Intelligent fuse control circuit and intelligent fuse

Abstract

This application provides an intelligent fuse control circuit and an intelligent fuse, including an internal trigger circuit and an external trigger circuit. A signal fuse element, a first pre-cutting section, and a second pre-cutting section are sequentially connected on a conductor. The external trigger circuit is connected to a first ignition device and triggers the first ignition device according to an external trigger signal, causing the first ignition device to generate high-pressure gas that pushes a first impact member to cut off the corresponding first pre-cutting section. The internal trigger circuit is connected to a second ignition device and triggers the second ignition device according to a second current generated after the first pre-cutting section is cut, causing the second ignition device to generate high-pressure gas that pushes a second impact member to cut off the corresponding second pre-cutting section. Through the interlocking triggering of the external and internal trigger circuits, two sets of breaks are formed on the conductor, allowing the current on the conductor to quickly transfer to the arc-extinguishing fuse element, reducing the erosion time of the arc-extinguishing fuse element under high current.

Description

Technical Field

[0001] This application belongs to the field of emergency protection device technology, specifically relating to an intelligent fuse control circuit and an intelligent fuse. Background Technology

[0002] With the rapid development of new energy vehicles towards higher voltage and higher power, and the gradual popularization of 800V and above voltage platforms, the rated current carrying capacity of core high-voltage circuits such as battery pack main circuits and electric drive systems is constantly increasing. This places stringent requirements on the reliability, breaking performance, and intelligence level of circuit protection devices. As a core protection component of the high-voltage circuit in new energy vehicles, intelligent fuses integrate the overcurrent protection function of traditional fuses with intelligent monitoring, prediction, and control capabilities. They can collect circuit current signals in real time, enabling fault prediction, precise fault breaking, and fault data feedback. Widely used in key scenarios such as the main circuit of new energy vehicle battery packs, high-voltage distribution boxes, and charging / discharging circuits, they are the last crucial line of defense for ensuring the safe and stable operation of the high-voltage system in new energy vehicles. Their performance directly determines the safety and reliability of the entire vehicle's high-voltage system, aligning with the development trend of high voltage and intelligence in new energy vehicles.

[0003] One of the key product issues currently being addressed in the application of smart fuses is the insulation resistance during breaking tests at different currents. Taking external triggering as an example, since the triggering current needs to include both minimum breaking current (e.g., 0A) and maximum breaking current (e.g., 16kA), the arc-extinguishing fuse needs to be cut off during external triggering to ensure that the product can achieve 0A breaking. However, since the time from the main conductive copper busbar being cut off to the arc-extinguishing fuse being cut off is generally tens to hundreds of microseconds, the cutting time is very fast. As a result, when testing breaking under low overload current, the arc energy can only accumulate near the structure that cuts off the arc-extinguishing fuse, causing severe carbonization of the internal plastic parts, which will seriously affect the insulation resistance after the product is broken. If a fusible part is designed at other locations on the arc-extinguishing fuse to disperse the arc energy, it will cause the resistance of the arc-extinguishing fuse to increase, affecting the speed at which the current transfers to the arc-extinguishing fuse after the main conductive copper busbar is cut off during maximum breaking, which in turn affects the maximum safe breaking capacity of the product, thus creating a design contradiction. In addition, regardless of whether it is internally triggered or externally triggered, the insulation resistance of the product will be low after the maximum current is broken due to the excessive arc energy and severe erosion of the surrounding arc-extinguishing materials, which will not meet the insulation requirements of the high-voltage system of new energy vehicles. Summary of the Invention

[0004] This application provides an intelligent fuse control circuit and an intelligent fuse, which aims to promote the rapid transfer of current on the conductor to the arc-extinguishing fuse and reduce the ablation time of the arc-extinguishing fuse itself under large short-circuit current.

[0005] In a first aspect, this application provides an intelligent fuse control circuit, including an internal triggering circuit and an external triggering circuit; The intelligent fuse includes at least one first ignition device, at least one second ignition device, at least one first impact member and at least one second impact member, at least one conductor and an arc-extinguishing fuse. The conductor is provided with a signal fuse, at least one first pre-cut-off part and at least one second pre-cut-off part connected in sequence. The two ends of the arc-extinguishing fuse are respectively connected to the conductor. The external triggering circuit is used to connect to the at least one first ignition device and trigger the at least one first ignition device according to the external triggering signal, so that the at least one first ignition device generates high-pressure gas to push at least one first impact member to cut off the corresponding at least one first pre-cut-off part. The internal triggering circuit is used to connect to the at least one second ignition device and to trigger the second ignition device according to the second current generated after the first pre-cut-off portion is cut off, so that the at least one second ignition device generates high-pressure gas to push at least one second impact member to cut off the corresponding at least one second pre-cut-off portion.

[0006] In conjunction with the first aspect, in one possible embodiment, the internal trigger circuit includes a first current limiting unit; a first end of the first current limiting unit is connected to the negative terminal of the second ignition device; a second end of the first current limiting unit is connected to the first end of the second pre-cutoff portion; the positive terminal of the second ignition device is connected to the first end of the signal fuse; the first end of the first pre-cutoff portion is connected to the second end of the signal fuse, and the second end of the first pre-cutoff portion is connected to the second end of the second pre-cutoff portion; wherein, the first current limiting unit is used to limit the second current flowing through the second ignition device to less than the internal trigger current of the second ignition device under normal conditions, and to limit the second current to greater than or equal to the internal trigger current when the first pre-cutoff portion is cut off.

[0007] In conjunction with the first aspect, in one possible embodiment, the internal triggering circuit includes a second current limiting unit; the first end of the second current limiting unit is used to connect to the negative terminal of the second ignition device; the second end of the second current limiting unit is used to connect between the second end of the signal fuse and the first end of the first pre-cut-off portion; wherein, the second current limiting unit is used to limit the first current flowing through the second ignition device to less than the trigger current under normal conditions, and to limit the first current to greater than or equal to the trigger current when an abnormal current is generated.

[0008] In conjunction with the first aspect, in one possible embodiment, a protection unit is included, which is connected between the first end of the second pre-cut-off section and the first current limiting unit, for cutting off the circuit between the second pre-cut-off section and the second ignition device when the current is greater than a preset threshold.

[0009] Secondly, this application also provides an intelligent fuse, including a fuse housing, wherein the fuse housing is provided with an intelligent fuse control circuit as described in the first aspect; wherein the fuse housing is provided with a first receiving chamber, a second receiving chamber, at least one first movable chamber, and at least one second movable chamber; an external trigger circuit board is provided in the first receiving chamber, and an internal trigger circuit board is provided in the second receiving chamber; the internal trigger circuit board is provided with the internal trigger circuit, and the external trigger circuit board is provided with the external trigger circuit; at least one first ignition device and at least one first impact member are provided in the first movable chamber, and the at least one first pre-cut-off portion is disposed on the impact path of the at least one first impact member; at least one second ignition device and at least one second impact member are provided in the second movable chamber, and the at least one second pre-cut-off portion is disposed on the impact path of the at least one second impact member.

[0010] In conjunction with the second aspect, in one possible embodiment, the fuse housing is further provided with an arc-extinguishing chamber, the arc-extinguishing chamber is provided with an arc-extinguishing fusible element, and the arc-extinguishing chamber is filled with an arc-extinguishing medium that surrounds the arc-extinguishing fusible element; the two ends of the arc-extinguishing fusible element are respectively connected to the first end of the second pre-cutting section and the first end of the first pre-cutting section.

[0011] In conjunction with the second aspect, in one possible embodiment, the fuse housing is provided with one or more third receiving chambers; a third impact member is housed in the third receiving chamber, and a first fixing part is provided on the third impact member, with the arc-extinguishing fusible element fixed to the first fixing part; the third receiving chamber is provided with a third opening, which is located in a third impact direction of the third impact member; when the third impact member impacts along the third impact direction, it enters the third receiving chamber through the third opening to impact the third impact member, thereby breaking the arc-extinguishing fusible element fixed to the first fixing part.

[0012] In conjunction with the second aspect, in one possible embodiment, the third impact member is provided with a first groove, and a first seal is provided in the first groove. The first groove and the cavity wall of the third accommodating chamber clamp the first seal by an interference fit.

[0013] In conjunction with the second aspect, in one possible embodiment, the fuse housing is further provided with a fourth receiving chamber for housing the protection unit.

[0014] In conjunction with the second aspect, in one possible embodiment, the fourth accommodating chamber is provided with a first channel communicating with the first end of the second pre-cutting part and a second channel communicating with the first accommodating chamber. The protection unit is connected to the internal trigger circuit through the first channel, and the protection unit is connected to the first end of the second pre-cutting part through the first channel.

[0015] As can be seen, the intelligent fuse control circuit in this application includes an internal triggering circuit and an external triggering circuit. A signal fuse, at least one first pre-cutting section, and at least one second pre-cutting section are sequentially connected on the conductor. The external triggering circuit is used to connect to at least one first ignition device and triggers at least one first ignition device according to an external triggering signal, so that at least one first ignition device generates high-pressure gas to push at least one first impact member to cut off the corresponding at least one first pre-cutting section. The internal triggering circuit is used to connect to at least one second ignition device and triggers the second ignition device according to the second current generated after the first pre-cutting section is cut off, so that at least one second ignition device generates high-pressure gas to push at least one second impact member to cut off the corresponding at least one second pre-cutting section. Thus, through the interlocking triggering of the external and internal triggering circuits, two sets of breaks are formed on the conductor, quickly increasing the insulation distance on the conductor, promoting the rapid transfer of current from the conductor to the arc-extinguishing fuse, and reducing the ablation time of the arc-extinguishing fuse itself under large short-circuit currents. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic block diagram of the intelligent fuse control circuit provided in the embodiments of this application; Figure 2 This is a circuit diagram of the internal trigger circuit provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the smart fuse provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the third impact member provided in the embodiments of this application; Figure 5This is a schematic diagram of the structure of the first type of third impact member and arc-extinguishing melt provided in the embodiments of this application; Figure 6 This is a schematic diagram of the structure of the second type of third impact member and the arc-extinguishing melt provided in the embodiments of this application; Figure 7 This is a schematic diagram showing the positions of the first protection unit and the fourth accommodating chamber provided in the embodiments of this application; Figure 8 This is a schematic diagram showing the positions of the second protection unit and the fourth accommodating chamber provided in the embodiments of this application; Figure 9 This is a schematic diagram showing the location of the third protection unit and the fourth accommodating chamber provided in the embodiments of this application. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0019] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, systems, products, or apparatuses.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] One of the key product issues currently being addressed in the application of smart fuses is the insulation resistance during breaking tests at different currents. Taking external triggering as an example, since the triggering current needs to include both minimum breaking current (e.g., 0A) and maximum breaking current (e.g., 16kA), the arc-extinguishing fuse needs to be cut off during external triggering to ensure that the product can achieve 0A breaking. However, since the time from the main conductive copper busbar being cut off to the arc-extinguishing fuse being cut off is generally tens to hundreds of microseconds, the cutting time is very fast. As a result, when testing breaking under low overload current, the arc energy can only accumulate near the structure that cuts off the arc-extinguishing fuse, causing severe carbonization of the internal plastic parts, which will seriously affect the insulation resistance after the product is broken. If a fusible part is designed at other locations on the arc-extinguishing fuse to disperse the arc energy, it will cause the resistance of the arc-extinguishing fuse to increase, affecting the speed at which the current transfers to the arc-extinguishing fuse after the main conductive copper busbar is cut off during maximum breaking, which in turn affects the maximum safe breaking capacity of the product, thus creating a design contradiction. In addition, regardless of whether it is internally triggered or externally triggered, the insulation resistance of the product will be low after the maximum current is broken due to the excessive arc energy and severe erosion of the surrounding arc-extinguishing materials, which will not meet the insulation requirements of the high-voltage system of new energy vehicles.

[0022] To address the aforementioned problems, this application provides an intelligent fuse control circuit and an intelligent fuse. This intelligent fuse control circuit and intelligent fuse can be applied to scenarios requiring rapid fuse disconnection. The intelligent fuse control circuit in this application includes an internal trigger circuit and an external trigger circuit; a conductor is provided with a signal fuse element, at least one first pre-cutting part, and at least one second pre-cutting part connected in sequence; the external trigger circuit is used to connect to at least one first ignition device and trigger the at least one first ignition device according to an external trigger signal, so that the at least one first ignition device generates high-pressure gas to push at least one first impact member to cut off the corresponding at least one first pre-cutting part; the internal trigger circuit is used to connect to at least one second ignition device and trigger the second ignition device according to a second current generated after the first pre-cutting part is cut, so that the at least one second ignition device generates high-pressure gas to push at least one second impact member to cut off the corresponding at least one second pre-cutting part. In this way, through the interlocking triggering of the external and internal triggering circuits, two sets of breaks are formed on the conductor, quickly increasing the insulation distance on the conductor and promoting the rapid transfer of current from the conductor to the arc-extinguishing melt, thus reducing the ablation time of the arc-extinguishing melt itself under large short-circuit currents. This solution can be applied to various scenarios, including but not limited to the applications mentioned above.

[0023] The specific structure will be described in detail below.

[0024] Please see Figure 1 and 2This application provides an intelligent fuse control circuit 100, including an internal trigger circuit 10 and an external trigger circuit 20.

[0025] Please combine Figure 3 The intelligent fuse 200 includes at least one first ignition device 231, at least one second ignition device 241, at least one first impact member 232 and at least one second impact member 242, at least one conductor and an arc-extinguishing fusible element 271. The conductor is provided with a signal fusible element RR, at least one first pre-cut-off part 31 and at least one second pre-cut-off part 32 connected in sequence. The two ends of the arc-extinguishing fusible element 271 are respectively connected to the conductor. The external triggering circuit 20 is used to connect to the at least one first ignition device 231 and trigger the at least one first ignition device 231 according to the external triggering signal, so that the at least one first ignition device 231 generates high-pressure gas to push at least one first impact member 232 to cut off the corresponding at least one first pre-cut-off part 31. The internal triggering circuit 10 is used to connect to the at least one second ignition device 241 and to trigger the second ignition device 241 according to the second current generated after the first pre-cut-off part 31 is cut off, so that the at least one second ignition device 241 generates high-pressure gas to push at least one second impact member 242 to cut off the corresponding at least one second pre-cut-off part 32.

[0026] In a specific implementation, the conductor is a one-piece structure, which is obtained by fabricating a first pre-cutting part 31, a second pre-cutting part 32 and a signal melt RR on a conductor; or it can be based on a first conductive busbar 33 and a second conductive busbar 34, with the first pre-cutting part 31 and the second pre-cutting part 32 fabricated on the first conductive busbar 33, and then the independent signal melt RR welded onto the first conductive busbar 33 and the second conductive busbar 34 to obtain the conductor.

[0027] It is understood that the first ignition device 231, the first impact member 232, and the first pre-cutting part 31 form a first fusion structure. The number of these three components in each group of first fusion structures can be one-to-one or different, and there is no requirement for uniqueness here. Similarly, the second ignition device 241, the second impact member 242, and the second pre-cutting part 32 form a second fusion structure. The number of these three components in each group of second fusion structures can be one-to-one or different, and there is no requirement for uniqueness here.

[0028] The external trigger circuit 20 is triggered by an external trigger signal. The external trigger signal is automatically output by the vehicle's control unit under corresponding abnormal operating conditions (such as abnormal current in the main circuit or abnormal collision, etc.), or it can be actively operated by the user. There is no unique limitation here.

[0029] When the external trigger circuit 20 receives an external trigger signal, the first ignition device 231 is detonated, generating high-pressure gas that pushes the first impact member 232 toward the first pre-cut-off section 31, cutting off the first pre-cut-off section 31 and thus disconnecting the conductor. At this time, part of the current between the first pre-cut-off section 31 and the second pre-cut-off section 32 is diverted to the internal trigger circuit 10, causing the current in the internal trigger circuit 10 to reach the triggering condition of the second ignition device 241. This causes the second ignition device 241 to be triggered after the first pre-cut-off section 31 is disconnected. After the second ignition device 241 is triggered and detonated, it generates high-pressure gas that pushes the second impact member 242 toward the second pre-cut-off section 32, cutting off the second pre-cut-off section 32. In this way, through the interlocking triggering of the external trigger circuit 20 and the internal trigger circuit 10, at least two sets of breaks are formed on the conductor, quickly increasing the insulation distance on the conductor and promoting the rapid transfer of current on the conductor to the arc-extinguishing melt 271, reducing the ablation time of the arc-extinguishing melt 271 itself under large short-circuit current.

[0030] In one possible embodiment, the internal trigger circuit 10 includes a first current limiting unit 11; the first end of the first current limiting unit 11 is connected to the negative terminal of the second ignition device 241; the second end of the first current limiting unit 11 is connected to the first end of the second pre-cutoff section 32; the positive terminal of the second ignition device 241 is connected to the first end of the signal fuse RR; the first end of the first pre-cutoff section 31 is connected to the second end of the signal fuse RR, and the second end of the first pre-cutoff section 31 is connected to the second end of the second pre-cutoff section 32; wherein, the first current limiting unit 11 is used to limit the second current flowing through the second ignition device 241 to less than the trigger current under normal conditions, and to limit the second current to greater than or equal to the trigger current when the first pre-cutoff section 31 is cut off.

[0031] Specifically, the first current limiting unit 11 includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 and the first end of the second resistor R2 are both used to connect to the negative terminal of the second ignition device 241. The second end of the first resistor R1 and the second end of the second resistor R2 are both used to connect to the first end of the second pre-cutoff section 32. This makes the first current limiting unit 11 connected in series between the second ignition device 241 and the first end of the second pre-cutoff section 32, forming a first trigger sub-circuit in parallel with the second ignition device 241 and the circuit formed by the signal fuse RR, the first pre-cutoff section 31 and the second pre-cutoff section 32. At the same time, the first current limiting unit 11 limits the current flowing through the second ignition device 241.

[0032] Optionally, the first end of the arc-extinguishing melt 271 can be connected between the first end of the first pre-cutting section 31 and the second end of the signal melt RR, and the second end of the arc-extinguishing melt 271 can be connected to the first end of the second pre-cutting section 32; alternatively, the first end of the arc-extinguishing melt 271 can also be connected to the first end of the signal melt RR, without being limited to a single point.

[0033] It is understandable that the first resistor R1 and the second resistor R2 are connected in parallel between the first end of the second ignition device 241 and the second pre-cut-off part 32, and the first resistor R1 and the second resistor R2 serve as backups for each other to prevent the failure of one of the resistors from causing the first current limiting unit 11 to fail.

[0034] In specific implementation, since the second ignition device 241 is connected to the first end of the signal fuse RR and the first end of the second pre-cut-off part 32, the voltage on the second ignition device 241 is actually the voltage on the conductor. Under normal conditions, since the resistance of the first current limiting unit 11 is much greater than that of the conductor, the current on the second ignition device 241 is much smaller than that on the conductor, and the second ignition device 241 will not be triggered. When the first pre-cut-off part 31 is cut off, the conductor is disconnected, so that the current is transferred to the circuit from the second ignition device 241, causing the current in the circuit to increase to be greater than or equal to the second current. The second ignition device 241 is triggered, which in turn pushes the second impact member 242 to cut off the second pre-cut-off part 32, forming at least two sets of breaks on the conductor, quickly opening the insulation distance on the conductor, promoting the rapid transfer of the current on the conductor to the arc-extinguishing fuse 271, and reducing the ablation time of the arc-extinguishing fuse 271 itself under large short-circuit current.

[0035] In one possible embodiment, the internal trigger circuit 10 includes a second current limiting unit 12; the first end of the second current limiting unit 12 is used to connect to the negative terminal of the second ignition device 241; the second end of the second current limiting unit 12 is used to connect between the second end of the signal fuse RR and the first end of the first pre-cut-off part 31; wherein, the second current limiting unit 12 is used to limit the first current flowing through the second ignition device 241 to less than the trigger current under normal conditions, and to limit the first current to greater than or equal to the trigger current when an abnormal current is generated.

[0036] Specifically, the second current limiting unit 12 includes a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 and the first end of the fourth resistor R4 are both used to connect to the negative terminal of the second ignition device 241. The second end of the third resistor R3 and the second end of the fourth resistor R4 are both used to connect between the second end of the signal fuse RR and the first end of the first pre-cut-off part 31. In this way, the second current limiting unit 12 is connected in series between the second ignition device 241 and the second end of the signal fuse RR, forming a second trigger sub-circuit connected in parallel with the signal fuse RR. At the same time, the second current limiting unit 12 limits the first current flowing through the second ignition device 241.

[0037] In the specific implementation, when the signal fuse RR is melted due to abnormal current, a high-voltage arc is generated, which makes the first current in the second trigger sub-circuit greater than or equal to the internal trigger current of the second ignition device 241. This causes the second ignition device 241 to be ignited and generate high-pressure gas to push the second impact member 242 to cut off the second pre-cutting part 32, forming at least two sets of breaks on the conductor. This quickly increases the insulation distance on the conductor, promotes the rapid transfer of current on the conductor to the arc-extinguishing fuse 271, and reduces the ablation time of the arc-extinguishing fuse 271 itself under large short-circuit current.

[0038] As can be seen, in this embodiment, a second current limiting unit 12 is set on the basis of the first current limiting unit 11, so that the second ignition device 241 can be triggered by both external trigger signal and by the melting arc of the signal fuse RR. Under the premise of ensuring that the smart fuse 200 can be triggered under any circumstances, the ability to form a multi-break accelerated transfer arc is increased.

[0039] The second ignition device 241 of the intelligent fuse 200 of this application can not only be triggered by the arc voltage generated by the melting of the signal fuse RR, but also be triggered by the arc voltage generated by the corresponding first impact member 232 cutting off the first pre-cut-off part 31 after the first ignition device 231 is triggered by an external trigger signal, so as to detonate successively.

[0040] Similarly, when the intelligent fuse 200 of this application is tested by external triggering, it can not only detonate the first ignition device 231 by an externally provided control signal (i.e., an external trigger signal), but also detonate the second ignition device 241 in succession by the triggering of the first ignition device 231, thereby forming two sets of breaks on the conductor, quickly opening the insulation distance on the conductor, promoting the rapid transfer of current on the conductor to the arc-extinguishing fuse 271, and reducing the ablation time of the arc-extinguishing fuse 271 itself under large short-circuit current.

[0041] In one possible embodiment, a protection unit 13 is included, which is connected between the first end of the second pre-cut-off section 32 and the first current limiting unit 11, for cutting off the circuit between the second pre-cut-off section 32 and the second ignition device 241 when the current is greater than a preset threshold.

[0042] In a specific implementation, the first end of the first current limiting unit 11 is connected to the first end of the second ignition device 241, and the second end of the first current limiting unit 11 is connected to the first end of the protection unit 13. The second end of the protection unit 13 is used to connect to the first end of the second pre-cut-off part 32 (i.e., the end away from the first pre-cut-off part 31 and the signal fuse RR) to limit the magnitude of the second current when the conductor shunts the current to the internal trigger circuit 10.

[0043] Specifically, the protection unit 13 includes a fuse F1, which can be a fast-blow low-current fuse. One end of the fuse F1 is connected to the second end of the first current limiting unit 11, and the other end is used to connect to the first end of the second pre-cut-off part 32. The fuse F1 is used to cut off the circuit between the second pre-cut-off part 32 and the second ignition device 241 when the current is greater than a preset threshold, so as to prevent the internal trigger circuit board 221 from burning continuously under high voltage and high current.

[0044] It is understandable that, for the second trigger sub-circuit formed by the first current limiting unit 11 and the second ignition device 241, the second current flowing through the second trigger sub-circuit must first reach the triggering condition of the second ignition device 241 and ignite the second ignition device 241, and then cause the fuse F1 in the protection unit 13 to melt and cut off the branch. Therefore, the selection of the fuse F1 in the protection unit 13 must meet the requirement that the rated voltage is the same as the rated voltage of the smart fuse 200, and the melting energy must be greater than the energy required for the second ignition device 241 to detonate, so as to ensure that the protection unit 13 melts only after the second ignition device 241 has detonated.

[0045] This application also provides an intelligent fuse, including a fuse housing, in which the aforementioned intelligent fuse control circuit 100 is disposed; wherein, the fuse housing is provided with a first receiving chamber 21, a second receiving chamber 22, at least one first movable chamber 23, and at least one second movable chamber 24; the first receiving chamber 21 houses an external trigger circuit board 211, and the second receiving chamber 22 houses an internal trigger circuit board 221; the internal trigger circuit board 221 is provided with an internal trigger circuit 10, and the external trigger circuit board 211 is provided with an external trigger circuit 20; the first movable chamber 23 is provided with at least one first ignition device 231 and at least one first impact member 232, and the at least one first pre-cutting portion 31 is disposed on the impact path of the at least one first impact member 232; the second movable chamber 24 is provided with at least one second ignition device 241 and at least one second impact member 242, and the at least one second pre-cutting portion 32 is disposed on the impact path of the at least one second impact member 242.

[0046] Specifically, the fuse housing is further provided with a first receiving chamber 21 and a second receiving chamber 22; the external trigger circuit board 211 is housed in the first receiving chamber 21 to fix the external trigger circuit board 211; and the internal trigger circuit board 221 is housed in the second receiving chamber 22 to fix the internal trigger circuit board 221.

[0047] An external trigger circuit 20 is mounted on the external trigger circuit board 211. The external trigger circuit 20 is connected from the external trigger circuit board 211 to the first ignition device 231 and the control unit outside the fuse via a first wire. An internal trigger circuit 10 is mounted on the internal trigger circuit board 221. The internal trigger circuit 10 is electrically connected from the internal trigger circuit board 221 to the second ignition device 241 and the conductor via a second wire. It is understood that the first wire and the second wire can be a single wire or composed of multiple separate wire segments; no unique limitation is made here.

[0048] In specific implementation, the fuse housing is divided into an upper housing and a lower housing, with the conductor as the boundary. The upper housing contains one or more first movable chambers 23 and one or more second movable chambers 24. A first ignition device 231 and a first impact member 232 are arranged as a group in the corresponding first movable chamber 23, and a second ignition device 241 and a second impact member 242 are arranged as a group in the corresponding second movable chamber 24. The fuse housing has a first opening 201 and a second opening 202. The conductor enters the fuse housing through the first opening 201 and exits through the second opening 202, or it can enter the fuse housing through the second opening 202 and exit through the second opening 202. One end of the first conductive bar 33 of the conductor exits through the first opening 201 to form a first terminal 35, and one end of the second conductive bar 34 of the conductor exits through the second opening 202 to form a second terminal 36. The conductor is positioned in the first impact direction of the first impact member 232 and the second impact member 242 in the second impact direction. In the second impact direction; when an abnormal current is generated in the main circuit, the signal melt RR is melted by the abnormal current, and a high voltage is generated at both ends of the signal melt RR. The second current limiting unit 12 collects the high voltage and transmits it to the ignition device. Since the high voltage is greater than the internal trigger current of the second ignition device 241, the second ignition device 241 is triggered, and the gunpowder in the second ignition device 241 is detonated, generating high temperature and high pressure gas, which pushes the second impact member 242 to move rapidly along the second active chamber 24, so that the second pre-cutting part 32 set in the second impact direction is broken.

[0049] As can be seen, in this embodiment, by setting the first accommodating chamber 21 and the second accommodating chamber 22 to fix the external trigger circuit 20 and the internal trigger circuit board 221, the current reliability is improved; at the same time, by accommodating the corresponding first ignition device 231, first impact member 232, second ignition device 241 and second impact member 242 in the first movable chamber 23 and the second movable chamber 24, the layout of the fuse structure is realized, which further improves the reliability of the fuse.

[0050] In one possible embodiment, please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 The fuse housing is further provided with an arc-extinguishing chamber 27, and an arc-extinguishing melt 271 is provided in the arc-extinguishing chamber 27. The arc-extinguishing chamber 27 is filled with an arc-extinguishing medium that surrounds the arc-extinguishing melt 271. The two ends of the arc-extinguishing melt 271 are respectively connected to the first end of the second pre-cutting part 32 and the first end of the first pre-cutting part 31.

[0051] Specifically, the fuse housing is provided with one or more third receiving chambers 25; a third impact member 251 is housed in the third receiving chamber 25, and a first fixing part 2511 is provided on the third impact member 251, and the arc-extinguishing fusible element 271 is fixed on the first fixing part 2511; the third receiving chamber 25 is provided with a third opening 252, and the third opening 252 is located in the third impact direction of the third impact member 251; when the third impact member 251 impacts along the third impact direction, it enters the third receiving chamber 25 through the third opening 252 to impact the third impact member 251, so as to break the arc-extinguishing fusible element 271 fixed on the first fixing part 2511.

[0052] In a specific implementation, one or more third receiving chambers 25 are provided in the lower part of the fuse housing. These third receiving chambers 25 are located below the first pre-cutting portion 31 and the second pre-cutting portion 32 of the conductor, while the first movable chamber 23 and the second movable chamber 24 are located above the first pre-cutting portion 31 and the second pre-cutting portion 32 of the conductor. That is, the conductor is positioned between the first movable chamber 23 and the corresponding third receiving chamber 25, and also between the second movable chamber 24 and the corresponding third receiving chamber 25. A third impact member 251 is housed in the third receiving chamber 25. A first fixing portion 2511 is provided on the third impact member 251. The arc-extinguishing fusible element 271 is positioned by being fitted onto the first fixing portion 2511, so that the arc-extinguishing fusible element 271 is not easily dislodged from the impact path of the third impact member 251. After the first impactor 232 moves along the first movable chamber 23 and breaks the first pre-cut section 31, it continues to impact the corresponding third accommodating chamber 25, causing the third impactor 251 to break the arc-extinguishing melt 271 after being impacted. This forms multiple sets of fractures on the arc-extinguishing melt 271 (the number of fractures corresponds to the number of weak breaks 2711 on the arc-extinguishing melt 271), thereby achieving the disconnection of the protected circuit. Similarly, when the second impactor 242 moves along the second movable chamber 23, it continues to impact the arc-extinguishing melt 251. After the second pre-cutting part 32 is broken by the movement, it then enters the corresponding third accommodating chamber 25 to impact the third impact member 251. After being impacted, the third impact member 251 breaks the arc-extinguishing fuse 271, thereby forming multiple sets of fractures on the arc-extinguishing fuse 271 (the number of fractures corresponds to the number of weak disconnected parts 2711 on the arc-extinguishing fuse 271), so as to cut off the protected circuit, accelerate the arc extinguishing time, and improve the breaking capacity and insulation resistance of the intelligent fuse 200 of the present invention.

[0053] In one possible embodiment, the third impact member 251 is further provided with a first limiting part 2512 and a second limiting part 2513, and a first limiting groove 2514 is formed between the first limiting part 2512 and the second limiting part 2513. When the arc-extinguishing fuse 271 is fixed on the first fixing part 2511, it is accommodated in the first limiting groove 2514, and the arc-extinguishing fuse 271 is restricted in the first limiting groove 2514 by the first limiting part 2512 and the second limiting part 2513, so as to prevent the arc-extinguishing fuse 271 from being displaced from the groove wall, bottom or other directions of the groove, thereby realizing the fixation of the arc-extinguishing fuse 271 and improving the reliability of the high-current intelligent fuse 200.

[0054] In an optional embodiment, when the third impactor 251 is impacted by the first impactor 232 and moves along the side wall of the third accommodating chamber 25 toward the bottom of the third accommodating chamber 25 together with the arc-extinguishing melt 271, if the arc-extinguishing melt 271 is only positioned by the obstruction of the arc-extinguishing medium filled inside the arc-extinguishing chamber 27, the position and number of fractures of the arc-extinguishing melt 271 by the third impactor 251 are relatively random. The prior art clamps the arc-extinguishing melt 271 at the contact position between the arc-extinguishing melt 271 and the third impactor 251 in the third accommodating chamber 25 by the interference fit between the cavity wall and the third impactor 251, and then, when the third impactor 251 impacts toward the bottom of the third accommodating chamber 25, the arc-extinguishing melt 271 is broken by the combined action of the impact force and the interference fit clamping force. In this method, as the third impactor 251 continues to move at the bottom of the third accommodating chamber 25, the fracture on the arc-extinguishing melt 271 will generate a continuous arc between the third impactor 251 and the surrounding walls of the third accommodating chamber 25. This results in severe carbonization of the plastic part surface, and the insulation resistance of the product after the breaking test, especially in the low-current test, will be very low, making it difficult to meet the customer's requirements for product breaking performance. Please refer to... Figure 2 , Figure 4 and Figure 5 In this embodiment, in order to solve this problem, a second fixing part is provided on the cavity wall of the arc extinguishing chamber 27, and the broken weak part 2711 (such as through hole, narrow neck, etc.) of the arc extinguishing melt 271 is sleeved on the second fixing part. When the arc extinguishing chamber 27 is filled with arc extinguishing medium, the second fixing part and the broken weak part 2711 can be wrapped.

[0055] In the width direction, the cross-sectional area of ​​the neck of the broken weak part 2711 is much smaller than the cross-sectional area of ​​other positions adjacent to the arc-extinguishing melt 271. Therefore, when the third impact member 251 moves downward in the third accommodating chamber 25 and the arc-extinguishing melt 271 is subjected to tensile force, the fracture position is preferably formed at the neck position of the broken weak part 2711. When the distance between the broken weak part 2711 and the cavity wall of the third accommodating chamber 25 is designed to be greater than the downward movement distance of the third impact member 251, the fracture of the broken weak part 2711 will always remain within the arc-extinguishing material. This accelerates the extinction of the arc and prevents the arc from eroding the third impact member 251 and the cavity wall of the third accommodating chamber 25, thereby improving the insulation resistance after the product is broken.

[0056] In addition, in the structural design of the intelligent fuse 200 of this application, a cutting structure that can cut off the arc-extinguishing fuse 271 is also added below the internal triggering corresponding second ignition device 241 structure. This allows multiple breaks to be formed on the arc-extinguishing fuse 271, which not only disperses the arc energy but also helps to accelerate the extinguishing process of the arc on the arc-extinguishing fuse 271, thereby improving the breaking current capability and insulation resistance performance of the product across the entire current protection range.

[0057] In one possible embodiment, please refer to Figure 6 The second impact member 242 is provided with a first groove 2515, and a first sealing member 2516 is provided in the first groove 2515. The first groove 2515 and the cavity wall of the third accommodating chamber 25 clamp the first sealing member 2516 by interference fit.

[0058] In a specific implementation, a groove (i.e., a first groove 2515) is provided on each side of the upper part of the third impact member 251. Then, a first sealing member 2516 is installed in the first groove 2515. When the third impact member 251 is installed into the through hole, it is ensured that the first sealing member 2516 can be stuck on the side walls on both sides of the through hole. Thus, when the arc-burning gas flows upward from the lower arc-extinguishing chamber 27 along the third accommodating chamber 25, the first sealing member 2516 can prevent the gas from overflowing. Moreover, the first sealing member 2516 can always be in a compressed and sealed state as the third impact member 251 moves downward, thereby reducing the impact of the shell molding dimensional tolerance on the product performance.

[0059] It is understandable that the first groove 2515 can also be an annular groove, and the first seal 2516 can be set as a sealing ring.

[0060] Furthermore, a sealing strip can also be added between the bottom of the third impact member 251 and the inner wall of the third accommodating chamber 25 to prevent the arc-extinguishing gas and high-temperature arc generated in the arc-extinguishing chamber 27 from overflowing to the outside of the housing and affecting the safety of other devices around the product.

[0061] In one possible embodiment, please refer to Figure 7 , Figure 8 and Figure 9 The fuse housing is further provided with a fourth receiving chamber 26, which is used to receive the protection unit 13.

[0062] In a specific implementation, the shape of the fourth accommodating chamber 26 is adapted to the protection unit 13, and the protection unit 13 is housed in the fourth accommodating chamber 26; the positional relationship between the fourth accommodating chamber 26 and the protection unit 13 is described below through a specific example.

[0063] Specifically, the fourth accommodating chamber 26 is provided with a first channel 261 communicating with the first end of the second pre-cutting part 32 and a second channel 262 communicating with the first accommodating chamber 21. The protection unit 13 is connected to the internal trigger circuit 10 through the first channel 261 and the protection unit 13 is connected to the first end of the second pre-cutting part 32 through the first channel 261.

[0064] Example 1 Please see Figure 7 A cavity can be reserved on the side of the upper housing of the fuse housing near the second pre-cut section 32 on the first conductive busbar 33 as a fourth accommodating chamber 26. The fourth accommodating chamber 26 is arranged perpendicular to the conductor, so that the first channel 261 is directly connected to the conductor and the second channel 262 is directly connected to the first accommodating chamber 21.

[0065] Furthermore, the conductor is provided with a connection hole 37, and the protection unit 13 is provided with a first connection end 131 (i.e., the first end) and a second connection end 132 (i.e., the second end). The second connection end 132 of the protection unit 13 can be inserted into the fourth accommodating chamber 26 through the second channel 262. The protection unit 13 slides into the fourth accommodating chamber 26, and finally the second connection end 132 is inserted into the connection hole 37, so that the protection unit 13 is connected to the first end of the second pre-cutting part 32 through the second connection end 132. After the protection unit 13 is accommodated in the fourth accommodating chamber 26, the internal trigger circuit board 221 is placed in the first accommodating chamber 21, and the first connection end 131 is soldered and fixed to the pads on the internal trigger circuit board 221, so that the protection unit 13 is connected to the internal trigger circuit 10 (specifically the first current limiting unit 11) through the first connection end 131.

[0066] Optionally, the protection unit 13 can be a fuse F1, which can be a tubular lead wire type fuse; the first connection end 131 and the second connection end 132 can be the crown spring on the fuse F1.

[0067] Example 2 Please see Figure 8 and Figure 9 Compared to Example 1, in Example 2, the fourth receiving chamber 26 can be arranged parallel to the plane of the internal trigger circuit board 221. The first channel 261 of the fourth receiving chamber 26 extends vertically from the top of the fuse housing to the connection hole 37. The fourth receiving chamber 26 can be a groove, in which the protection unit 13 is directly received. In this case, the second connection end 132 of the protection unit 13 is far from the connection hole 37, so it can pass through. Alternatively, the first end of an additional third wire 133 can be connected to the first connection end 131, and then the second end of the third wire 133 can be connected to the internal trigger circuit board 221 and connected to the internal trigger circuit 10. Similarly, the first end of an additional fourth wire 134 can be connected to the second connection end 132, and then the fourth wire 134 can be connected to the connection hole 37 along the first channel 261, and the second end of the third wire 133 can be soldered into the connection hole 37.

[0068] As can be seen, in this embodiment, after the second pre-cutting part 32 is cut off, the protection unit 13 melts and disconnects the conductor from the internal trigger circuit 10, so as to prevent the external system high voltage on the conductor from being continuously applied to the internal trigger circuit 10, causing the internal trigger control circuit board to experience a high voltage arcing phenomenon.

[0069] While this application discloses the above information, it is not limited thereto. Any person skilled in the art can easily conceive of variations or substitutions without departing from the spirit and scope of this application, and can make various alterations and modifications, including combinations of the different functions and implementation steps described above, as well as software and hardware implementation methods, all of which are within the protection scope of this application.

Claims

1. A smart fuse control circuit, characterized in that, Includes internal trigger circuits and external trigger circuits; The intelligent fuse includes at least one first ignition device, at least one second ignition device, at least one first impact member and at least one second impact member, at least one conductor and an arc-extinguishing fuse. The conductor is provided with a signal fuse, at least one first pre-cut-off part and at least one second pre-cut-off part connected in sequence. The two ends of the arc-extinguishing fuse are respectively connected to the conductor. The external triggering circuit is used to connect to the at least one first ignition device and trigger the at least one first ignition device according to the external triggering signal, so that the at least one first ignition device generates high-pressure gas to push at least one first impact member to cut off the corresponding at least one first pre-cut-off part. The internal triggering circuit is used to connect to the at least one second ignition device and to trigger the second ignition device according to the second current generated after the first pre-cut-off portion is cut off, so that the at least one second ignition device generates high-pressure gas to push at least one second impact member to cut off the corresponding at least one second pre-cut-off portion.

2. The intelligent fuse control circuit according to claim 1, characterized in that, The internal triggering circuit includes a first current limiting unit; The first end of each of the first current-limiting units is used to connect to the negative terminal of the second ignition device; the second end of each of the first current-limiting units is used to connect to the first end of the second pre-cutoff section; the positive terminal of the second ignition device is connected to the first end of the signal melt; the first end of the first pre-cutoff section is connected to the second end of the signal melt, and the second end of the first pre-cutoff section is connected to the second end of the second pre-cutoff section; wherein... The first current limiting unit is used to limit the second current flowing through the second ignition device to less than the internal trigger current of the second ignition device under normal conditions, and to limit the second current to greater than or equal to the internal trigger current when the first pre-cut-off part is cut off.

3. The intelligent fuse control circuit according to claim 2, characterized in that, The internal triggering circuit includes a second current limiting unit; The first ends of the second current limiting unit are all used to connect to the negative terminal of the second ignition device; the second end of the second current limiting unit is used to connect between the second end of the signal melt and the first end of the first pre-cut-off portion; wherein, The second current limiting unit is used to limit the first current flowing through the second ignition device to less than the trigger current under normal conditions, and to limit the first current to greater than or equal to the trigger current when an abnormal current is generated.

4. The intelligent fuse control circuit according to claim 2 or 3, characterized in that, It includes a protection unit connected between the first end of the second pre-cut-off section and the first current limiting unit, which is used to cut off the circuit between the second pre-cut-off section and the second ignition device when the current is greater than a preset threshold.

5. A smart fuse, characterized in that, The fuse includes a fuse housing, wherein the fuse housing is provided with an intelligent fuse control circuit as described in any one of claims 1-4; wherein, The fuse housing is provided with a first receiving chamber, a second receiving chamber, at least one first movable chamber, and at least one second movable chamber; The first accommodating chamber houses an external trigger circuit board, and the second accommodating chamber houses an internal trigger circuit board; the internal trigger circuit is arranged in the internal trigger circuit board, and the external trigger circuit is arranged in the external trigger circuit board; The first active chamber is provided with at least one first ignition device and at least one first impact member, and the at least one first pre-cutting part is disposed on the impact path of the at least one first impact member; The second active chamber is provided with at least one second ignition device and at least one second impact member, and the at least one second pre-cutting part is disposed on the impact path of the at least one second impact member.

6. The intelligent fuse according to claim 5, characterized in that, The fuse housing is further provided with an arc-extinguishing chamber, the arc-extinguishing chamber is provided with an arc-extinguishing fusible element, and the arc-extinguishing chamber is filled with an arc-extinguishing medium that surrounds the arc-extinguishing fusible element; the two ends of the arc-extinguishing fusible element are respectively connected to the first end of the second pre-cutting section and the first end of the first pre-cutting section.

7. The intelligent fuse according to claim 6, characterized in that, The fuse housing is provided with one or more third receiving chambers; The third accommodating chamber contains a third impactor, and the third impactor is provided with a first fixing part, and the arc-extinguishing melt is fixed on the first fixing part; The third accommodating chamber is provided with a third opening, which is located in the third impact direction of the third impact member; when the third impact member impacts along the third impact direction, it enters the third accommodating chamber through the third opening to impact the third impact member, thereby breaking the arc-extinguishing melt fixed on the first fixing part.

8. The intelligent fuse according to claim 7, characterized in that, The third impact member is provided with a first groove, and a first sealing member is provided in the first groove. The first groove and the cavity wall of the third accommodating chamber clamp the first sealing member by an interference fit.

9. The intelligent fuse according to any one of claims 5-8, characterized in that, The fuse housing also includes a fourth receiving chamber for housing the protection unit.

10. The intelligent fuse according to claim 9, characterized in that, The fourth accommodating chamber is provided with a first channel communicating with the first end of the second pre-cutting part and a second channel communicating with the first accommodating chamber. The protection unit is connected to the internal trigger circuit through the first channel and is connected to the first end of the second pre-cutting part through the first channel.

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