Welding fixing structure of battery pack

Abstract

The utility model discloses a welding and fixing structure of a battery pack, and relates to the technical field of battery modules. Comprising a battery module and a circuit board, the battery module comprises a fixing support, a plurality of lithium batteries arranged in the fixing support and a strip-shaped nickel sheet connected with the lithium batteries, a bonding pad is arranged on the circuit board, a soldering lug is arranged on the bonding pad and is a metal sheet, the area of the soldering lug is equivalent to that of the bonding pad, one end of the nickel sheet is connected with the lithium batteries, and the other end of the nickel sheet is connected with the soldering lug; a plurality of columnar lithium batteries are limited and fixed through the fixing bracket, so that the lithium batteries are reasonably arranged, the shock resistance is firm, and the safety of the battery pack is improved; through the arrangement of the steel soldering lug, the welding protection effect on the bonding pad can be effectively achieved, the high temperature generated when the nickel piece is welded to the bonding pad cannot directly act on the bonding pad, the damage rate of the circuit board is reduced, and the production cost is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery modules, and in particular to a welding fixing structure of a battery pack. Background Art

[0002] A multi-cell lithium battery pack is welded to a circuit board that controls its charging and discharging. The electrodes at both ends of the lithium battery are nickel sheets. The nickel sheets can be attached to both ends of the battery by spot welding with an electric welder. The other end of the nickel sheet needs to be spot welded to the copper pad on the circuit board. On the one hand, it provides a current path, and on the other hand, it firmly fixes the battery to the circuit board. There are generally two conventional processing methods: using tin as a flux, using a soldering iron or a placement machine to weld them together, or using an electric welder for spot welding.

[0003] The former requires more tin to be retained at the welding point, so the tin material consumption is higher and the production cost is high. If a soldering iron is used for welding, it takes more time (about five or six seconds or even more) to heat such a large soldering pad, the welding efficiency is low, and it is difficult to achieve a beautiful weld.

[0004] The latter can achieve rapid welding (the welding process may take less than 0.3 seconds), but the working principle of the electric welder for nickel sheet welding is to provide a momentary high current to the nickel sheet and its connecting part. Because the resistance is greatest at the contact point between the two, the heat generated by the high current will be concentrated there, eventually melting the contact surface of the two and fusing them together. Because the welding current of the electric welder is high and the copper pads of the circuit board are relatively thin, if the welding is done directly, the high current flowing through the copper pads can easily burn through the pads, resulting in welding failure and scrapping the circuit board. If the welding time is shortened, it is easy to cause poor welding and cold joints. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a welding fixing structure for a battery pack. By arranging a welding piece on the welding pad and placing the welding piece between the nickel sheet and the welding pad, the welding piece is used to prevent damage to the welding pad of the circuit board, thereby achieving the effect of protecting the circuit board and improving the welding strength.

[0006] The above technical purpose of the present utility model is achieved through the following technical solutions: a welding fixing structure of a battery pack, including a battery module and a circuit board, the battery module including a fixing bracket, a plurality of lithium batteries placed in the fixing bracket, and a strip-shaped nickel sheet connecting the plurality of lithium batteries, the circuit board is fixed on the fixing bracket, a soldering pad is provided on the circuit board, a soldering piece is provided on the soldering pad, the soldering piece is a metal sheet, the area of ​​the soldering piece is equivalent to that of the soldering pad, one end of the nickel sheet is connected to the lithium battery, and the other end thereof is connected to the soldering piece.

[0007] The present utility model is further configured as follows: The circuit board includes a board body, the pads are arranged at the edge of the board body, leads are provided at the pads, the pads are electrically connected to the board body, the solder tabs are fixedly connected to the pads by tin soldering and are electrically connected to the pads through the leads, and the nickel sheets and the solder tabs are fixedly connected by spot welding with an electric welding machine.

[0008] The present utility model is further configured as follows: The thickness of the solder tab is 0.2 - 0.5 mm, the solder tab is a steel sheet, and the solder tab is rectangular.

[0009] The present utility model is further configured as follows: The fixing bracket includes a "U" - shaped housing, an accommodating cavity is formed inside the housing, several of the lithium batteries are placed in the accommodating cavity, several limiting grooves are opened on the housing at the bottom of the accommodating cavity, the limiting grooves correspond to the lithium batteries one by one, wires are provided at the bottoms of the limiting grooves, and protective layers are pasted on the sides of the limiting grooves.

[0010] The present utility model is further configured as follows: The lithium battery is column - shaped, the lithium battery is vertically inserted into the limiting groove, and its bottom is electrically connected to the wire. The fixing bracket further includes a cover plate, the cover plate covers the upper end face of the lithium battery, a copper sheet is fixedly arranged on the electrode parts of two adjacent lithium batteries, a nickel sheet is welded to the middle of the upper end face of the copper sheet, and the nickel sheet is sequentially connected to several copper sheets.

[0011] The present utility model is further configured as follows: The length of the nickel sheet is greater than the length of the fixing bracket, the thickness of the nickel sheet is 0.3 - 1 mm, and at least two nickel sheets are provided.

[0012] In summary, the present utility model has the following beneficial effects: By using the fixing bracket to limit and fix several column - shaped lithium batteries, the lithium batteries are arranged reasonably, earthquake - resistant and firm, improving the safety of the battery pack; By providing the steel solder tabs, the pads can be effectively protected during welding, so that the high temperature and heat generated when the nickel sheet is welded to the pads cannot directly act on the pads, reducing the damage rate of the circuit board and saving the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of the solder tab of the present utility model;

[0014] Figure 2 is a schematic structural diagram of the battery module of the present utility model;

[0015] Figure 3 is a schematic structural diagram of the lithium battery of the present utility model.

[0016] In the figure: 1. Battery module; 2. Circuit board; 21. Pad; 3. Fixing bracket; 31. Cover plate; 4. Nickel sheet; 5. Lithium battery; 51. Copper sheet; 6. Solder tab. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0018] like Figure 1 、 Figure 2 、 Figure 3 As shown, the utility model provides a welding fixing structure of a battery pack, which consists of a battery module 1 and a circuit board 2, and the battery module 1 is electrically connected to the circuit board 2; the battery module 1 includes a fixing bracket 3, a plurality of lithium batteries 5 and a nickel sheet 4, the lithium batteries 5 are arranged in rows in the fixing bracket 3, and the lithium batteries 5 are provided in at least two rows, the two rows of lithium batteries 5 are close to each other, and a copper sheet 51 is connected between two adjacent parallel lithium batteries 5 in the two rows of lithium batteries 5, the copper sheet 51 is connected to the electrode of the lithium battery 5, and the nickel sheet 4 connects the plurality of lithium batteries 5 in sequence. Specifically, the nickel sheet 4 is connected to the copper sheet 51 between the two rows of lithium batteries 5, and can connect the two rows of lithium batteries 5 in series. One end of the nickel sheet 4 is also connected to the circuit board 2, and the circuit board 2 is fixed on the fixing bracket 3 when in use.

[0019] like Figure 1 As shown, a soldering pad 21 is provided at an edge of the circuit board 2, and a copper lead is provided at the soldering pad 21. The copper lead is used to electrically connect the connected nickel sheet 4 to the circuit board 2. The circuit board 2 is used for charge and discharge control of the battery module 1, and the circuit board 2 used here is common in the prior art. Other structures of the circuit board 2 are not described here. The rectangular soldering pad 21 corresponds to the rectangular soldering piece 6 in shape and has a similar area. When in use, the soldering piece 6 is fixedly connected to the soldering pad 21 by tin welding. The soldering piece 6 is a thin sheet made of steel. The thickness of the soldering piece 6 is preferably 0.2 mm. The material of the soldering piece 6 is made of The scraps cut during sheet metal processing are waste materials for recycling, which is beneficial to cost saving. The specifications of the welding pieces 6 are uniform, and they can be put into the placement machine and quickly, accurately and consistently welded to the pads 21 in batches by the placement machine, which is beneficial to improving production efficiency. Placing the steel welding piece 6 between the nickel piece 4 and the pad 21 can effectively improve the protection of the circuit board 2 during welding. The welding piece 6 can block the high temperature generated by the electric welder when welding the nickel piece 4, which directly affects the circuit board 2, and has a buffering protection effect, thereby reducing the damage rate of the circuit board 2, thereby reducing production costs, and is beneficial to enterprise promotion.

[0020] like Figure 1 、 Figure 2As shown, the fixing bracket 3 for accommodating the lithium battery 5 has a "U"-shaped housing. The space in the middle of the housing forms an accommodation cavity. A number of limiting grooves are opened on the housing at the bottom of the accommodation cavity. The limiting grooves correspond to the lithium batteries 5 one by one. The lower part of the lithium battery 5 extends into the limiting grooves, and the bottom of the lithium battery 5 is connected to the wires in the limiting grooves. A protective layer is covered on the inner side surface of the limiting grooves. The protective layer is made of a soft material, such as sponge, rubber ring, foaming material, and is used to squeeze and limit the lithium battery 5 extending into the limiting grooves. At the same time, the soft material can also play a protective role for the lithium battery 5; the cover plate 31 is a decentralized structure. The cover plate 31 is composed of multiple plate members. The cover plate 31 is used to cover the upper end of the lithium battery 5 after the lithium battery 5 is placed in the limiting groove. The copper sheet 51 is located below the cover plate 31. The nickel sheet 4 passes through between the two cover plates 31. The thickness of the nickel sheet 4 is 0.3 - 1 mm, and at least two nickel sheets 4 are provided; the combination of the fixing bracket 3 and the cover plate 31 can effectively provide the functions of limiting and protecting the installation of the lithium battery 5, prevent the lithium battery 5 from shaking during use, and is beneficial to improving the safety of the battery module 1.

[0021] The above are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A welding fixing structure for a battery pack, comprising a battery module (1) and a circuit board (2), characterized in that: The battery module (1) includes a fixing bracket (3), a plurality of lithium batteries (5) placed in the fixing bracket (3), and a strip-shaped nickel sheet (4) connecting the plurality of lithium batteries (5). The circuit board (2) is fixed on the fixing bracket (3). There is a pad (21) on the circuit board (2), and there is a welding piece (6) on the pad (21). The welding piece (6) is a metal sheet, and the area of the welding piece (6) is equivalent to that of the pad (21). One end of the nickel sheet (4) is connected to the lithium battery (5), and the other end is connected to the welding piece (6).

2. The welding fixing structure of a battery pack according to claim 1, characterized in that: The circuit board (2) includes a board body. The pad (21) is arranged at the edge part of the board body. There are leads at the pad (21). The pad (21) is electrically connected to the board body. The welding piece (6) is fixedly connected to the pad (21) by soldering and is electrically connected to the pad (21) through the leads. The nickel sheet (4) and the welding piece (6) are fixedly connected by spot welding with an electric welding machine.

3. The welding fixing structure of a battery pack according to claim 2, characterized in that: The thickness of the welding piece (6) is 0.2 - 0.5 mm. The welding piece (6) is a steel sheet and is rectangular in shape.

4. The welding fixing structure of a battery pack according to claim 1, characterized in that: The fixing bracket (3) includes a "U"-shaped housing. An accommodating cavity is formed inside the housing. A plurality of the lithium batteries (5) are placed in the accommodating cavity. A plurality of limiting grooves are formed in the housing at the bottom of the accommodating cavity. The limiting grooves correspond to the lithium batteries (5) one by one. Wires are provided at the bottoms of the limiting grooves, and protective layers are pasted on the sides of the limiting grooves.

5. The welding fixing structure of a battery pack according to claim 4, characterized in that: The lithium battery (5) is columnar. The lithium battery (5) is vertically inserted into the limiting groove, and its bottom is electrically connected to the wire. The fixing bracket (3) further includes a cover plate (31). The cover plate (31) covers the upper end face of the lithium battery (5). A copper sheet (51) is fixedly arranged on the electrode parts of two adjacent lithium batteries (5). The nickel sheet (4) is welded to the middle of the upper end face of the copper sheet (51), and the nickel sheet (4) connects a plurality of copper sheets (51) in sequence.

6. The welding fixing structure of a battery pack according to claim 5, characterized in that: The length of the nickel sheet (4) is greater than the length of the fixing bracket (3). The thickness of the nickel sheet (4) is 0.3 - 1 mm, and at least two nickel sheets (4) are provided.

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