An energized fuse with a melt structure

Abstract

The application discloses an excitation fuse with a fuse structure, which comprises a shell, an excitation source, at least one conductive row, and a fuse structure. The shell is provided with a first cavity and a second cavity filled with arc-extinguishing medium. The driving force release end of the excitation source is communicated with the first cavity, and the conductive row penetrates through the shell and the first cavity. The fuse structure is at least partially arranged in or penetrates through the arc-extinguishing medium in the second cavity. The fuse structure comprises a fuse and an insulating spacer, at least one insulating spacer is arranged on the fuse in the current direction, the fuse penetrates through the insulating spacer, the insulating spacer is used for partially or completely isolating the arc at the breaking point of the fuse, and the insulating spacer releases gas under the high temperature of the arc and cools the arc. The excitation fuse uses the fuse structure, so that the breaking performance, the insulation performance after breaking and the withstand voltage performance of the fuse can be improved.

Description

Technical Field

[0001] This invention relates to the field of circuit protection, and to a fusible structure for use in circuit protection, particularly an excitation fuse having a fusible structure. Background Technology

[0002] An excitation fuse typically includes an excitation source, a piston, a conductor bus, and an arc-extinguishing fuse element. The excitation source, acting on a received trigger signal, releases driving force, displacing the piston. The piston breaks the conductor bus, thus disconnecting the circuit and providing circuit protection. To improve breaking capacity and arc-extinguishing capability, an arc-extinguishing fuse element is connected in parallel with the conductor bus. The resistance of the arc-extinguishing fuse element is much greater than the resistance of the conductor bus. Under normal current flow, most of the current flows through the conductor bus, and the current flowing through the arc-extinguishing fuse element is negligible. When the conductor bus is disconnected, the current flows through the arc-extinguishing fuse element, which melts or is mechanically broken. After the fuse element breaks, the arc-extinguishing medium participates in arc extinguishing. When the arc-extinguishing fuse element breaks, an arc is generated at the break point, which can easily lead to arcing or breakdown, making it difficult to establish good insulation after the arc-extinguishing fuse element breaks.

[0003] When both the fusible element of the thermal fuse and the arc-extinguishing fusible element of the excitation fuse are melted, the fusible element and its narrow diameter melt or vaporize, forming a break after melting. This is essentially a micro-explosion under overall safety control, as well as the diffusion of conductive aggregates and ceramization. Because physical insulation cannot be effectively established at the break, the diffusion of metal ions at the fusible element break is relatively random after the break, resulting in unstable or poor insulation performance after the break. Due to the poor or unstable insulation at the break, there is a risk of large leakage current, breakdown, and failure to break (explosion, etc.) under high voltage.

[0004] For example, existing induced fuses include an excitation source, a piston, at least one conductive busbar, a first cavity, and a second cavity. The excitation source and piston are located in the first cavity, and the conductive busbar passes through the housing and the first cavity. The piston is positioned corresponding to the conductive busbar. The fusible element, connected in parallel to the conductive busbar, is located in the second cavity, which is filled with an arc-extinguishing medium. Because the second cavity utilizes the housing space outside the first cavity, it is relatively narrow and has a relatively small volume. After the fusible element breaks, the arc generated at the fracture point on the fusible element is prone to arcing or breakdown. Effective physical insulation cannot be established at the fracture point, resulting in poor insulation performance. Its drawbacks are more serious than those of ordinary induced fuses. Summary of the Invention

[0005] The purpose of this invention is to provide an excitation fuse with a fusible element structure. By changing the fusible element structure and setting an insulating isolator on the fusible element, a number of chambers are established in the arc-extinguishing chamber through the insulating isolator. The insulating isolator isolates the cooling arc, thereby improving the post-break insulation performance and breaking capacity of the excitation fuse.

[0006] To achieve the above objectives, the present invention provides an excitation fuse with a fusible element structure, comprising a housing, an excitation source, at least one conductive busbar, and a fusible element structure; The housing has a first cavity and a second cavity filled with an arc-extinguishing medium; the chamber where the driving force release end of the excitation source is located is connected to the first cavity; the conductive bus passes through the housing and the first cavity; the melt structure is at least partially located in / or passes through the arc-extinguishing medium in the second cavity; The melt structure includes a melt and an insulating isolator. The melt passes through the arc-extinguishing medium in the second cavity. The two ends of the melt are electrically connected to the conductive busbar in parallel. At least one insulating isolator is provided between the two ends of the melt in the current direction. The melt passes through the insulating isolator, which is disposed in the arc-extinguishing medium in the second cavity. The insulating isolator is used to partially or completely isolate the electric arc at the melt fracture point and releases gas at the high temperature of the electric arc to cool the arc. When the excitation source acts according to the received trigger signal, it releases a driving force. The driving force acts on the conductive busbar, causing the conductive busbar to disconnect, and the melt melts.

[0007] Preferably, the insulating insulating element and the molten material are gap-fitted or sealed together.

[0008] Preferably, when a sealed connection is made, the insulating insulating element and the melt are integrally injection molded, or the gap between the insulating insulating element and the melt is sealed with sealant.

[0009] Preferably, the insulating insulating element is provided with a notch or through hole through which the molten material passes.

[0010] Preferably, the sealant is used to fill the gap between the melt and the notch or through hole.

[0011] Preferably, the cross-sectional shape of the insulating insulating member includes at least one angular shape, or at least partially arcuate shape.

[0012] Preferably, the cross-sectional shape of the insulating insulating member includes at least one of the following shapes: square, circular, rhomboid, trapezoidal.

[0013] Preferably, a groove is provided on the surface of at least one side of the insulating isolator along the direction of the melt current.

[0014] Preferably, at least one type of narrow neck is provided between the two ends of the melt, and the section with the maximum width on one or both sides of the narrow neck in the direction of current is a heat dissipation section; at least one of the insulating isolation members is provided at the narrow neck or the heat dissipation section.

[0015] Preferably, when the neck is provided with one specification, the molten material includes an arc-extinguishing section and a heat dissipation section, and the neck is the arc-extinguishing section; when the neck is provided with two or more specifications, the molten material includes an arc-initiating section, an arc-extinguishing section and a heat dissipation section, the neck that first initiates the arc and melts is the arc-initiating section, and the neck that later initiates the arc and melts is the arc-extinguishing section; at least one insulating isolator is provided at the arc-initiating section or the arc-extinguishing section.

[0016] Preferably, the insulating isolator is disposed at the arc initiation segment.

[0017] Preferably, the shape of the insulating isolator matches the shape of the second cavity, and the insulating isolator isolates the second cavity into several independent chambers that are not interconnected.

[0018] Preferably, the insulating isolator is in sealed contact with the second cavity, thereby isolating the second cavity into several independent chambers that are not interconnected.

[0019] Preferably, the driving force released by the excitation source is high-pressure gas.

[0020] Preferably, the device further includes a piston located in the first cavity, the piston being disposed corresponding to the conductive busbar.

[0021] Preferably, the conductive busbar includes at least two insulated conductive busbars; the impact ends of the piston are respectively disposed corresponding to the conductive busbars; at least one of the conductive busbars is connected in parallel with the melt structure, and the melt structure is located in the second cavity.

[0022] Preferably, when there are two or more conductive bars, the conductive bars are arranged side by side, staggered layer by layer, or staggered position by position.

[0023] Preferably, a thermoplastic fuse is provided in the second cavity, and the molten structure is disposed in the thermoplastic fuse.

[0024] Preferably, the second cavity is located outside the piston displacement path or in front of the piston displacement path.

[0025] The excitation fuse of this invention uses a fusible element structure in a relatively small arc-extinguishing chamber. An insulating isolator divides the arc-extinguishing chamber into several compartments to isolate the arc generated after the fusible element breaks, preventing arc breakdown. The insulating isolator effectively thins the arc near it, effectively limiting its shape and size. Simultaneously, the high temperature generated by the arc vaporizes the insulating tube isolator, releasing a large amount of gas. This gas disperses metal ions near the insulating tube isolator, forming effective arc isolation and insulation. This significantly improves the insulation and withstand voltage performance of the fusible element after melting in the arc-extinguishing chamber. Therefore, the overall breaking performance, insulation performance, and withstand voltage performance of the excitation fuse are improved, effectively ensuring the reliability and stability of the excitation fuse's breaking performance. Furthermore, it enhances the flexibility and adjustment range of the fuse element design. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the three-dimensional structure of the melt.

[0027] Figure 2 This is a front view schematic diagram of the melt structure.

[0028] Figure 3 This is a top view schematic diagram of the melt structure.

[0029] Figure 4 This is a schematic diagram of an insulating insulating component with grooves.

[0030] Figure 5 This is a schematic diagram of an insulating insulating component with through holes.

[0031] Figure 6 This is a schematic diagram of a melt with a narrow neck of a certain specification.

[0032] Figure 7 This is a schematic diagram of a melt with two different specifications of narrow necks.

[0033] Figure 8 This is a schematic diagram illustrating the principle of setting the fusible element structure in an excitation fuse.

[0034] Figure 9 This is a structural diagram of a compact excitation fuse.

[0035] Figure 10 It is a three-dimensional sectional view of a compact excitation fuse with a fusible element structure.

[0036] Figure 11 This is a schematic diagram of the cross-sectional structure of the second cavity containing the melt structure.

[0037] Figure 12 This is a schematic diagram showing the appearance of the second cavity located at the bottom of the excitation fuse.

[0038] Figure 13 yes Figure 12 A three-dimensional sectional view.

[0039] Figure 14 yes Figure 12 A schematic diagram of a second cavity structure with a melt structure.

[0040] Attached Figure 1. Melt element; 2. Insulating isolation component; 3. Heat dissipation section; 4. Notch structure; 5. Through hole; 6. Neck; 7. First neck; 8. Second neck; 20. Sealing ring; 21. Upper shell; 22. Middle shell; 23. Lower shell; 24. Excitation source; 25. Piston; 26. First conductive busbar; 27. Arc extinguishing medium; 28. Second conductive busbar; 29. ​​Screw; 30. Sealant; 31. Thermo-melting fuse; 32. Fuse housing; 33. Top cover. Detailed Implementation

[0041] The excitation fuse with a fusible structure of the present invention includes a housing, an excitation source, at least one conductive bus, and a fusible structure. The housing has a first cavity and a second cavity filled with an arc-extinguishing medium; the chamber where the driving force release end of the excitation source is located is connected to the first cavity, and the conductive bus passes through the housing and the first cavity; the melt structure is at least partially located in / or passes through the arc-extinguishing medium in the second cavity; The melt structure includes a melt and an insulating isolator. The melt passes through the arc-extinguishing medium in the second cavity. The two ends of the melt are electrically connected to the conductive busbar in parallel. At least one insulating isolator is provided between the two ends of the melt in the current direction. The melt passes through the insulating isolator, which is located in the arc-extinguishing medium in the second cavity. The insulating isolator is used to partially or completely isolate the arc at the melt break and releases gas at the high temperature of the arc to cool the arc. When the excitation source acts according to the received trigger signal, it releases the driving force. The driving force acts on the conductive busbar, causing the conductive busbar to disconnect, and the melt melts.

[0042] The excitation fuse of the present invention adds a fusible element structure to the arc-extinguishing chamber of the excitation fuse. An insulating isolator on the fusible element structure divides the arc-extinguishing chamber into several chambers. When an electric arc is generated, the insulating isolator can actively extinguish the arc. The active arc-extinguishing method and its working principle are as follows: The insulating isolator itself is made of insulating material, providing at least partial isolation between the molten portions on both sides of the insulating isolator and at least partial isolation between the arc generated by the melting of the molten portion, thereby improving insulation and breaking performance. When there is no gap between the insulating isolator and the arc-extinguishing chamber, complete isolation is formed between the molten portions on both sides of the insulating isolator and the arc generated by the melting of the molten portion on both sides of the insulating isolator, further improving insulation and breaking performance.

[0043] When there is a gap between the insulating isolator and the second cavity, the insulating isolator expands thermally at high temperature, shrinking the gap between the insulating isolator and the arc-extinguishing chamber through which the power supply arc passes, further isolating the arc. Moreover, with the appropriate hardness of the insulating isolator, the arc isolation effect is even better.

[0044] The insulating isolator partially or completely vaporizes under the action of a high-temperature electric arc, blowing away the arc and facilitating its extinguishing, thereby further improving its breaking performance.

[0045] The following describes preferred embodiments in detail with reference to the accompanying drawings. The directional terms used are for reference only and do not constitute a limitation on the technical solution of this invention.

[0046] Melt structure, see Figures 1 to 3 The system includes a melt 1, an insulating separator 2, and a heat dissipation section 3. The melt 1 is a long, sheet-like structure made of a conductive material. Several heat dissipation sections 3 are spaced along the current direction (i.e., the length direction) of the melt 1, with the heat dissipation section 3 having the largest cross-sectional area and the largest heat dissipation area. The heat dissipation sections 3 can quickly transfer the heat generated by the melt to the outside of the melt, thereby reducing the temperature of the melt.

[0047] Insulating isolators 2 are provided at intervals on the molten material 1 in the direction of current flow. (See reference) Figures 1 to 3 An insulating isolator 2 is disposed between adjacent heat dissipation sections in the current direction. The maximum outer diameter of the insulating isolator 2 is greater than the maximum width of the melt structure, i.e., greater than the width of the heat dissipation section, thus providing support and arc isolation for the melt 1. The insulating isolator 2 is made of an insulating, high-temperature resistant, and flame-retardant material. It may include at least one of insulating, high-temperature resistant, and flame-retardant materials such as rubber, ceramics, and engineering plastics. In a preferred embodiment, the insulating isolator is made of an insulating material that can generate and release gas at the high temperature of the arc, preferably, for example, silicone rubber; when it is a ceramic material, it is used in combination with other materials, for example, filling the gap between the melt and the ceramic with rubber or engineering plastics. The ratio of the thickness of the insulating isolator in the current direction to the length of the melt is between 1:1000 and 1:5. The thickness of the insulating element is 0.5–20 mm, preferably 0.5–3.5 mm; more preferably 1.0–2.0 mm, and can be specifically designed as 1.0 mm or 1.5 mm; the Shore hardness range is 30–90 HA, preferably 60–90 HA, and can be specifically designed as 60 HA, 70 HA, 80 HA, or 90 HA. Within the Shore hardness range, higher hardness results in better performance and easier processing.

[0048] The cross-sectional shape of the insulating separator 2 includes at least one angular shape, or at least partially arcuate shape, such as at least one of a square, circular, rhomboid, or trapezoidal structure. See also Figure 4 In one embodiment, the insulating isolator 2 can have a square cross-sectional shape. To facilitate assembly between the insulating isolator 2 and the molten material, a notch structure 4 is provided on the insulating isolator 2 for the molten material 1 to pass through. The notch structure 4 extends through the thickness of the insulating isolator 2, i.e., both sides in the current direction. Grooves are respectively provided on the two sides of the square insulating isolator 2 in the current direction. When grooves are provided, the insulating isolator 2 is thinner in the middle and thicker at the edges, which facilitates assembly and operation and improves the operability of the process; at the same time, the strength of the insulating isolator 2 is improved without increasing the thickness of the molten material passing through. During assembly, the molten material 1 passes through the notch structure 4, and then the gap between the molten material 1 and the notch structure 4 is filled with sealant, thus fixing the molten material 1 to the notch structure 4 of the insulating isolator 2 with sealant. Preferably, the sealant can be 703 silicone or 5088 glue, etc.

[0049] See Figure 5 In one preferred embodiment, the insulating isolator 2 can be a circular structure with a through hole 5 at its center for the molten material 1 to pass through. Grooves are respectively provided on both sides of the insulating isolator 2 in the current direction. The molten material 1 passes through the through hole 5 and is positioned on the insulating isolator 2, which provides support for the molten material 1. The molten material 1 and the through hole 5 can be in a clearance fit, or the clearance can be filled with sealant. When the molten material 1 and the insulating isolator 5 are in a clearance fit, the clearance is sufficient to prevent the electric arc from passing through.

[0050] The melt 1 and the insulating separator 2 can be independent components that are then assembled together, or they can be integrally molded by injection molding.

[0051] Depend on Figure 4 and Figure 5 It can be seen that the melt 1 passes through the insulating isolator 2, and the outer periphery of the melt 1 at the position where it passes through the insulating isolator 2 is completely covered by the insulating isolator 2, or the insulating isolator 2 is completely covered by the sealant, thus forming a complete isolation of the electric arc at the melt fracture.

[0052] In some embodiments, at least a portion of the melt 1 in the width direction may be surrounded by an insulating isolator 2, so that the insulating isolator 2 supports the melt 1, partially isolates the melt portions on both sides of the insulating isolator 2, and partially isolates the electric arc generated at the melt fracture.

[0053] Preferably, the insulating isolator 2 covers the outer periphery of the melt 1 and has a sealed contact with the melt 1, which improves the complete insulation and isolation performance of the melt portion on both sides of the insulating isolator 2 and the arc at the port. At the same time, it forms the most reliable support for the melt 1 and does not require additional support elements.

[0054] The insulating isolator 2 has grooves on both sides of the current direction surface. Alternatively, grooves can be provided on only one side surface. In some embodiments, grooves may not be provided.

[0055] At least one type of narrow neck 6 is provided on the melt 1 in the direction of current. The specifications of the narrow neck here refer to the width and shape of the narrow neck. One specification means that the width and shape of the narrow neck are the same, and two specifications of narrow necks mean that the width and shape of the narrow necks are different.

[0056] See Figures 1 to 2 The narrowest section of melt 1 is the neck 6, and the widest section is the heat dissipation section 3, which is located on one or both sides of the neck 6. Figure 1 and Figure 2 In the process, the narrowest part of the molten material 1 is divided into several segments, namely, several narrow necks 6 are provided on the molten material 1, and each narrow neck 6 has the same width and shape, that is, several narrow necks 6 of the same specification are provided on the molten material 1. When the molten material breaks, because the width is the narrowest at the narrow neck 6, the resistance is the highest, and the temperature rises the fastest at the narrow neck 6. The temperature at the narrow neck 6 first rises to the melting point of the molten material 1, and the molten material 1 breaks off by arc from the narrow neck 6. Since the narrow necks 6 are all of the same specification, there may be many narrow necks where the molten material 1 breaks off. Figure 1 and Figure 2 In the same specification, the narrow neck 6 is defined as the arc-extinguishing section. During the process of heating the narrow neck 6 to the point of melting, most of the heat energy at the narrow neck 6 is conducted along the length of the melt towards the heat dissipation section 3. Since the heat dissipation section 3 is wider and has a larger heat dissipation area, the heat dissipation effect through the heat dissipation section 3 is better than that through the narrow neck 6. Figure 1 and Figure 2 In the middle, the insulating isolation element 2 is set at the narrow neck 6, that is, at the arc extinguishing section.

[0057] See Figure 6 Several identical narrow necks 6 are provided on the melt 1 in the direction of current flow. The width of the narrow neck 6 is the width of the melt through which the current flows. The width of the narrow neck 6 (i.e., the actual width of the melt flowing through the narrow neck, excluding the width of the through hole at the narrow neck) is smaller than the width of the melt on one side of the narrow neck 6 (the actual width of the melt flowing through). Therefore, the narrow necks 6 of the same specification are all arc-extinguishing sections, and the maximum width of the melt on one or both sides of the narrow neck 6 is the heat dissipation section 3.

[0058] See Figure 7Two types of narrow necks are spaced apart on the melt 1 in the direction of current flow. The narrow neck with the smallest current-passing width is the first narrow neck 7, and the narrow neck with a larger current-passing width is the second narrow neck 8. The melt portion with the largest actual current-passing width located on one or both sides of the narrow neck is the heat dissipation section 3. The actual current-passing width of the first narrow neck 7 is smaller than that of the second narrow neck 8, that is, the resistance at the first narrow neck 7 is greater than the resistance at the second narrow neck 8. Therefore, when the melt melts, the heating rate of the first narrow neck 7 is greater than that of the second narrow neck 8. The temperature at the first narrow neck 7 reaches the melting point of the melt first, and the temperature at the second narrow neck 8 reaches the melting point later. The first narrow neck 7 is the first to arc and melt, and the second narrow neck 8 is the second to arc and melt. Therefore, the first narrow neck 7, which is the first to arc and melt, is defined as the arc-starting section, and the second narrow neck 8, which is the second to arc and melt, is defined as the arc-extinguishing section.

[0059] As can be seen from the above, as long as a narrow neck is provided on the melt 1, the melt 1 must include an arc-extinguishing section and a heat dissipation section. When a narrow neck of one specification is provided on the melt 1, the melt 1 includes an arc-extinguishing section and a heat dissipation section; when a narrow neck of two or more specifications is provided on the melt 1, the melt 1 includes an arc-starting section, an arc-extinguishing section, and a heat dissipation section.

[0060] The insulating isolator 2 can be disposed at any point on the arc-initiating section, arc-extinguishing section, and heat-dissipating section of the molten material 1, suitable for application requirements with different arc-extinguishing and insulation performance. The insulating isolator is preferably disposed on the arc-initiating section or the arc-extinguishing section, that is, at the neck. When the molten material only has an arc-extinguishing section and a heat-dissipating section, the insulating isolator is preferentially disposed on the arc-extinguishing section. This improves the insulation performance of the molten material after breakage and shortens the arc duration. When the insulating isolator is disposed on the arc-initiating section, it can improve the insulation performance after breakage while reducing the arc energy during the breaking process. In some embodiments, at least one insulating isolator is disposed on the arc-initiating section.

[0061] The melting rate of melt 1 is adjusted by the actual flow width of the neck 6. The smaller the actual flow width, the greater the melting rate.

[0062] The aforementioned fusible link structure can be integrated into a circuit protection device for the protection of external circuits. When the circuit protection device is used for external circuit protection, the integrated fusible link structure is connected to the external circuit in series or parallel. For example, when the circuit protection device is a thermal fuse, the fusible link structure acts as the fuse element and is connected in series with the external circuit. When the fusible link structure melts, the external circuit is disconnected. When the circuit protection device is an active fuse, the fusible link structure is connected in parallel to the conductor of the active fuse. The conductor is connected in series with the external circuit, so the fusible link structure is connected in parallel with the external circuit. When the conductor of the active fuse breaks, the fusible link structure melts or is mechanically disconnected, completely disconnecting the external circuit and achieving protection for the external circuit.

[0063] The following describes the structure of the thermoelectric fuse and the excitation fuse that adopt the above-mentioned fusible element structure.

[0064] For excitation fuses using the above-described fusible element structure, see [link / reference]. Figure 8 The system includes a shell, an excitation source 24, a piston 25, a first conductive busbar 26, an arc-extinguishing medium 27, and a melt structure. In this embodiment, the shell is assembled from an upper shell 21, a middle shell 22, and a lower shell 23. The structure of the shell is not limited to the structure assembled from the upper shell 21, the middle shell 22, and the lower shell 23; it can also be assembled from left and right sides, or from two or more shell parts. A first cavity and a second cavity are provided in the shell. The excitation source 24 and the piston 25 are disposed in the first cavity, and the first conductive busbar 26 passes through it. The resistance value of the melt 1 in the melt structure is much greater than the resistance value of the first conductive busbar 26. Under normal operating conditions, the current flows through the first conductive busbar 26, and the current flowing through the melt 1 is negligible.

[0065] The excitation source 24 can act according to the received trigger signal, releasing driving force as the power to interrupt the conductive busbar. The driving force released by the excitation source 24 can be high-pressure gas, high-pressure fluid, or mechanical force, such as torque.

[0066] The excitation source 24 and piston 25 are respectively disposed in the first cavity of the upper shell 21. The excitation source 24 closes the top opening of the upper shell 21, and the end of the excitation source 24 that releases driving force is positioned towards the piston 25. A sealing ring 20 is provided at the contact surface between the piston 25 and the inner wall of the upper shell 21 to seal the contact surface between the piston 25 and the upper shell 21. The cavity where the end of the excitation source 24 that releases driving force is located is connected to the cavity where the end of the piston away from the first conductive busbar 26 is located. The first conductive busbar 26 passes between the upper shell 21 and the middle shell 22 and through the first cavity. The piston 25 is located between the excitation source 24 and the first conductive busbar 26. A pre-break is formed by a weak point on the first conductive busbar 26 located in the first cavity, and the piston 25 is positioned corresponding to the pre-break of the first conductive busbar 26.

[0067] A second cavity is provided in the lower shell 23 as an arc-extinguishing chamber. Figure 8In this structure, the second cavity is located below the first cavity, that is, in front of the piston displacement path. The second cavity is filled with an arc-extinguishing medium 27. A molten structure passes through the arc-extinguishing medium 27 within the second cavity, wherein the molten element 1 of the molten structure passes through the arc-extinguishing medium 27, and both ends of the molten element 1 pass through the second cavity and are electrically connected to the two outer sides of the pre-break point of the first conductive busbar 26 in the current direction, thus connecting the molten element 1 to the first conductive busbar 26 in parallel, forming a parallel relationship between the molten element 1 and the pre-break point of the first conductive busbar 26. An insulating isolator 2 is in sealed contact with the inner wall of the second cavity, providing support for the molten element 1 and simultaneously isolating the second cavity into several independent and non-communicating chambers. The sealing contact can be achieved through a gapless fit or by filling the contact gap with sealant for sealing and fixation. A gapless fit can be achieved by matching the shape of the insulating isolator 2 with the shape of the second cavity. When the shape of the insulating isolator 2 does not match the shape of the second cavity, a sealant can be filled between the insulating isolator 2 and the second cavity to achieve a seal. The insulating isolator 2 isolates the second cavity into several independent chambers that are not interconnected, thus completely isolating the molten portions on both sides of the insulating isolator 2 and completely isolating the electric arc on both sides of the insulating isolator 2.

[0068] Working principle: During normal operation, current flows through the first conductive busbar 26. The resistance of the melt 1 is much greater than the resistance of the conductive busbar 26, so the current flowing through the melt 1 can be ignored.

[0069] When an abnormal situation occurs, i.e., an overcurrent, the excitation source 24 acts according to the received trigger signal, releasing high-pressure gas as a driving force to drive the piston 25 to move. The moving piston 25 breaks the pre-break of the first conductive busbar 26, forming a break on the first conductive busbar 26. The current flows through the molten element 1. When the molten element 1 melts, an arc column is formed. Because the insulating isolator 2 acts as a barrier, the arc column will immediately become thinner as it has to pass through the insulating isolator 2. The size of the arc column is effectively limited. With the help of the good cooling effect of the insulating isolator 2, the arc temperature decreases, the arc voltage increases, and the current decreases. At the same time, the insulating isolator 2 generates a large amount of gas at high temperature, and the molten metal ions around the insulating isolator 2 are blown away, forming effective arc isolation and insulation at this position, which fully improves the post-break insulation and withstand voltage performance of the product, while ensuring the reliability of the excitation fuse protection performance.

[0070] In some embodiments, a gap may exist between the insulating isolator 2 and the inner wall of the second cavity. The insulating isolator 2 isolates the second cavity into several chambers, which can only be connected through the gaps. With this structure, the insulation performance is relatively worse than that of a sealed contact between the insulating isolator 2 and the second cavity. Under the high temperature of the electric arc, the insulating isolator expands thermally, which can reduce the gap. When the gap is small, it may even disappear. Therefore, after the melt melts and generates an arc in each isolated chamber, it is difficult for the arc to pass through the gap into another chamber, making arc crossing unlikely. Simultaneously, the insulating isolator refines and cools the generated arc, preventing arc breakdown. Therefore, even if a gap exists between the insulating isolator 2 and the second cavity, it can still improve the insulation performance after the melt breaks.

[0071] Figure 8 The excitation fuse has a second cavity where the arc-extinguishing fuse element is located in front of the piston displacement direction, which increases the volume in the excitation fuse housing and makes the excitation fuse relatively large in size and weight.

[0072] To make the structure of the excitation fuse more compact and to make full use of the space in the existing housing of the excitation fuse, the arc extinguishing chamber is set in the housing outside the piston displacement path, making full use of the unused space in the existing housing, thereby improving space utilization.

[0073] Excite the fuse, see Figures 9 to 11The system includes a housing, an excitation source 24, a piston 25, a first conductive busbar 26, an arc-extinguishing medium 27, and a second conductive busbar 28. The housing is composed of an upper shell 21, a middle shell 22, and a lower shell 23, which are fixedly connected by screws 29. A first cavity for piston displacement and at least one second cavity located outside the piston displacement direction of the first cavity are provided within the housing. The excitation source 24 is disposed in the first cavity portion of the upper shell 21, and the contact portion between the excitation source 24 and the first cavity is sealed. The piston 25 is disposed in the first cavity portion of the middle shell 22, and the piston 25 is in sealed contact with the inner wall of the first cavity. To achieve this sealed contact, a sealing ring is provided on the outer circumferential surface of the piston 25 to seal the contact surface between the piston 25 and the first cavity. A limiting protrusion is provided on the outer circumference of the end of the piston 25 facing the excitation source 24, and the limiting protrusion is engaged between the contact surfaces of the upper shell 21 and the middle shell 22, defining the initial position of the piston 25. When piston 25 moves, it disconnects from the connection with the limiting protrusion, releasing the initial position limitation of piston 25, and piston 25 moves along the first cavity. The first conductive busbar 26 and the second conductive busbar 28 are insulated from each other and arranged side-by-side between the middle shell 22 and the lower shell 23, and the first conductive busbar 26 and the second conductive busbar 28 pass through the first cavity. The piston 25 has impact ends corresponding to the first conductive busbar 26 and the second conductive busbar 28 at one end facing the conductive busbars. The distance between the impact ends of piston 25 corresponding to the first conductive busbar 26 and the second conductive busbar 28 and the first conductive busbar 26 and the second conductive busbar 28 can be the same or different. When the distance is the same, the impact ends of piston 25 simultaneously disconnect the first conductive busbar 26 and the second conductive busbar 28; when the distance is different, the impact ends of piston 25 disconnect the first conductive busbar 26 and the second conductive busbar 28 sequentially.

[0074] The second cavity is located in the middle shell 22, outside the first cavity, i.e., outside the first cavity in the piston displacement direction. Two arc-shaped grooves are formed on the end face of the middle shell 22 facing the upper shell 21, on opposite sides of the first cavity. The upper shell 21 and the middle shell 22 are joined, and the two arc-shaped grooves of the middle shell 22 are closed to form two arc-shaped second cavities. A molten structure is respectively arranged in each of the two arc-shaped second cavities. The second cavities are filled with an arc-extinguishing medium, and the molten structure passes through the arc-extinguishing medium. The first conductive busbar 26 and the second conductive busbar 28 are respectively connected in parallel with the molten material 1 of the molten structure in one of the second cavities. The molten structure in the second cavity includes the molten material 1 and an insulating isolator 2. The insulating isolator 2 is in sealed contact with the inner wall of the second cavity, insulatingly isolating the second cavity into several independent and unconnected chambers. The gap between the insulating isolator 2 and the inner wall of the second cavity is filled with sealant 30 to achieve a sealed contact. The sealant is preferably 703 glue or 5088 glue. The molten element 1 is preferably positioned at the center of the second cavity. With this structure, when the molten element melts, the arc can only exist within a certain range due to the insulating effect of the insulating isolator 2. Furthermore, when the arc passes through the insulating isolator 2, the insulating isolator 2 weakens and cools the arc. Simultaneously, the insulating isolator 2 releases gas at the high temperature of the arc, which disperses metal ions, forming effective arc isolation and insulation at this location. This significantly improves the product's post-break insulation and withstand voltage performance, while ensuring the reliability of the fuse's protective performance.

[0075] The excitation fuse can be configured with one, two, three, or even more conductive busbars. When there are two or more conductive busbars, the insulation spacing must be met. Furthermore, multiple conductive busbars can be arranged side-by-side, staggered vertically, or offset vertically. When arranged side-by-side, multiple conductive busbars can be placed on the same horizontal plane or on different horizontal planes. When staggered vertically, multiple conductive busbars can be partially stacked or completely offset vertically. When multiple conductive busbars are arranged in staggered vertically, or partially stacked vertically, it is preferable to offset them at the pre-break point. This configuration allows for a relatively smaller size of the excitation fuse.

[0076] One conductor busbar is connected to one circuit for circuit protection, and two conductor busbars are each connected to one circuit. When used in a three-phase circuit, the two conductor busbars are each connected to one phase of the circuit.

[0077] Working principle of trigger fuse: Under normal operating conditions, current flows through the first conductive busbar 26 and the second conductive busbar 208. Since the resistance of the melt 1 is much greater than that of the first conductive busbar 26 and the second conductive busbar 208, the current flowing through the melt 1 can be ignored.

[0078] When there is an overcurrent, the excitation source 24 acts according to the received trigger signal, releases the driving force to drive the piston 25 to move and simultaneously cut off or sequentially cut off the first conductive busbar 26 and the second conductive busbar 28, forming breaks on the first conductive busbar 26 and the second conductive busbar 28 respectively. When the first conductive busbar 26 and the second conductive busbar 28 are disconnected, the current flowing through the first conductive busbar 26 and the second conductive busbar 28 flows through the molten element 1 connected in parallel. The molten element 1 heats up with the current flowing through it, causing its temperature to rise. The molten element 1 begins to melt and vaporize, and the molten element breaks off at the narrow neck. Because an insulating isolator 2 is provided in the current transmission path of the molten element 1, and sealant is filled in the gap between the insulating isolator 2 and the second cavity, the insulating isolator 2 and the sealant 30 block the hot air flow generated by the arc, preventing arc breakdown. At the same time, with the cooling effect of the insulating isolator 2, the arc around the insulating isolator 2 is cooled down quickly, effectively increasing the arc voltage and improving the arc extinguishing performance of the fuse. In addition, taking advantage of the function of the insulating isolator 2 in easily generating gas at high temperatures, the released gas disperses the molten metal ions around the insulating isolator 2, effectively establishing insulation on both sides of the current transmission of the insulating isolator 2, making the break point of the molten element completely physically insulated, improving the post-break insulation performance and breaking reliability of the excitation fuse.

[0079] Figures 9 to 11 To activate the use of a fusible element structure in the fuse, Figure 8 It is a parallel molten structure with a conductive busbar, and the molten structure is located in front of the piston displacement path. Figures 8 to 11 Both methods involve directly placing the fusible element structure within the second cavity. Alternatively, the fusible element structure can be fabricated as a thermoplastic fuse and then placed directly into the second cavity. Another option is to place the thermoplastic fuse directly below the casing of the activating fuse, and then connect the fusible element of the thermoplastic fuse in parallel to the conductive bar of the activating fuse. This structure can save multiple assembly steps and improve assembly efficiency.

[0080] See Figures 12 to 14The first conductive busbar 26 and the second conductive busbar 28 are insulated from each other and arranged side by side, but at different levels, i.e., there is a height difference between the first conductive busbar 26 and the second conductive busbar 28. The two impact ends of the piston 25 are respectively set at the pre-break points of the first conductive busbar 26 and the second conductive busbar 28. The second cavity is set in the lower housing 23, located below the first cavity, i.e., in front of the displacement path of the piston 25. Two thermoelectric fuses 31 are arranged in the second cavity, one of which has its fusible element 1 connected in parallel to the first conductive busbar 26, and the other thermoelectric fuse is connected in parallel to the second conductive busbar 28. The thermoelectric fuse 31 includes a fuse housing assembled from parts, which includes a fuse housing 32 and a top cover 33. The fuse housing is filled with an arc-extinguishing medium, and a fusible element structure is provided in the arc-extinguishing medium. The insulating isolator 2 matches the shape of the inner wall of the fuse housing and is in sealed contact with the fuse housing, insulatingly isolating the inside of the fuse housing into several independent and non-interconnected chambers. The fusible element 1 passes through the joint of the insulating isolator 2, the fuse housing 32 and the top cover 33 and is connected in parallel with the corresponding conductive bar.

[0081] In the above embodiments, the excitation fuses are all equipped with a piston. In some embodiments, a piston may not be provided, and the driving force released by the excitation source directly acts on the conductive busbar to disconnect it. The driving force released by the excitation source can be high-pressure gas or mechanical force, etc. When the excitation source releases mechanical force, such as a cylinder, electric cylinder, or electromagnetic drive, the action of the cylinder, electric cylinder, or electromagnetic drive is controlled by the control circuit to release the mechanical driving force. When action is required, the control circuit is activated according to the trigger signal, thereby activating the excitation source of the cylinder, electric cylinder, or electromagnetic drive, releasing the mechanical force as the driving force to disconnect the conductive busbar.

[0082] As described above, when the molten material structure is disposed in the second cavity, which serves as the arc-extinguishing chamber, the shape of the insulating isolator 2 may or may not match the shape of the second cavity. Preferably, the shape of the insulating isolator matches the shape of the second cavity, forming a gapless assembly after assembly. This creates a sealed contact between the insulating isolator and the second cavity, improving the insulation performance of the molten material portions on both sides of the insulating isolator and ensuring high breakage reliability.

[0083] When the shape of the insulating isolator does not match that of the second cavity, preferably, the insulating isolator and the second cavity are in sealed contact. The sealing contact is achieved by filling the space between the insulating isolator and the second cavity with sealant to achieve sealing and fixation, which improves the overall stability of the molten structure set in the second cavity, improves the insulation performance of the molten parts on both sides of the insulating isolator, and has high breakage reliability and lower failure probability.

[0084] Preferably, the insulating isolator is shaped to match the second cavity, and a seal is applied between the insulating isolator and the second cavity. This sealant makes the insulating isolator and the second cavity more tightly bonded, resulting in better sealing performance, higher stability of the melt structure, and higher insulation performance and breakage reliability.

[0085] In the above embodiments, except for the two ends where the melt connects to the busbar, the entire melt structure is disposed in the arc-extinguishing medium of the second cavity. That is, the neck of the melt, the insulating isolation component, etc. of the melt structure are all disposed in the arc-extinguishing medium. In some embodiments, the melt structure may be partially disposed in the arc-extinguishing medium of the second cavity according to design requirements.

Claims

1. An excitation fuse with a fusible element structure, characterized in that, Includes a housing, an excitation source, at least one busbar, and a molten structure; The housing has a first cavity and a second cavity filled with an arc-extinguishing medium; the chamber where the driving force release end of the excitation source is located is connected to the first cavity; the conductive bus passes through the housing and the first cavity; the melt structure is at least partially located in / or passes through the arc-extinguishing medium in the second cavity; The melt structure includes a melt and an insulating isolator. The melt passes through the arc-extinguishing medium in the second cavity. The two ends of the melt are electrically connected to the busbar in parallel. At least one insulating isolator is provided between the two ends of the melt in the current direction. The melt passes through the insulating isolator. The insulating isolator is disposed in the arc-extinguishing medium in the second cavity. The insulating isolator is used to partially or completely isolate the electric arc at the melt fracture and release gas at the high temperature of the electric arc to cool the electric arc. When the excitation source acts according to the received trigger signal, it releases the driving force. The driving force acts on the conductive busbar, causing the conductive busbar to disconnect, and the molten metal melts.

2. The excitation fuse according to claim 1, characterized in that, The insulating insulating component is gap-fitted or sealed to the molten material.

3. The excitation fuse according to claim 2, characterized in that, When a sealed connection is made, the insulating isolation component is integrally injection molded with the melt, or the gap between the insulating isolation component and the melt is sealed with sealant.

4. The excitation fuse according to claim 3, characterized in that, The insulating isolator is provided with a notch or through hole through which the molten material passes.

5. The excitation fuse according to claim 4, characterized in that, The sealant is used to fill the gap between the melt and the notch or through hole.

6. The excitation fuse according to claim 1, characterized in that, The cross-sectional shape of the insulating insulating element includes at least one angular shape, or at least partially arcuate shape.

7. The excitation fuse according to claim 6, characterized in that, The cross-sectional shape of the insulating insulating element includes at least one of the following shapes: square, circular, rhomboid, and trapezoidal.

8. The excitation fuse according to claim 1, characterized in that, Along the direction of the melt current, a groove is provided on the surface of at least one side of the insulating isolator.

9. The excitation fuse according to claim 1, characterized in that, At least one type of narrow neck is provided between the two ends of the melt, and the section with the maximum width on one or both sides of the narrow neck in the direction of current is a heat dissipation section; at least one of the insulating isolation members is provided at the narrow neck or the heat dissipation section.

10. The excitation fuse according to claim 9, characterized in that, When the narrow neck of one specification is provided, the molten material includes an arc-extinguishing section and a heat dissipation section, and the narrow neck is the arc-extinguishing section; when the narrow neck of two or more specifications is provided, the molten material includes an arc-initiating section, an arc-extinguishing section and a heat dissipation section, and the narrow neck that first initiates the arc and melts is the arc-initiating section, and the narrow neck that subsequently initiates the arc and melts is the arc-extinguishing section; at least one of the insulating isolation components is provided at the arc-initiating section or the arc-extinguishing section.

11. The excitation fuse according to claim 10, characterized in that, The insulating isolation element is disposed at the arc initiation section.

12. The excitation fuse according to claim 1, characterized in that, The shape of the insulating isolator matches the shape of the second cavity, and the insulating isolator isolates the second cavity into several independent chambers that are not interconnected.

13. The excitation fuse according to claim 1, characterized in that, The insulating isolator is in sealed contact with the second cavity, thereby isolating the second cavity into several independent chambers that are not interconnected.

14. The excitation fuse according to claim 1, characterized in that, The driving force released by the excitation source is high-pressure gas.

15. The excitation fuse according to any one of claims 1 to 14, characterized in that, It also includes a piston located in the first cavity, the piston being disposed corresponding to the conductive busbar.

16. The excitation fuse according to claim 15, characterized in that, The conductive busbar includes at least two insulated conductive busbars; the impact end of the piston is respectively disposed corresponding to the conductive busbars; at least one of the conductive busbars is connected in parallel with the melt structure, and the melt structure is located in the second cavity.

17. The excitation fuse according to claim 16, characterized in that, When there are two or more conductive bars, the conductive bars are arranged side by side, staggered layer by layer, or staggered position by position.

18. The excitation fuse according to claim 15, characterized in that, A thermoplastic fuse is provided in the second cavity, and the molten structure is disposed in the thermoplastic fuse.

19. The excitation fuse according to claim 15, characterized in that, The second cavity is located outside the piston displacement path or in front of the piston displacement path.

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