achieve the object, the present invention provides a housing having a bottom surface provided with a wiring hole, a plurality of cable connecting parts disposed inside the housing, and a wiring hole. And a plurality of cable fixtures for fixing a plurality of cables inserted into the housing and connected to the cable connecting parts. The plurality of cable fixtures fix the plurality of cables in a state of being inclined with respect to the bottom surface.

  According to the present invention, there is an effect that it is not necessary to process the casing, and damage over time of the cable covering can be reduced.

The figure which shows the structure of the solar energy power generation system which concerns on embodiment of this invention. The perspective view of the junction box for photovoltaic power generation systems concerning an embodiment The figure which shows the internal structure of the connection box for photovoltaic power generation systems which concerns on embodiment The figure which shows the structure of the cable fixing tool used for the cable fixing structure which concerns on embodiment The disassembled perspective view of the cable fixing tool used for the cable fixing structure which concerns on embodiment The figure which shows the insertion state of the cable to the cable fixing tool used for the cable fixing structure which concerns on embodiment The figure which shows the wiring state inside the junction box for photovoltaic power generation systems which concerns on embodiment The figure which shows the wiring state inside the junction box for photovoltaic power generation systems which concerns on embodiment The figure which shows the wiring state inside the junction box for photovoltaic power generation systems which concerns on embodiment

  Hereinafter, a cable fixing structure and a connection box for a photovoltaic power generation system according to an embodiment of the present invention will be described in detail based on the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a diagram showing a configuration of a photovoltaic power generation system according to an embodiment of the present invention. The solar power generation system includes a solar cell module 16 that receives sunlight to generate power, a power conversion device 15 that converts electric power generated in the solar cell module 16 into AC power, a solar cell module 16 and the power conversion device 15 And a connection box 100 which is a connection box for a photovoltaic power generation system. The power converter 15 may be called a power conditioner. The first cable 3 a connected to the solar cell module 16 and the second cable 3 b connected to the power converter 15 are drawn into the connection box 100 and electrically connected inside the connection box 100. Yes. Hereinafter, when it is not necessary to distinguish the first cable 3a and the second cable 3b, they are referred to as cables 3.

  FIG. 2 is a perspective view of the junction box for the photovoltaic power generation system according to the embodiment. As shown in FIG. 2, the connection box 100 includes a housing 1 whose front surface is open and a lid 2 that closes the front surface of the housing 1. A plurality of wiring holes 10 are formed in the bottom surface 1 a of the housing 1. The cable 3 is drawn into the housing 1 through the wiring hole 10.

  FIG. 3 is a diagram illustrating an internal structure of the junction box for the photovoltaic power generation system according to the embodiment. As shown in FIG. 3, a plurality of switches 7, which are first cable connection parts to which the first cable 3 a is connected, and the second cable 3 b are connected to the inside of the housing 1. The board 8 on which the terminal block 4, which is the cable connection component, and a plurality of backflow prevention diodes 14 that prevent the power from flowing into the solar cell module 16, is housed. The switch 7 has a terminal block 7a to which the first cable 3a is connected. The plurality of switches 7, the terminal block 4, and the plurality of backflow prevention diodes 14 are electrically connected by internal wiring (not shown). Therefore, when the first cable 3a is connected to the terminal block 7a and the second cable 3b is connected to the terminal block 4, the first cable 3a and the second cable 3b are connected to the switch 7 and the backflow prevention diode. 14 and the terminal block 4 are electrically connected. The board 8 is provided with a cable fixture attachment hole 6 to which a cable fixture 5 described later is attached in a space between the switch 7 and the terminal block 4 and the wiring hole 10.

  FIG. 4 is a diagram illustrating a configuration of a cable fixture used in the cable fixing structure according to the embodiment. FIG. 5 is an exploded perspective view of a cable fixing tool used in the cable fixing structure according to the embodiment. The cable fixture 5 is used for wire tension stopper. The cable fixture 5 is composed of a metal fitting 13 and an insulating component 9 arranged at a portion in contact with the cable 3. The insulating component 9 is made of an elastic insulator.

  The metal fitting 13 includes a concave cable insertion portion 12 into which the cable 3 is inserted, and a fixing portion 11 that is fixed to the substrate 8. The metal fitting 13 is provided with a cable insertion portion 12 between the fixing portions 11 at both ends, and has a hat shape in a side view as viewed from the direction of arrow A in FIG. The fixing part 11 is formed with a screw fastening hole 11a through which a screw is passed.

  The insulating component 9 has a shape that engages with the cable insertion portion 12 and has a U-shape when viewed from the side as viewed from the direction of arrow A in FIG. The insulating component 9 is fitted into the cable insertion portion 12 so that the cable 3 and the metal fitting 13 are not in direct contact.

  The metal fitting 13 has a strength that prevents the cable fixture 5 from being deformed even when a tensile load is applied to the cable 3 and the cable fixture 5 due to the cable 3 being pulled at the time of construction or due to stress on the connection portion due to its own weight. To do. In addition, since the insulating component 9 is disposed in the cable insertion portion 12, the cable fixture 5 fixes the cable 3 in a state where the insulating component 9 having elasticity is interposed between the cable 3 and the metal fitting 13. . Therefore, the insulation between the cable 3 and the metal fitting 13 is ensured, and the stress applied to the cable 3 is alleviated by the elastic deformation of the insulating component 9, and the proof stress against the tensile load is improved by the frictional force with the insulating component 9. Can be made.

  FIG. 6 is a diagram illustrating an insertion state of the cable to the cable fixture used in the cable fixing structure according to the embodiment. The cable 3 is compressed by the cable fixture 5 by inserting the cable 3 into the cable insertion portion 12 in which the insulating component 9 has been installed and tightening the screw 17 through the screw fastening hole 11 a into the cable fixture attachment hole 6. The gap between the cables 3 is narrowed, and the cable 3 is fixed on the substrate 8 in a state where the cable 3 is pushed into the cable insertion portion 12.

  FIG. 7 is a diagram illustrating a wiring state inside the connection box for the photovoltaic power generation system according to the embodiment. As shown in FIG. 7, the first cable 3a is drawn into the housing 1 through the wiring hole 10 every two pairs, and the first cable 3a is fixed on the substrate 8 by the cable fixture 5. The tension is stopped. The fixed first cable 3 a is connected to the terminal block 7 a of the switch 7. Similarly, the pair of second cables 3 b is also fixed on the substrate 8 by the cable fixture 5 and connected to the terminal block 4. In addition, although the cable 3 from the several solar cell module 16 was made into every two pairs, it can fix similarly in the case of one pair. Furthermore, by extending the cable insertion portion 12, three or more pairs of cables 3 can be fixed to the substrate 8 with the cable fixture 5.

  FIG. 8 is a diagram showing a wiring state inside the junction box for the photovoltaic power generation system according to the embodiment, and shows an enlarged portion B in FIG. 7. A direction perpendicular to the bottom surface 1 a of the housing 1 indicated by an arrow C in FIG. 8 is defined as a wiring direction of the cable 3. Further, the direction in which the line connecting the screw fastening holes 11a of the cable fixture 5 indicated by the arrow D in FIG. 8 extends is defined as the direction in which the cable fixture 5 is attached. As shown in FIG. 7, the cable fixture 5 is fixed in a state where the attachment direction is inclined with respect to the wiring direction of the cable 3. Thereby, since the stress in the direction in which the cable 3 is pulled when the cable 3 is pulled is dispersed by the friction between the cable fixture 5 and the cable 3, the proof stress against the tensile load is improved. Further, since the stress in the direction in which the cable 3 is pulled is dispersed by the cable fixture 5, the stress in the direction in which the cable 3 comes out from the terminal block 7 a and the terminal block 4 of the switch 7 is relieved.

  FIG. 9 is a diagram illustrating a wiring state inside the connection box for the photovoltaic power generation system according to the embodiment. As shown in FIG. 9A, when the angle between the wiring direction of the cable 3 and the mounting direction of the cable fixture 5 is small, the force in the pulling direction is not dispersed and the effect of the tension stopper is reduced. On the other hand, as shown in FIG. 9 (b), when the angle formed by the wiring direction of the cable 3 and the mounting direction of the cable fixture 5 is large, a plurality of switches 7 and A large cable holding space is required between the terminal block 4 and the wiring hole 10, and the housing 1 needs to be enlarged. Accordingly, the inclination of the cable 3 with respect to the bottom surface 1a, in other words, the angle formed by the wiring direction of the cable 3 and the mounting direction of the cable fixture 5 is preferably 10 degrees or more in order to obtain a tension stopping effect. In order to prevent the cable holding space from becoming wide, the angle is preferably set to 45 degrees or less.

  According to the cable fixing structure according to the embodiment, it is possible to reduce damage over time of the covering of the cable 3 without performing special processing on the housing 1.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  DESCRIPTION OF SYMBOLS 1 Case, 1a Bottom face, 2 Lids, 3 Cable, 3a 1st cable, 3b 2nd cable, 4 Terminal block, 5 Cable fixing tool, 6 Cable fixing tool mounting hole, 7 Switch, 7a Terminal block part, 8 Board, 9 Insulating part, 10 Wiring hole, 11 Fixing part, 11a Screw fastening hole, 12 Cable insertion part, 13 Hardware, 14 Backflow prevention diode, 15 Power converter, 16 Solar cell module, 17 Screw

Claims (6)

A housing having a bottom surface provided with wiring holes;
A plurality of cable connection parts arranged inside the housing;
A plurality of cable fixtures for fixing a plurality of cables inserted into the housing from the wiring hole and connected to the cable connecting component;
The plurality of cable fixtures fix the plurality of cables in a state of being inclined with respect to the bottom surface. The cable fixture has a metal fitting provided with a concave cable insertion part into which a plurality of the cables are inserted, and an insulating component arranged in the cable insertion part,
2. The cable fixing structure according to claim 1, wherein the plurality of cable fixtures fix the plurality of cables in a state where the insulating component is interposed between each of the plurality of cables and the metal fitting. 3. .   The cable fixing structure according to claim 1, wherein each of the plurality of cables is inclined with respect to the bottom surface in a range of 10 degrees to 45 degrees. The cable connection component includes a first cable connection component and a second cable connection component electrically connected to the first cable connection component;
The plurality of cables include a first cable connected to the first cable connection part and a second cable connected to the second cable connection part. 4. The cable fixing structure according to any one of 3 above. A connection box for a photovoltaic power generation system using the cable fixing structure according to claim 4,
Said 1st cable is a cable connected to a solar cell module, and said 2nd cable is a cable connected to a power converter device, The connection box for photovoltaic systems characterized by the above-mentioned.   The said 1st cable connection component is a switch, The connection box for solar power generation systems of Claim 5 characterized by the above-mentioned.

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