A current cut-out for starting batteries

Abstract

The utility model discloses a kind of current fuse devices of starting battery, it is related to battery pack technical field, solve the problem that it is difficult to design fusible fuse due to the high instantaneous current of starting battery.The device includes: circuit board;First busbar;Second busbar, second busbar and the current collection end electrical connection of circuit board and fuse element;Fuse element, fuse element is set between first busbar and second busbar, and the current collection end electrical connection of circuit board is respectively connected with first busbar and second busbar with the two sides of fuse element, multiple holes are set on fuse element, multiple holes are evenly distributed along the length direction of fuse element, to form fuse section between adjacent two holes, the melting point of fuse section is lower than copper.The device uses the principle of parallel shunt, shunts large current, and the melting point of lower fuse section will not be fused due to large current, ensure that current passes normally, once short-circuit fuse section is fused, protect battery.

Description

Technical Field

[0001] This utility model relates to the field of battery pack technology, and in particular to a current protection device for starting a battery. Background Technology

[0002] The battery pack consists of multiple battery cells connected in series and parallel. Several battery cells are placed inside the battery system housing and then connected in series and parallel via wires or busbars. A circuit board is installed inside the battery system housing; its main functions include managing the battery charging and discharging process, monitoring battery status, and protecting battery safety.

[0003] Inside the battery pack, the positive and negative terminals and posts of the battery cells are connected to the circuit board via a busbar. The busbar collects the current from several battery cells, transmits it to the circuit board, and then flows out through the circuit board, where it is relayed to the corresponding posts by the busbar. To protect the battery, modern busbars often include a fuse. The fuse is used to immediately disconnect the circuit in case of short circuits, overcurrent, or other unexpected situations, protecting the internal battery cells from damage and preventing spontaneous combustion and explosion.

[0004] In existing technology, the busbars in a battery pack used as a starting battery, which are used to output current, are generally divided into two parts: a first busbar and a second busbar. The first busbar is connected to the negative terminal of the battery cell, and the second busbar is connected to the negative terminal of the battery. A fuse is placed between the first and second busbars, and the two terminals of the fuse are electrically connected to the first and second busbars, respectively. The fuse contains a fusible link made of a copper alloy. Since the instantaneous current of a starting battery is usually quite high, and the resistance of a copper alloy is low, it can ensure that the current can pass smoothly. However, because its melting point is usually high, once a short circuit occurs, the temperature generated is usually not high enough to reach the melting point, making it difficult to completely melt the fusible link and thus interrupt the circuit. If a material with a very low melting point is used for the fuse, it is difficult to ensure that a large instantaneous current can pass through, which would cause the fusible link to melt instantly. Utility Model Content

[0005] The purpose of this invention is to solve the above-mentioned problems by designing a current protection device for a starting battery, which solves the problem that it is difficult to design a fusible fuse due to the high instantaneous current of the starting battery.

[0006] The technical solution of this utility model to achieve the above objectives is a current protection device for a starting battery, comprising: Circuit board; The first bus is used to collect current; The second bus is used to collect current, and the second bus is electrically connected to the current acquisition terminal of the circuit board and the fuse. A fuse is disposed between a first busbar and a second busbar, and both sides of the fuse are electrically connected to the current acquisition terminals of the first busbar and the second busbar and the circuit board, respectively. The fuse has multiple holes that are evenly distributed along the length of the fuse to form a fuse section between two adjacent holes that is easy to melt due to high temperature, thereby protecting the circuit. The melting point of the fuse section is lower than that of copper.

[0007] Preferably, the middle regions on both sides of the fused portion are recessed inward.

[0008] Preferably, the bottom of the first busbar and the second busbar are respectively provided with a first connecting piece and a second connecting piece. The opposite sides of the first connecting piece and the second connecting piece are bent downward to form a bent portion. The bent portion of the first connecting piece is inserted into the corresponding socket on the circuit board and welded and fixed, and is electrically connected to the fuse. The bent portion of the second connecting piece is inserted into the corresponding socket on the circuit board and welded and fixed, and is electrically connected to the fuse and the current acquisition terminal of the circuit board.

[0009] Preferably, the two sides of the fuse are bent downward to form a connecting part, and the connecting parts on both sides of the fuse are respectively inserted into the corresponding holes on the circuit board, and are electrically connected to the first connecting piece and the second connecting piece and the current acquisition terminal of the circuit board respectively.

[0010] Preferably, multiple clearance openings are provided along the length of the bend to divide the bend into multiple segments.

[0011] Preferably, an upper insulating member and a lower insulating member are respectively provided above and below the fuse, and the upper insulating member and the lower insulating member are fixedly connected to each other and the fuse is sandwiched between them.

[0012] Preferably, the circuit board has clearance holes for accommodating the upper and lower insulating components.

[0013] Its advantages over existing technologies are: The fuse in the current-protected device of this invention's starting battery is made of a low-temperature metal with a melting point lower than copper. Current flows from the first busbar to the fuse. Multiple holes in the fuse divide it into multiple fusing sections. As the current passes through the fuse, it simultaneously passes through these multiple fusing sections, which divert the current, preventing the lower-melting-point section from melting due to a large current, thus ensuring normal current flow before proceeding to the second busbar. In the event of a short circuit or overcurrent, the current will increase further. This will increase the current flowing through the fusing section, generating a temperature exceeding its melting point, causing it to melt and break the circuit, thus preventing damage to the battery cell. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the current protection device for starting the battery; Figure 2 This is a schematic diagram of the current protection device for starting the battery when the fuse, upper insulation, and lower insulation are removed. Figure 3 This is a schematic diagram of the first busbar structure; Figure 4 This is a schematic diagram of the bottom structure of the second busbar; Figure 5 This is a schematic diagram of the installation of the fuse, upper insulation component, and lower insulation component; Figure 6 This is a schematic diagram of the circuit board structure; Figure 7 This is a schematic diagram of the structure of the fuse.

[0015] In the diagram, 1 is the circuit board; 101 is the socket; 102 is the clearance hole; 2 is the first busbar; 3 is the second busbar; 4 is the fuse; 401 is the fuse part; 402 is the hole; 403 is the connecting part; 5 is the upper insulating part; 6 is the lower insulating part; 7 is the first connecting piece; 701 is the bending part; 8 is the second connecting piece; and 9 is the negative terminal. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0017] A preferred embodiment of this utility model provides a current protection device for a starting battery. This device improves upon the existing protection structure in starting batteries. While ensuring normal current flow, it can melt without excessively high temperatures in the event of a short circuit or overcurrent, thereby disconnecting the circuit and protecting the battery.

[0018] For details, see Figure 1 , Figure 2 The current protection device of the starting battery mainly includes components such as circuit board 1, first busbar 2, second busbar 3, fuse 4, upper insulator 5, and lower insulator 6.

[0019] Circuit board 1 serves as the battery management system for the starting battery, providing overcharge protection, over-discharge protection, overcurrent protection, short circuit protection, and temperature monitoring.

[0020] Both the first busbar 2 and the second busbar 3 are fixedly mounted on the circuit board 1. (See also...) Figure 3 , Figure 4Multiple mounting holes are provided on the first busbar 2 and the second busbar 3. Correspondingly, multiple mounting holes are also provided on the circuit board 1. The first busbar 2 and the second busbar 3 are fixed to the upper sides of the circuit board 1 by screws.

[0021] like Figure 2 , Figure 6 As shown, two rows of sockets 101 are provided on the circuit board 1, and the two rows of sockets 101 correspond to the first busbar 2 and the second busbar 3 respectively. Each row has multiple sockets 101.

[0022] The first busbar 2 is typically connected to the negative terminals of several battery cells, collecting and pooling the current from the battery cells. The second busbar 3 is typically connected to the negative terminal 9, which is mounted on the second busbar 3.

[0023] See Figure 3 , Figure 4 A first connecting piece 7 and a second connecting piece 8 are respectively provided at the bottom of the first busbar 2 and the second busbar 3. The first connecting piece 7 and the second connecting piece 8 are welded and fixed to the bottom of the first busbar 2 and the second busbar 3, respectively. The connecting piece is made of metal.

[0024] The first connecting piece 7 and the second connecting piece 8 are bent downward at 90° on opposite sides to form a bent portion 701. The bent portion 701 has multiple clearance openings, which are evenly distributed along the length of the bent portion 701, so that the bent portion 701 is divided into multiple segments, which correspond to the two rows of sockets 101 on the circuit board 1 respectively.

[0025] The bent portion 701 of the first connecting piece 7 is divided into multiple segments, each segment being inserted into a corresponding socket 101 on the circuit board 1. Each segment is further divided into multiple smaller segments so that molten solder can flow smoothly to the back of the bent portion 701 during soldering. The inner wall of the socket 101 has a metal layer so that the bent portion 701 can be soldered and fixed inside the socket 101.

[0026] Note that the bent portion 701 of the first connecting piece 7 is not directly electrically connected to the circuit board 1.

[0027] The bent portion 701 of the second connecting piece 8 is also divided into multiple segments, each segment being inserted into a corresponding socket 101 on the circuit board 1. Each segment is further divided into multiple smaller segments so that molten solder can flow smoothly to the back of the bent portion 701 during soldering. The inner wall of the socket 101 also has a metal layer. After the bent portion 701 is inserted into the socket 701, it is soldered and fixed to the inner wall on one side of the socket 101, and electrically connected to the fuse 4 and the current acquisition terminal of the circuit board 1.

[0028] Fuse 4 functions as a fuse. See also Figure 7The fuse element 4 has four holes 402 in its middle region, forming a hollow area. The four holes 402 are evenly distributed along the length of the fuse element 4. A fuse portion 401 is formed between two adjacent holes 402, forming a total of five fuse portions 401. The five fuse portions 401 are connected in parallel.

[0029] The middle regions on both sides of each fuse section 401 in the width direction are recessed inward, making the middle position of the fuse section 401 the narrowest. Once a short circuit occurs, the fuse will only melt at the narrowest point of the fuse section 401.

[0030] Both sides of the fuse 4 are bent downwards at 90° along its length to form connecting portions 403. The connecting portions 403 are also divided into multiple segments, each corresponding to a socket 101 on the circuit board 1. The connecting portion 403 on the left side of the fuse 4 is inserted into the socket 101 into which the bent portion 701 of the first connecting piece 7 is inserted, and is welded and fixed together with the bent portion 701 of the first connecting piece 7. Therefore, the connecting portion 403 on the left side of the fuse 4 is electrically connected to the bent portion 701 of the first connecting piece 7, but is not electrically connected to the circuit board 1.

[0031] After the connecting part 403 on the right side of the fuse 4 is inserted into the socket 101 into which the bent part 701 of the second connecting piece 8 is inserted, it is welded and fixed to the inner wall of the socket 101 on the side away from the second connecting piece 8, and is electrically connected to the current acquisition terminal of the circuit board 1.

[0032] In other words, the connecting part 403 on the right side of the fuse 4 comes into contact with the bent part 701 of the second connecting piece 8, and the current enters the second connecting piece 8 through the connecting part 403 on the right side of the fuse 4, and then enters the second busbar 3 through the second connecting piece 8.

[0033] Specifically, the current flows from the first busbar 2 to the fuse 4, is split at the five fuse sections 401 of the fuse 4, then flows into the second connecting piece 8 from the connecting part 403 on the right side of the fuse 4, then flows out from the second busbar 3, and finally flows to the negative terminal 9.

[0034] With the total input current and output current remaining constant, the fuse 4 shuns the current, so that the current passing through each fuse part 401 is smaller than the total current, thus all five fuse parts 401 are prone to melting.

[0035] The fuse 4 is a metal plate made of low-temperature metal materials, such as tin-based alloys, silver-based alloys, lead-antimony alloys, etc. The melting point is usually only a few hundred degrees, which is much lower than that of copper.

[0036] Multiple fuse sections 401 formed on the fuse element 4 divert the current. The current flowing through a single fuse section 401 is relatively small, so it will not melt due to a large current. In the event of a short circuit, overcurrent, or other similar situation, the current will increase further and exceed the melting point. Eventually, the fuse section 401 will melt at its narrowest point, breaking the circuit.

[0037] like Figure 5 The upper insulating member 5 and the lower insulating member 6 are fixed together by rivets, and the multiple fusible parts 401 in the middle of the fusible member 4 are hidden in the interlayer between the upper insulating member 5 and the lower insulating member 6. This serves two purposes: first, to protect the insulation; and second, if the fusible part 401 melts, the resulting molten metal will drip onto the lower insulating member 6, without damaging the battery cell and the circuit board 1.

[0038] Correspondingly, a rectangular clearance hole 102 is provided on the circuit board 1 to accommodate the upper insulating member 5 and the lower insulating member 6, so that the fuse 4 and the upper insulating member 5 are approximately flush with the upper surfaces of the first busbar 2 and the second busbar 3, which is more aesthetically pleasing and saves more space.

[0039] The above technical solution only embodies the preferred technical solution of this utility model. Any changes that may be made by those skilled in the art to certain parts of it embody the principle of this utility model and fall within the protection scope of this utility model.

Claims

1. A current protection device for a starting battery, characterized in that, include: Circuit board (1); The first bus (2) is used to collect current; The second bus (3) is used to collect current, and the second bus (3) is electrically connected to the current acquisition terminal of the circuit board (1) and the fuse (4); A fuse (4) is disposed between the first busbar (2) and the second busbar (3), and both sides of the fuse (4) are electrically connected to the current acquisition terminals of the first busbar (2) and the second busbar (3) and the circuit board (1), respectively. The fuse (4) has multiple holes (402) evenly distributed along the length of the fuse (4) so ​​as to form a fuse part (401) between two adjacent holes (402) that is easy to melt due to high temperature, thereby protecting the circuit. The melting point of the fuse part (401) is lower than that of copper.

2. The current protection device for the starting battery according to claim 1, characterized in that, The middle area on both sides of the fuse portion (401) is recessed inward.

3. The current protection device for the starting battery according to claim 1, characterized in that, The bottom of the first busbar (2) and the second busbar (3) are respectively provided with a first connecting piece (7) and a second connecting piece (8). The opposite sides of the first connecting piece (7) and the second connecting piece (8) are bent downward to form a bent part (701). The bent part (701) of the first connecting piece (7) is inserted into the corresponding socket (101) on the circuit board (1) and welded and fixed, and electrically connected to the fuse (4). The bent part (701) of the second connecting piece (8) is inserted into the corresponding socket (101) on the circuit board (1) and welded and fixed, and electrically connected to the current acquisition terminal of the circuit board (1) and the fuse (4).

4. The current protection device for the starting battery according to claim 3, characterized in that, The two sides of the fuse (4) are bent downward to form a connecting part (403). The connecting parts (403) on both sides of the fuse (401) are respectively inserted into the corresponding sockets (101) on the circuit board (1) and are electrically connected to the current acquisition terminal of the circuit board (1) of the first connecting piece (7) and the second connecting piece (8).

5. The current protection device for the starting battery according to claim 1, characterized in that, Multiple clearance openings are provided along the length of the bending portion (701) to divide the bending portion (701) into multiple segments.

6. The current protection device for the starting battery according to claim 1, characterized in that, An upper insulating member (5) and a lower insulating member (6) are respectively provided above and below the fuse (4). The upper insulating member (5) and the lower insulating member (6) are fixedly connected and the fuse (4) is sandwiched between them.

7. The current protection device for the starting battery according to claim 6, characterized in that, The circuit board (1) has clearance holes (102) for accommodating the upper insulating member (5) and the lower insulating member (6).

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