A mechanical interruption and fusing combined multi-break excitation fuse

Abstract

A mechanically interrupting and melting combined multi-break excitation fuse, characterized in that it comprises a shell, a cavity is opened in the shell, at least one conductor is arranged in the shell and passes through the cavity; at least one excitation device and an interrupting device are arranged in the shell cavity; the excitation device can receive an external excitation signal to drive the interrupting device to operate, disconnect the conductor corresponding to it and form at least two breaks on the conductor; at least one fuse is arranged in parallel on the conductor; the fuse is connected in parallel with at least one of the breaks, and the fuse is connected in series with at least one break. The excitation fuse of the present invention improves the breaking capacity and arc extinguishing capacity while ensuring the circuit is disconnected.

Description

Technical Field

[0001] The present invention relates to the fields of electric power protection, control and electric vehicles, and in particular to a fuse for controlling the cut-off of a current transmission circuit through an external signal. Background Art

[0002] The fuse for overcurrent protection of a circuit is melted based on the heat generated by the current flowing through the fuse. The main problem is that the current for melting and vaporizing the fuse element and the heat generated by the load working through the fuse element are distinguished by temperature difference to determine whether it operates, which has certain principle constraints: Since the heat generation for withstanding current and the heat generation for interrupting current are both due to the current flowing through the fuse element of the fuse, on the one hand: if the temperature rise and power consumption of the fuse are low during the working current, or if it can withstand a strong short-term overload / impact current (such as the short-term large current when an electric vehicle starts or climbs a slope), a certain amplitude of fault current cannot reach a fast enough cut-off protection speed; on the other hand: under the condition of a fast enough protection speed for a certain amplitude of fault current, it is difficult to carry a higher working current, with a higher temperature rise and power consumption, or it is difficult to withstand a large overload / impact current without damage, and it brings additional requirements for better heat dissipation conditions, a larger volume, and a higher cost. For example, in the main circuit of a new energy vehicle, if there is a low-amplitude overload or short-circuit current in the load, choosing a traditional fuse with a small rated current specification cannot meet the requirements of normal load current and short-time excessive current operation, and if choosing a traditional fuse with a large rated current specification cannot meet the requirements of protection speed. In the battery pack of a new energy vehicle, when the battery is low in power, the output current amplitude is not large in case of a short circuit. If the fuse cannot be melted quickly in time, it may still cause the arc at the short-circuit point to burn for too long or the battery pack to continuously generate heat due to excessive current, resulting in damage or fire.

[0003] In addition, the thermal fuse cannot communicate with external devices and cannot be triggered by other signals except current. If the circuit cannot be cut off in time when the vehicle experiences serious collisions, water immersion, or the battery temperature is too high after being exposed to the sun, it may lead to serious events such as damage to the battery pack or even vehicle burning, or the vehicle body remains charged, affecting the escape of personnel.

[0004] At present, there is an excitable switch structure for a fast-breaking circuit in the market, which mainly includes a gas generating device and a conductive terminal. The gas generating device generates high-pressure gas to drive a piston to break the conductive terminal, achieving the purpose of quickly disconnecting the circuit. However, it has some serious deficiencies and defects: limited by the fact that the over-current at the break burns the arc in the air, it is difficult to extinguish the arc of a large-amplitude fault current, or a large space volume is required; the arc is cooled and broken by air, and the extinction is greatly affected by air pressure, temperature and humidity, air impurities, etc., and the reliability is poor; during the breaking process, the arc directly burns the head of the piston, and the burning damage will affect the smooth arc extinction; if the air in a small volume space extinguishes the arc of a large-amplitude current, the insulation resistance after breaking is also relatively low, resulting in the need for a larger volume for arc extinction, etc. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a fuse that disconnects a conductor by fusing combined with mechanical force. By utilizing the reliable large-amplitude current breaking ability of the fuse, through integrated design, the fuse is connected in parallel on some breaks and connected in series on some breaks under certain conditions. The fuse is connected in parallel with a conductive plate to reduce the temperature rise power consumption in the non-breaking state and improve the anti-current impact ability. The fuse only requires a very small current-carrying capacity. When a breaking action is required, the actuator and the breaking device are used to disconnect part of the conductive plate. The fuse greatly reduces the arc energy of the break connected in parallel with it, protects the parallel break to safely recover the insulation dielectric performance under large current, and uses the fuse connected in series on some breaks to limit the arc energy value passing through the series break, protects the break to safely break a certain amplitude of over-current, and does not exceed the safety limit; by using the linkage of the breaking device, the action sequence of the break can be controlled differently, flexibly using the fuse to protect the parallel break and the parallel break, improving the large-amplitude over-current breaking ability, and can also quickly complete the breaking for small-current amplitude over-current, achieving fast and reliable breaking of all over-currents from zero current to the maximum breaking ability, greatly reducing the volume and saving costs.

[0006] To solve the above technical problems, the technical solution provided by the present invention is a mechanical breaking and fusing combined multi-break excitation fuse, which is characterized by including a housing, a cavity is provided in the housing, at least one conductor passes through the housing and passes through the cavity; at least one excitation device and a breaking device are provided in the cavity of the housing; the excitation device can receive an external excitation signal to drive the breaking device to act, disconnect the corresponding conductor and form at least two breaks on the conductor; at least one fuse is connected in parallel on the conductor; the fuse is connected in parallel with at least one break, and the fuse is connected in series with at least one break. The existence of the series break ensures that when the fuse cannot be fused, the circuit must also be disconnected through the series break.

[0007] An arc extinguishing chamber filled with an arc extinguishing medium is provided in the housing; part or all of the fuse melts passes through the arc extinguishing chamber, and the fusing break of the fuse melts is located in the arc extinguishing chamber. The arc extinguishing medium helps to extinguish the arc.

[0008] The break connected in parallel with the fuse melts disconnects first to form, and the break connected in series with the fuse melts disconnects later to form.

[0009] At least two adjacent cavities are formed in the housing, and a conductor passes through the housing and through the adjacent cavities; an excitation device and a breaking device are arranged in each cavity on one side of the conductor; the excitation devices and breaking devices in different cavities can be on the same side or different sides of the conductor; at least one impact head is arranged on the breaking device, and the excitation device can receive an external excitation signal to drive the corresponding breaking device to break the conductor to form at least one break. The purpose is to control the formation sequence of the breaks on the conductor through the sequence of receiving the excitation signals by different excitation devices.

[0010] At least two impact heads are arranged at intervals on the breaking device, and each impact head forms at least one break on the conductor.

[0011] The distances between the impact heads and the conductor are different; the impact head closest to the conductor forms the break on the conductor first; the fuse melts are connected in parallel at the break that disconnects first. The purpose is to realize the formation sequence of the breaks on the conductor by the different distances between the impact heads of the breaking device and the conductor.

[0012] The excitation device is a gas generating device; the breaking device is a piston, and the contact surface between the breaking device and the cavity is in sealed contact or in a gap contact less than 0.1 mm. Ensure that the high-pressure gas generated by the excitation device can drive the breaking device to disconnect the conductor.

[0013] A limiting structure for maintaining the initial position of the breaking device is arranged between the breaking device and the cavity.

[0014] A break-weakening part for reducing the strength of the conductor is arranged on the conductor corresponding to the breaking device, and the break is formed at the break-weakening part. The break-weakening part is a reduced cross-section structure opened on the conductor, a structure for increasing the stress at the break of the conductor, and / or a material with low mechanical strength is used at the break of the conductor. The reduced cross-section structure is one or a combination of structures such as opening a notch on one or both sides of the conductor, opening a U-shaped groove, a V-shaped groove across its width on one or both sides of the conductor, and opening a hole on the conductor.

[0015] A fusing weak point is provided on the melt, and the melt fuses at the fusing weak point. The melt weak point is a variable cross-section structure, a narrow diameter, and / or a low-temperature melting conductor provided on the melt, and / or conductor materials with different conductivities are applied. By providing a disconnection weak point that reduces the mechanical strength of the conductor and a fusing weak point for fusing on the melt, the disconnection speed of the conductor and the melt is accelerated, and the design of the disconnection position is carried out.

[0016] The melt extends around at least one series port and then is connected to a parallel port, forming an arc path after the electromagnetic field generated by the conductor interacts with the electromagnetic field to elongate the conductor fracture.

[0017] The impact end of the impact head is a contracted surface structure, a pointed structure, an inclined surface structure, or a structure with concave tips on both sides.

[0018] The excitation fuse of the present invention can be applied to distribution power supplies, energy storage devices, electrical equipment, and / or vehicles.

[0019] The fuse of the present invention is designed with three working states: 1. The interruption device does not act, the conductive plate has no fracture, the main current passes through the conductive plate, and a very small current passes through the melt, realizing reliable operation with low power consumption. Its required rated current is very small, and the typical value is 10 - 30 amperes; 2. The interruption device interrupts the conductive plate, preferentially interrupts the conductive plate in parallel with the melt to form a fracture, the large current passes through the uninterrupted conductive plate and the melt, and the melt fuses; the arc energy at the fracture of the conductive plate is very small, and most of the arcs are extinguished by the fusing of the melt, and the insulation dielectric performance is quickly restored, with a typical value of the order of 100 us; 3. The interruption device first interrupts the conductive plate without a parallel melt to form a fracture, with a typical value of the order of ms, and can interrupt zero current and small-amplitude currents. Because the generated arc is small, it can be directly extinguished by air without the need for melt-assisted arc extinguishing.

[0020] The excitation device is preferably a gas generating device; current is used to stimulate a chemical reaction to release chemical energy, similar to the release of energy and pressure gas by gunpowder combustion, and pressure gas can be excited in less than 1 ms, which is relatively fast. The interruption device cooperating with the pressure gas is preferably a piston.

[0021] Compared with traditional fuses, the excitation fuse of the present invention has the following advantages: 1. A conductive plate is connected in parallel, improving the current-carrying and impulse current resistance capabilities, reducing the temperature rise power consumption, and reducing the volume and cost; 2. It can issue an excitation signal to act, realizing controlled disconnection, with a very fast action speed, and the rated power of the parallel fuse is very small, and it can quickly cut off the fault current with a large amplitude; 3. Even if the current amplitude is not large, due to the series connection of the fracture, small-amplitude currents and even zero current in special cases can be quickly cut off. At the same time, it can be disconnected by using a separate mechanical disconnection or a combination of mechanical and melt fusing according to needs, meeting the circuit protection requirements of various occasions.

[0022] Compared with traditional excitation fuses, the excitation fuse of the present invention has the following advantages: 1. It can disconnect the conductive plate through multiple breaks, improving the breaking reliability; 2. The fuse element can protect the parallel breaks, reducing the arc energy passing through the parallel breaks, which is conducive to the rapid recovery of the dielectric strength of the insulation medium. It can quickly break through a low-rated current to achieve high-current breaking and the safe recovery of the insulation of the parallel breaks; 3. By setting series breaks, it makes up for the problem that small-magnitude overcurrents caused by the parallel fuse element method cannot be broken if they are lower than the rated current of the fuse, or the magnitude is not large enough, resulting in too long breaking time of the fuse; 4. By setting the disconnection sequence of different breaks, it can be adjusted to adopt a separate mechanical disconnection or a combination of mechanical and fuse element fusing disconnection according to needs, to meet the circuit protection requirements of various occasions. Description of the Drawings

[0023] Figure 1 , Schematic diagram of the longitudinal sectional structure of the front of the fuse of the present invention.

[0024] Figure 2 , Schematic diagram of the longitudinal sectional structure of another embodiment of the present invention.

[0025] Figure 3 , Schematic diagram of the connection between the fuse element and the series breaks and parallel breaks, generating magnetic arc extinguishing. Detailed Embodiments

[0026] For the above technical solutions, embodiments are now given and specifically described in conjunction with the drawings. The fuse of the present invention mainly includes a housing, a conductor, an excitation device, and a breaking device; see Figure 1 , among which.

[0027] The housing 100 has a cavity that penetrates the upper end of the housing. A conductor 101 is inserted through the housing 100, and the conductor 101 passes through the cavity opened in the housing 100, dividing the cavity into two parts. Both ends of the conductor extend out of the housing and can be connected to an external circuit. The conductor can also be arranged inside the housing, and then conductive terminals are respectively connected to both ends thereof. The conductive terminals are arranged at both ends of the housing and extend out of the housing, and are connected to the external circuit through the conductive terminals. The shape of the conductor can be a plate-like structure, or any cross-sectional shape, such as circular, square, irregular, tubular, etc. and their combined shapes. In the following description, a conductive plate is taken as an example for illustration. The conductor can be one, or several conductors can be arranged in parallel in the housing. In the present invention, the upper and lower housing structures are used for illustration, and the housing can be a combination of left and right housings, not limited to the combination of upper and lower housings.

[0028] An excitation device 102 and an interruption device 103 are sequentially arranged from top to bottom in the cavity located above the conductive plate 4. The excitation device 102 is fixedly arranged at the top of the cavity and is limited by a limiting step arranged in the cavity, and its upper part is fixed by a pressing plate or a bushing (not shown). The excitation device 102 is a gas generating device in this embodiment, which can receive an excitation signal when a fault occurs sent from the outside, ignite and detonate to generate high-pressure gas, form a driving force, and drive the interruption device to act. The excitation device can also be a mechanical structure device that can receive an external excitation signal, such as a cylinder, a hydraulic cylinder, a motor, etc., and provide a driving force to the interruption device by receiving an external signal.

[0029] The breaking device 103 is arranged in the cavity between the excitation device and the conductive plate. There is a certain distance between the impact end of the breaking device and the conductive plate to ensure the impact force of the breaking device. Of course, the breaking device can also be directly arranged on the conductive plate to ensure that the conductive plate is broken. When the excitation device is a gas generating device, the contact surface between the breaking device and the cavity is sealed or has a small gap that does not affect the driving force, so as to ensure that when the excitation device is a gas generating device, the generated driving force acts entirely on the breaking device and will not leak, so as to avoid insufficient driving force. The sealed contact is realized by setting a seal 104 between the breaking device and the cavity, or can also be realized by interference fit. When the breaking device is not driven by the driving force and is in its initial position, a limiting structure (not shown) is arranged at the contact surface between the breaking device and the cavity to ensure that the breaking device is fixed in the initial position and will not displace in the cavity to cause malfunction. The limiting structure can be that small bumps are arranged at intervals on the outer periphery of the breaking device, and grooves are opened on the inner wall of the corresponding cavity, and the bumps of the breaking device are snapped into the grooves to realize position limitation. This limiting structure can be disconnected under impact when the breaking device receives the driving force from the excitation device to release the limiting effect. At least two impact heads (105, 106) with different heights are arranged at intervals along the length direction of the conductive plate under the breaking device. The impact end of the impact head, that is, the end of the impact head used to cut the conductive plate, can be a contracted surface structure, a pointed structure, or the center part of the end face of the impact head is concave and the two sides are pointed structures, or other structures that are beneficial to breaking the conductive plate. For example: the contracted surface structure is a convex arc structure, and the pointed structure is a blade-like structure, an inclined surface sharp angle structure, or a conical sharp angle structure. The breaking device is a structure that can be driven by the excitation device. For example, it is a piston or slider type structure. When the excitation device is a gas generating device and the breaking device is displaced by the generated high-pressure gas, the contact surface between the breaking device and the cavity in the shell is in sealed contact or in contact with a small gap less than 0.1 mm, which can ensure that the generated high-pressure gas drives the breaking device to displace and cut the conductive plate. For breaking devices with dimensions above several millimeters, retaining a gap of 0.1 mm or even smaller, the small amount of leaked gas will not affect the movement of the breaking device and a good driving force can be obtained; the driving force obtained by sealing the contact surface between the breaking device and the cavity is greater, but generally the friction force received by the breaking device is also greater. Therefore, how to seal depends on the driving force of the high-pressure gas generated by the gas generating device. The sealed contact can be realized by setting a seal between the breaking device and the cavity, or can also be sealed by interference fit. When the excitation device is a device such as a cylinder or a hydraulic cylinder that can receive an external excitation signal to act and provide a driving force, the contact between the breaking device and the cavity does not need to be sealed.

[0030] On one side of the corresponding positions of the conductive plate below the impact head of the breaking device, a plurality of spaced breaking weak points (107, 108) are respectively provided. In this embodiment, the breaking weak points (107, 108) are provided on one side of the corresponding impact head positions of the conductive plate below the impact head of the breaking device. There are two spaced breaking weak points 107 corresponding to the impact head 106, and one breaking weak point 108 corresponding to the impact head 105. A supporting device is arranged between the breaking weak point 107 and the breaking weak point 108 to support the conductive plate. When the supporting device is located below the conductive plate, the supporting device can be a supporting boss. When it is located on the side of the conductive plate, it can be a fixed supporting arm; it can also be located above the conductive plate, and the conductive plate passes through it to play a supporting role. In this embodiment, when the conductive plate is impacted by the impact head of the breaking device, the impact head 105 first breaks the breaking weak point 108 of the conductive plate to form a fracture on the conductive plate. As the impact head continues to move, the impact head 10 forces the distance of the fracture generated by the breaking weak point to increase; as the breaking device continues to move downward, the impact head 106 breaks the two breaking weak points 107 on the conductive plate to respectively form a fracture at the two breaking weak points 107. As the separated part of the conductive plate continues to move under the forcing of the impact head, the distances of the fractures generated by the three breaking weak points continue to increase. In this embodiment, through the two impact heads of the breaking device, three fractures can be formed on the conductive plate, and the fractures at the breaking weak point 107 and the breaking weak point 108 are formed successively. Of course, the distances between the multiple impact heads on the breaking device and the conductive plate can be the same, then the fractures at the three breaking weak points are formed simultaneously. Figure 1 Two fractures are formed on the horizontally arranged conductive plate by one impact head 106. The conductive plate can also be set in a bent or inclined state, and two breaking weak points are arranged at intervals thereon. The impact head can first break the earliest contacted breaking weak point to form a fracture, and then break the other breaking weak point to form a fracture.

[0031] An arc extinguishing housing 109 is also provided below the housing 100. A cavity is opened on the arc extinguishing housing 109, and an arc extinguishing medium 110 is filled in the cavity. See Figure 1, Two melt bodies 111 are arranged in the arc extinguishing medium, and the fusing weak points of the melt bodies are located in the arc extinguishing medium. The fusing weak points of the melt bodies can be narrow diameters, variable cross-section structures, or a section of material with different electrical conductivity is lapped on the melt body, and the change of heat generation performance is caused by the change of resistance to accelerate fusing; it can also be a section of low-temperature fusing material (lower than the melting point of the melt body material itself) is lapped on the melt body to accelerate the fusing speed. After both ends of the melt body 111 pass upward through the arc extinguishing housing 109 and the wall of the housing 100, the two ends are respectively connected in parallel with the conductive plates located on both sides of the disconnection weak point 108, forming a parallel connection with the disconnection weak point 108 where a break is formed on the conductive plate, and a series connection with the two disconnection weak points 107 where two breaks are formed. When multiple breaks are generated on the conductor, it is necessary to ensure that the melt body is at least connected in parallel with one break and in series with one break. The melt bodies connected in parallel at the break can be one or multiple.

[0032] The melt bodies connected in parallel at the break are beneficial to the recovery of the insulating medium at the break. When the break is formed, since the resistance at the break is much larger than the resistance of the parallel melt bodies, the overcurrent energy is mainly dissipated from the parallel melt bodies. The overcurrent energy dissipated from the parallel melt bodies is about 70%, and only a small amount of energy passes through the break, and the generated arc is smaller (less insulating medium is broken down at the break), and the arc can be quickly extinguished to restore the insulating performance at the break. For the two breaks at the disconnection weak point 107 connected in series with the melt body, due to the energy dissipation at the disconnection weak point 108, the overcurrent energy with a large amplitude of about 30% dissipated is not enough to cause damage such as ablation to the two breaks at the disconnection weak point 107. Generally, the parallel break is disconnected first, and the series break has not appeared yet. The overcurrent flows through the conductive plate to the melt body. For a large-amplitude overcurrent, after a delay of several hundred microseconds, the series break appears. At this time, the melt body has already started the fusing action. Even if the melt body has not started the fusing action yet, since it has been preheated before the series break on the conductive plate appears, the melt body will also fuse within a short time after the series break appears. Figure 1 Taking [example] as an example, there are three breaks in total, namely the two breaks at the disconnection weak point 107 and the fusing break at the melt body 111, for voltage division. Therefore, the series break will not appear to break a large-amplitude current alone, and only a small-amplitude overcurrent needs to be cut off. Thus, both breaks are well protected through the melt body. For the series break with stronger arc energy tolerance, it can also appear simultaneously with or slightly later than the series break. The series break has a limiting effect on the overcurrent amplitude.

[0033] The arc extinguishing housing 109 can be manufactured separately or be an integral structure with the housing. Figure 1 In [description], by setting impact heads with different heights on a breaking device, multiple breaks are successively formed on the conductive plate. It is also possible to set multiple groups of excitation devices and breaking devices, and multiple breaks are successively formed on the conductive plate according to the sequence of receiving excitation signals by different excitation devices.

[0034] Refer to Figure 2, is a structural schematic diagram of two sets of excitation devices and interruption devices. The housing is composed of an upper housing 300, a lower housing 301, and an arc extinguishing housing 302, and the contact surfaces between the housings are in sealed contact. Two adjacent sets of cavities are provided in the upper housing and the lower housing, and a conductive plate 303 is located between the upper housing and the lower housing. In each set of cavities in the upper housing, an excitation device 304 and an interruption device 305 are sequentially arranged. An impact head 306 is provided on the interruption device 305. A break-weak part 310 is provided on the conductive plate corresponding to the impact head. Parallel fuses 307 are connected in parallel on the conductive plates on both sides of the break-weak part of the conductive plate closest to the impact head of the interruption device. An arc extinguishing chamber filled with an arc extinguishing medium 308 is provided in the arc extinguishing housing, and the fuse-weak part of the fuse is arranged in the arc extinguishing medium. When the excitation device is a gas generating device, a seal 309 is provided between the interruption device and the cavity, and the seal is an O-ring. It can also be set by interference fit.

[0035] In Figure 2 , the conductive plate is disconnected by two sets of excitation devices and interruption devices. The two sets of excitation devices can receive external excitation signals at the same time and drive the interruption devices to disconnect the conductive plate at the same time. In this case, when the distances between the impact heads on the interruption devices and the conductive plate are the same, multiple break points are formed on the conductive plate at the same time; when the distances between the impact heads on the interruption devices and the conductive plate are different, the impact head closest to the conductive plate forms a break point on the conductive plate first. In this case, the fuse is connected in parallel at the break point formed first. When the number of break points is three or more, the break points formed first can be two or more, and the fuse can be connected in parallel with multiple break points formed at the same time, but it must be ensured that at least one break point is connected in series with the fuse.

[0036] It can also be set that the two sets of excitation devices receive excitation signals successively, and drive the interruption devices to disconnect the conductive plate according to the order of receiving the excitation signals to form multiple break points formed successively. When an interruption device forms a break point on the conductive plate, the fuse is connected in parallel with the break point formed first and in series with the break points formed later. The break points formed first can be two or more, and the fuse can be connected in parallel with multiple break points formed at the same time, but it must be ensured that at least one break point is connected in series with the fuse.

[0037] The purpose of the above-mentioned requirement that at least one break point must be connected in series with the fuse is that when the fault current is small and insufficient to melt the fuse, the circuit must be ensured to be disconnected. At this time, the break point connected in series with the fuse is disconnected to ensure that the circuit is disconnected.

[0038] As can be seen from the above, the break points are formed successively on the conductive plate, which can be formed by the different distances between the impact heads on the interruption devices and the conductive plate, or by the order of receiving the excitation signals by different excitation devices.

[0039] The working principle of parallel melt arc extinguishing lies in that: the conduction resistance of the conductive plate and the resistivity of the melt differ by an order of magnitude. Under normal circumstances, almost all of the current flows through the conductive plate, and only a very small current passes through the melt.

[0040] After the conductive plate is mechanically disconnected, the resistivity at the break of the conductive plate instantaneously increases almost to the point of blocking. At this time, most of the overcurrent energy passes through the melt, and a small part forms an arc at the break for discharge. Therefore, phenomena such as break erosion will not occur at the break. Most of the overcurrent passing through the melt will not cause erosion or other effects on the break in series with it. At this time, the melt and the series connection form a voltage division to improve the breaking voltage ability. The arc generated at the break of the melted melt is extinguished in the arc extinguishing medium, and the arc at the break in series with it is smaller and is extinguished through the air.

[0041] In the above embodiment, the material of the melt is metal or other conductive materials; the arc extinguishing medium can be materials such as air, liquid, and solid for arc extinguishing. The impact head of the breaking device is a flat structure, a shrinking surface structure, a pointed structure, etc.

[0042] In the above embodiment, the purpose of setting the weak break point of the conductive plate is to reduce the mechanical strength at the break of the conductive plate. The following measures for weakening the break strength can be selected or used simultaneously but are not limited to: a. reducing the break cross-section, and the weak break point is a reduced cross-section, a U-shaped groove, a V-shaped groove, a hole, a hollow, etc. or a combined structure thereof, and the weak break point can be set at any angle of the cross-section of the conductive plate; b. stress concentration at the break, using a variable cross-section structure to generate stress concentration in the transition zone, such as leaving a gap, and / or using shear force; c. using a low-strength conductor material for the break, such as tin, etc.; d. using mechanical force to press and / or fix a prefabricated break, etc.

[0043] In the above fuse structure, the contact surfaces between the housing and the housing, the conductive plate and the housing, the arc extinguishing chamber and the housing, the melt and the housing, etc. are all sealed. This is to prevent high-pressure gas from leaking out to reduce the driving force and prevent the arc from leaking out, etc., which may affect the working safety of the fuse.

[0044] In the above embodiment, the melt can also extend to the series break with the conductive plate 400, see Figure 3, the melt 401 is connected in parallel to the weak break 404 formed by a break in the conductive plate through the connecting wire 402 and the connecting wire 403, and is connected in series to the weak break 405 formed by the break in the conductive plate. A part of the current on the connecting wire 403 is in the opposite direction or perpendicular to the current direction of the conductive plate at the series break position. According to the electromagnetic field theory, the magnetic force generated at the series break can stretch and move the arc generated at the series break to extinguish the arc. According to the theory of magnetic field generated by current, the setting relationship of each break position between the melt and the conductive plate needs to satisfy that the generated Lorentz magnetic force can stretch the arc at the break and move the arc when the break is formed, thereby cooling the arc and improving the arc extinguishing ability of the series break.

[0045] In the above embodiment, several conductive plates can also be arranged in parallel in the housing, and both ends of the conductive plates are respectively connected to the external circuit through conductive terminals. When multiple conductive plates are connected in parallel, since it can play a current shunting role, the parallel conductive plates can broaden the breaking current range.

[0046] The working principle of the present invention: Take Figure 1 as an example for illustration.

[0047] When there is no fault current, but the circuit needs to be disconnected under certain specific conditions, a condition can be preset in the external control system to send an excitation signal to the excitation device. At this time, the excitation device receives the excitation signal and acts, detonating to release high-pressure gas, driving the breaking device to disconnect the conductive plate successively. At this time, since the current flowing through the arc extinguishing melt is not enough to fuse the arc extinguishing melt, the circuit is disconnected through the breaking device;

[0048] When a fault current occurs, but the fault current is small, when the excitation device receives an excitation signal from the outside, the excitation device is detonated to release high-pressure gas, driving the breaking device to impact the limiting mechanism downward to impact the conductive plate; since there are multiple impact heads and the distances from the conductive plate are different, when impacting the conductive plate, the impact head 105 closest to the conductive plate first disconnects the weak break of its corresponding conductive plate, that is, first disconnects the position of the weak break 108. At this time, the fault current is not enough to fuse the melt. Since the fault current is small, the arc generated at the break at the weak break 108 is small and can be extinguished by air; after the weak break 108 is disconnected, the breaking device continues to move downward, and the impact head 106 with a higher height on it impacts the conductive plate to disconnect its corresponding weak break 107, causing the conductive plate to be disconnected for the second time, forming two breaks in series with the melt in the conductive plate to completely disconnect the circuit. Due to the discharge of the overcurrent at the break in parallel with the melt, the current at the break in series with the melt has become smaller, and the generated arc has become very small and can be extinguished by air.

[0049] When a fault current occurs and the fault current is relatively large, when the excitation device receives an external excitation signal, the ignition and detonation excitation device is activated, causing the excitation device to release high-pressure gas, driving the interruption device to break through the limit mechanism and displace downward to impact the conductive plate; the conductive plate first breaks at the weak break point 108. At the moment of break, most of the current flows through the melt in parallel. Therefore, the arc at the break of the weak break point 108 in parallel with the melt is very small and can be easily extinguished by air; the melt melts at the weak melting point in the arc extinguishing medium, and the generated arc is extinguished through the arc extinguishing medium; at the same time, as the interruption device continues to displace, the conductive plate breaks at the weak break point 107, generating the second and third break points in series with the melt. Due to the voltage division of the melt, the arcs at the second and third break points are also very small due to voltage division and can be well extinguished by air.

[0050] When a fault current occurs and the fault current is very large, the melt first melts, and the generated large arc is extinguished in the arc extinguishing medium; at the same time, the weak break point 108 in parallel with the melt breaks to form a break. Due to the partial discharge of the overcurrent energy at the melt break, the arc generated at the break in parallel with it is not sufficient to damage the break and can be extinguished by air. Then, as the interruption device continues to displace, the second and third break points are formed on the conductive plate, and the arcs generated by voltage division become smaller and are more easily extinguished.

[0051] Figure 1 Among them, when the several impact heads of the interruption device are flush, several break points can be formed simultaneously; when there is no fault current or the fault current is relatively small, the parallel melt does not melt, and the multiple break points can reduce the arc and ensure arc extinguishing through air; when the fault current is relatively large, while the multiple break points are generated, the parallel melt also melts, and the arc extinguishing medium participates in arc extinguishing, which can quickly extinguish the arc and improve the arc extinguishing ability; when the fault current is very large, the parallel melt melts, the arc extinguishing medium participates in arc extinguishing, and after the multiple break points, the current is completely disconnected for arc extinguishing.

[0052] Similarly, Figure 2 The working principle of Figure 1 is almost the same as that of

[0053] The only difference is that the excitation devices can act simultaneously, or can act or not act according to the order of the excitation signals received by each of them. For example, when there is no fault current, the excitation device in the chamber without a parallel melt can be given an excitation signal to make the excitation device act, driving the interruption device to break the conductive plate to achieve circuit disconnection protection; while the excitation device and the interruption device at the conductive plate with a parallel melt do not act. When multiple break points need to be disconnected successively, the excitation device that needs to be disconnected first can be given an excitation signal, and then the excitation signal for the later-disconnected excitation device can be delayed to achieve the purpose of successive disconnection.As can be seen from the above, the fuse of the present invention can be actuated by different actuating devices according to the order of receiving actuation signals, driving the interrupting device to successively form break points on the conductive plate; or by the different heights of the impact heads of the interrupting device, causing several successively delayed break points on the conductive plate to achieve multiple arc extinguishments, improving the arc extinguishing ability; at the same time, broadening the breaking current range, achieving breaking in the full current range, and improving the breaking ability; and the break points that are delayed in disconnection can ensure the physical disconnection of the conductive plate, improving the reliability of the fuse and making the performance of the fuse more excellent.

Claims

1. A mechanical interruption and fusing combined multi-break excitation fuse, characterized in that It includes a housing with a cavity formed therein. At least one conductor passes through the housing and through the cavity. At least one excitation device and one interruption device are arranged in the cavity of the housing. The excitation device can receive an external excitation signal to drive the interruption device to act, disconnect the corresponding conductor and form at least two breaks on the conductor. At least one fuse is arranged in parallel on the conductor. The fuse is in parallel with at least one of the breaks and in series with at least one of the breaks. The break in parallel with the fuse disconnects first, and the break in series with the fuse disconnects later.

2. The mechanical interruption and fusing combined multi-break excitation fuse according to claim 1, characterized in that An arc extinguishing chamber filled with an arc extinguishing medium is arranged in the housing. Part or all of the fuse passes through the arc extinguishing chamber, and the fusing break of the fuse is located in the arc extinguishing chamber.

3. The mechanical interruption and fusing combined multi-break excitation fuse according to any one of claims 1 or 2, characterized in that At least two adjacent cavities are formed in the housing, and the conductor passes through the housing and through the adjacent cavities. An excitation device and an interruption device are arranged in each cavity on one side of the conductor. The excitation devices and interruption devices in different cavities are located on the same side or different sides of the conductor. At least one impact head is arranged on the interruption device. The excitation device can receive an external excitation signal to drive the corresponding interruption device to interrupt the conductor and form at least one break.

4. The mechanical interruption and fusing combined multi-break excitation fuse according to any one of claims 1 or 2, characterized in that At least two impact heads are arranged at intervals on the interruption device, and each impact head forms at least one break on the conductor.

5. The mechanical interruption and fusing combined multi-break excitation fuse according to claim 4, characterized in that The distances between the impact heads and the conductor are different. The impact head closest to the conductor forms the break on the conductor first. The fuse is connected in parallel at the break that disconnects first.

6. The mechanical interruption and fusing combined multi-break excitation fuse according to claim 1, characterized in that The excitation device is a gas generating device. The interruption device is a piston, and the contact surface between the interruption device and the cavity is in sealed contact or has a gap contact less than 0.1 mm.

7. The mechanical interruption and fusing combined multi-break excitation fuse according to claim 1, characterized in that A limiting structure for maintaining the initial position of the interruption device is arranged between the interruption device and the cavity.

8. The mechanical interruption and fusing combined multi-break excitation fuse according to claim 1, characterized in that A break-weakening portion for reducing the strength of the conductor is arranged on the conductor corresponding to the interruption device, and the break is formed at the break-weakening portion.

9. The mechanical interruption and fusing combination multi-break excitation fuse according to claim 8, characterized in that The break-weakening portion is a reduced cross-section structure opened on the conductor, a structure for increasing the stress at the break of the conductor, and / or a material with low mechanical strength is used at the break of the conductor.

10. The mechanical interruption and fusing combined multi-break excitation fuse according to claim 9, characterized in that The reduced cross-section structure is one or a combination of structures such as opening a notch on one or both sides of the conductor, opening a U-shaped groove, a V-shaped groove across its width on one or both sides of the conductor, and opening a hole on the conductor.

11. The mechanical interruption and fusing combined multi-break excitation fuse according to any one of claims 1 or 2, characterized in that A fusing-weakening portion is arranged on the fuse, and the fuse fuses at the fusing-weakening portion.

12. The mechanical interruption and fusing combined multi-break excitation fuse according to claim 11, characterized in that The weakening portion of the fuse is a variable cross-section structure opened on the fuse, a narrow diameter, and / or a low-temperature melting conductor arranged on the fuse, and / or conductor materials with different conductivities are applied.

13. The mechanical interruption and fusing combined multi-break excitation fuse according to claim 1, characterized in that The fuse extends around at least one series break and then is connected to the parallel break, forming an arc path that interacts with the electromagnetic field of the conductor to elongate the break of the conductor after the break is formed.

14. The mechanical interruption and fusing combination multi-break excitation fuse according to claim 3, characterized in that The impact end of the impact head is a contracted surface structure, a pointed structure, an inclined surface structure, or a structure with concave tips on both sides.

15. The mechanical interruption and fusing combined multi-break excitation fuse according to claim 4, characterized in that The impact end of the impact head is a contracted surface structure, a pointed structure, an inclined surface structure, or a structure with concave tips on both sides.

16. Application of the mechanical interruption and fusing combined multi-break excitation fuse according to any one of the above claims in a power distribution power supply, an energy storage device, an electrical equipment and / or a vehicle.

Images