Opening grid and energized fuse having the same

Abstract

The utility model relates to a kind of breaking grid, it includes the grid main body (201) made of electric insulating material, it is designed as about vertical axis (A1) is substantially axisymmetric;And at least one piece of insulating blade (202) made of insulating material, wherein insulating blade (202) includes the body portion (202B) of being completely embedded into the grid main body (201) and the blade tip portion (202A) of being located the lowermost end of insulating blade (202) along vertical axis (A1) direction and being protruded outside the grid main body (201).Therefore, the utility model can significantly improve the electrical performance of the excitation fuse, including response time, breaking current, arc-extinguishing performance and the like.The utility model also relates to an excitation fuse with the same.

Description

Technical Field

[0001] This utility model relates to the field of switchgear technology, and in particular to a breaking grid and an excitation fuse having the same. Background Technology

[0002] Fuses are commonly used short-circuit current protection devices in AC or DC circuits. Most protection devices in existing DC power systems use fuses, such as those manufactured by Eaton Bussmann, which work on the principle of electrothermal accumulation. When the current passing through the fuse generates sufficient heat, the internal metal conductor melts and arcs, thereby generating an arc voltage that reduces the short-circuit current.

[0003] The aforementioned fuses that rely on the principle of electrothermal accumulation have limitations in applications such as the main circuit protection of new energy vehicles, where it is difficult to match the thermal fuse with the load. For example, if the load experiences a low-multiple overload or short circuit, a low-current fuse cannot handle short-term current overshoot, while a high-current fuse cannot meet the requirements for rapid protection. In the lithium battery packs that currently power new energy vehicles, the output current under short-circuit conditions is approximately several times the rated current. The fuse protection time is insufficient, leading to overheating and fire in the battery pack. Since both the withstand current heating and the breaking current heating melting originate from the current flowing through the fuse, this type of protection device that uses current-based heating cannot achieve a sufficiently fast breaking speed for a certain amplitude fault current under conditions of large rated current or strong withstand short-term overload / impact current (such as the short-term large current during electric vehicle startup or hill climbing), or achieve a high rated current or withstand large overload / impact current without damage under conditions of sufficiently fast protection speed for a certain amplitude fault current.

[0004] Another drawback of fuses based on the principle of heat accumulation in new energy vehicles is their inability to communicate with external devices. They cannot be triggered by signals other than current, such as the vehicle's ECU, BMS, or other sensors. This contradicts the current trend of intelligent and networked vehicles. Even more unacceptable is that if the battery overheats after a severe collision, water immersion, or exposure to direct sunlight, the circuit cannot be cut off in time, potentially leading to battery pack combustion and ultimately, serious damage to the vehicle.

[0005] To address this, a type of excitation fuse, also known as a smart fuse (Pyro-Fuse), has been developed. This type of excitation fuse can actively disconnect the protected circuit within a specified time under the excitation of an external control signal, completing the disconnection action within milliseconds (ms). Therefore, it has attracted widespread attention in new energy vehicles and the semiconductor industry. The aforementioned excitation fuse operates by utilizing the pressure generated by the explosion of a pyrotechnic device, such as gunpowder, to drive the copper busbar cutting mechanism, i.e., the opening grid, until the opening grid breaks the copper busbar, thus achieving rapid fuse disconnection.

[0006] However, in practice, it has been found that existing products generally design the breaking grid to be placed immediately adjacent to the copper busbar break. Since the copper busbar break is often the weakest point, it is also one of the hottest areas. Especially with increasingly higher current ratings, the temperature rise of products is also increasing (often exceeding 200 degrees Celsius), thus raising the temperature resistance requirements for the breaking grid. At the same time, existing breaking grids also need to meet requirements such as good insulation performance and sufficient strength to break the copper busbar at high speed, making it difficult for existing breaking grids to simultaneously meet all these requirements.

[0007] Therefore, there is a need in the art to provide an open-circuit grid that can simultaneously solve the above-mentioned shortcomings, is cost-effective, and can meet increasingly stringent technical requirements without substantially modifying the current production process of the open-circuit grid, as well as an excitation fuse having the open-circuit grid. Utility Model Content

[0008] The present invention aims to provide an open grid sheet that can at least solve some of the above-mentioned problems.

[0009] This invention also aims to provide an excitation fuse that applies the above-described improved breaking grid.

[0010] According to one aspect of the present invention, a breaking grid is provided, which is suitable for being movably arranged along a vertical axis within the mounting cavity of an excitation fuse to break a copper busbar located below it. The breaking grid comprises: a grid body injection-molded from an electrically insulating material, designed to be generally axially symmetrical about a vertical axis; and at least one insulating blade injection-molded from an insulating material, wherein the insulating blade has a body portion with a first blade surface and a second blade surface opposite to the first blade surface, and a blade tip portion adapted to be inserted into a corresponding break. The body portion is shaped to fit completely into the grid body, and the blade tip portion is located at the lowermost end of the insulating blade along the vertical axis and protrudes beyond the grid body.

[0011] Therefore, compared with existing breaking grids, this invention can significantly improve the electrical performance of the excitation fuse, including response time, breaking current, and arc suppression performance, at a lower and more acceptable cost without substantial modification to the current breaking grid manufacturing process. Through numerous comparative experiments conducted by the inventors, it has been found that the breaking current and response time of the breaking grid of this invention are significantly superior to existing breaking grids, and it completely eliminates adverse events such as breaking failure or poor insulation performance caused by carbon buildup or carbonization of the blade.

[0012] As a preferred aspect, the blade tip is designed to be a single, single portion located at the midpoint of the insulating blade in a horizontal direction perpendicular to the vertical axis.

[0013] As a preferred aspect, the blade tip is designed to be paired and located on two sides of the insulating blade in a horizontal direction perpendicular to the vertical axis.

[0014] In a preferred aspect, the severable grid further includes a cylindrical weighting block made of metal that is fully embedded in the grid body, wherein the weighting block is coaxially arranged with the grid body and spaced apart from the insulating blade along the vertical axis.

[0015] In a preferred aspect, the grid body has at least one pair of recessed positioning holes at its lowest end along the vertical axis, wherein the pair of positioning holes are located on two sides of the insulating blade.

[0016] As a preferred aspect, the grid body has a pair of limiting portions protruding in a transverse direction perpendicular to the vertical axis at its midpoint along the vertical axis.

[0017] As a preferred aspect, the grid body has a plurality of mating portions extending continuously in the horizontal direction at its lower end along the vertical axis, wherein the mating portions are designed as serrated shapes with rounded roots.

[0018] As a preferred aspect, the electrical insulating material of the grid body may be a thermoplastic material including polyhexamethylene adipamide (PA66), polyamide 6 (PA6), polyphenylene sulfone (PPSU), and polycarbonate (PC).

[0019] As a preferred aspect, the insulating material of the insulating blade may be a thermosetting material including polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyetherimide (PEI), and polyimide (PI).

[0020] According to another aspect of the present invention, an excitation fuse is also disclosed, wherein the excitation fuse comprises an insulating housing made of an electrically insulating material and a breaking grid plate located therein, wherein the insulating housing comprises an upper housing closed at the upper end and open at the lower end and a lower housing open at both the upper and lower ends, wherein the upper housing and the lower housing are connected to each other in a form-fitting manner by means of a snap-fit ​​portion to form a mounting cavity for accommodating the breaking grid plate, wherein at least one copper busbar is clamped between the upper housing and the lower housing and has at least one break located directly below the breaking grid plate, wherein the breaking grid plate is the aforementioned breaking grid plate.

[0021] Other features and advantages of this invention will partly be apparent to those skilled in the art upon reading this application, and partly will be described below in conjunction with the accompanying drawings in the detailed description. Attached Figure Description

[0022] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings, wherein:

[0023] Figure 1 This is a cross-sectional view of the excitation fuse according to this utility model;

[0024] Figure 2 It is based on Figure 1 A front view of a first embodiment of the excitation fuse's breaking grid, wherein the breaking grid is inverted to show more details;

[0025] Figure 3 It is based on Figure 2 Another front view of the opening grid of the excitation fuse, in which part of the structure has been removed to show internal details;

[0026] Figure 4 It is based on Figure 2 A cross-sectional view of the opening grid of the excitation fuse, showing more internal details;

[0027] Figure 5 and 6 yes Figure 2 The image shows cross-sectional views of different locations of the breaking tab in the activated fuse, wherein... Figure 5 It is located in the central position and Figure 6 Located near the side end;

[0028] Figure 7 It is based on Figure 1 A front view of a second embodiment of the excitation fuse's breaking grid, wherein the breaking grid is inverted to show more details;

[0029] Figure 8 It is based on Figure 7 A cross-sectional view of the opening grid of the excitation fuse, showing more internal details.

[0030] Explanation of reference numerals in the attached figures:

[0031] 100 - Excitation fuse; 101 - Upper housing; 102 - Lower housing; 103 - Copper busbar;

[0032] 104A, 104B - fracture surface; 200 - fractured grid plate; 201 - grid plate body; 201A - positioning hole;

[0033] 202-Insulating blade; 202A-Blade tip; 202B-Body body; 202C-Mating part;

[0034] 202D - Limiting part; 203 - Weighting block; A1 - Vertical axis; H1 - Horizontal direction;

[0035] L1 - Lateral direction. Detailed Implementation

[0036] The schematic scheme of the excitation fuse and its breaking grid disclosed in this utility model is now described in detail with reference to the accompanying drawings. Although the drawings are provided to illustrate some embodiments of this utility model, the drawings are not necessarily drawn to the dimensions of the specific embodiments, and certain features may be enlarged, removed, or partially cut to better illustrate and explain the disclosure of this utility model. Some components in the drawings may be repositioned according to actual needs without affecting the technical effect. The phrase "in the drawings" or similar terms appearing in the specification do not necessarily refer to all drawings or examples.

[0037] Certain directional terms used in the description of the accompanying drawings below, such as “inner,” “outer,” “above,” “below,” and other directional terms, will be understood to have their normal meaning and refer to those directions as normally viewed in the accompanying drawings. Unless otherwise specified, the directional terms used in this specification are generally in accordance with the conventional directions understood by those skilled in the art.

[0038] The terms “first,” “first,” “second,” “second,” and similar terms used in this utility model do not indicate any order, quantity, or importance, but are used to distinguish one component from other components.

[0039] The terms "joining", "connection" and similar terms used in this utility model include both indirect connection of two components with the aid of an intermediate layer such as an adhesive or welding agent or an intermediate component such as a connector or transition piece, and direct connection of two components without the aid of any intermediate layer such as an adhesive or welding agent or an intermediate component such as a connector or transition piece.

[0040] Excitation fuse

[0041] Figure 1 The excitation fuse 100 and its breaking plate 200 of this utility model are illustrated by way of example. In this example, the breaking plate 200 of the excitation fuse 100 can simultaneously disconnect each phase circuit when a fault occurs in the protected circuit, thereby greatly improving the reliability of the excitation fuse 100. Preferably, the excitation fuse 100 and its breaking plate 200 of this utility model are suitable for industrial applications, including new energy vehicles or photovoltaic devices, and therefore the excitation fuse 100 of this utility model needs to meet the electrical performance and technical requirements of the above-mentioned industrial applications, including response time, breaking current, and arc suppression performance.

[0042] like Figure 1 As shown, the activated fuse 100 may include an insulating housing and a breaking grid 200. Specifically, the interior of the insulating housing has mounting cavities for arranging the breaking grid 200, allowing the breaking grid 200 located therein to move up and down along the vertical axis A1. The insulating housing may include, for example, an upper housing 101 and a lower housing 102, which may be injection-molded or molded from an electrically insulating material (e.g., PA66, PPS, etc.). Figure 1 As shown, the upper housing 101, located above, can be a semi-closed cavity structure with a closed upper end and an open lower end, while the lower housing 102 can be designed as a cavity structure with both an open upper and lower end. Therefore, the lower end of the upper housing 101 can be aligned with the upper end of the lower housing 102 and can be snapped onto the lower housing 102 in a form-fitting manner through a snap-fit ​​portion 102B, preferably integrally formed on the upper end of the lower housing 102. This allows the cavities of the upper housing 101 and the lower housing 102 to fit together to form a mounting cavity for accommodating the openable grid 200. Figure 1 The portion of the junction between the upper housing 101 and the lower housing 102 shown can be fitted to form an opening communicating with the internal mounting cavity, so that the broken grid plate 200 located in the mounting cavity can pass through it.

[0043] Furthermore, a receiving cavity for accommodating a gas generator (not shown) is provided above the upper housing 101. This gas generator is designed to generate high-pressure gas by receiving an external signal for ignition, thereby pushing the switching grid 200 located below it to move downwards at high speed. As an example, the gas generator has a pair of electrodes that receive a trigger signal from the outside. The gas generator can be an ignition tube or an MGG gas generator. When a current signal is transmitted to the gas generator through the pair of electrodes, the propellant inside the gas generator is ignited, generating a large amount of high-pressure gas that fills the internal cavity of the upper housing 101, pushing the switching grid 200 located below the gas generator to move rapidly.

[0044] To ensure sufficient thrust, the gas generator is preferably fixed within the upper housing 101. A mounting base (not shown) may be installed within the upper housing 101. The mounting base can be fixed to the upper housing 101 in any suitable manner, for example, by a snap-fit ​​structure relative to the upper housing 101, an interference fit with the upper housing 101, or a bonding agent. The constricted section of the gas generator is shaped to fit within the inner bore of the mounting base, pressing against the bottom of the receiving groove in the upper housing 101, restricting the movement of the gas generator relative to the upper housing 101, and ensuring sufficient thrust is generated upon gas release. For internal sealing, a sealing element, such as a sealing ring, may be fitted around the outer periphery of the mounting base, pressing the sealing ring between the outer periphery of the mounting base and the inner periphery of the upper housing 101. This prevents high-pressure gas from leaking from the top of the upper housing 101.

[0045] like Figure 1 As shown, multiple copper busbars 103 can be clamped between the upper housing 101 and the lower housing 102, and both ends of each copper busbar 103 can extend from between the upper housing 101 and the lower housing 102 to connect to the respective phase circuit. The portion of the copper busbar 103 located below the breaking grid 200 may have first and second breaks 104A and 104B, preferably two in total, wherein the first and second breaks 104A and 104B are thinner than the other portions of the copper busbar 103, so as to break under the impact of the corresponding insulating blade 202, which is described in detail below. As a result, the copper busbar 103 used to form electrical conduction in each phase circuit is cut into two parts at the first and second breaks 104A and 104B, thereby breaking the circuit of the corresponding phase. The insulating blade 202 is slidably mounted in the blade slot 201A of the breaking grid 200 described in detail below and located above the corresponding copper busbar 103, so that when the insulating blade 202 is forced to move, it impacts the first and second breaks 104A and 104B by means of the kinetic energy of the high-pressure gas and its own gravitational potential energy.

[0046] The first and second breaks 104A and 104B of the copper busbar 103 may be provided with guide holes that are thinned in the thickness direction near the first and second breaks 104A and 104B. Correspondingly, a portion of the end face (lower end face) of the insulating blade 202 adjacent to the first and second breaks 104A and 104B, such as the blade tip 202A, extends downward toward the first and second breaks 104A and 104B to form a guide section. The dimension of the guide section in the transverse direction of its extension direction, i.e., the transverse dimension, may be smaller than that of the grid plate. Thus, when the multiple insulating blades 202 are forced to move toward the multiple copper busbars 103, the blade tip 202A of each insulating blade 202 passes through the corresponding guide hole with a matching shape first. This allows the multiple insulating blades 202 that are not in the desired same orientation due to mechanical errors, installation errors, or uneven forces, such as some insulating blades 202 being tilted relative to other insulating blades 202, to be corrected to the desired same vertical state because their respective guide sections pass through the corresponding guide holes. As a result, the corresponding insulating blades 202 adjacent to each guide section can thus act synchronously on the corresponding first and second breaks 104A and 104B, so that the multiple insulating blades 202 can simultaneously cut the corresponding first and second breaks 104A and 104B.

[0047] Optionally, the plurality of insulating blades 202 and the guide sections extending therefrom can be designed as rectangular sheets. Exemplarily, the thickness of the insulating blades 202 and the width of the first and second breaks 104A and 104B can be 2 mm to 5 mm, preferably 3 mm, and the thickness of the copper busbar 103 at the first and second breaks 104A and 104B is preferably, for example, 0.5 mm to 1 mm. Preferably, in addition to forming grooves of the same shape as the first and second breaks 104A and 104B on the surface of the copper busbar 103, V-grooves or other conceivable shapes can also be formed on the surface of the copper busbar 103 in areas corresponding to the first and second breaks 104A and 104B to facilitate the intended breaking of the first and second breaks 104A and 104B.

[0048] Optionally, the upper side of the lower housing 102 in the excitation fuse 100 may be provided with an anti-rotation part that extends upward through each copper busbar 103 to the inner side of the upper housing 101. The anti-rotation part may be located on both sides of the breaking grid 200 in the upper housing 101 and then cooperate with the anti-rotation groove in the grid body 201 described in detail below. On the one hand, this facilitates the positioning and installation of the upper housing 101, copper busbar 103 and lower housing 102. On the other hand, the guiding cooperation between the anti-rotation part and the anti-rotation groove of the grid body 201 can ensure that the grid body 201 is guided during the downward movement driven by high-pressure gas, thereby preventing the grid body 201 from undergoing undesirable self-rotation, which would degrade the breaking effect of the insulating blade 202.

[0049] like Figure 1As shown, the upper housing 101, the copper busbar 103 and the lower housing 102 are shaped to form a labyrinth-like sealing structure to minimize the leakage of gas injected by the gas generator, thereby ensuring the pushing effect on the multiple insulating blades 202.

[0050] Optionally, the arc-suppressing groove located within the lower housing 102 may include an extension hole relative to the first and second breaks 104A and 104B to allow further movement of the insulating blade 202 after it has cut through the first and second breaks 104A and 104B. The lower housing 102 may also preferably include a structure such as a wire mesh located within the extension hole to reduce the arc temperature.

[0051] Opening grid plate

[0052] like Figure 1 and 2 As best shown in section 6, the breaking grid 200 may include, for example, a grid body 201, which is axisymmetric about the vertical axis A1, and preferably two insulating blades 202, preferably injection-molded from an electrically insulating material (e.g., PA66, PPS, etc.). Those skilled in the art will understand that, for a two-phase excitation fuse, the breaking grid 200 may include two copper busbars 103 and two opposing insulating blades 202, while for a three-phase excitation fuse, the breaking grid 200 may include three copper busbars 103 and three opposing insulating blades 202. Exemplarily, the copper busbars 103 may be straight plates, and the plurality of copper busbars 103 may be in the transverse plane, i.e., perpendicular to… Figure 1 The figures are arranged at intervals on the plane of the page where they are located. Correspondingly, multiple insulating blades 202 can be positioned one-to-one with multiple copper busbars 103 within the grid body 201.

[0053] like Figure 1 and 2 As best shown in Figure 6, the insulating blade 202 comprises two blades arranged side by side; the insulating blade 202 extends from the body 201 of the breaking grid 200 toward corresponding first and second breaks 104A and 104B in the copper busbar 103. Figure 1 As shown, before the gas generator is triggered by receiving an external signal, the end of the insulating blade 202 in the open grid 200 is located inside the corresponding first and second breaks 104A and 104B.

[0054] like Figures 2 to 4As shown, preferably, when the breaking grid 200 is in an inverted state, the end of the insulating blade 202 shown here has an inverted V-shaped structure and has a single blade tip 202A located at the lowest point of the insulating blade 202 along the vertical axis A1 and at the middle position along the horizontal direction perpendicular to the vertical axis (A1). Correspondingly, a downward-opening stress concentration groove is provided at the centerline of the lower surface of the first and second breaks 104A and 104B, wherein the stress concentration groove is opposite to the single blade tip 202A of the insulating blade 202 of the breaking grid 200 located at the middle position. Through the cooperation of the blade tip 202A of the insulating blade 202 with the stress concentration groove, stress concentration is easily generated at the centerline of the copper busbar 103, and the insulating blade 202 of the breaking grid 200 can more easily cut the copper busbar 103 from the middle position.

[0055] like Figures 2 to 4 As shown, to ensure that the insulating blade 202 is guided relative to the grid body 201 during movement under the pressure of high-pressure gas, the body portion 202B, having a first blade surface and a second blade surface opposite to the first blade surface, is completely fitted into the grid body 201 in a form-fit manner. This fitting can be achieved by means of the following method: The insulating blade 202, injection molded from insulating material, is designed to have a plurality of mating portions 202C extending continuously in the horizontal direction H1 at its lower end along the vertical axis A1, wherein these mating portions 202C are designed with a serrated shape with rounded roots. The insulating blade 202 is then placed in an injection mold and subsequently injected with thermoplastic materials including polyhexamethylene adipamide (PA66), polyamide 6 (PA6), polyphenylene sulfone (PPSU), and polycarbonate (PC). The amount of thermoplastic material injected during the injection molding process is controlled in such a way that, after injection molding, the tip 202A of the insulating blade 202, located at the lowermost end along the vertical axis A1, protrudes beyond the grid body 201.

[0056] As a result, due to the form fit or form lock between the thermoplastic material of the injection-molded grid body 201 and the multiple mating portions 202C of the insulating blade 202 during cooling, the body portion 202B of the insulating blade 202 is completely embedded within the grid body 201 so that it does not shift relative to the grid body 201. This ensures that during the downward movement of the grid body 201 in response to the push of high-pressure gas, the cutting operation of the first and second breaks 104A and 104B is performed by means of the blade tip 202A at the lowermost end of the insulating blade 202. At the same time, the rounding operation of the root of the mating portion 202C helps to ensure the structural strength of the insulating blade 202 itself and prevents unacceptable stress concentration during injection molding and subsequent breaking operations.

[0057] Preferably, to ensure that the insulating blade 202 is accurately positioned within the mold used for injection molding the grid body 201 and to prevent the force of the flowing molten plastic, such as Figure 5 and 6 As shown, the grid body 201 has a pair of limiting portions 202D protruding in a transverse direction L1 perpendicular to the vertical axis A1 at its midpoint along the vertical axis A1. These limiting portions 202D are configured to engage with a mating structure in the mold, thereby fixing the insulating blade 202 in place within the mold. Further, as... Figure 6 As shown, it is only necessary to have a limiting part 202D at the middle position of the grid body 201 in the horizontal direction.

[0058] Similarly, to ensure reliable positioning of the injection-molded grid body 201, such as... Figure 5 and 6 As shown, preferably, the grid body 201 has at least one pair of recessed positioning holes 201A at its lowest end along the vertical axis A1, wherein the pair of positioning holes 201A are located at the positions of two sides of the insulating blade 202. Optionally, the depth of the pair of positioning holes 201A extending along the vertical axis A1 is designed to be higher than the uppermost height of the mating part 202C.

[0059] Preferably, such as Figure 3 and 4 As shown, the breaking grid 200 further includes a cylindrical weight-adding block 203 made of metal, completely embedded in the grid body 201. This weight-adding block is coaxially arranged with the grid body 201 and spaced apart from the insulating blade 202 along the vertical axis A1. Specifically, the weight-adding block 203 is made of 304 stainless steel to provide sufficient strength and weight. Preferably, the center of the weight-adding block 203 coincides with the center of the breaking grid 200 body to ensure balance during movement. As a result, by providing the embedded weight-adding block 203 inside the breaking grid 200, the overall weight of the breaking grid 200 can be controlled by adjusting the weight of the weight-adding block 203 to control its operating speed, preventing breakage due to impact caused by excessive speed. The weight-adding block 203 enhances the structural strength of the breaking grid 200 and reduces the risk of breakage.

[0060] More preferably, the diameter of the weight-adding block 203 is at least 4 mm smaller than the diameter of the breaking grid plate 200. Since the breaking grid plate 200 is made of electrically insulating thermoplastic, by reasonably configuring the size ratio between the weight-adding block 203 and the breaking grid plate 200, it is ensured that the weight-adding block 203 is encased in electrically insulating thermoplastic and not exposed, and that the surrounding electrically insulating thermoplastic has sufficient strength to prevent damage during movement.

[0061] It should also be pointed out that, despite Figures 2 to 6 The diagram shows a breaking grid 200 with paired insulating blades 202 for performing breaking operations on copper busbars 103 with first and second breaks 104A and 104B (referred to as a double-blade direct-opening type). If only breaking operations on copper busbars 103 with a single break are required, a breaking grid 200 with only a single insulating blade 202 is also feasible (referred to as a single-blade direct-opening type). Alternatively, it is also feasible to design a breaking grid 200 with multiple blades having two or more insulating blades (referred to as a multi-blade direct-opening type). These variations are all covered within the scope of protection intended by this application.

[0062] Insulating blade

[0063] exist Figures 2 to 8 Various embodiments of the insulating blade 202 applicable to the breaking grid 200 according to the present invention are shown. Among them, in Figures 2 to 6 A first feasible embodiment is shown, and in Figures 7 to 8 A second feasible embodiment is shown in the figure.

[0064] As mentioned above, conventional cutting blades made of plastic materials are relatively prone to stretching under high copper busbar temperatures and are easily damaged and ablated due to their limited mechanical strength. To address these problems associated with conventional cutting blades made of plastic materials, one aspect of this invention provides an insulating blade 202 injection-molded from an insulating material, preferably a high-performance engineering material. Specifically, as an example, the cutting blade according to this invention is injection-molded from thermosetting materials including polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyetherimide (PEI), and polyimide (PI).

[0065] Compared to existing plastic materials, this type of cutting blade 202, injection molded from thermosetting materials including polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyetherimide (PEI), and polyimide (PI), can exhibit better high-temperature resistance, superior mechanical strength, and improved ablation resistance. Specifically, the softening temperature of the insulating blade 202 in this invention is designed, for example, to be above 200 degrees Celsius.

[0066] refer to Figures 2 to 6 An exemplary insulating blade 202 is shown, comprising a blade body injection molded from a thermosetting material. In the illustrated embodiment, the insulating blade 202 is integrally injection molded from a thermosetting material including polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyetherimide (PEI), and polyimide (PI). The body portion 202B of the insulating blade 202 has a first blade body surface ( Figure 3 The surface facing outwards from the paper surface), and the second blade surface opposite to the surface of the first blade body ( Figure 3 The blade body 202A consists of a surface facing inwards (in the direction of the paper surface) and a blade tip 202A extending from the body portion 202B, located at the lowermost end of the insulating blade 202 along the vertical axis A1, and protruding beyond the grid body 201. The blade thickness, defined by the distance between the first and second blade surfaces, is 2 mm to 5 mm. The blade tip 202A is designed as a V-shape extending obliquely upwards from the lowermost end towards both sides of the blade body, with the included angle of this V-shape preferably in the range of 135 degrees to 150 degrees.

[0067] exist Figures 7 to 8 The diagram shows another embodiment of the insulating blade 202 suitable for the opening grid 200 of this utility model, wherein... Figures 2 to 6 The difference in the embodiment shown is that the blade tip 202A of the insulating blade 202 is not unique and located in the middle of the horizontal direction (V-shaped design). Instead, the blade tip 202A is designed as a pair, located on two sides of the insulating blade 202 along the horizontal direction H1 perpendicular to the vertical axis A1 (inverted V-shaped design). It is believed that this design helps to avoid breakage of the blade tip 202A due to large impact forces during the breaking operation, wherein the generally arc-shaped blade portion 202C helps to distribute the impact force, thereby improving the reliability during high-speed breaking operations.

[0068] As can be seen from the above, this utility model utilizes the design of the breaking grid 200 in the excitation fuse 100 as a combination of a grid body 201 made of thermoplastic material and an insulating blade 202 made of thermosetting material. During the process of the breaking grid 200 breaking the arc generated by the copper busbar 103, the arc-extinguishing effect is improved by leveraging the arc-resistant properties of the thermoplastic material. Furthermore, the embedded thermosetting material blade has high strength and is more resistant to high temperatures, allowing the breaking grid 200 to operate normally and break the copper busbar 103 even in high-temperature environments (such as temperatures exceeding 200°C). As a result, the electrical performance of the excitation fuse, including response time, breaking current, and arc-extinguishing performance, can be significantly improved at a relatively low and acceptable cost without substantial modifications to the current manufacturing process of the breaking grid. Through multiple comparative experiments conducted by the inventors, it was found that the current that the breaking grid 200 of this utility model can break and the response time are significantly better than those of existing breaking grids, and it completely eliminates adverse events such as breaking failure or poor insulation performance caused by carbon buildup or carbonization of the blade.

[0069] It should be understood that although this specification describes various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0070] The above description is merely an illustrative embodiment of this utility model and is not intended to limit the scope of this utility model. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of this utility model should fall within the protection scope of this utility model.

Claims

1. A breaking grid (200) suitable for being movably arranged along a vertical axis (A1) within the mounting cavity of an excitation fuse (100) and for breaking the copper busbar (103) located below it at its breaks (104A, 104B), characterized in that, The interrupted gate (200) includes: The grid body (201), injection molded from an electrically insulating material, is designed to be substantially axially symmetric about a vertical axis (A1); and At least one insulating blade (202) is injection molded from insulating material, wherein the insulating blade (202) has a body portion (202B) with a first blade surface and a second blade surface opposite to the first blade surface, and a blade tip portion (202A) adapted to be inserted into the corresponding cut (104A, 104B), wherein the body portion (202B) is shaped to be completely embedded in the grid body (201), and the blade tip portion (202A) is located at the lowermost end of the insulating blade (202) along the vertical axis (A1) and protrudes outside the grid body (201).

2. The open-circuit gate (200) as claimed in claim 1, characterized in that, wherein The blade tip (202A) is designed to be a single, single part located at the center of the insulating blade (202) in a horizontal direction perpendicular to the vertical axis (A1).

3. The open-circuit gate (200) as described in claim 1, characterized in that, The blade tip (202A) is designed to be a pair and located on two sides of the insulating blade (202) in a horizontal direction perpendicular to the vertical axis (A1).

4. The open-circuit gate (200) as described in claim 2 or 3, characterized in that, The opening grid (200) further includes a cylindrical weighting block made of metal that is fully embedded in the grid body (201), wherein the weighting block is coaxially arranged with the grid body (201) and spaced apart from the insulating blade (202) along the vertical axis (A1).

5. The open-circuit gate (200) as described in claim 2 or 3, characterized in that, The grid body (201) has at least one pair of recessed positioning holes at its lowest end along the vertical axis (A1), wherein the pair of positioning holes are located on two sides of the insulating blade (202).

6. The open-circuit gate (200) as described in claim 2 or 3, characterized in that, The grid body (201) has a pair of limiting portions protruding in a transverse direction perpendicular to the vertical axis (A1) at its midpoint along the vertical axis (A1).

7. The open-circuit gate (200) as described in claim 2 or 3, characterized in that, The grid body (201) has a plurality of mating portions (202C) extending continuously along the horizontal direction at its lower end along the vertical axis (A1), wherein the mating portions (202C) are designed as serrated shapes with rounded roots.

8. The open-circuit gate (200) as described in claim 2 or 3, characterized in that, The electrical insulating material of the grid body (201) can be a thermoplastic material including polyhexamethylene adipamide (PA66), polyamide 6 (PA6), polyphenylsulfone (PPSU) and polycarbonate (PC).

9. The open-circuit gate (200) as described in claim 2 or 3, characterized in that, The insulating material of the insulating blade (202) may be a thermosetting material including polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyetherimide (PEI), and polyimide (PI).

10. An excitation fuse (100), characterized in that, The excitation fuse (100) includes an insulating housing injection molded from an electrically insulating material and a breaking grid (200) located therein, wherein the insulating housing includes an upper housing closed at the top and open at the bottom and a lower housing open at both the top and the bottom, wherein the upper housing and the lower housing are connected to each other by means of a snap-fit ​​portion to form a mounting cavity for receiving the breaking grid (200), wherein at least one copper busbar (103) is held between the upper housing (101) and the lower housing (102) and has at least one break (104A, 104B) located directly below the breaking grid (200), wherein the breaking grid (200) is the breaking grid (200) as claimed in any one of claims 1 to 9.

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