CN215815777U - Excitation protection device for nested breaking conductor and melt - Google Patents

Abstract

An excitation protection device for a nested broken conductor and a melt comprises a shell, an excitation source, an impact device, a conductor and a melt connected with the conductor in parallel, wherein a nested protection device is arranged at a melt pre-breaking position below the conductor pre-breaking position, and an accommodating cavity for a broken part of the conductor to fall into is arranged on the nested protection device at the melt pre-breaking position; the accommodating cavity is matched with the shape of the conductor breaking part; the conductor breaking portion can push the nested protection device to break the melt under the driving of the impact device. The excitation protection device can prevent the electric arc from reigniting at the conductor fracture and improve the arc extinguishing capability by arranging the nested protection device.

Description

Excitation protection device for nested breaking conductor and melt

Technical Field

The invention relates to the field of power control and electric automobiles, in particular to an excitation protection device for controlling a circuit to be disconnected when a fault occurs.

Background

At present, except for a traditional thermal fuse, a protection structure for quickly cutting off a circuit, namely an excitation fuse, exists in a battery pack protection device of an electric vehicle, and the application range is gradually expanded. The traditional fuse is a protective device which utilizes the current heat accumulation effect to enable a current sensing point (narrow neck) arranged on a melt to melt and break off and extinguish an electric arc in a certain time. The excitation fuse is a fast protection device which cuts off a conductor by mechanical force in a short time and forms a physical fracture in a circuit.

The traditional fuse has the advantages of being mature and stable, being capable of being broken with high upper limit and strong arc extinguishing capability, and has the defects that: the current impact resistance is poor; the heating value is large; the circuit can be disconnected for a long time under low-multiple fault current, and quick protection cannot be realized; the fuse can not achieve complete physical isolation after fusing, which is mainly reflected in that the insulation resistance value after fusing is small, and the value range is 0.1 MOmega-50 MOmega; the volume and weight are large. The excitation fuse has the advantages that the rapid protection is realized by rapidly cutting off the opening, the current impact resistance is good, the heating value is small, the complete physical isolation can be realized after the excitation fuse is cut off, and the numerical range of the insulation resistance after the excitation fuse is cut off is more than 550 MOmega; the defects are that the arc extinction is not high, the arc extinction capacity is weak (depending on air cooling arc extinction or extrusion arc extinction) due to the fact that the arc extinction is achieved by cutting off the opening alone.

Combining the advantages and disadvantages of the fuse and the excitation fuse, a scheme of improving arc extinguishing capability and breaking capability by connecting a fuse body in parallel on a conductor of the excitation fuse has appeared, and a better scheme is further appeared on the basis of the scheme, namely the excitation fuse of the conductor and the fuse body connected in parallel on the conductor are sequentially broken. In the scheme, under the condition of small-multiple fault current, a circuit is disconnected by mainly utilizing a broken conductor, and a melt is not fused and only cut off; under the medium-multiple fault current, the conductor is firstly broken, the current is transferred to the melt, the melt starts to fuse, and the melt is cut off in the fusing process and arc extinction and breaking are accelerated; under the condition of large-multiple fault current, the conductor is firstly broken, the current is transferred to the melt, the melt is quickly and completely fused, and finally the melt is broken under the condition of no current, so that complete physical isolation is realized.

The current problems with such an excitation fuse are:

1. the conductors before and after being cut are exposed in the air, and if the melt is fused too fast after the conductors are cut under the condition of large fault current, the arc reignition condition is easily generated at the cut of the conductors.

2. After the disconnection, the conductor fracture is lack of protection and is easily polluted by leaked gunpowder gas or substances burnt by electric arcs, so that the insulation performance is reduced.

3. The fracture of the conductor is lack of sealing, insulation is built completely by air medium, the insulation building is greatly influenced by the outside, and the fracture of the conductor can not be effectively matched with arc extinguishing melt in high-temperature, high-humidity and high-altitude areas, so that breaking failure is caused.

Disclosure of Invention

In order to solve the technical problem, the invention provides an excitation protection device for nested breaking of a conductor and a melt, and the conductor pre-breaking opening is effectively protected in a sealing mode. After the conductor is broken, current flows from the parallel melt, and at the moment, the protective structure is nested on the conductor to quickly and effectively seal and protect the fracture of the conductor and quickly establish insulation. Because the insulation of the conductor interruption is established quickly, a smaller quenching melt can be used and can be blown out more quickly, and the situation that the conductor interruption is re-ignited due to the over-voltage is too high can not occur. Meanwhile, the broken part of the melt can be protected, and the breaking capacity of the melt is further enhanced.

In order to solve the technical problems, the invention provides an excitation protection device for a nested broken conductor and a melt, which comprises a shell, an excitation source, an impact device, a conductor and a melt connected with the conductor in parallel, and is characterized in that a nested protection device is arranged at a melt pre-breaking position below the conductor pre-breaking position, and an accommodating cavity for a conductor breaking part to fall into is arranged on the nested protection device at the melt pre-breaking position; the accommodating cavity is matched with the shape of the conductor breaking part; the conductor breaking portion can push the nested protection device to break the melt under the driving of the impact device.

Preferably, the nested protection device at the melt pre-fracture comprises two nested protection blocks which are oppositely arranged, and the nested protection blocks are respectively arranged at the melt pre-fracture at intervals; the containing cavity is formed between the two nested protection blocks.

Preferably, an auxiliary arc extinguishing groove is formed in the bottom of the shell below each nested protection block; the lower end of the nested protection block is positioned at the opening of the auxiliary arc extinguishing groove.

Preferably, a rib is arranged at the bottom of the shell, and an auxiliary arc extinguishing structure is arranged on the rib; and the auxiliary arc extinguishing structures positioned on two sides of the convex edge and the side wall of the cavity where the auxiliary arc extinguishing structures are positioned form the auxiliary arc extinguishing groove.

Preferably, the nesting protection device at the melt pre-fracture comprises two nesting protection blocks which are relatively nested and arranged at the upper side and the lower side of the melt pre-fracture; the nested protection block close to one side of the conductor is provided with the accommodating cavity.

Preferably, at least one arc extinguishing chamber is arranged on the nested protection device at the pre-fracture of the melt, an arc extinguishing medium is filled in the arc extinguishing chamber, and the melt penetrates through the arc extinguishing chamber.

Preferably, at least one arc extinguishing chamber is arranged on the nested protection device on the melt at intervals; vertical grooves with openings deviating from the conductor are arranged between the arc extinguishing chambers or on one side or two sides of the arc extinguishing chambers, melt nested cutting blocks are arranged in the vertical grooves, a movement gap is reserved between the top ends of the melt nested cutting blocks and the top parts of the vertical grooves, and the lower ends of the melt nested cutting blocks extend out of the nested protection device at the melt pre-breaking opening; the melt is positioned on the top end face of the melt nested cutting block, and weak breaking parts are respectively arranged on the melt on two sides of the top end face of the melt nested cutting block.

Preferably, a nested protection device covering the conductor pre-fracture is arranged at the conductor pre-fracture.

Preferably, the nesting protection device at the conductor pre-fracture comprises nesting protection blocks which are oppositely nested on the upper side and the lower side of the conductor pre-fracture.

Preferably, the housing includes an upper housing, a lower housing, and a bottom cover, the conductor being located between the upper housing and the lower housing, the bottom cover closing the lower housing; and the lower shells positioned on two sides of the nested protection device at the melt pre-fracture are respectively provided with a melt arc-extinguishing chamber for the melt to pass through, and the melt arc-extinguishing chamber is filled with arc-extinguishing medium.

Preferably, the side wall of the melt arc-extinguishing chamber through which the melt passes is provided with a bevel structure; a breaking weakness is provided in the melt in the arc suppressing substance adjacent one side of the ramp structure, where the melt is snapped off when the nested protection device on the melt is pushed downward.

Preferably, a through hole groove for the melt to pass through is formed in a housing wall between the melt arc-extinguishing chamber and the conductor, and two ends of the melt respectively pass through the through hole groove and then are connected with the conductor in parallel.

Preferably, a buffer device for buffering after the melt is cut off is arranged on the bottom cover.

Preferably, the nested protection device and the auxiliary arc extinguishing structure are made of materials capable of generating arc extinguishing gas when being heated.

According to the nested break-off conductor and melt excitation protection device, after the conductor is broken off, the conductor fracture is protected and insulated quickly by using the nested protection device at the conductor, and the electric arc is prevented from reigniting at the conductor fracture; current can only flow through the parallel melt, the impact device drives the conductor break-off part to continue to break off the melt, at least one mechanical fracture is formed on the melt, the arc extinguishing medium is assisted by the aid of the protective device nested in the melt, arc extinguishing is further achieved, and breaking capacity and arc extinguishing capacity are improved.

According to the nested structure on the conductor and the melt, the melt with smaller specifications can be used for the parallel connection of the melt, after the conductor is disconnected, the melt is rapidly fused in the arc extinguishing medium and is mechanically disconnected, a plurality of fractures are formed on the melt, the plurality of fractures are matched with the melt to nest the protection device and the arc extinguishing medium for arc extinguishing, and the situation that the conductor fractures are re-ignited by electric arc can not occur due to overvoltage. When a melt with a smaller specification is used, the cross-sectional area of the melt is smaller, the step current is also lower, the arc extinguishing pressure of the melt cutting structure is reduced, the product can be cut off normally more easily, the arc extinguishing capability is improved, the rapid protection is realized, and the insulation performance after the cut-off is excellent.

Drawings

Fig. 1 is a schematic structural diagram of a normal operating state of embodiment 1.

Fig. 2 is a schematic diagram of the structure of example 1 in which the insulation is built by nesting a protection device on the conductor after the conductor is broken.

Fig. 3 is a schematic structural diagram of a nested protection device at the position where a conductor broken part and the nested protection device covering the conductor broken part enter a melt in example 1.

FIG. 4 is a schematic drawing showing the structure of example 1 with both the conductor and the melt broken away.

Fig. 5 is a schematic structural diagram of a normal operating state of embodiment 2.

Fig. 6 is a schematic diagram of the structure of example 2 in which the insulation is built by nesting a protection device on the conductor after the conductor is broken.

Fig. 7 is a schematic structural diagram of a nested protection device of example 2 where a conductor break and the nested protection device covering the conductor break enter a melt.

FIG. 8 is a schematic view of example 2 with both the conductor and the melt broken away.

FIG. 9 is a schematic structural view of the location of a first fracture of the first melt break in example 2.

FIG. 10 is a schematic structural view of the location of a secondary fracture of a second break in the melt of example 2.

Detailed Description

The invention relates to an excitation protection device for a nested break conductor and a melt, which mainly comprises an excitation source, an impact device, a shell, a conductor and a melt connected with the conductor in parallel, wherein the conductor or the melt is simultaneously provided with a nested protection device or only the melt is provided with the nested protection device; when no parallel melt exists and no insulating protective sleeve is arranged on the conductor, a nested protection device can be arranged in the shell below the conductor, so that a disconnected part of the conductor enters the nested protection device under the driving of the impact device, the impact device and the nested protection device are in interference fit, the insulating sealing of the fracture of the conductor is completed, and the breaking of fault current is completed. When the fuse-element is connected in parallel, the nested protection device is arranged on the fuse-element, and the insulating protective sleeve is not arranged on the conductor, the nested protection device on the fuse-element is positioned in front of the displacement of the conductor break-off part, the conductor break-off part and the impact device enter the nested protection device on the fuse-element together, and an insulating seal is formed around the conductor break-off part, at the moment, the fault current can only flow through the parallel fuse-element, and the parallel fuse-element starts to complete the fusing arc-extinguishing work. Then the impact device continues to drive the nesting protection device on the melt to break the melt under the action of the impact device, and the insulation capability after the break is further enhanced. When the conductor and the melt are respectively provided with the nested protection devices, the impact device drives the conductor disconnecting part with the nested protection devices to displace into the nested protection devices on the melt together, so that a reliable double-layer sealing structure is formed and insulation is established. At the moment, fault current can only flow through the parallel connection melt, and the parallel connection melt starts to complete fusing arc extinguishing work. And then the impact device continues to drive the nested protection device on the melt to disconnect the melt, so that the conductor and the melt are sequentially disconnected, and the insulation capability after disconnection is further enhanced.

The housing may be of an upper and lower housing structure, a left and right housing structure, or the like. The conductor is in sealed contact with the shell, so that the electric arc is prevented from flying out from the contact surface to damage external devices when the shell is disconnected, and external dust, water and the like are prevented from entering the shell. The shell is made of insulating materials.

The excitation source is fixed in the shell and is a gas generating device, and high-pressure gas can be generated after receiving a specified electric signal to drive the impact device to displace and cut off the conductor. In order to ensure that the impact device, the conductor breaking part and the like can smoothly move in the shell, a cavity for the impact device, the conductor breaking part, the nested protection device and the like to move is arranged in the shell.

The conductor or the melt is provided with a pre-fracture. The nested protection device may be positioned at a pre-break of the conductor or melt. The pre-fracture is a part where the conductor or the melt is broken by the impact of the impact device. The two sides of the pre-fracture are provided with weak fracture parts. The breaking weakness can be in the form of a 'V' -shaped groove, a 'U' -shaped groove, a reduced section or a pre-rolled opening and other structures with reduced strength.

The melt is bent into a space geometric shape and is conveniently arranged in the cavity of the shell. The melt and the impact device are respectively positioned at two sides of the conductor, and the conductor and the melt are sequentially positioned in front of the displacement of the impact device. The two ends of the melt are electrically connected with the conductor to form a parallel connection relationship, and the electrical connection form can adopt bolt crimping, conductive elastic sheet connection, welding and the like. A throat, i.e. a pre-melt of the melt, is also provided on the melt. The melt can be mechanically broken under the impact of an impact device and can also be fused in a hot melting state.

An arc-extinguishing medium is filled in the cavity where the melt throat is located to assist in arc extinction. An auxiliary arc extinguishing structure is arranged at the bottom of the shell. The bottom of the shell is sealed by a shell bottom cover.

The impact device is located between the excitation source and the conductor. The impact device is in sealing contact with the inner cavity of the shell, the complete separation of the upper cavity and the lower cavity of the impact device is realized, the influence of high-pressure gas on the insulating capability of a fracture can be avoided, fault current is prevented from being led into a driving loop, and meanwhile, the high-pressure gas is independently sealed between the impact device and an excitation source, so that the impact device can be prevented from rebounding after moving in place. In order to keep smooth linear displacement of the impact device, a limiting sliding groove is formed in a cavity where the impact device is located, two opposite sides of the impact device are arranged in the limiting sliding groove, the impact device is prevented from rotating in the shell, and a pre-fracture surface of a conductor or a melt is ensured to be broken at an impact end of the impact device. The initial position of the percussion device is defined by a limit structure. The impact device is made of an insulating material.

The following description of the preferred embodiments is made with reference to the accompanying drawings.

Example 1

Referring to fig. 1, the housing includes a hermetically mated upper housing 204 and lower housing 212, the lower housing 212 being sealed by a bottom cover 214. The shell is made of insulating materials. The upper shell and the lower shell are formed in an injection molding mode and can also be formed in other forming modes. Cavities which run through the upper end and the lower end of the upper shell and the lower shell are arranged in the upper shell and the lower shell. The conductor 207 is arranged between the upper shell and the lower shell in a penetrating way, two ends of the conductor 207 are positioned outside the shell and can be connected with an external circuit, and the conductor 207 positioned in the shell penetrates through the cavities formed in the upper shell and the lower shell.

In the cavity of the upper housing on the side of the conductor 207, there are arranged in succession an impact device 203 and an excitation source 201, which in this embodiment is an electronic ignition device. The impact device is located between the excitation source and the conductor. The upper end part in the cavity of the upper shell is provided with a step hole structure, and the excitation source is arranged at the step hole and is limited in position through the step hole. A protective cover 202 is pressed on the periphery of the upper shell, the protective cover is pressed on a step on the excitation source, and the excitation source is positioned through the protective cover 202 and a limit step in the cavity of the upper shell. The excitation source can be connected with an external control system, receives an excitation electric signal from the outside and triggers the action to release high-pressure gas as driving force for driving the impact device.

The impact device 203, which is a piston structure in this embodiment, is made of an insulating material, and may be formed by injection molding or other molding methods. The end surface of the striking device 203 on the side close to the conductor 207 is provided as a striking end, and the conductor is cut by the striking end to form a fracture in the conductor. The upper end face of the impact device is provided with an arc-shaped concave surface structure 203a, and the arc-shaped concave surface structure aims to enable high-pressure gas released by an excitation source to be concentrated and directly act on the upper end face of the impact device, so that the maximum driving force is obtained, meanwhile, the weight of the impact device can be reduced, and materials are saved. A plurality of limiting lugs 203a are arranged on the peripheral surface of the impact device at intervals, limiting grooves are correspondingly formed in the cavity wall of the upper shell, and the limiting lugs 203a are arranged in the limiting grooves in the cavity wall to limit the initial position of the impact device. The limiting projection 203a is in a tip-shaped structure inclined upwards, and aims to enable the limiting projection 203a to be separated from the limiting groove more quickly when the impact is applied, so that the impact device is released from being restrained. When the excitation protection device is in a normal working state, i.e. an initial position, it is necessary to ensure that the impact device does not impact the conductor, which affects the normal operation of the conductor, and therefore, the initial position of the impact device needs to be defined. However, the limit bump 203a is required to be disconnected when the impact device is impacted by the driving force released by the excitation source, so that the impact device is released from the constraint, and the displacement of the impact device is ensured. The impact device 203 and the cavity in which it is located need to be in sealing contact, so an annular structure is provided on the outer circumferential surface of the impact device, and a sealing ring 203b is provided in the annular structure. The impact device can be ensured to be always in sealing contact with the cavity where the impact device is positioned under the action of the sealing ring when the impact device is displaced. In order to ensure that the cavity in which the percussion device is located is always in sealing contact during displacement of the percussion device, a sealing ring 203b is preferably arranged at the upper peripheral surface of the percussion device. In this embodiment, the striking device 203 is shaped as a T-shaped structure, the upper end of which is in full sealing contact with the cavity in which it is located, and the column of the T-shaped structure is partially in non-contact with the cavity in which it is located, in order to reduce the frictional resistance during the movement of the striking device. In order to ensure that the impact device makes linear displacement in the cavity, the cavity walls of the cavity at two opposite sides are provided with limiting sliding grooves (not shown), sliding blocks are arranged at corresponding positions of the impact device, the sliding blocks on the impact device are clamped in the limiting sliding grooves, the linear displacement of the impact device is ensured, and the impact device is prevented from rotating in the cavity. Simultaneously, in order to prevent error installation, the depth or width of the limiting sliding groove and the sliding block on one side can be made different from that of the other side. In order to ensure the linear displacement of the impact device, a vertical convex edge can be arranged on the cavity wall of the cavity, and a limit sliding groove is arranged at one position of the impact device to realize the linear displacement limitation. The impact end surface of the impact device is of a plane structure.

The conductor 207 has a strip plate-like structure and is made of copper, silver or other conductive metal material with good conductivity. The structure can be a straight-line flat plate structure or a zigzag flat plate structure. Two breaking weaknesses 207a are arranged on the conductor 207 positioned in the cavity of the upper shell and the lower shell at intervals, a pre-breaking hole 208 is formed between the two breaking weaknesses by the conductor part, and the impact end of the impact device 203 is opposite to the pre-breaking hole of the conductor. When the conductor pre-fracture 208 is impacted by the impact device, the conductor part at the conductor pre-fracture is completely separated from the conductor 207 under the impact action of the impact device to form a conductor fracture part, and a fracture is formed between two fracture weak points of the conductor. In the present embodiment, each breaking weak point 207 is formed by V-grooves formed on the upper and lower surfaces of the conductor 207. A nested protection device is sleeved on the conductor pre-breaking hole 208. The conductor nesting protection device comprises a conductor upper nesting protection block 205 and a conductor lower nesting protection block 206 which are oppositely arranged on the upper surface and the lower surface of a conductor pre-breaking hole 208. The conductor upper nested protection block 205 and the conductor lower nested protection block 206 are oppositely nested, a conductor pre-breaking port is coated in the conductor upper nested protection block 205 and the conductor lower nested protection block 206, and two ends of the conductor upper nested protection block 205 and the conductor lower nested protection block 206 are respectively located at the thinnest positions of the weak points of the conductor breaking. The upper conductor nesting protection block 205 and the lower conductor nesting protection block 206 are made of insulating materials and are arranged in a fit mode with the conductors. By the structural design, the nested protection device and the conductor pre-fracture position can be ensured to have no redundant air; after the pre-fracture is broken, the nested protection device covers the broken part of the conductor to the maximum extent.

The lower housing 212 is an integrally formed structure, and is formed by injection molding or other molding methods. A cavity 212a is formed in the lower case below the pre-cut of the conductor 207, and the cavity 212a penetrates the upper and lower end faces of the lower case. Cavities 215 are respectively arranged on two opposite sides of the cavity 212a, the upper ends of the cavities 215, which are in contact with the upper shell and the conductor, are sealed structures, and the lower ends of the cavities are opened. The cavity 212a is a stepped cavity structure, and the width of the cavity above the step is greater than the width of the cavity below the step. The width of the cavity close to the conductor is consistent with that of the nested protection device on the conductor, so that the conductor disconnection part with the nested protection device can enter the cavity below the conductor disconnection part, and the two ends of the conductor disconnection part are attached to the cavity wall, so that the extrusion electric arc can be elongated. Holding grooves (not shown) with lower end openings are symmetrically arranged on two opposite sides of the cavity below the step and used for holding the nested protection device at the pre-breaking position of the melt. A through-hole groove through which the melt 211 passes is opened at the sealed upper end of the cavity 215.

The melt 211 is made of a conductive material and has a fusible sheet structure. Be provided with the interval on the fuse-element and be provided with two sets of weak departments of disconnection, every weak department of disconnection of group includes the weak department of disconnection that two intervals set up, and the weak department of disconnection of every group constitutes the pre-fracture mouth of a fuse-element. And a nesting protection device is sleeved at the pre-fracture of each melt respectively. The melt position nesting protection device comprises a left nesting protection block 209 and a right nesting protection block 210 which are assembled in two containing grooves below the step of a cavity 212a in the lower shell in an interference fit mode respectively, and after the assembly is completed, the left nesting protection block 209 and the right nesting protection block 210 are symmetrically arranged on two opposite sides of the cavity 212a and are respectively located below the weak conductor breaking position. The lower ends of the left nested protection block 209 and the right nested protection block 210 extend towards the center of the cavity 212a in a step shape, so that the shapes of the left nested protection block and the right nested protection block are in L-shaped structures. The upper parts of the left nested protection block 209 and the right nested protection block 210 which are symmetrically arranged are flush with the inner wall of the cavity 212a where the left nested protection block and the right nested protection block are located, and the upper sides of the left nested protection block and the right nested protection block form a limiting step-shaped structure corresponding to the nested protection device at the position of the conductor pre-fracture and the conductor breaking part.

The melt is positioned at the lower end face of the lower shell, passes through the cavity 212a, the left nested protection block 209 and the right nested protection block 210, and the cavity 215 is positioned at the opening end of the lower end face of the lower shell, then the two ends of the melt are respectively bent and enter the cavity 215, and then penetrate out through the through-hole grooves in the cavity 215 to be connected with the conductor between the upper shell and the lower shell in parallel, and the connection mode comprises conductive connection modes such as bolt connection, welding connection and the like. After the melt and the conductor are connected in parallel, the shape of the melt is in a space geometric structure.

The lower end face of the lower shell is provided with a bottom cover 214, and the contact part of the bottom cover 214 and the outer side face of the lower shell is assembled in a step clamping sleeve mode and used for sealing the lower shell. And the volume of the cavity 212a and the cavity 215 below the pre-cut of the conductor 207 is increased through the bottom cover 214; cavity 212a is not in communication with cavity 215. After the bottom cover closes the lower case, the melt penetrates into the cavity 212a and the cavity 215. A convex edge is arranged on the inner end face of the bottom cover at the bottom of the cavity 212a, and two sides of the convex edge are respectively provided with a limiting groove which extends into the inner end face of the bottom cover. The convex edge is provided with an auxiliary arc extinguishing structure 213 in an upward pressing manner, the bottom of the auxiliary arc extinguishing structure 213 is clamped in the limiting groove of the inner end face of the bottom cover in an interference fit manner to form an auxiliary arc extinguishing groove, and the bottom of the auxiliary arc extinguishing structure has a buffering effect. The auxiliary arc extinguishing structure 213 is in a zigzag structure, and the auxiliary arc extinguishing grooves on both sides thereof are located at the bottom of the cavity 212a on both sides of the bottom cover rib. The lower ends of the left nested protection block 209 and the right nested protection block 210 are respectively positioned in the auxiliary arc extinguishing grooves at two sides of the auxiliary arc extinguishing structure, one side of the lower ends of the left nested protection block 209 and the right nested protection block 210 is partially contacted with the side surface of the auxiliary arc extinguishing structure, and the rest side surfaces are contacted with the inner wall of the cavity 212 a. The cavity 215 is filled with an arc-extinguishing medium, and a fuse-weak portion of the melt is located in the cavity 215, typically as a neck, or other structure that increases resistance.

The working flow of the embodiment is as follows: referring to fig. 2 to 4, after the excitation source 201 receives an external excitation electrical signal, the excitation source acts to release high-pressure gas to drive the impact device 203 to make linear displacement, the impact end of the impact device 203 impacts the pre-cut opening covered with the nested protection device on the conductor 207 to break the conductor from the pre-cut opening to form a conductor break part, as shown in fig. 2, after the conductor break part moves downwards for a distance of 2 to 3mm, the nested protection device on the conductor starts to form a first layer of sealing structure, and insulation is established between the conductor break parts. The impact device continuously drives the conductor disconnected part coated with the nested protection device to enter a space between the left nested protection block 209 and the right nested protection block 210 in the cavity 212a of the lower shell, so that the conductor disconnected part is completely coated in the conductor nested protection device and the melt nested protection device and is completely insulated from the surroundings under the combined action; then, the impact device continues to drive the conductor disconnected part, the nested protection device for coating the conductor disconnected part and the nested protection device at the melt part to jointly move downwards, so that the left nested protection block 209 and the right nested protection block 210 respectively enter the cavities at two sides of the auxiliary arc extinguishing structure, the melt pre-fracture is disconnected, and two fractures are formed on the melt; the impact device drives the left nested protection block 209 and the right nested protection block 210 to drive the melt break-off part to continuously move in cavities at two sides of the auxiliary arc-extinguishing structure for further arc-extinguishing until the nested protection device covering the conductor break-off part abuts against the upper end face of the auxiliary arc-extinguishing structure above the convex edge, and the movement stops.

The arc extinguishing principle is as follows: when the conductor pre-breaking port is broken, the conductor breaking part with the nested protection device falls into the middle of the nested protection device at the melt under the driving of the impact device, and due to the combined action of the nested protection device covering the conductor breaking part and the nested protection device at the melt, the conductor breaking part is rapidly disconnected with the main circuit and establishes insulation, and the electric arc is difficult to form reignition at the position. At the moment, fault current can only flow through the parallel connection fusant, the fusant with smaller specification can be used for fusing more quickly, and overvoltage generated during fusing can not cause the phenomena of breakdown and arc reignition between conductor fractures of the main circuit. Then the impact device continuously pushes the nested protection device at the melt to move and break the melt, and residual electric arcs at two break ports formed on the melt are extruded together by the nested protection device at the melt and the auxiliary arc extinguishing structure to complete arc extinguishing.

Example 2

The main differences between the embodiment and the embodiment 1 are that the structure of the nested protection device at the melt is changed, and the gradient of the contact surface of the lower shell and the upper shell is changed. In example 1, the nested protection devices at the melt are arranged in a left-right symmetrical mode, and in example 2, the nested protection devices at the melt are arranged in an up-down mode, and specifically, refer to fig. 5. The melt nesting protection device comprises an upper nesting protection block 309 and a lower nesting protection block 310 which are positioned on the upper surface and the lower surface of the melt and are oppositely nested; the portion of the melt located in cavity 312a is encapsulated by upper nested protection block 309 and lower nested protection block 310. The upper nested protection block 309 is located at a step in the cavity 312a and has a recess 309a therein, the shape of the inner wall of the recess conforming to the shape of the inner wall of the cavity 312 a. A vertical groove 309b is formed in the center of the lower surface of the upper nested protection block 309, and two small grooves are formed in two opposite sides of the vertical groove. The lower nesting protection block 310 is in a cover-shaped structure, two grooves corresponding to the small grooves on the two sides of the vertical groove are arranged on the upper surface of the lower nesting protection block, and through-hole grooves penetrating through the upper end surface and the lower end surface of the lower nesting protection block 310 are formed in the positions corresponding to the vertical grooves 309 b. The upper nested protection block 309 and the lower nested protection block 310 are relatively nested, and the vertical grooves 309b and the through hole grooves of the upper nested protection block and the lower nested protection block form vertical grooves 309b which are deeper and have lower ends penetrating through the lower end face of the lower nested protection block; after the grooves on the two sides of the vertical groove 309b are butted, two sealed accommodating cavities 316 are formed on the melt nested protection device respectively, and the melt passes through the accommodating cavities 316.

The lower end surface of the melt 311 passing through the cavity wall of the cavity 312a is provided with an inclined surface, and correspondingly, the contact part of the bottom cover 314 and the inclined surface of the lower end surface of the cavity wall of the cavity 312a is also provided with an inclined surface.

The melt 311 is located at the end face of the lower end of the lower shell, the melt 311 passes through the cavity 312a, the cavity 315, the cavity wall end face inclined plane adjacent to the cavity 312a and the cavity 315, the contact end face of the melt upper nested protection block 309 and the melt lower nested protection block 310, a vertical groove 309b formed by the melt upper nested protection block 309 and the melt lower nested protection block 310, and the accommodating cavities 316 located at two sides of the vertical groove, then two ends of the melt are respectively bent into the cavity 315, and then penetrate out through a through hole in the cavity 315 to be connected in parallel with a conductor located between the upper shell and the lower shell, and the connection mode comprises conductive connection modes such as bolt connection, welding connection and the like. After the melt and the conductor are connected in parallel, the shape of the melt is in a space geometric structure.

A bottom cover 314, wherein grooves are arranged on the bottom cover 314 at positions corresponding to the cavities 312a and 315 on the lower shell; a snap step is provided on the end surface of the bottom cover 314 on the side. When the lower cover 314 is arranged at the lower end face of the lower shell, the fastening step at the end face of the upper side of the lower cover 314 is abutted against the fastening step arranged on the lower shell to seal the lower shell; at the same time, the cavities 312a and 315 in the lower housing are sealed and elongated by the grooves in the bottom cover. Bottom cap 314 holds melt 311 tightly between lower housing cavity 312a and the adjacent cavity wall slope of cavity 315 to facilitate the melt being pulled apart. The melt is bent at the inclined surface side of the inner cavity wall of the cavity 315, so that the nested protection device at the melt can break the melt in the cavity 312a conveniently. A buffer 313, which is a cushion in this embodiment, is disposed at the bottom of the cavity 312a on the bottom cover 314. Arc extinguishing media are respectively filled in the accommodating cavity 316 and the cavity 315 between the upper nested protection block 309 and the lower nested protection block 310. The melt fuse weakness is located in the receiving cavity 316 and/or the cavity 315.

A nested melt cutting block 317 is in interference fit in the vertical groove, and a movement gap is reserved between the upper end surface of the nested melt cutting block 317 and the top of the vertical groove; the melt is located at the upper end face of nested melt shut-off block 317. Breaking weaknesses are respectively arranged on the melts at the two sides of the nested melt cutting block 317 in the vertical groove.

The workflow of this example 2: referring to fig. 6 to 8, when the conductor pre-breaking port is broken by the impact device, the conductor breaking portion coated with the nested protection device falls into the groove of the upper nested protection block 309 under the pushing of the impact device, and under the combined action of the nested protection device coated with the conductor breaking portion and the upper nested protection block, the conductor breaking portion and the main circuit are broken and move downwards for 2-3 mm, insulation is rapidly established, and the electric arc is difficult to form reignition at the position. The impacting device continues to push the upper nested protection block to move downwards and pull the melt, the melt is pulled apart at 401 shown in fig. 9, a primary cut-out of the melt is formed, the primary cut-out is located in the cavity 315 and is surrounded by the arc-extinguishing medium, and the arc-extinguishing medium helps to extinguish the arc. Then, the impact device drives the conductor disconnected part and the nested protection device, the upper nested protection block, the lower nested protection block and the nested melt cutting block 317 which cover the conductor disconnected part to continuously displace downwards, the nested melt cutting block 317 and the buffer pad 313 stop moving after being impacted, the melt in the vertical groove is broken, and a melt secondary cutting opening is formed at 402 shown in fig. 10, so that the insulation performance after the cutting is improved.

When the fault current is high, breaking and fusing fractures can form on the melt after the conductor is disconnected. The melt fuse fracture is formed in a chamber filled with an arc-extinguishing medium, further improving the arc-extinguishing capability.

The principle of arc extinction is the same as that of embodiment 1.

Example 3

On the basis of the embodiment 1 and the embodiment 2, the nested protection device on the conductor can be removed, and because the impact device adopts insulating substances, when the impact end surface of the impact device impacts the conductor, the impact end surface covers the conductor pre-fracture and drives the conductor pre-fracture into the nested protection device at the melt pre-fracture, so that the insulation can be realized and the electric arc reignition can be prevented.

The principle of arc extinction is the same as that of embodiment 1.

In the above embodiments, the upper shell, the lower shell and the bottom cover are sealed, so that not only can the fracture be prevented from being polluted by foreign objects, but also the high-temperature arc can be prevented from being sprayed out of the shell to damage surrounding devices.

The nested protection device and the auxiliary arc extinguishing structure can be made of materials which can generate arc extinguishing gas when being heated, such as rubber, nylon materials or other materials which can generate gas when being heated. In the breaking process, the nested protection device and the auxiliary arc extinguishing structure are heated to generate gas, so that the fracture air pressure is increased to compress the electric arc, and the electric arc is more easily extinguished.

Claims (14)

1. An excitation protection device for interrupting a conductor and a melt in a nested manner comprises a shell, an excitation source, an impact device, a conductor and a melt connected with the conductor in parallel, and is characterized in that the nested protection device is arranged at a melt pre-breaking position below the conductor pre-breaking position, and an accommodating cavity for a conductor breaking part to fall into is arranged on the nested protection device at the melt pre-breaking position; the accommodating cavity is matched with the shape of the conductor breaking part; the conductor breaking portion can push the nested protection device to break the melt under the driving of the impact device.

2. The excitation protection device for the nested break-off conductor and the melt according to claim 1, wherein the nested protection device at the melt pre-fracture comprises two nested protection blocks which are oppositely arranged, and the nested protection blocks are respectively arranged at intervals at the melt pre-fracture; the containing cavity is formed between the two nested protection blocks.

3. The excitation protection device for nested break-out conductors and melts of claim 2, wherein a secondary arc extinguishing groove is provided at the bottom of the housing below each nested protection block; the lower end of the nested protection block is positioned at the opening of the auxiliary arc extinguishing groove.

4. The excitation protector for nested break-off conductors and melts of claim 2, wherein a rib is provided at the bottom of the housing, and an auxiliary arc extinguishing structure is lapped on the rib; and the auxiliary arc extinguishing structures positioned on two sides of the convex edge and the side wall of the cavity where the auxiliary arc extinguishing structures are positioned form the auxiliary arc extinguishing groove.

5. The excitation protection device for the nested break-out conductor and the melt of claim 1, wherein the nested protection device at the melt pre-break comprises two nested protection blocks which are relatively nested and arranged at the upper side and the lower side of the melt pre-break; the nested protection block close to one side of the conductor is provided with the accommodating cavity.

6. The excitation protection device for nested break-out conductors and melts of claim 5, wherein at least one arc extinguishing chamber is provided on the nested protection device at the melt pre-break, and arc extinguishing media are filled in the arc extinguishing chamber, and the melts pass through the arc extinguishing chamber.

7. The energized protection device of nested break-out conductors and melt of claim 6, wherein at least one of the arc quenching chambers is spaced above the nested protection device on the melt; vertical grooves with openings deviating from the conductor are arranged between the arc extinguishing chambers or on one side or two sides of the arc extinguishing chambers, melt nested cutting blocks are arranged in the vertical grooves, a movement gap is reserved between the top ends of the melt nested cutting blocks and the top parts of the vertical grooves, and the lower ends of the melt nested cutting blocks extend out of the nested protection device at the melt pre-breaking opening; the melt is positioned on the top end face of the melt nested cutting block, and weak breaking parts are respectively arranged on the melt on two sides of the top end face of the melt nested cutting block.

8. An incentivized protection device for nested break-out of conductors and melts as described in any one of claims 1 to 7, wherein a nested protection device is provided at said conductor pre-break which encases said conductor pre-break.

9. The energized protection device of nested break-out conductors and melt of claim 8, wherein the nested protection device at the conductor pre-break includes nested protection blocks positioned on upper and lower sides of the conductor pre-break opposite to each other.

10. An excitation protection device for a nested break-off conductor and melt according to any of claims 1 to 7 and 9, wherein said housing comprises an upper housing, a lower housing, and a bottom cover, said conductor being located between said upper and lower housings, said bottom cover closing said lower housing; and the lower shells positioned on two sides of the nested protection device at the melt pre-fracture are respectively provided with a melt arc-extinguishing chamber for the melt to pass through, and the melt arc-extinguishing chamber is filled with arc-extinguishing medium.

11. The excitation protection device for nested break-off conductors and melt of claim 10, wherein the melt passes through a sloped structure at the side wall of the melt-arc-extinguishing chamber; a breaking weakness is provided in the melt in the arc suppressing substance adjacent one side of the ramp structure, where the melt is snapped off when the nested protection device on the melt is pushed downward.

12. The excitation protection device for the nested break-off conductor and the melt according to claim 10, wherein a through hole groove for the melt to pass through is formed in a wall of the housing between the melt arc extinguishing chamber and the conductor, and two ends of the melt are connected in parallel with the conductor after respectively passing through the through hole grooves.

13. The excitation protection device for a nested break conductor and melt of claim 10 wherein a buffer means for buffering after melt break is provided on the bottom cover.

14. An excitation protector for nested break-off conductors and melts as claimed in any one of claims 1 to 7, 9 and 11 to 13, wherein the nested protector and the auxiliary arc suppressing structure are made of materials capable of generating arc suppressing gas when heated.

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