Double-break controllable protection device

Abstract

The application relates to the technical field of circuit protection devices, and discloses a double-break controllable protection device, which comprises a conductive row, a trigger body, a signal transmission module and multiple break components. The trigger body is connected in series on the conductive row and is composed of a through-flow metal body and a low-melting metal body. The through-flow metal body is provided with a plurality of bends, and the low-melting metal body is arranged at the bends. The signal transmission module comprises an inner trigger line, an outer trigger line, a mainboard and multiple electronic components, and is used for transmitting external or internal voltage signals to the break components for cutting off. The multiple break components are used for cutting off the circuit at different positions of the conductive row. When the trigger body passes a large current, the through-flow metal body sharply generates heat. When the temperature reaches the melting point of the low-melting metal body, the low-melting metal body and the through-flow metal body generate a metallurgical effect, so that the melting point of the through-flow metal body is reduced and the through-flow metal body is rapidly fused. The voltage signal generated after the trigger body is fused is transmitted to the break components through the inner trigger line for cutting off.

Description

Technical Field

[0001] This invention relates to the field of circuit protection device technology, specifically a double-break controllable protection device. Background Technology

[0002] In the field of circuit protection for power systems and various electrical equipment, protection devices are core components that ensure the safe and stable operation of circuits and prevent damage to equipment or safety accidents caused by fault currents such as overloads and short circuits. With the development of power electronics technology, the power density of circuit systems is constantly increasing, which places higher demands on the current-carrying capacity, response speed, control flexibility, and breaking reliability of protection devices.

[0003] Most circuit protection devices in the present technology adopt a single breaking component structure. During long-term use, such devices are prone to a decline in breaking capacity or arc extinguishing capacity due to component aging and environmental factors. Once a fault current occurs, the protection may fail because the circuit cannot be reliably cut off. At the same time, the withstand voltage capacity and insulation performance after breaking of a single breaking component are limited, making it difficult to meet the protection requirements of high-voltage and high-power circuit systems.

[0004] In terms of trigger control, traditional protection devices mostly adopt a single internal or external trigger mode, which lacks control flexibility. For example, devices that rely solely on internal triggering are difficult to cope with the active protection requirements in complex circuit environments, while devices that rely solely on external triggering cannot achieve autonomous protection when external control signals fail, resulting in significant application limitations.

[0005] Furthermore, existing protection devices often use a single metal conductor in their fuse triggering structure. To balance current carrying capacity and fuse response speed, compromises must be made in the selection of the metal material: if a high-conductivity metal is chosen to ensure large current flow, its melting point is high, resulting in a slow fuse response and inability to promptly cut off fault current; if a low-melting-point metal is chosen to speed up the response, its current carrying capacity is weak, making it prone to false melting under normal operating current, affecting the normal operation of the circuit. Simultaneously, the layout of heat-generating components in some triggering structures is unreasonable, leading to excessive temperature rise and poor heat dissipation. This not only affects the operational stability of the device but may also accelerate the aging of surrounding electronic components. Additionally, existing conductor structures have weak impact resistance, making them susceptible to mechanical damage when instantaneous surge currents occur in the circuit, causing premature failure of the protection device.

[0006] In summary, existing circuit protection devices suffer from technical defects such as insufficient control flexibility, poor heat dissipation effect, difficulty in balancing current carrying and fusing response, weak impact resistance, and limited breaking reliability and insulation performance. They cannot fully meet the safety protection needs of current high-power and complex circuit systems. Therefore, there is an urgent need for a new type of circuit protection device that can solve the above problems. Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] To address the shortcomings of existing technologies, this invention provides a dual-break controllable protection device, which has the advantages of flexible control, good heat dissipation, balanced current carrying and fusing response, strong impact resistance, reliable breaking and excellent insulation performance. It solves the technical problems of existing circuit protection devices, such as insufficient control flexibility, poor heat dissipation, difficulty in balancing current carrying and fusing response, weak impact resistance, and limited breaking reliability and insulation performance, which cannot meet the safety protection requirements of high-power complex circuit systems.

[0009] (II) Technical Solution

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A double-break controllable protection device, comprising:

[0012] Conductive busbar;

[0013] The trigger body is connected in series on the busbar and consists of a current-carrying metal body and a low-melting-point metal body. The current-carrying metal body has several bends, and the low-melting-point metal body is placed at the bends. The current-carrying metal body is responsible for carrying the normal current and generating heat when the current is applied. The low-melting-point metal body is used to lower the melting point of the current-carrying metal body.

[0014] The signal transmission module, including an internal trigger line, an external trigger line, a motherboard, and multiple electronic components, is used to transmit external or internal voltage signals to the switching component for disconnection.

[0015] Multiple interruption components, wherein at least two interruption components are provided on the conductive bus for interrupting the circuit at different positions on the conductive bus;

[0016] When a large current flows through the trigger body, the current-carrying metal body will generate heat rapidly. When the temperature reaches the melting point of the low-melting-point metal body, the low-melting-point metal body and the current-carrying metal body will undergo a metallurgical effect, causing the melting point of the current-carrying metal body to decrease and then melt rapidly. The voltage signal generated after the trigger body melts is transmitted to the switching component through the internal trigger line to cut off the circuit.

[0017] Preferably, it also includes a protective upper cover and a protective lower cover. The main body of the conductive busbar, the trigger body, the switching component, and other components of the signal transmission module except for the external trigger wire are all arranged in the space formed by the protective upper cover and the protective lower cover to protect the internal devices.

[0018] Preferably, the flow-through metal body is any one of copper, silver, copper alloy, or silver alloy, and the low-melting-point metal body is tin or tin alloy.

[0019] Preferably, the signal transmission module includes a dual threshold determination unit, a time node recording unit, a voltage acquisition unit, and an interruption control unit; the dual threshold determination unit sets a trigger threshold voltage Uth and a judgment threshold voltage Um; the time node recording unit records the first signal time T0 when the voltage across the trigger body first exceeds Uth, and calculates the second signal time T1, which is equal to the first signal time T0 plus the interval time ΔT; the voltage acquisition unit acquires the stable voltage value Uc across the trigger body at time T1; and the interruption control unit controls different numbers of interruption components to break the circuit according to the relationship between Uc and Um.

[0020] Preferably, the trigger body is composed of two parallel and independently arranged first trigger sub-body and second trigger sub-body, with an insulating gap between the two trigger sub-body; the first trigger sub-body includes a first current-carrying metal body and a first low-melting-point metal body, and the second trigger sub-body includes a second current-carrying metal body and a second low-melting-point metal body. When the trigger body passes a gradually increasing current, the first low-melting-point metal body begins to melt before the second low-melting-point metal body.

[0021] The signal transmission module is used to identify the voltage levels at both ends of the trigger body and control different numbers of switching components to disconnect the circuit according to the voltage levels.

[0022] Preferably, the flow-through metal body has two downwardly recessed bends, and a narrow neck is provided in the part of the flow-through metal body between the two bends. The narrow neck is provided with a plurality of spaced through holes extending to both sides of the flow-through metal body to facilitate rapid breakage of the flow-through metal body. The bend of the flow-through metal body used to install the low-melting-point metal body is a trigger bend, and the other bend on the flow-through metal body is an auxiliary bend. The recess depth and recess span of the trigger bend are smaller than the recess depth and recess span of the auxiliary bend.

[0023] Preferably, the first trigger body is located below the second trigger body.

[0024] Preferably, the first low-melting-point metal body is a tin-lead alloy, and the second low-melting-point metal body is a bismuth-tin alloy.

[0025] Preferably, a non-conductive medium is provided inside the upper and lower protective covers.

[0026] Preferably, the length and cross-sectional area of ​​the flow-through metal body of the first trigger body and the second trigger body are the same.

[0027] (III) Beneficial Effects

[0028] Compared with the prior art, the present invention provides a double-break controllable protection device, which has the following beneficial effects:

[0029] 1. This dual-break controllable protection device, firstly, has both self-triggered and externally triggered structures, allowing for more flexible control of the device. Furthermore, the centrally located heating element structure better reduces temperature rise and facilitates heat dissipation. Secondly, the combination of a low-melting-point metal body and a current-carrying metal body ensures both high current flow and melting at the rated heat output, achieving lower temperatures and safer current flow. Additionally, the bends in the current-carrying metal body accommodate the low-melting-point metal body and increase impact resistance. Most importantly, the multiple breaking components not only prevent a decrease in breaking or arc-extinguishing capability due to aging or minor faults in individual components but also improve the circuit's withstand voltage and enhance insulation after breaking.

[0030] 2. This dual-break controllable protection device, firstly, because the arc generated when a high-current circuit melts will affect voltage changes, utilizes voltage delay detection to distinguish between small current and large current overloads, matching different numbers of breaking components to operate, avoiding over-protection or under-protection, adapting to diverse fault scenarios, reducing the breaking cost of small current overloads, and improving the reliability of large current breaking; secondly, the dual threshold judgment mechanism effectively filters arc fluctuations and electromagnetic interference, reducing the misjudgment rate of classification.

[0031] 3. This dual-break controllable protection device features: First, clear voltage classification characteristics. Through differentiated fusing of the dual trigger sub-body, a three-level voltage signal is formed, accurately distinguishing between normal current flow, small current overload, and large current short circuit, thus improving classification identification. Second, precise and efficient classification and breaking. In a small current overload, only the first trigger sub-body fuses, controlling one breaking component to operate. In a large current short circuit, both trigger sub-body fuses, controlling all components to operate, balancing protection accuracy and reliability. Third, wider applicability: It can adapt to DC, high voltage, and strong electromagnetic interference scenarios, with strong anti-interference capability of the voltage signal, expanding the application range compared to traditional single trigger body. Furthermore, it has a failure warning function, detecting sub-body aging and failure in advance, avoiding protection device malfunction, reducing circuit fault risk, and improving maintenance convenience. Finally, superior current flow performance: the parallel connection of the twin sub-body reduces the total resistance of the trigger body, reducing current loss during normal operation, reducing heat generation, and extending the life of the trigger body.

[0032] 4. This dual-break controllable protection device firstly achieves directional rapid fracture, improving protection reliability. The narrow through-hole forms a stress-weak area, guiding the current-carrying metal body to fracture along a preset path, avoiding the problems of random fracture location and incomplete fracture in the original bending structure. This ensures that the circuit is quickly cut off after the trigger body melts, improving the effectiveness of self-protection. Secondly, the low-melting-point metal body is fixed in the trigger bend with a smaller recess depth and span, improving the installation stability of the low-melting-point metal body. Furthermore, the impact resistance of the current-carrying metal body is improved through the auxiliary bend with a larger recess depth and span. Attached Figure Description

[0033] Figure 1 This is an exploded view of the structure of Embodiment 1 of the present invention.

[0034] Figure 2 This is a structural appearance diagram of Embodiment 1 of the present invention.

[0035] Figure 3 This is a cross-sectional view of Embodiment 1 of the present invention.

[0036] Figure 4 This is a schematic diagram of the structure after removing the protective top cover and the protective bottom cover in Embodiment 1 of the present invention.

[0037] Figure 5 This is a schematic diagram of the conductive bus and trigger body in Embodiment 1 of the present invention.

[0038] Figure 6 This is a schematic diagram of the signal transmission module according to Embodiment 1 of the present invention.

[0039] Figure 7 This is a schematic diagram of the structure of the interruption component according to Embodiment 1 of the present invention.

[0040] Figure 8 This is a schematic diagram of the structure of the interruption component according to Embodiment 1 of the present invention.

[0041] Figure 9 This is a schematic diagram of the trigger body in Embodiment 1 of the present invention.

[0042] Figure 10 This is a front view of the trigger body in Embodiment 1 of the present invention.

[0043] Figure 11 This is a schematic diagram of the structure of the first trigger sub-body and the second trigger sub-body in Embodiment 2 of the present invention.

[0044] In the diagram: 1. Conductive busbar; 2. Trigger body; 21. Current-carrying metal body; 22. Low-melting-point metal body; 211. Auxiliary bend; 212. Trigger bend; 213. Neck; 201. First trigger sub-body; 202. Second trigger sub-body; 3. Signal transmission module; 31. Inner trigger wire; 32. Outer trigger wire; 4. Switching component; 51. Protective upper cover; 52. Protective lower cover. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0047] In addition, a fixed connection refers to a connection in which parts or components are fixed and there is no relative movement; a transmission connection refers to a connection in which mechanical motion or torque is transmitted to other working parts through a transmission component; a sliding connection refers to a connection in which two objects are in contact but not fixed and can slide relative to each other; and a rotational connection refers to a connection in which two objects are in contact but not fixed and can rotate relative to each other.

[0048] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0049] Example 1:

[0050] This embodiment provides a double-break controllability protection device, which has the following technical features.

[0051] In this embodiment, please refer to Figure 1-10 A dual-break controllable protection device includes: a conductive busbar 1; a trigger body 2, which is connected in series on the conductive busbar 1 and consists of a current-carrying metal body 21 and a low-melting-point metal body 22. The current-carrying metal body 21 has several bends, and the low-melting-point metal body 22 is placed at the bends. The current-carrying metal body 21 is responsible for carrying current normally and heating up when energized, while the low-melting-point metal body 22 is used to lower the melting point of the current-carrying metal body 21; a signal transmission module 3, including an inner trigger line 31, an outer trigger line 32, a motherboard, and multiple electronic components, for transmitting external or internal voltage signals to the breaking assembly 4 for interruption; and multiple breaking assemblies 4, with at least two breaking assemblies 4 provided on the conductive busbar 1 for interrupting the circuit at different positions on the conductive busbar 1.

[0052] When a large current is applied to the trigger body 2, the current-carrying metal body 21 will generate heat rapidly. When the temperature reaches the melting point of the low-melting-point metal body 22, the low-melting-point metal body 22 and the current-carrying metal body 21 will undergo a metallurgical effect, causing the melting point of the current-carrying metal body 21 to decrease and then melt rapidly. The voltage signal generated after the trigger body 2 melts is transmitted to the switching component 4 through the inner trigger line 31 for disconnection.

[0053] This dual-break controllable protection device has several advantages. First, it features both self-triggered and externally triggered structures, allowing for more flexible control. The centrally located heating element further reduces temperature rise and facilitates better heat dissipation. Second, the combination of a low-melting-point metal body 22 and a current-carrying metal body 21 ensures both high current flow and melting at the rated heat output, resulting in lower temperatures and safer current flow. Furthermore, the bend in the current-carrying metal body 21 accommodates the low-melting-point metal body 22 and increases impact resistance. Most importantly, the multiple breaking components 4 not only prevent a decrease in breaking or arc-extinguishing capability due to aging or minor faults in individual components but also improve the circuit's withstand voltage and enhance insulation after breaking.

[0054] It should be noted that the flow-through metal body 21 is any metal with strong flow-through capacity, and the low-melting-point metal body 22 is a metal with a low melting point that can have a metallurgical effect with the flow-through metal body 21.

[0055] Further features include a protective upper cover 51 and a protective lower cover 52. The main body of the conductive busbar 1, the trigger body 2, the switching component 4, and all other components of the signal transmission module 3 except for the external trigger line 32 are housed within the space formed by the protective upper cover 51 and the protective lower cover 52 to protect the internal components.

[0056] Specifically, the upper protective cover 51 and the lower protective cover 52 are equipped with non-conductive media, such as quartz sand, which can further reduce the temperature.

[0057] Furthermore, the flow-through metal body 21 is any one of copper, silver, copper alloy, or silver alloy, and the low-melting-point metal body 22 is tin or tin alloy.

[0058] It should be noted that the self-triggering structure consists of a trigger body, an internal trigger wire, and a switching component, achieving autonomous triggering through the voltage signal generated by the fuse breaking of the trigger body. The external triggering structure consists of an external trigger wire, an external signal receiving unit on the motherboard, and a switching component, capable of receiving active cut-off signals (such as voltage signals ranging from 5-24V DC) from an external controller. The motherboard has a trigger mode switch, defaulting to the self-triggering priority mode. When an external trigger signal is received, it automatically switches to the external triggering mode, enabling flexible switching between the two control modes.

[0059] It should be noted that the heating element (trigger) adopts a centrally mounted structure. Specifically, the trigger is fixed in the middle area of ​​the conductive busbar and located at the geometric center of the inner cavity of the housing formed by the upper and lower protective covers. A 5-10mm heat dissipation gap is reserved between the trigger and the housing wall, and heat dissipation fins are installed on the upper protective cover at the position corresponding to the trigger. This central structure allows the heat generated by the trigger to be evenly diffused in all directions. Combined with the heat dissipation gap and fins, it improves heat dissipation efficiency and reduces the overall temperature rise.

[0060] It should be noted that each interrupting assembly includes an arc-extinguishing chamber, a moving contact, a stationary contact, and a flexible drive mechanism. The arc-extinguishing chamber is filled with steel wire blocks as the arc-extinguishing medium. Multiple interrupting assemblies are connected in series on a busbar, with a spacing of 15-20 mm between adjacent interrupting assemblies. When a trigger signal is received, the flexible drive mechanism drives the moving contact to separate from the stationary contact, and the generated arc is quickly extinguished by the cooling and adsorption effect of the steel wire blocks. Multiple interrupting assemblies connected in series form a multi-stage arc-extinguishing structure, which improves the circuit's withstand voltage through voltage division. After interruption, a double insulation barrier is formed between adjacent components, enhancing the insulation capability.

[0061] It should be noted that the flow-through metal body and the low-melting-point metal body are fixed by snap-fit ​​or brazed to form a metallurgical bonding layer; the metallurgical effect is that the low-melting-point metal body and the flow-through metal body form a solid solution at high temperature, and the melting point of the solid solution is lower than that of the pure flow-through metal body, thereby achieving rapid melting and breaking of the flow-through metal body.

[0062] Example 2:

[0063] This embodiment provides a dual-break controllable protection device. The difference between Embodiment 2 and Embodiment 1 is that in Embodiment 1, each breaking component 4 is triggered simultaneously. That is, the signal transmission module 3 only controls all breaking components 4 to break simultaneously when it detects the voltage change caused by the interruption of the trigger body 2. In Embodiment 2, the number of actions of the breaking components 4 is precisely matched according to the overcurrent level.

[0064] In this embodiment, the signal transmission module 3 is equipped with a dual threshold determination unit, a time node recording unit, a voltage acquisition unit, and an interruption control unit. The dual threshold determination unit sets a trigger threshold voltage Uth and a judgment threshold voltage Um. The time node recording unit is used to record the first signal time T0 when the voltage at both ends of the trigger body 2 first exceeds Uth, and calculate the second signal time T1. The second signal time T1 is equal to the first signal time T0 plus the interval time ΔT. The voltage acquisition unit is used to acquire the stable voltage value Uc at both ends of the trigger body 2 at time T1. The interruption control unit controls different numbers of interruption components 4 to interrupt the circuit according to the relationship between Uc and Um.

[0065] This dual-break controllable protection device, firstly, utilizes voltage delay detection to distinguish between small and large current overloads, since the arc generated when a high-current circuit melts will affect voltage changes. It matches different numbers of breaking components to operate, avoiding over-protection or under-protection, adapting to diverse fault scenarios, reducing the breaking cost of small current overloads, and improving the reliability of large current breaking. Secondly, the dual-threshold judgment mechanism effectively filters arc fluctuations and electromagnetic interference, reducing the misjudgment rate of classification.

[0066] Furthermore, the trigger threshold voltage Uth = In * Rt is set, where In is the reference current for the melting threshold of trigger body 2, and Rt is the resistance value of trigger body 2 at the temperature close to melting.

[0067] Furthermore, the threshold voltage Um and the interval time ΔT are determined by experimental data. The voltage across the trigger body 2 used in the experiment is monitored in real time, and the voltage signal change curve from the start of melting to voltage stabilization is recorded. The vertical axis of the curve is the voltage value, and the horizontal axis is the time. The total time from the start of melting to voltage stabilization is Ts, and the interval time ΔT is a characteristic value between 50%Ts and 80%Ts. The voltage value corresponding to ΔT is determined by the curve to be the threshold voltage Um.

[0068] Furthermore, the signal transmission module 3 integrates an RC filter circuit and a peak hold circuit to filter high-frequency fluctuations in the arc voltage.

[0069] Furthermore, the control logic of the switching control unit is configured as follows: when Uc≥Um, control one switching component 4 to operate; when Uc<Um, control all switching components 4 to operate synchronously.

[0070] Furthermore, the interruption control unit is equipped with a fault fallback mechanism: if the voltage across the trigger body 2 does not reach Uth at time T1, or if the interruption component 4 is not triggered for more than 0.05 seconds, the interruption component 4 will be activated immediately to disconnect the circuit.

[0071] It should be noted that the dual threshold determination unit includes two operational amplifiers (model LM324), a reference voltage source (model REF3025), and an adjustable resistor network. The reference voltage source provides a stable reference voltage, and the adjustable resistor network adjusts the output trigger threshold voltage Uth and the judgment threshold voltage Um respectively. The first operational amplifier compares the voltage across the trigger body acquired with Uth and outputs a first comparison signal. The second operational amplifier compares Uc acquired at time T1 with Um and outputs a second comparison signal. Both comparison signals are transmitted to the switching control unit.

[0072] It should be noted that the experimental conditions for determining the interval time ΔT are as follows: the specifications of the trigger used in the experiment are consistent with those of the trigger used in actual applications (the current-carrying metal body is copper with a cross-sectional area of ​​2 mm²). 2 The low-melting-point metal is tin, with a volume of 0.5 cm³. 3 The current carrying capacity is 1.2 times the trigger body's fusing threshold current, and the ambient temperature is 25℃±5℃; Ts is the total time from the onset of fusing signs in the trigger body (voltage rises by 0.5V for the first time) to voltage stabilization (voltage fluctuation is less than 0.1V within 100ms); ΔT is selected based on the time corresponding to the midpoint of the time period with the smallest voltage fluctuation within the range of 50%Ts-80%Ts. For example, when Ts=200ms, ΔT=120ms (60%Ts) is selected.

[0073] Example 3:

[0074] This embodiment provides a dual-break controllability protection device. The difference between Embodiment 3 and Embodiment 1 is that in Embodiment 1, the trigger body 2 only includes a current-carrying metal body 21 and a low-melting-point metal body 22. In Embodiment 3, the graded identification is improved by differentiating the melting of the dual trigger sub-body.

[0075] In this embodiment, please refer to Figure 11 The trigger body 2 consists of two parallel and independently arranged first trigger sub-body 201 and second trigger sub-body 202, with an insulating gap between the two trigger sub-body; the first trigger sub-body 201 includes a first current-carrying metal body and a first low-melting-point metal body, and the second trigger sub-body 202 includes a second current-carrying metal body and a second low-melting-point metal body. When the trigger body 2 passes a gradually increasing current, the first low-melting-point metal body begins to melt before the second low-melting-point metal body.

[0076] The signal transmission module 3 is used to identify the voltage level at both ends of the trigger body 2 and control different numbers of switching components 4 to disconnect the circuit according to the voltage level.

[0077] This dual-break controllable protection device firstly features clear voltage classification characteristics. Through differentiated fusing of the two trigger sub-body, it forms a three-level voltage signal, which can accurately distinguish between three states: normal current flow, small current overload, and large current short circuit, improving classification identification. Secondly, the classification and breaking are precise and efficient. In the case of small current overload, only the first trigger sub-body 201 fuses, controlling the action of one breaking component 4. In the case of large current short circuit, both trigger sub-body fuses, controlling the action of all components, balancing protection accuracy and reliability. Thirdly, it has a wider range of applicable scenarios: it can be adapted to DC, high voltage, and strong electromagnetic interference scenarios, and the voltage signal has strong anti-interference capability, expanding the scope of application compared to the traditional single trigger body 2. In addition, it has a failure warning function, which detects the aging and failure of the sub-body in advance, avoids the failure of the protection device, reduces the risk of circuit failure, and improves the convenience of operation and maintenance. Finally, it has better current flow performance: the parallel connection of the twin sub-body reduces the total resistance of the trigger body 2, reduces current loss during normal operation, reduces heat generation, and extends the service life of the trigger body 2.

[0078] Furthermore, the first trigger sub-body 201 is located below the second trigger sub-body 202 to prevent the second trigger sub-body 202 from melting and dripping onto it, thus preventing it from melting and breaking.

[0079] Furthermore, the first low-melting-point metal body is a tin-lead alloy, and the second low-melting-point metal body is a bismuth-tin alloy.

[0080] Furthermore, the length and cross-sectional area of ​​the current-carrying metal body of the first trigger body 201 and the second trigger body 202 are the same to ensure that the current is evenly distributed during normal operation.

[0081] Furthermore, the voltage recognition logic of the signal transmission module 3 is configured as follows: when the voltage is equal to or close to 0V, it is determined to be normal current flow, and the switching component 4 does not operate; when the voltage suddenly increases but is much less than the total circuit voltage, it is determined to be a small current overcurrent, and one switching component 4 is controlled to operate; when the voltage is equal to or close to the total circuit voltage, it is determined to be a large current overcurrent, and all switching components 4 are controlled to operate synchronously.

[0082] Furthermore, the signal transmission module 3 is equipped with a fault fallback mechanism: if a stable voltage is detected before reaching the total circuit voltage, all disconnection components 4 are immediately activated to disconnect the circuit.

[0083] It should be noted that the first and second low-melting-point metal bodies have different melting points, which is the core reason for achieving differentiated melting. At the same time, the first and second current-carrying metal bodies have the same specifications, and the current is evenly distributed and the heating power is the same during normal operation. Therefore, when the current is overloaded, the first low-melting-point metal body, which has a lower melting point, reaches the melting temperature first and melts first. The second low-melting-point metal body melts after the current increases further and heat accumulates, forming a staged melting effect.

[0084] Example 4:

[0085] This embodiment provides a dual-break controllable protection device, which, in addition to the technical solutions of the above embodiments, also has the following technical features.

[0086] In this embodiment, the flow-through metal body 21 has two downwardly recessed bends. The flow-through metal body 21 has a narrow neck 213 between the two bends. The narrow neck 213 has multiple spaced through holes extending to both sides of the flow-through metal body 21 to facilitate rapid breakage of the flow-through metal body 21. The bend of the flow-through metal body 21 used to install the low-melting-point metal body 22 is a trigger bend 212. The other bend on the flow-through metal body 21 is an auxiliary bend 211. The recess depth and recess span of the trigger bend 212 are smaller than the recess depth and recess span of the auxiliary bend 211.

[0087] This dual-break controllable protection device firstly achieves directional rapid fracture, improving protection reliability. The through hole of the narrow neck 213 forms a stress-weak area, guiding the current-carrying metal body 21 to fracture along a preset path, avoiding the problems of random fracture location and incomplete fracture in the original bending structure, ensuring that the circuit is quickly cut off after the trigger body 2 melts, thus improving the effectiveness of self-protection. Secondly, the low-melting metal body 22 is fixed in the trigger bend 212 with a smaller recess depth and span, improving the installation stability of the low-melting metal body 22, and the impact resistance of the current-carrying metal body 21 is improved by the auxiliary bend 211 with a larger recess depth and span.

[0088] When this embodiment four is applied to embodiment two, it can also produce additional effects. The narrow neck 213 can increase the fracture speed of the flow-through metal body 21 and can quickly respond to the signal of the dual threshold determination unit, avoiding the lag in graded protection caused by fracture delay.

[0089] When this fourth embodiment is applied to the third embodiment, it is finely adjusted so that the depth and span of the indentation of the trigger bend 212 of the first flow-through metal body are smaller than the depth and span of the indentation of the trigger bend 212 of the second flow-through metal body, thereby making the volume of the first low-melting-point metal body smaller than that of the second low-melting-point metal body, so that it melts faster.

[0090] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0091] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A double-break controllable protection device, characterized in that, include: Conductor bus (1); The trigger body (2) is connected in series on the busbar (1) and consists of a current-carrying metal body (21) and a low-melting-point metal body (22). The current-carrying metal body (21) has several bends, and the low-melting-point metal body (22) is placed at the bends. The current-carrying metal body (21) is responsible for carrying the current normally and heating up when the current is carried. The low-melting-point metal body (22) is used to reduce the melting point of the current-carrying metal body (21). The signal transmission module (3) includes an internal trigger line (31), an external trigger line (32), a motherboard, and multiple electronic components, used to transmit external or internal voltage signals to the switching component (4) for disconnection; Multiple interruption components (4), at least two interruption components (4) are provided on the conductive bus (1) for interrupting the circuit at different positions on the conductive bus (1); When the trigger body (2) carries a large current, the current-carrying metal body (21) will generate heat rapidly. When the temperature reaches the melting point of the low-melting-point metal body (22), the low-melting-point metal body (22) and the current-carrying metal body (21) will undergo a metallurgical effect, causing the melting point of the current-carrying metal body (21) to decrease and then melt quickly. The voltage signal generated after the trigger body (2) melts is transmitted to the switching component (4) through the inner trigger line (31) for disconnection. The signal transmission module (3) is equipped with a dual threshold determination unit, a time node recording unit, a voltage acquisition unit, and an interruption control unit. The dual threshold determination unit is equipped with a trigger threshold voltage Uth and a judgment threshold voltage Um. The time node recording unit is used to record the first signal time T0 when the voltage at both ends of the trigger body (2) first exceeds Uth, and to calculate the second signal time T1. The second signal time T1 is equal to the first signal time T0 plus the interval time ΔT. The voltage acquisition unit is used to acquire the stable voltage value Uc at both ends of the trigger body (2) at time T1. The interruption control unit controls different numbers of interruption components (4) to interrupt the circuit according to the relationship between Uc and Um.

2. The double-break controllable protection device according to claim 1, characterized in that, It also includes a protective upper cover (51) and a protective lower cover (52). The main body of the conductive bus (1), the trigger body (2), the switching component (4), and the other components of the signal transmission module (3) except for the outer trigger line (32) are all arranged in the space formed by the protective upper cover (51) and the protective lower cover (52) to protect the devices inside.

3. The double-break controllable protection device according to claim 1, characterized in that, The flow-through metal body (21) is any one of copper, silver, copper alloy or silver alloy, and the low-melting-point metal body (22) is tin or tin alloy.

4. The double-break controllable protection device according to claim 1, characterized in that, The trigger body (2) consists of two parallel and independently arranged first trigger sub-body (201) and second trigger sub-body (202), with an insulating gap between the two trigger sub-body; the first trigger sub-body (201) includes a first current-carrying metal body and a first low-melting-point metal body, and the second trigger sub-body (202) includes a second current-carrying metal body and a second low-melting-point metal body. When the trigger body (2) passes a gradually increasing current, the first low-melting-point metal body begins to melt before the second low-melting-point metal body. The signal transmission module (3) is used to identify the voltage level at both ends of the trigger body (2) and control different numbers of switching components (4) to disconnect the circuit according to the voltage level.

5. A double-break controllable protection device according to any one of claims 1 or 4, characterized in that, The flow-through metal body (21) has two downwardly recessed bends. The flow-through metal body (21) has a narrow neck (213) between the two bends. The narrow neck (213) has multiple spaced through holes extending to both sides of the flow-through metal body (21) to facilitate the rapid breakage of the flow-through metal body (21). The bend of the flow-through metal body (21) used to install the low-melting metal body (22) is a trigger bend (212). The other bend on the flow-through metal body (21) is an auxiliary bend (211). The recess depth and recess span of the trigger bend (212) are smaller than the recess depth and recess span of the auxiliary bend (211).

6. The double-break controllable protection device according to claim 4, characterized in that, The first trigger sub-body (201) is located below the second trigger sub-body (202).

7. The double-break controllable protection device according to claim 4, characterized in that, The first low-melting-point metal body is a tin-lead alloy, and the second low-melting-point metal body is a bismuth-tin alloy.

8. The double-break controllable protection device according to claim 2, characterized in that, The upper protective cover (51) and the lower protective cover (52) contain non-conductive media.

9. A double-break controllable protection device according to claim 4, characterized in that, The first trigger subbody (201) and the second trigger subbody (202) have the same length and cross-sectional area of ​​the flow-through metal body.

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