Breaking grid sheet and excitation fuse with same

Abstract

The utility model relates to a breaking grid sheet, comprising a grid sheet main body (201) made of an electrical insulating material, the grid sheet main body (201) is designed to be substantially axisymmetric about a vertical axis (A1), and the inner side of the grid sheet main body (201) is provided with at least one blade groove (201A) extending along the vertical direction; and at least one insulating blade (202) made of an insulating material, the insulating blade (202) having a first blade body surface, a second blade body surface opposite to the first blade body surface, and a cutting edge portion (202C) located between the first blade body surface and the second blade body surface and adapted to be inserted into a corresponding fracture (104A, 104B), wherein the cutting edge portion (202C) has an acute included angle when viewed in the cross-sectional direction thereof. Therefore, the electrical performance, including response time, breaking current, arc extinction performance and the like, of the excitation fuse can be remarkably improved. The utility model also relates to an excitation fuse having 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 the breaking grid in existing products is generally designed to be placed 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, thus raising the temperature resistance requirements for the breaking grid. The temperature at this point often exceeds 200 degrees Celsius. Simultaneously, the breaking grid often needs to withstand arc erosion when interrupting large currents, leading to carbon buildup or carbonization. Carbon buildup or carbonization is undesirable, as it can cause fuse failure or reduce insulation performance after excitation. 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 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 and for breaking a copper busbar located below it, wherein the breaking grid comprises: a grid body made of an electrically insulating material, which is designed to be generally axisymmetric about a vertical axis and has at least one blade groove extending in a vertical direction on the inner side of the grid body; and at least one insulating blade made of an insulating material, wherein the insulating blade has a first blade surface, a second blade surface opposite to the first blade surface, and a cutting edge portion located between the two, adapted to be inserted into the corresponding break, wherein the cutting edge portion has an acute angle when viewed along its cross-sectional direction.

[0011] Therefore, compared with the existing breaking grid, this invention, by designing the breaking grid in the excitation fuse as a combination of a grid body made of injection-molded material and an insulating blade made of insulating material, can significantly improve the electrical performance of the excitation fuse, including response time, breaking current, and arc suppression performance, at a relatively low and acceptable cost without substantial modification to the current production process of breaking grids. Through numerous comparative experiments conducted by the inventors, it has been found that the current breaking capacity and response time of the excitation fuse of this invention are significantly superior to those of existing excitation fuses, 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 portion further has a tip portion located at its lowest end, wherein the blade portion is designed to extend obliquely upward from the tip portion to both sides of the insulating blade, wherein the included angle through which the blade portion extends when viewed from the front is an obtuse angle.

[0013] As a preferred aspect, the blade portion further has a tip portion at its uppermost end, wherein the blade portion is designed to extend obliquely downward from the tip portion to both sides of the insulating blade, wherein the included angle through which the blade portion extends when viewed from the front is an obtuse angle.

[0014] As a preferred aspect, the blade portion is characterized in that it is generally arc-shaped or straight-shaped.

[0015] As a preferred aspect, the blade tip is rounded.

[0016] As a preferred aspect, the insulating blade also has locking holes located on two opposing sides for shaped-fitting the grid body.

[0017] As a preferred aspect, the insulating material may be an alumina ceramic material, a zirconia ceramic material, a nitride ceramic material, or a carbide ceramic material.

[0018] In a preferred aspect, the insulating material may be a thermoplastic material including polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyhexamethylene adipamide (PA66), and polyphenylene sulfone (PPSU), or a thermosetting material including sheet molding compound (SMC) and block molding compound (BMC).

[0019] 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.

[0020] As a preferred aspect, the upper side of the lower housing is provided with an anti-rotation portion extending upward through each copper busbar to the inner side of the upper housing, and the breaking grid has an anti-rotation groove extending vertically, wherein the anti-rotation portion is inserted into the anti-rotation groove of the breaking grid so that the grid body is guided during movement along the vertical axis.

[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 Front view of the insulating blade of the excitation fuse in the middle;

[0025] Figure 3 It is based on Figure 2 A side view of the insulating blade of the excitation fuse in the circuit;

[0026] Figure 4 This is an exploded view of the breaking grid in the excitation fuse according to the present invention, wherein the insulating blade is separated from the grid body to show more details;

[0027] Figures 5 to 7 yes Figure 4The diagram shows an assembly of the breaking grid in an excitation fuse, with the breaking grid shown from different perspectives.

[0028] Figure 8 yes Figure 4 The cross-sectional view of the breaking grid in the activated fuse is shown in the figure;

[0029] Figure 9 yes Figure 8 The image shows a partially enlarged cross-sectional view of the insulating blade and the main body of the breaking grid in the excitation fuse.

[0030] Figures 10 to 11 Another embodiment of an insulating blade suitable for the opening grid sheet of this utility model is shown;

[0031] Figures 12 to 13 Another embodiment of the insulating blade suitable for the opening grid sheet of this utility model is shown;

[0032] Figures 14 to 17 Another embodiment of the insulating blade for the breaking grid sheet applicable to this utility model is shown;

[0033] Figures 18 to 19 Another embodiment of the opening grid of the excitation fuse applicable to this utility model is shown.

[0034] Explanation of reference numerals in the attached figures:

[0035] 100 - Excitation fuse; 101 - Upper housing; 102 - Lower housing; 102A - Anti-rotation part;

[0036] 102B - Connecting part; 103 - Copper busbar; 104A, 104B - Break; 105 - Arc suppression groove;

[0037] 200-Break-off grid plate; 201-Grid plate body; 201A-Blade groove; 201B-Anti-rotation groove;

[0038] 202-Insulating blade; 202A-Locking hole; 202B-Blade tip; 202C-Blade edge;

[0039] A - First included angle; B - Second included angle; C - Rounded corner; A1 - Vertical axis. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] Excitation fuse

[0045] Figures 1 to 7 as well as Figures 18 to 19 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.

[0046] like Figures 1 to 7 as well as Figures 18-19As 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 that communicates with the internal mounting cavity, so that the open grid plate 200 located in the mounting cavity can pass through it.

[0047] 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.

[0048] 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.

[0049] like Figure 1 and 4 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.

[0050] 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 202B, 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 202B 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.

[0051] 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.

[0052] Optionally, the upper side of the lower housing 102 in the excitation fuse 100 may be provided with an anti-rotation portion 102A extending upward through each copper busbar 103 to the inner side of the upper housing 101. The anti-rotation portion 102A may be located on both sides of the breaking grid 200 inside the upper housing 101 and subsequently cooperate with the anti-rotation groove 201B 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 portion 102A and the anti-rotation groove 201B of the grid body 201 ensures 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 rotation, which would degrade the breaking effect of the insulating blade 202.

[0053] like Figure 1 As 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.

[0054] Optionally, the arc-suppressing groove 105 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.

[0055] Opening grid plate

[0056] like Figure 1 and 4As best shown in Figure 5, the breaking grid 200 may include a grid body 201, which is axisymmetric about the vertical axis A1, and preferably two insulating blades 202 disposed therein, for example, by injection molding or molding 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 plate-shaped, 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.

[0057] like Figure 1 and 4 As best shown in Figure 5, 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.

[0058] like Figure 2 As shown, preferably, the end of the insulating blade 202 has a V-shaped structure. 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 positioned opposite to the tip of the insulating blade 202 of the breaking grid 200. The cooperation between the tip of the insulating blade 202 and the stress concentration groove facilitates stress concentration at the centerline of the copper busbar 103, making it easier for the insulating blade 202 of the breaking grid 200 to cut the copper busbar 103 from the middle position.

[0059] like Figures 4 to 5As shown in Figures 6 to 8, to ensure that the insulating blade 202 is guided relative to the grid body 201 during movement under the pressure of high-pressure gas, blade grooves 201A extending vertically are provided side-by-side inside the grid body 201, wherein the width of the blade groove 201A and the width of the insulating blade 202 are preferably in an interference fit relationship. As a result, before the grid 200 is triggered, the insulating blade 202 is reliably held within the blade groove 201A of the grid body 201 without undesirable falling or displacement. Here, the interference fit between the blade groove 201A and the insulating blade 202 can be achieved by integrally injection molding the insulating blade 202 and the grid body 201, or by forcefully inserting the insulating blade 202 into the already injection-molded blade groove 201A of the grid body 201.

[0060] like Figures 4 to 5 As shown, between the paired blade slots 201A, the grid body 201 also has anti-rotation slots 201B that extend vertically, designed as follows: Figure 1 The anti-rotation portion 102A extending upward from the lower housing 102 forms a shape fit with the grid body 201, thereby ensuring that the grid body 201 is guided during the downward movement driven by high-pressure gas, thus preventing the grid body 201 from undergoing undesirable rotation, which would degrade the breaking effect of the insulating blade 202.

[0061] It should also be pointed out that, despite Figures 4 to 5 Figures 6 to 8 show a breaking grid 200 (which may be referred to as a double-blade direct-opening type) with paired insulating blades 202 for performing breaking operations on copper busbars 103 with first and second breaks 104A and 104B. If only breaking operations on copper busbars 103 with a single break are required, then... Figures 18 to 19 The breaking grid 200 shown in the figure, which has only a single insulating blade 202, is also feasible (which can be called 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 (which can be called a multi-blade direct-opening type), and these variations are all covered within the scope of protection intended by this application.

[0062] Insulating blade

[0063] exist Figures 2 to 3 Figures 9 to 17 show various embodiments of the insulating blade 202 that can be applied to the opening grid 200 according to the present invention.

[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 made of an insulating material, preferably a ceramic material or a high-performance engineering material.

[0065] That is, as an example, the cutting blade according to this invention is made of ceramic material, such as preferably 96% alumina (Al2O3) ceramic single-crystal α-alumina (Al2O3), wherein the cutting edge of the blade is oriented perpendicular to the c-axis of the crystal structure of the ceramic material to improve the strength and fracture resistance of the blade edge. Alternatively, it is also conceivable that the cutting insulating blade can be made of thermoplastic materials including polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyhexamethylene adipamide (PA66), and polyphenylene sulfone (PPSU), or thermosetting materials including sheet molding compound (SMC) and block molding compound (BMC).

[0066] In this document, the ceramic material can be any suitable ceramic material, such as α-alumina (i.e., sapphire) or zirconia ceramic, or nitride or carbide ceramic. In an exemplary embodiment, the ceramic material is a single-crystal ceramic, such as single-crystal α-alumina. The ceramic material can be synthesized using any suitable process, such as the Kyropolis method for forming ingots, the Bagdasarov method (for forming plate-like bulk materials), or the Stepanov method. After forming the ceramic blank, the ceramic material can be cut and subsequently sharpened to form the cutting edge 202C of the insulating blade 202. Compared to existing plastic materials, such a cutting blade 202 made of ceramic material can have 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 to be above 800 degrees Celsius, thereby fundamentally eliminating the possibility of carbonization or carbon buildup of the insulating blade 202 during the breaking process due to the high temperature of the copper busbar 103 or the ablation of the electric arc; furthermore, the compressive strength of the insulating blade 202 is above 2000 MPa, preferably 2500 MPa, and its flexural strength is above 300 MPa, preferably 310 MPa, which is far higher than that of known plastic blades.

[0067] Furthermore, since the ceramic substrate forming the insulating blade 202 may be prone to breakage, especially in the relatively thin area (thickness) where the blade tip is formed, according to another aspect of the present invention, the insulating blade 202 formed of ceramic includes a rounded corner design with a unique included angle and / or blade tip geometry to mitigate breakage or other damage, thereby improving the performance of the insulating blade 202.

[0068] refer to Figure 1-3 An exemplary insulating blade 202 is shown, comprising a blade body made of alumina ceramic material. In the illustrated embodiment, the blade body is entirely made of alumina ceramic material. The insulating blade 202 has a first blade body surface, a second blade body surface opposite to the first blade body surface, a cutting edge 202C located between the two, and a blade tip 202B located at the lowermost end of the cutting edge 202C. The blade thickness, defined by the distance between the first and second blade body surfaces, is 2 mm to 5 mm. Here, the cutting edge 202 is designed to extend obliquely upward from the lowermost blade tip 202B to both sides of the blade body, wherein the first included angle A through which the cutting edge 202 extends is preferably in the range of 135 degrees to 150 degrees.

[0069] like Figure 3 As shown, the insulating blade 202 illustrated herein has a unique geometry configured to mitigate breakage or other damage to improve the performance of the insulating blade 202. In an exemplary embodiment, the insulating blade 202 is configured such that the cutting edge 202C located between the first and second blade body surfaces... Figure 3 The cross-section has a second included angle B, wherein the second included angle B is in the range of approximately 45 degrees to approximately 60 degrees. More specifically, the second included angle B can be in the range of approximately 50 degrees to approximately 55 degrees. Furthermore, it is preferable to round the corners of the blade tip 202B to prevent the blade tip 202B from breaking during the cutting operation.

[0070] To achieve a reliable connection between the insulating blade 202 and the grid body 201, it is preferable to have, for example, semi-circular locking holes 202A on two opposing sides of the insulating blade 202, thereby enabling reliable connection between the insulating blade 202 and the grid body 201. Figure 9In the assembled state shown, some thermoplastic material of the grid body 201 is allowed to flow into the retaining hole 202A to form a reliable form-fit connection (in the case where the insulating blade 202 and the grid body 201 are integrally injection molded), or the stop protrusion in the grid body 201 is allowed to form-fit into the retaining hole 202A when the insulating blade 202 is forcefully inserted into the blade groove 201A (in the case where the insulating blade 202 and the grid body 201 are formed separately and assembled later). As a result, the insulating blade 202 is reliably held in the desired position within the blade groove 201A of the grid body 201 (e.g., Figures 6 to 7 (As shown).

[0071] exist Figures 10 to 11 Another embodiment of the insulating blade 202 suitable for the opening grid 200 of this utility model is shown, wherein this embodiment is similar to... Figures 2 to 3 The difference in the illustrated embodiment lies in the type of ceramic material. Specifically, in this embodiment, the ceramic material is selected as zirconia ceramic. Preferably, the zirconia content in this ceramic composition ranges from approximately 5% to 17.5% v%. It is believed that compositions with zirconia content outside this range will reduce the mechanical strength of the insulating blade 202 during high-speed switching operations. To maximize the mechanical strength of the insulating blade 202, the zirconia content in this composition should range from approximately 7.5% to 17.5% v, and more preferably from approximately 10% to 15% v.

[0072] Thus, the innovation of this embodiment compared to other embodiments lies in the discovery that a certain small but effective amount of zirconium oxide content is the determining factor for maximizing the mechanical strength of the insulating blade 202. According to this invention, at least 5 to 17.5 vol% zirconium oxide should be present.

[0073] exist Figures 12 to 13 The diagram shows another embodiment of the insulating blade 202 suitable for the opening grid 200 of this utility model, wherein... Figures 1 to 3 The difference in the embodiments shown is that the insulating blade 202 does not include a blade edge 202C with a sharp tip 202B, but is instead designed with a generally arc-shaped blade edge 202C, i.e., the insulating blade 202 resembles the outline of a circular shovel. It is believed that this design helps to prevent breakage of the tip 202B due to large impact forces during the cutting operation, wherein the generally arc-shaped blade edge 202C helps to distribute the impact force, thereby improving reliability during high-speed cutting operations. In this embodiment, the insulating blade 202 is also configured such that the blade edge 202C located between the first and second blade body surfaces... Figure 13The cross-section has a second included angle B, wherein the second included angle B is in the range of approximately 45 degrees to approximately 60 degrees. More specifically, the second included angle B can be in the range of approximately 50 degrees to approximately 55 degrees. Furthermore, it is preferable to round the corners of the cutting edge 202C to prevent the cutting edge 202C from breaking during the cutting operation.

[0074] exist Figures 14 to 15 The diagram shows another embodiment of the insulating blade 202 suitable for the opening grid 200 of this utility model, wherein... Figures 1 to 3 The difference in the embodiments shown is that the insulating blade 202 does not include a cutting edge 202C with a sharp tip 202B, but is instead designed to have a generally straight cutting edge 202C, i.e., the insulating blade 202 resembles the outline of a flat-headed shovel. It is believed that this design helps to prevent breakage during the cutting operation due to the large impact force on the tip 202B, where the generally straight cutting edge 202C helps to distribute the impact force, thereby improving reliability during high-speed cutting operations. In this embodiment, the insulating blade 202 is also configured such that the cutting edge 202C located between the first and second blade body surfaces... Figure 15 The cross-section has a second included angle B, wherein the second included angle B is in the range of approximately 45 degrees to approximately 60 degrees. More specifically, the second included angle B can be in the range of approximately 50 degrees to approximately 55 degrees. Furthermore, it is preferable to round the corners of the cutting edge 202C to prevent the cutting edge 202C from breaking during the cutting operation.

[0075] exist Figures 16-17 The diagram shows another embodiment of the insulating blade 202 suitable for the opening grid 200 of this utility model, wherein... Figures 1 to 3 The difference in the embodiment shown is that the sharp blade tip 202B in the insulating blade 202 shown here is not located at the lowest end of the blade portion 202C, but at the highest end of the blade portion 202C, that is, the insulating blade 202 here has a scissor-like profile. It is believed that this design helps to avoid breakage of the blade tip 202B due to the large impact force during the cutting operation, thereby improving reliability during high-speed cutting operations. In this embodiment, the insulating blade 202 is also configured such that the blade portion 202C located between the first and second blade body surfaces... Figure 17 The cross-section has a second included angle B, wherein the second included angle B is in the range of approximately 45 degrees to approximately 60 degrees. More specifically, the second included angle B can be in the range of approximately 50 degrees to approximately 55 degrees. Furthermore, it is preferable to round the corners of the cutting edge 202C to prevent the cutting edge 202C from breaking during the cutting operation.

[0076] As can be seen from the above, this utility model, by designing the breaking grid 200 in the excitation fuse 100 as a combination of a grid body 201 made of injection-molded material and an insulating blade 202 made of ceramic material, can significantly improve the electrical performance of the excitation fuse 100, including response time, breaking current, and arc suppression performance, at a relatively low and acceptable cost without substantial modification to the current production process of the breaking grid. Through multiple comparative experiments conducted by the inventors, it was found that the current that the excitation fuse 100 of this utility model can break and the response time are significantly better than those of existing excitation fuses, and it completely eliminates adverse events such as breaking failure or poor insulation performance caused by carbon buildup or carbonization of the blade.

[0077] 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.

[0078] 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: A grid body (201) made of an electrically insulating material is designed to be substantially axially symmetric about a vertical axis (A1) and has at least one blade groove (201A) extending vertically on the inner side of the grid body (201); and At least one insulating blade (202) made of insulating material, wherein the insulating blade (202) has a first blade surface, a second blade surface opposite to the first blade surface, and a cutting edge (202C) located between the two and adapted to be inserted into corresponding cuts (104A, 104B), wherein the cutting edge (202C) has an acute angle when viewed along its cross-sectional direction.

2. The open-circuit gate (200) as claimed in claim 1, characterized in that, wherein The blade portion (202C) also has a tip portion (202B) located at its lowest end, wherein the blade portion (202C) is designed to extend obliquely upward from the tip portion (202B) to both sides of the insulating blade (202), wherein the included angle through which the blade portion (202C) extends when viewed from the front is an obtuse angle.

3. The open-circuit gate (200) as claimed in claim 1, characterized in that, wherein... The blade portion (202C) also has a tip portion (202B) located at its uppermost end, wherein the blade portion (202C) is designed to extend obliquely downward from the tip portion (202B) to both sides of the insulating blade (202), wherein the included angle through which the blade portion (202C) extends when viewed from the front is an obtuse angle.

4. The interrupted gate (200) as described in claim 1, characterized in that, The blade portion (202C) is designed to be generally arc-shaped or straight.

5. The open-circuit gate (200) as described in claim 2 or 3, characterized in that, The blade tip (202B) is rounded.

6. The open-circuit gate (200) as described in claim 3 or 4, characterized in that, The insulating blade (202) also has two locking holes (202A) located on two opposing sides for forming a shape fit with the grid body.

7. The open-circuit gate (200) as described in claim 3 or 4, characterized in that, The insulating material may be alumina ceramic, zirconium oxide ceramic, nitride ceramic, or carbide ceramic.

8. An excitation fuse (100), characterized in that, The excitation fuse (100) includes an insulating housing made of 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 7.

9. The excitation fuse (100) as claimed in claim 8, characterized in that, The above The upper side of the lower housing (102) is provided with an anti-rotation portion (102A) extending upward through each copper busbar (103) to the inner side of the upper housing (101), and the opening grid plate (200) has an anti-rotation groove (201B) extending vertically, wherein the anti-rotation portion (102A) is inserted into the anti-rotation groove (201B) of the opening grid plate (200) so that the grid plate body (201) is guided during movement along the vertical axis (A1).

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