CN114203494A

CN114203494A - Quick intelligent fuse

Info

Publication number: CN114203494A
Application number: CN202111615028.2A
Authority: CN
Inventors: 不公告发明人
Original assignee: Lignin
Current assignee: Lignin
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2022-03-18

Abstract

The invention discloses a quick intelligent fuse which is a circuit safety protection device in a high-voltage loop of a battery system and comprises a base assembly, a cutting assembly, a copper bar and a base assembly. The cutting assembly is arranged in the cylindrical cavity of the base assembly, the copper bar is arranged between the base assembly and the base assembly, the copper bar comprises a cutting opening, and the cutting opening is arranged corresponding to the cutting assembly; the built-in second electric ignition tube of the cutting assembly is used for communicating the elastic connecting piece with the second contact sliding block to generate explosion airflow generated by secondary explosion to blow electric arcs when the cutting assembly moves downwards to cut off the copper bar, so that a safe and rapid cutting circuit of the rapid intelligent fuse is ensured. Through the mode, the invention can improve the electrical characteristics, has small energy consumption and low temperature rise in normal work, has high insulation resistance after a fault occurs, establishes effective physical isolation in a circuit, ensures the system safety, can reduce the application difficulty and cost in the prior art, effectively protects the energy spectrum range and can cover wider voltage and current ranges.

Description

Quick intelligent fuse

Technical Field

The invention relates to a fuse, in particular to a quick intelligent fuse.

Background

The existing high-voltage loop fuse of the battery system is often a passive fuse, and the passive fuse has the following problems: the high-voltage system cannot be actively protected, and only passive protection can be realized; only partial current range protection can be realized for a high-voltage system; the fuse is a current protector made by the principle that after the current exceeds a specified value for a period of time, the melt is melted by the heat generated by the fuse, so that the circuit is disconnected. In the prior art in the current market, a fuse is connected with a conductive copper bar in parallel, and current (according to different proportions) flows through the fuse and the copper bar simultaneously in a normal state. When a fault occurs, the central controller of the system judges and sends an action signal to detonate the explosive preset in the fuse to drive the firing pin to cut off the copper bar, so that the parallel fuse is induced to be disconnected, and finally the fault current is cut off. Under normal state, fuse and copper bar are parallelly connected, shunt in coordination. Although the current passing through the fuse is much smaller than the current on the copper bar, the cost is that the resistance of the fuse is much higher than that of the copper bar, and as a result, the fuse generates heat obviously in a normal state.

In this case, numerous problems or failures may result, in order of severity: 1. the protection device has large heat emission, and the ambient temperature is improved; 2. the fuse works at high temperature for a long time, and the service life is shortened due to the thermal fatigue effect; 3. if the parallel fuse is disconnected in advance and is not detected, once a fault occurs, all fault currents pass through the copper bar, and the copper bar breaking mechanism (such as an ignition switch) is difficult to effectively extinguish the arc, so that arc spraying, burning and even explosion can be caused greatly; 4. in the prior art, an electronic circuit mechanism is relatively complex, the system failure risk is relatively high, and the like; 5. under the condition of a certain installation space, the energy spectrum range of the prior art is severely limited, and particularly when the current is increased, the size of the device is too large, and the requirement of miniaturization is difficult to meet.

Disclosure of Invention

The invention mainly solves the technical problem of providing a quick intelligent fuse which can resist the allowed overcurrent impact and does not generate misoperation under the normal working condition, and simultaneously, when a fault occurs, the circuit breaking speed is fast enough to meet the specified protection requirement.

In order to solve the technical problems, the invention adopts a technical scheme that: the quick intelligent fuse comprises a base assembly (1), a cutting assembly (2), a copper bar (3) and a base assembly (4), wherein the base assembly (1) comprises a first electric ignition tube (11), a first sliding contact (12) and a second sliding contact (13) which are distributed on two sides of a cylindrical cavity copper bar in the direction, the first sliding contact (12) extends towards the outer side of the base to form a reserved detection port, and the second sliding contact (13) can be communicated with the copper bar (3); the cutting assembly (2) comprises a cutting part, a second electric ignition tube (21) and elastic connecting pieces (22), the elastic connecting pieces (22) are arranged on two sides of the cutting assembly (2), and the elastic connecting pieces (22) can be communicated with a second sliding contact (13) of the base assembly (1) when the cutting assembly (2) moves downwards; the base assembly (4) comprises fireproof silencing cotton (41) and locking columns (42) which are distributed on two sides of the copper bar direction; the copper bar (3) comprises a cut-off port, and the cut-off port and the cut-off part of the cut-off assembly (2) are arranged correspondingly.

In the invention, the fast intelligent fuse further comprises a trigger signal sending component, and the trigger signal sending component is arranged in a control unit of a system where the fast intelligent fuse is located. In the invention, the second electric ignition tube (21) is not connected with the copper bar (3) in parallel and is not connected into a circuit in a normal state, so that the fatigue damage or abnormal detonation of the second electric ignition tube (21) caused by pulse current in a system can be avoided, secondary explosion is generated, and the electric arc generated at the cut-off of the copper bar (3) is blown away by utilizing the explosion airflow, thereby playing the role of quickly and intelligently extinguishing the arc of the fuse. In the invention, small steps are arranged on two sides of the cylindrical cavity opening copper bar (3) of the base assembly (1) in the direction, so that the cutting assembly (2) is installed into the base assembly (1) under the assistance of a clamp, an elastic connecting piece (22) of the cutting assembly (2) is ejected after the rapid intelligent fuse acts, and the cutting assembly (2) is prevented from moving axially in the cylindrical cavity of the base assembly (1) after the rapid intelligent fuse acts. In the invention, the base assembly (4) comprises fireproof noise reduction cotton (41) and lock columns (42) which are distributed on two sides of the copper bar (3) in the direction, the fireproof noise reduction cotton (41) can effectively reduce noises generated by explosion and eliminate sparks brought by airflow, and the lock columns (42) can clamp cut-off copper bar blocks to prevent the copper bar block reconnection of circuits caused by vibration and the like.

The invention has the beneficial effects that:

the fast intelligent fuse is strong in capability of bearing impact current, and the system malfunction is few: under normal conditions, the current that flows through quick intelligent fuse only passes through copper bar (3), and other parts do not have the current to pass through including second electric ignition tube (21) etc. and mean that the stability of device under the normal condition is decided by copper bar (3), does not receive the influence of other parts. The stability of the quick intelligent fuse is fully verified and can be reliably guaranteed. In contrast, in the prior art, current proportionally passes through the switch and the fuse connected in parallel with the switch in a normal state, but due to shunt requirements, the resistance of the fuse is much higher than that of the switch connected in parallel, and the impact current easily causes the device to be disconnected in advance, so that the system malfunctions.

The quick intelligent fuse is good in breaking characteristic and strong in protection capability, and is convenient to detect the state of the device: before the fault of the quick intelligent fuse occurs, the second electric ignition tube (21) is not connected with the copper bar (3) in parallel and is not connected into a circuit in a normal state, so that the fatigue damage or abnormal detonation of the second electric ignition tube (21) caused by pulse current in the system can be avoided, and the potential hazard is eliminated for subsequent safe fusing of the quick intelligent fuse. In contrast, in the prior art, current proportionally passes through the switch and the arc-extinguishing fuse connected in parallel with the switch under a normal state, but the resistance of the arc-extinguishing fuse is much higher than that of the switch connected in parallel, and long-term through-current can cause the fuse to have poor characteristics and even fuse in advance, so that the intelligent fuse blows arc, burns and even explodes when acting.

Thirdly, the first electric ignition tube (11) explodes to push the cutting assembly to cut (2) the copper bar (3), and the elastic connecting piece (22) is connected and conducted with the second sliding contact (13), and is of a mechanical structure, safe and reliable.

Fourthly, the spectrum (current and voltage) range of the protection of the fast intelligent fuse is wide: voltage range of the fast intelligent fuse: 70-3000V, current range: dozens to 1500A.

And fifthly, the resistance and the temperature rise of the quick intelligent fuse are lower than those of the prior art by more than 15%.

Sixthly, the rapid intelligent fuse can be arranged among the series-connected electric cores in the battery pack body and used for reducing voltage drop of the pack body when the battery pack body is soaked in water, reducing the risk of arc discharge and explosion, and isolating abnormal electric core blocks when thermal runaway, so that the application scene is wider.

Description of the drawings:

in order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, wherein:

FIG. 1 is a schematic diagram of a fast intelligent fuse embodiment of the present invention;

1, a base assembly; 2 cutting off the assembly; 3, copper bars; 4, a base assembly; 11 a first electric squib; 12 a first sliding contact; 13 a second sliding contact; 21 a second electric squib; 22 an elastic connection member; 41 fireproof noise reduction cotton; 42 lock cylinder

FIG. 2 is a schematic diagram of the first electrical squib exploded upon initiation of operation of the fast intelligent fuse of FIG. 1;

fig. 3 is a schematic diagram of the structure of a second electrical squib exploded during operation of the fast intelligent fuse of fig. 1;

fig. 4 is a schematic diagram illustrating the operation of the fast intelligent fuse shown in fig. 1.

The specific implementation mode is as follows:

the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. Referring to fig. 1 and 2, a fast intelligent fuse is provided, which includes a base assembly (1), a disconnecting assembly (2), a copper bar (3), and a base assembly (4). The base assembly (1) comprises a first electric ignition tube (11), a first sliding contact (12) and a second sliding contact (13), wherein the first sliding contact (12) and the second sliding contact (13) are distributed on two sides of the copper bar in the direction of the cylindrical cavity, the first sliding contact (12) extends towards the outer side of the base to form a reserved detection port, and the second sliding contact (13) can be communicated with the copper bar (3); the cutting assembly (2) comprises a cutting part, a second electric ignition tube (21) and elastic connecting pieces (22), the elastic connecting pieces (22) are arranged on two sides of the cutting assembly (2), and the elastic connecting pieces (22) can be communicated with a second sliding contact (13) of the base assembly (1) when the cutting assembly (2) moves downwards; the base assembly (4) comprises fireproof silencing cotton (41) and locking columns (42) which are distributed on two sides of the copper bar direction; the copper bar (3) comprises a cut-off port, and the cut-off port and the cut-off part of the cut-off assembly (2) are arranged correspondingly. The first electric ignition tube (11) is used for exploding to generate a high-voltage area in a closed cavity formed by the cylindrical cavity of the base assembly (1) and the cutting assembly (2), and then pushing the cutting assembly (2) to move downwards to drive a cutting part of the cutting assembly (2) to cut off the copper bar (3). The second electric ignition tube (21) is used for communicating the elastic connecting piece (22) on the cutting assembly (2) with the second sliding contact (13) of the base assembly (1) when the cutting assembly (2) moves downwards to cut off the cutting opening of the copper bar (3), and the second electric ignition tube (21) is connected into a circuit and is rapidly exploded to generate high-pressure and high-speed gas to blow off electric arcs generated at the cutting opening of the copper bar (3), so that the second electric ignition tube plays a role in generating high-pressure and high-speed gas to blow off the electric arcs through explosion. The elastic connecting piece (22) is communicated with the first sliding contact (12), and whether the internal resistance of the second electric ignition tube (21) is normal or not can be detected through the pin detection port of the first sliding contact (12). Base assembly (1) cartridge type cavity mouth copper bar (3) direction both sides are done little step, are convenient for cut off assembly (2) and install into under anchor clamps are supplementary base assembly (1) and quick intelligent fuse action back elastic connecting piece (22) of cutting off assembly (2) pop out, prevent that quick intelligent fuse action the later-mentioned assembly (2) of cutting off is in base assembly (1) cartridge type intracavity axial activity. Base assembly (4) are including distributing at fire prevention amortization cotton (41) and lock post (42) of copper bar (3) direction both sides, and fire prevention amortization cotton (41) its noise that can effectively reduce the explosion production and the spark of eliminating the air current and taking out, and lock post (42) can block the copper bar cutting off block that cuts off down, prevents to cut off the block reconnection circuit because of copper bar such as vibration. The first electric ignition tube (11) and the trigger signal sending part are connected in series on the control circuit, the ignition of the first electric ignition tube (11) is controlled by the trigger signal sending part, the trigger signal sending part is integrated in a control system (such as a BMS of a new energy automobile), and the control circuit provides trigger ignition current (1A-3A) in the invention.

The protection method of the rapid intelligent fuse comprises the following steps:

firstly, under the normal operating condition of system, the electric current passes through copper bar (3), and elastic connecting piece (22) and first sliding contact (12) formation intercommunication setting of cutting off assembly (2), and second electric ignition tube (21) are in the off-state and do not have the electric current to pass through, quick intelligent fuse's resistance value is decided by copper bar (3).

When a fault occurs, the triggering signal sending part sends detonation current to the first electric ignition tube (11) to detonate gunpowder in the gunpowder part of the first electric ignition tube (11), a high-voltage region is formed in the sealed cavity by explosion to enable the cutting assembly (2) to descend, and the cutting part on the cutting assembly (2) cuts off the copper bar (3) at the cutting opening, as shown in figure 2.

And thirdly, in the descending process of the cutting assembly (2), the elastic connecting piece (22) is in contact conduction with the second sliding contact point (13), and the second electric ignition tube (21) is connected into the circuit and rapidly explodes to generate high-pressure and high-speed gas to blow away electric arcs generated at the cutting opening of the copper bar (3), as shown in figure 3.

Fourth, the second electric igniter pipe (21) explosion area is the non-airtight cavity, only prevent that fire prevention amortization cotton (41) blocks to be unanimous with outside atmosphere ordinary pressure, do not have too big influence to the continuation of cutting off assembly (2) down, cut off assembly (2) this moment and promote copper bar (3) cutting off piece and continue to descend until the cutting off piece card on the lock post of base assembly (4), elastic connecting piece (22) on cutting off assembly (2) continue to pop out the card on the little step of base assembly (1), stop and cut off assembly (2) possibility of ascending, and then form physical isolation between the cut-off mouth of copper bar (3), prevent that system's fault current from recanalizing, as figure 4.

Under normal operating condition, quick intelligent fuse can guarantee that the system bears the overcurrent impact of allowwing and does not take place the malfunction and break off in advance to even make the system also can stable work under abominable operating mode like electric automobile. When a fault occurs, the quick intelligent fuse can quickly cut off fault current within a specified time, safe and effective physical isolation is established in a circuit, and the fault is stopped without continuing to be expanded, so that the safety of a system such as an electric automobile and personnel is reliably protected. When a fault occurs, the quick intelligent fuse acts after receiving the trigger signal, and the action speed meets the specified requirement for ensuring safety.

The invention can improve the electrical characteristics of the prior art, and when a system applied by the quick intelligent fuse works normally, the energy consumption of the quick intelligent fuse is low and the temperature rise is low; after the fault occurs, the insulation resistance of the quick intelligent fuse is high, effective physical isolation is established in the circuit, and the system safety is guaranteed. The invention can reduce the application difficulty and cost of the prior art, the effective protection energy spectrum range of the rapid intelligent fuse is wide, the range of voltage and current is wider than that of the prior art, and the user pain of complicated product selection, various specifications, high application cost and the like in the prior art is relieved. The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the present specification, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A quick intelligent fuse is characterized by comprising a base assembly (1), a cut-off assembly (2), a copper bar (3) and a base assembly (4), wherein the base assembly (1) comprises a first electric ignition tube (11), a first sliding contact (12) and a second sliding contact (13) which are distributed on two sides of a cylindrical cavity copper bar in the direction, the first sliding contact (12) extends towards the outer side of the base to form a reserved detection port, and the second sliding contact (13) can be communicated with the copper bar (3); the cutting assembly (2) comprises a cutting part, a second electric ignition tube (21) and elastic connecting pieces (22), the elastic connecting pieces (22) are arranged on two sides of the cutting assembly (2), and the elastic connecting pieces (22) can be communicated with a second sliding contact (13) of the base assembly (1) when the cutting assembly (2) moves downwards; the base assembly (4) comprises fireproof silencing cotton (41) and locking columns (42) which are distributed on two sides of the copper bar direction; the copper bar (3) comprises a cut-off port, and the cut-off port and the cut-off part of the cut-off assembly (2) are arranged correspondingly.

2. A fast intelligent fuse according to claim 1, characterised in that the second electrical squib (21) is not connected in parallel with the copper bar (3) and is not connected into the circuit in a normal state, so as to avoid fatigue damage or abnormal detonation of the second electrical squib (21) caused by the pulse current in the system.

3. A rapid intelligent fuse according to claim 1, characterized in that the elastic connector (22) is provided in communication with the first sliding contact (12), and whether the internal resistance of the second electric squib (21) is normal or not can be detected through the pin detection port of the first sliding contact (12).

4. The fuse of claim 1, wherein the two sides of the copper bar (3) of the cylindrical cavity of the base assembly (1) are stepped to facilitate the installation of the cut-off assembly (2) into the base assembly (1) with the aid of a clamp and the ejection of the elastic connector (22) of the cut-off assembly (2) after the fuse is operated, so as to prevent the axial movement of the cut-off assembly (2) in the cylindrical cavity of the base assembly (1) after the fuse is operated.

5. The quick intelligent fuse according to claim 1, characterized in that the base assembly (4) comprises fireproof noise reduction cotton (41) and locking columns (42) distributed on two sides of the copper bar (3) in the direction, the fireproof noise reduction cotton (41) can effectively reduce noise generated by explosion and eliminate sparks brought out by airflow, and the locking columns (42) can clamp cut-off blocks of the copper bar, so as to prevent a circuit of a system for connecting the cut-off blocks of the copper bar repeatedly due to vibration and the like.