Welding tool for main-grid-free battery

Abstract

The utility model discloses a welding tool for a main-grid-free battery, which comprises a rectangular frame, and a plurality of groups of fibers for pressing and fixing a welding strip on the surface of a battery piece and transmitting heat to the welding strip are arranged in the rectangular frame at intervals; and the fiber yarns are carbon fiber yarns with heat conductivity, elasticity and wear resistance. According to the device, the number of fibers is set according to the number of welding points, the fibers are perpendicular to a welding strip and densely and uniformly press the welding strip on the surface layer of a battery, and the welding effect is improved; the fibers are in flexible contact with the battery piece, the strength is uniform, and the situation that the conversion efficiency of the battery piece is influenced by the change of an internal microstructure caused by overhigh yield of the battery piece is avoided; the fiber pressing strength is adjusted through the bundle fastening piece, excessive pressing is effectively avoided, meanwhile, fiber loosening caused by long-time use is avoided, the service life is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The utility model relates to a welding tool for solar cell strings, in particular to a welding tool for non-main-grid batteries. Background Art

[0002] Traditional main-grid solar cell wafers have obvious main grid lines for collecting the current on the fine grid lines. The main grid lines will block part of the incident light, thereby affecting the power generation efficiency of the solar cell wafers. With the development of technology, non-main-grid batteries are gradually moving towards industrialization. The welding tapes used in the string welding process are finer, and their diameter is only 40% - 60% of the welding tape of traditional main-grid solar cell wafers. At the same time, in order to meet the efficiency of current transmission, the number of welding tapes increases by 2 - 3 times. The existing welding tools are usually made of aluminum alloy, with a single-piece weight between 400g and 500g. A plurality of cross beams are evenly arranged inside, and a large number of metal welding points are arranged on the cross beams. During the welding process, the metal welding points press the welding tape on the surface of the solar cell wafer, and transfer heat to the welding position directly and indirectly to weld the welding tape firmly on the surface of the solar cell wafer. The existing welding tool equipment is heavy in quality, and it is easy to cause micro-cracks in the solar cell wafers during the pressure welding process. Research data shows that especially in heterojunction solar cell wafers, only after the process of being pressed by the welding tool, the efficiency attenuation will occur by 0.5% - 0.7%. The increase in the welding tapes of non-main-grid batteries requires more cross beams to be added, further increasing the quality of the tool equipment and increasing the risk of micro-cracks; furthermore, after the welding tapes become thinner, the existing tool equipment cannot meet the welding precision; in addition, the springs inside the metal welding heads are prone to fatigue failure after long-term use, resulting in excessive pressure on the surface of the solar cell wafers, further increasing the risk of damage to the internal microscopic structure of the solar cell wafers and affecting the conversion efficiency of the solar cells. Summary of the Utility Model

[0003] Purpose of the Utility Model: The purpose of the utility model is to provide a welding tool for non-main-grid batteries to avoid the reduction of the conversion efficiency of solar cell wafers caused by pressure welding.

[0004] Technical Solution: The welding tool for non-main-grid batteries described in the utility model includes a rectangular frame, and a plurality of groups of fiber filaments for pressing and fixing the welding tape on the surface of the solar cell wafer and transferring heat to the welding tape are arranged at intervals inside the rectangular frame; the fiber filaments are carbon fiber filaments with heat conductivity, elasticity and wear resistance.

[0005] Further, the number of the fiber filaments is 15 - 30, and the wire diameter is 0.1 - 0.3mm.

[0006] Further, two rows of round holes are symmetrically arranged on both sides of the rectangular frame; the round holes include a lower row of round holes for threading and pressing the surface solder tapes of the battery cells with fiber filaments, and an upper row of round holes for fixing the fiber filaments. The upper row of round holes is provided with 2 - 6 groups, and the hole diameter is 2 - 4 mm; the lower row of round holes is provided with 20 - 50 groups, and the hole diameter is 0.5 - 1 mm. A filament fastener for taking in and letting out the fiber filament is provided for each fiber filament, and the tightness of the fiber filament is adjusted through the filament fastener, so that a suitable and uniform force is applied to the surface of the battery cell to complete the series soldering of the battery cells, preventing the destruction of the internal microstructure of the battery cell due to excessive pressure and thus reducing the conversion efficiency of the battery cell. The fiber filament passes through the round holes in the upper row and the lower row to form multiple loops: if the number of loops is small, the tightness consistency of the carbon fiber filaments is good, the force applied to the battery cell is more uniform, the soldering effect is better, and at the same time, the microcracks of the battery cell caused by uneven stress can be reduced; if the number of loops is large, it is convenient for maintenance, and more loops can be set by increasing the number of round holes 4 in the upper row, reducing the consumption of materials caused by replacing materials due to damage in individual places.

[0007] Further, the filament fastener includes a cylinder A that cooperates with the upper row of round holes to fix one end of the fiber filament and a cylinder B that is fixed to the cylinder A and is used to fasten the other end of the fiber filament; the diameter of the cylinder B is larger than that of the cylinder A, and a winding groove for taking in and letting out the fiber filament is provided on the cylinder B.

[0008] Beneficial effects: Compared with the prior art, the present utility model has the following advantages: 1. The number of fiber filaments is set according to the number of welding points, and the fiber filaments are perpendicular to the solder tapes, densely and evenly pressing them on the surface of the battery cell, improving the soldering effect; 2. The fiber filaments are in flexible contact with the battery cell and the force is uniform, avoiding the change of the internal microstructure of the battery cell due to excessive yield of the battery cell and thus affecting the conversion efficiency of the battery cell; 3. The pressing strength of the fiber filaments is adjusted through the filament fastener, effectively avoiding over-pressing while avoiding the relaxation of the fiber filaments caused by long-term use, improving the service life and reducing the maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic structural view of the present utility model;

[0010] Figure 2 is a cross-sectional view of the structure of the present utility model;

[0011] Figure 3 is a side view of the structure of the present utility model;

[0012] Figure 4 is a schematic structural view of the filament fastener of the present utility model;

[0013] Figure 5 is a perspective view of the structure of the present utility model;

[0014] Figure 6 This is a working schematic diagram of the structure of the present utility model. Specific embodiments

[0015] The technical solution of the present utility model will be further described below with reference to the accompanying drawings.

[0016] As Figure 1 and 2 shown, a welding tooling for a main-grid-free battery includes a rectangular frame 1. Inside the rectangular frame 1, multiple groups of carbon fiber filaments 2 for pressing and fixing the solder tapes on the surface of the battery cells and transmitting heat to the solder tapes are arranged at intervals. The carbon fiber filaments 2 are fixed between the rectangular frames 1 through beam fasteners 3. It has thermal conductivity, elasticity and wear resistance. The number is set to 20, and the wire diameter is 0.2 mm (the number of carbon fiber filaments 2 can also be set between 15 - 30 according to the number and thickness of the solder tapes on the battery cells, and the wire diameter is set to 0.1 - 0.3 mm). As Figure 3 On both sides of the rectangular frame 1, two rows of round holes are symmetrically arranged: the lower row of round holes 5 is used for threading and pressing the carbon fiber filaments 2 for fixing the solder tapes on the surface of the battery cells. There are 20 groups, and the hole diameter is 0.5 mm (the number of groups can also be set between 20 - 50 according to the need, and the hole diameter is 0.5 - 1 mm); the upper row of round holes 4 is used for fixing the carbon fiber filaments 2. There are 2 groups, and the hole diameter is 3 mm (the number of groups can also be set between 2 - 6 according to the need, and the hole diameter is 2 - 4 mm). One carbon fiber filament 2 is configured with one beam fastener 3. As Figure 4 shown, the beam fastener 3 includes a cylinder A 6 that cooperates with the upper row of round holes 4 to fix one end of the fiber filament and a cylinder B 7 that is fixed to the cylinder A 6 and is used to fasten the other end of the fiber filament 2. The diameter of the cylinder B 7 is larger than that of the cylinder A 6, and a wire winding groove 8 for winding and releasing the fiber filament is provided on the cylinder B 7. As Figure 5 shown, one end of the carbon fiber filament 2 is fixed on the cylinder A 6 of the wire take-up fastener 3. The cylinder A 6 is fixed in the upper row of round holes 4 on one side of the rectangular frame 1. The carbon fiber filament 2 passes through the upper row of round holes 4 on the other side, then sequentially passes through 20 groups of lower row of round holes 5, and then passes through another pair of upper row of round holes 4 and returns to the wire take-up fastener 3, and then winds its other end in the wire winding groove 8 on the cylinder B 7 to form a loop. One or a small number of loops make the tightness consistency of the carbon fiber filaments 2 more uniform, the force applied to the battery cells more uniform, and the welding effect better. At the same time, it can reduce the micro-cracks of the battery cells caused by uneven stress. For the convenience of maintenance, the number of upper row of round holes 4 can be increased to set more loops, reducing the consumption of materials caused by replacing materials due to damage in individual places.

[0017] When in use, as Figure 6As shown in the figure, the entire welding tooling is placed above the non-grid cell, making the carbon fiber wire 2 perpendicular to the solder tape of the non-grid cell. The tightness of the carbon fiber wire 2 is adjusted through the wire bunch fastener 3, so that it evenly presses the solder tape and transfers heat to the solder tape to complete the series welding of the cells.

Claims

1. A welding tooling for a main-gridless battery, comprising a rectangular frame (1), characterized in that, Multiple groups of fiber filaments (2) for pressing and fixing the surface solder tapes of battery cells and transferring heat to the solder tapes are arranged at intervals within the described rectangular frame (1); the fiber filaments (2) are carbon fiber filaments with heat conductivity, elasticity, and wear resistance.

2. The welding tooling for the ownerless grid battery according to claim 1, characterized in that, The number of the fiber filaments (2) is 15 - 30.

3. The welding tooling for the ownerless grid battery according to claim 1 or 2, characterized in that The wire diameter of the fiber filaments (2) is 0.1 - 0.3 mm.

4. The welding tooling for the main-gridless battery according to claim 1, wherein Two rows of round holes are symmetrically arranged on both sides of the described rectangular frame (1); the round holes include lower row round holes (5) for threading and pressing the fiber filaments for fixing the surface solder tapes of battery cells and upper row round holes (4) for fixing the fiber filaments.

5. The welding tooling for the main-gridless battery according to claim 4, characterized in that, There are 2 - 6 groups of the upper row round holes (4), and the hole diameter is 2 - 4 mm.

6. The welding tooling for the main-gridless battery according to claim 4, wherein There are 20 - 50 groups of the lower row round holes (5), and the hole diameter is 0.5 - 1 mm.

7. The welding tooling for the ownerless grid battery according to claim 4, characterized in that, A filament fastener (3) for winding and unwinding the fiber filament is arranged on one fiber filament (2); multiple loops formed by the fiber filament (2) threading through the upper row round holes (4) and the lower row round holes (5) are provided.

8. The welding tooling for the ownerless grid battery according to claim 7, characterized in that, The filament fastener (3) includes a cylinder A (6) that cooperates with the upper row round hole (4) to fix one end of the fiber filament and a cylinder B (7) fixed to the cylinder A (6) for fastening the other end of the fiber filament (2); the diameter of the cylinder B (7) is larger than that of the cylinder A (6), and a wire winding groove (8) for winding and unwinding the fiber filament is provided on the cylinder B (7).

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