Over-temperature and over-current protection fuse

Abstract

The utility model relates to an over-temperature and over-current protection fuse which comprises a shell, a loop cut-off action mechanism is arranged in the shell, and conductor terminals extending out of the two ends of the shell are arranged on the two sides of the loop cut-off action mechanism respectively. The top and the bottom of the loop cut-off action mechanism are respectively provided with a melt with two ends extending to the two sides of the loop cut-off action mechanism, and the two ends of the melt are respectively connected with the conductor terminals through low-melting-point alloy; the melt is also provided with narrow-diameter structures, and the narrow-diameter structures are respectively located at the top and the bottom of the loop cut-off action mechanism. When the thermal runaway of the single battery occurs, the series bridge circuit and the parallel bridge circuit can be cut off, the fault battery is isolated, the thermal transfer phenomenon of a series loop is avoided, and the thermal runaway process of the fault battery is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of fuses, and in particular relates to an over-temperature and over-current protection fuse. Background Art

[0002] Fuse, commonly known as "fuse", is an overcurrent protection device, widely used in power distribution systems and control systems, mainly for short circuit protection or overload protection. Its working principle is: under the specified voltage conditions, the line current passes through the fuse, using the thermal effect of the current. When the heat accumulates to a certain extent, the current sensing point (narrow diameter) of the fuse melts and disconnects within the specified time, thereby safely disconnecting the fault current device.

[0003] At present, battery packs are usually used in group applications to increase capacity by connecting single cells in series and parallel. Thermal runaway of batteries usually occurs in the form of internal short circuits. When thermal runaway of single cells occurs, heat transfer occurs in the series circuit, affecting the series-connected batteries. The parallel circuit generates current backflow, causing overcurrent and accelerating the thermal runaway process of the faulty battery. Therefore, how to isolate the faulty battery according to the different fault mechanisms of the series-parallel circuits is an urgent problem to be solved in the industry. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides an over-temperature and over-current protection fuse, which can cut off the series bridge and parallel bridge circuits when a single cell thermal runaway occurs, isolate the faulty battery, avoid heat transfer in the series circuit, and reduce the thermal runaway process of the faulty battery.

[0005] In order to achieve the above object, the technical solution of the utility model is:

[0006] An over-temperature and over-current protection fuse comprises a housing, a circuit cut-off mechanism is arranged in the housing, and conductor terminals exposed at two ends of the housing are arranged on both sides of the circuit cut-off mechanism;

[0007] A melt having two ends extending to both sides thereof is provided at the top and bottom of the circuit cutting action mechanism, and the two ends of the melt are connected to the conductor terminal through a low melting point alloy;

[0008] The melt is also provided with a narrow diameter structure, and the narrow diameter structure is respectively located at the top and the bottom of the circuit cutting action mechanism.

[0009] In the above-mentioned over-temperature and over-current protection fuse, when the fuse is in a normal state, the circuit cutting action mechanism is in a compressed state;

[0010] When the fuse is in an over-temperature or over-load state, the low-melting-point alloy melts, and the melt and the conductor terminal separate under the force of the circuit-cutting action mechanism, disconnecting the circuit;

[0011] When the fuse is in a state of instantaneous high current, the narrow diameter structure of the fuse is disconnected, and the fracture of the narrow diameter structure is elongated under the force of the circuit cutting action mechanism, thus disconnecting the circuit.

[0012] In the above-mentioned over-temperature and over-current protection fuse, the circuit cutting action mechanism includes a fixed support, a compression spring, an upper movable plate and a lower movable plate; the fixed support is provided with a through hole, and the compression spring is inserted into the through hole; the upper movable plate and the lower movable plate are respectively arranged at the top and bottom of the fixed support, and are respectively connected to the two ends of the compression spring.

[0013] In the above-mentioned over-temperature and over-current protection fuse, terminal slots are respectively provided on both sides of the fixed support, and the conductor terminal is located at one end of the shell and is clamped in the terminal slot.

[0014] In the above-mentioned over-temperature and over-current protection fuse, the fixed support, the upper movable plate and the lower movable plate are all made of insulating materials.

[0015] In the above-mentioned over-temperature and over-current protection fuse, a clamping portion is provided in the middle section of the conductor terminal, and the conductor terminal is clamped on the side plates at both ends of the shell through the clamping portion.

[0016] In the above-mentioned over-temperature and over-current protection fuse, a cover plate for sealing the shell is provided on the top of the shell.

[0017] Technical effects and advantages of the utility model:

[0018] The utility model provides an over-temperature and over-current protection fuse. A circuit cut-off action mechanism is provided, and a melt is respectively provided at the top and the bottom of the circuit cut-off action mechanism, and the two ends of the melt are respectively connected to the conductor terminal through a low melting point alloy. When an overload current occurs and causes the fuse temperature to be higher than the melting point of the low melting point alloy, or a thermal runaway of the battery occurs and causes the fuse temperature to be higher than the melting point of the low melting point alloy, the low melting point alloy melts, the melt falls off from the conductor terminal, the circuit cut-off action mechanism loses its compression force, and the built-in spring tends to return to a normal state. Under the action of the circuit cut-off action mechanism force, the fuse is The lower fuse is separated from the conductor terminal to cut off the circuit; when a large instantaneous current passes through the circuit, the narrow neck structure of the fuse melts and the fuse is disconnected. The circuit cutting mechanism also loses its compression force, and the built-in spring tends to return to normal. Under the action of the action mechanism force, the arc is elongated to accelerate the separation of the narrow neck structure, thereby cutting off the circuit and isolating the faulty battery. When a single cell thermal runaway occurs, heat transfer in the series circuit is avoided, affecting the series battery group, and current backflow in the parallel circuit can be prevented, resulting in overcurrent, thereby reducing the thermal runaway process of the faulty battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a schematic diagram of the explosion structure of the utility model;

[0020] Figure 2 It is a schematic diagram of the overall structure of the utility model;

[0021] Figure 3 It is a schematic diagram of the explosion structure of the fixed support of the utility model;

[0022] Figure 4 It is a schematic diagram of the structure of the utility model in normal state;

[0023] Figure 5 This is a schematic diagram of the utility model in an over-temperature or over-load fusing state;

[0024] Figure 6 It is a schematic diagram of the utility model in a state of instantaneous high current fusing.

[0025] Numbers in the figure: 1, conductor terminal; 2, shell; 3, low melting point alloy; 4, melt; 5, circuit cutting action mechanism; 51, fixed support; 52, compression spring; 53, upper movable plate; 54, lower movable plate; 55, terminal slot; 6, cover plate. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below with reference to the embodiments given in the accompanying drawings.

[0027] In order to solve the problem of heat transfer in the series circuit when a single battery cell is thermally runaway, affecting the series battery pack, current backflow in the parallel circuit, causing overcurrent, and accelerating the thermal runaway process of the faulty battery, and how to isolate the faulty battery according to the different fault mechanisms of the series and parallel circuits, the utility model proposes the following design.

[0028] See Figure Figure 1-2 As shown, an over-temperature and over-current protection fuse is provided, which includes a housing 2, a circuit cutting action mechanism 5 is arranged inside the housing 2, and conductor terminals 1 exposed at both ends of the housing 2 are respectively arranged on both sides of the circuit cutting action mechanism 5.

[0029] A fuse 4 with two ends extending to both sides is provided at the top and bottom of the circuit cutting action mechanism 5, and the two ends of the fuse 4 are connected to the conductor terminal 1 through the low melting point alloy 3; a narrow diameter structure is also provided on the fuse 4, and the narrow diameter structure is respectively located at the top and bottom of the circuit cutting action mechanism 5. The narrow diameter structure is mainly used to quickly blow the fuse when the fuse is in an instantaneous large current, thereby playing a role of rapid protection.

[0030] For specific implementation, see Figure 3As shown, the circuit cutting action mechanism 5 of the present application includes a fixed support 51, a compression spring 52, an upper movable plate 53 and a lower movable plate 54; the fixed support 51 is provided with a through hole, and the compression spring 52 is passed through the through hole; the upper movable plate 53 and the lower movable plate 54 are respectively arranged at the top and bottom of the fixed support 51, and are respectively connected to the two ends of the compression spring 52.

[0031] In a specific implementation, the fixed support 51, the upper movable plate 53 and the lower movable plate 54 are all made of insulating materials.

[0032] For details, see Figure 4 As shown, when the fuse is in a normal state, the circuit cutting action mechanism 5 is in a compressed state.

[0033] For details, see Figure 5 As shown, when the fuse is in an over-temperature or over-load state, the low-melting-point alloy 3 melts, and the melt 4 and the conductor terminal 1 are separated under the force of the circuit cutting action mechanism 5 to break the circuit.

[0034] For details, see Figure 6 As shown, when the fuse is in a transient high current state, the narrow diameter structure of the fuse 4 is disconnected, and the narrow diameter structure of the fuse 4 is elongated under the force of the circuit cutting action mechanism 5 being ejected, thereby disconnecting the circuit.

[0035] When implementing it, participate Figure 3 As shown, the two sides of the fixing support 51 of the present application are respectively provided with terminal slots 55 . During assembly, one end of the conductor terminal 1 located in the housing 2 is clamped in the terminal slot 55 .

[0036] For specific implementation, see Figure 2 As shown, a clamping portion is provided in the middle section of the conductor terminal 1 , and during installation, the conductor terminal 1 can be clamped on the side plates at both ends of the housing 2 through the clamping portion.

[0037] For specific implementation, see Figure 2 As shown, the present application further provides a cover plate 6 on the top of the housing 2 to seal it.

[0038] The working principle of the present application is that when an overload current occurs and causes the temperature of the fuse to be higher than the melting point of the low-melting-point alloy 3, or when the battery has thermal runaway and causes the temperature of the fuse to be higher than the melting point of the low-melting-point alloy 3, the low-melting-point alloy 3 melts, the melt 4 falls off from the conductor terminal 1, the circuit cutting action mechanism 5 loses its compression force, and the built-in spring tends to return to a normal state. Under the action of the force of the circuit cutting action mechanism 5, the melt 4 is separated from the conductor terminal 1, and the circuit is cut off; when an instantaneous large current passes through the circuit, the narrow neck structure of the melt 4 melts, the melt 4 is disconnected, and the circuit cutting action mechanism 5 also loses its compression force. The built-in spring tends to return to a normal state. Under the action of the action mechanism force, the arc is elongated to accelerate the separation of the narrow neck structure, and the circuit is cut off, thereby isolating the faulty battery. When a single cell has thermal runaway, heat transfer in the series circuit is avoided, which affects the series battery group, and current backflow in the parallel circuit can be prevented, resulting in overcurrent, thereby reducing the thermal runaway process of the faulty battery.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. An over-temperature and over-current protection fuse, characterized in that: It comprises a housing (2), a circuit disconnection mechanism (5) is arranged inside the housing (2), and conductor terminals (1) exposed at two ends of the housing (2) are respectively arranged on both sides of the circuit disconnection mechanism (5); A melt (4) with two ends extending to both sides thereof is provided at the top and bottom of the circuit cutting action mechanism (5), and the two ends of the melt (4) are connected to the conductor terminal (1) via a low melting point alloy (3). The melt (4) is also provided with a narrow diameter structure, and the narrow diameter structure is respectively located at the top and bottom of the circuit cutting action mechanism (5).

2. The over-temperature and over-current protection fuse according to claim 1, characterized in that: When the fuse is in a normal state, the circuit cut-off action mechanism (5) is in a compressed state; When the fuse is in an over-temperature or over-load state, the low melting point alloy (3) melts, and the melt (4) and the conductor terminal (1) are separated under the action of the circuit cutting action mechanism (5) springing open, thereby disconnecting the circuit; When the fuse is in an instantaneous high current state, the narrow diameter structure of the fuse (4) is disconnected, and the narrow diameter structure of the fuse (4) is elongated under the action force of the circuit cutting action mechanism (5) to disconnect the circuit.

3. The over-temperature and over-current protection fuse according to claim 1, characterized in that: The circuit cut-off mechanism (5) comprises a fixed support (51), a compression spring (52), an upper movable plate (53) and a lower movable plate (54); the fixed support (51) is provided with a through hole, and the compression spring (52) is inserted into the through hole; the upper movable plate (53) and the lower movable plate (54) are respectively arranged at the top and bottom of the fixed support (51), and are respectively connected to the two ends of the compression spring (52).

4. The over-temperature and over-current protection fuse according to claim 3, characterized in that: Terminal slots (55) are respectively provided on both sides of the fixed support (51), and one end of the conductor terminal (1) located on the housing (2) is clamped in the terminal slot (55).

5. The over-temperature and over-current protection fuse according to claim 4, characterized in that: The fixed support (51), the upper movable plate (53) and the lower movable plate (54) are all made of insulating material.

6. The over-temperature and over-current protection fuse according to claim 1, characterized in that: A clamping portion is provided in the middle section of the conductor terminal (1), and the conductor terminal (1) is clamped on the side plates at both ends of the housing (2) through the clamping portion.

7. The over-temperature and over-current protection fuse according to claim 1, characterized in that: The top of the housing (2) is provided with a cover plate (6) for sealing the housing (2).

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