A protection device for energizing a stage access melt

Abstract

The invention discloses a kind of stage access melt's excitation protection device, including shell, conductor, excitation source and impact device;Conductive part is provided on the impact device, and one end of conductive part extends the end face of impact device impact end, and in initial position, conductive part is not contacted with conductor;Melt is set in arc-extinguishing chamber in shell or impact device, and melt two ends are respectively connected with conductive part or through conductive contact piece with conductive part electrically;When impact device is displaced and is disconnected conductor to reach dead point position in the process of forming fracture under the excitation of excitation source, the relationship between conductive part and melt and conductor is in turn: not connected, parallel connection, series connection with the fracture side of conductor, and is separated from electrically connected.The excitation protection device of the invention can realize small current and zero current breaking;It can realize fast protection;Post-breakdown insulation performance is excellent;Breaking capacity is high, arc-extinguishing capacity is strong;Current impact resistance is good, and heat output is small.

Description

Technical Field

[0001] This invention relates to the fields of power and new energy vehicles, and in particular to protection devices for circuits in these fields. Background Technology

[0002] Currently, in addition to traditional thermal fuses, battery pack protection devices for electric power control and new energy vehicles also include a fast-cutting structure (i.e., an excitation protection device), which is gradually expanding its application. A fuse is a protective device that utilizes the thermal accumulation effect of current to melt and extinguish the arc at a current sensing point (neck) on the fusible element within a certain time. An excitation protection device is a fast-cutting protection device that uses an excitation source to drive an insulating impact device to disconnect the conductor connected to the circuit, forming a physical break and thus disconnecting the circuit.

[0003] The advantages of excitation protection devices are rapid protection through quick-cutting openings, good resistance to current surges, low heat generation, and complete physical isolation after disconnection. The disadvantages are a limited breaking capacity due to the cutting opening alone and weak arc-extinguishing capability (relying on air cooling or compression for arc extinguishing). The advantages of fuses are maturity and stability, high breaking capacity, and strong arc-extinguishing capability. The disadvantages are: poor resistance to current surges; relatively high heat generation; long circuit disconnection time under low fault currents, failing to achieve rapid protection; incomplete physical isolation after fuse melting; and larger size and weight.

[0004] Considering the advantages and disadvantages of both excitation protection devices and fuses, a further solution has emerged: fixing and connecting a fusible element in parallel to the conductor of the aforementioned excitation protection device to improve arc extinguishing and breaking capacity. This involves an excitation protection device that relies on the melting of the fusible element to extinguish the arc after the conductor is broken. This solution can significantly increase the breaking capacity of the excitation protection device and avoid some of the inherent drawbacks of fuses. However, because relying on the melting of the fusible element cannot achieve breaking under low current and zero current conditions; and at the lower limit of the breaking current range, the melting of the fusible element takes a relatively long time, failing to achieve rapid protection, and the insulation performance after breaking is poor. Due to these drawbacks, the application range of excitation protection devices with a fusible element fixed and connected in parallel to the conductor is limited. Summary of the Invention

[0005] The purpose of this invention is to provide an excitation protection device in which, in the initial state, the melt and the conductor are not connected in parallel, and the melt cannot connect to the circuit. Only through the movement of the impact device, the melt is connected in parallel to the conductor before the conductor is disconnected after the impact device moves, so that the circuit can be connected by the melt after the conductor is disconnected. After the impact device moves to its position, the melt and the conductor lose their conductive contact, and the circuit is disconnected.

[0006] To achieve the above technical objectives, the present invention provides a staged excitation and protection device for molten metal, comprising a housing, a conductor passing through the housing, an excitation source and an impact device located within the housing, with both ends of the conductor located outside the housing. The excitation source receives an excitation signal and drives the impact device to disconnect the conductor. A conductive element is provided on the impact device, with one end of the conductive element extending beyond the impact end face of the impact device. In the initial position, the conductive element is not in contact with the conductor. The molten metal passes through the arc-extinguishing chamber within the housing or the impact device, with both ends of the molten metal electrically connected to the conductive element or electrically connected to the conductive element through conductive contacts. During the process of the impact device displacing under the excitation of the excitation source and disconnecting the conductor to form a fracture and reach the dead point position, the relationships between the conductive element and the molten metal and the conductor are sequentially: not connected, connected in parallel, connected in series with both sides of the conductor fracture, and disconnected from the conductive connection.

[0007] Preferably, each end of the melt is electrically connected to a conductive contact, and the conductive contact passes through the arc-extinguishing chamber and is located outside the arc-extinguishing chamber; at least one of the conductive contacts is in conductive contact with the conductive element. During the process of the impact device displacing under the excitation of the excitation source and breaking the conductor to form a fracture and reaching the dead point position, the conductive element and the conductive contact remain in conductive contact until the conductor breaks and then the conductive contact is released.

[0008] Preferably, a conductive element is provided on the side of the impact end of the impact device, wherein one of the conductive contacts is in conductive contact with the conductive element, and the other conductive contact is in conductive connection with a conductor.

[0009] Preferably, two mutually insulated conductive elements are provided on opposite sides of the impact end of the impact device, and the two conductive contacts are in conductive contact with one of the conductive elements respectively.

[0010] Preferably, the portion of the conductive element extending beyond the impact end face of the impact device is a spring sheet structure.

[0011] Preferably, the end of the conductive contact that contacts the conductive element has an elastic structure.

[0012] Preferably, when the arc-extinguishing chamber is located inside the impact device, through holes are provided on both sides of the impact end of the impact device, near the side position, and the conductive element passes through the through holes and is connected to both ends of the melt.

[0013] Preferably, the impact device has a mating insulating structure at the outer surface of the through hole through which the two conductive components pass and at the corresponding bottom position of the housing cavity.

[0014] Preferably, the insulating structure includes mutually nested and sealed grooves and protrusions, the grooves or protrusions being respectively disposed on the outer side of the through hole through which the two conductive components pass in the impact device, and at the corresponding position at the bottom of the housing cavity.

[0015] Preferably, the arc-extinguishing chamber is located on the housing on one side of the dead point position of the impact device displacement.

[0016] Preferably, the impact end of the impact device has an inverted trapezoidal structure, a conical structure, or a blade-like structure.

[0017] Preferably, the upper part of the impact device is in sealed contact with the cavity inside the housing, and a guide device is provided in the cavity inside the housing to provide displacement guidance for the impact device.

[0018] Preferably, when the arc-extinguishing chamber is in the impact device, the melt passing through the arc-extinguishing chamber is integrally connected to the conductive element.

[0019] Preferably, several arc-extinguishing grids are provided at the housing at the dead point position of the displacement of the impact device.

[0020] Preferably, the end face shape formed by the arc-extinguishing grids matches the impact end face shape of the impact device.

[0021] The excitation protection device of the present invention can achieve interruption under small current and zero current conditions; it can achieve rapid protection; it has excellent insulation performance after interruption; it has high breaking capacity and strong arc extinguishing ability; it has good resistance to current impulse and low heat generation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure in the initial position of Example 1.

[0023] Figure 2 This is a schematic diagram of the structure of Example 1 before the melt and conductor are in conductive contact and the conductor is disconnected.

[0024] Figure 3 This is a schematic diagram of the structure in Example 1 where the impact device moves to the dead position and both the conductor and the melt break.

[0025] Figure 4 This is a schematic diagram of the structure in the initial position of Example 2.

[0026] Figure 5 This is a schematic diagram of the structure of Example 2 before the melt and conductor are in conductive contact and the conductor is disconnected.

[0027] Figure 6 This is a schematic diagram of the structure in Example 2 where the impact device moves to the dead point position and both the conductor and the melt break.

[0028] Figure 7 This is a schematic diagram of the structure in the initial position of Example 3.

[0029] Figure 8 This is a schematic diagram of the structure of Example 3 before the melt and conductor are in conductive contact and the conductor is disconnected.

[0030] Figure 9 This is a schematic diagram of the structure in Example 3 where the impact device moves to the dead point position and both the conductor and the melt break.

[0031] Figure 10 Figure 4 is a schematic diagram of the structure, where Figure a is a schematic diagram of the structure with an arc-extinguishing grid and Figure b is a schematic diagram of the structure after the action. Detailed Implementation

[0032] Regarding the above technical solutions, several preferred embodiments are given below and described in detail with reference to the figures.

[0033] Example 1

[0034] The casing is made of insulating material and can be molded using methods such as injection molding. (See attached image) Figures 1 to 3 The device includes a first housing 10 and a second housing 11. A conductor 3 is located between the first housing 10 and the second housing 11. The contact surfaces of the first housing 10 and the second housing 11 are sealed. This sealing can be achieved by setting nested grooves and protrusions or sealing rings on the contact surfaces. This contact surface sealing prevents foreign objects from contaminating the break point and also prevents high-temperature arcs from damaging surrounding components. It also extends the sealing length of the impact device within the cavity. The first housing 10 and the second housing 11 have interconnected cavities. The conductor, a long strip-shaped structure, passes through these cavities. Both ends of the conductor are located outside the housing and can be connected to external circuits for circuit protection. A break weak point and a rotation weak point are formed on the conductor located within the housing cavity. The impact end of the impact device 2 corresponds to the break weak point. The break weak point is a structure that reduces the mechanical strength of the conductor, such as a variable cross-section structure, for example, notches on both sides of the conductor, grooves on the conductor, or through holes at intervals. The rotation weak point has grooves on the conductor, and its mechanical strength is higher than that of the break weak point.

[0035] Excitation source 1 is located in the upper part of the cavity of the first housing 10. The excitation source can be integrally formed into the first housing 10 by injection molding, or the upper part of the cavity of the first housing can be set as a stepped hole structure, and the excitation source can be set at the stepped hole and fixed in the stepped hole structure by a pressure cap or pressure sleeve. Excitation source 1 is a gas generating device that can release high-pressure gas according to the received excitation signal to drive the displacement action of the impact device.

[0036] An impact device 2 is disposed in the first housing cavity below the excitation source 1. The impact device 2 is made of insulating material and has an approximate T-shaped structure. The upper part of the impact device is in sealed contact with the cavity it is in. This sealed contact can be achieved through an interference fit or by placing a sealing device, such as a sealing ring, between the impact device and the cavity. The impact end has a contraction surface structure. Figures 1 to 3 It resembles an inverted trapezoidal structure, but it can also be a conical or blade-shaped structure.

[0037] A limiting structure is installed between the impact device and the cavity it is in to restrict the initial position of the impact device. The impact device can only overcome the limiting structure and move out of displacement when it is driven by high-pressure gas from the excitation source.

[0038] The conductive element 21, a conductive sheet structure, is fixedly mounted on opposite sides of the impact end of the impact device. It can be fixed to the impact device using methods such as injection molding, snap-fit ​​connection, bolt connection, or riveting. The end of the conductive element 21 closest to the conductor extends beyond the impact end face of the impact device. This end of the conductive element is a spring-loaded structure 21a, flared outwards from the impact end face. The ends of the two conductive elements extending beyond the impact end face are located on either side of the weak point where the conductor is broken. When the impact device is in its initial position, there is a certain distance between the ends of the conductive elements extending beyond the impact end face and the conductor. An upward-sloping chamfered structure is provided on the side of the impact device above the other end of the conductive element. Sufficient insulation distance is maintained between the end of the conductive element furthest from the conductor and the excitation source above the impact device.

[0039] A vertical guide groove is provided on the cavity wall through which the first housing and the second housing pass. On the outer peripheral surface of the impact device in sealed contact with the cavity, a protrusion is provided at the position of the guide groove, which slides in the guide groove. The guide groove and the protrusion form a guide device to guide the impact device.

[0040] The second housing 11 has an independent arc-extinguishing chamber 11a located below the cavity of the second housing, and filled with an arc-extinguishing medium. The arc-extinguishing chamber can be formed by setting a sealing cover plate on the second housing, or it can be formed by setting an independent arc-extinguishing chamber structure placed inside the second housing.

[0041] The melt 4 passes through the arc-extinguishing chamber 11a and is surrounded by the arc-extinguishing medium. A narrow neck is provided on the melt 4. Both ends of the melt 4 are electrically connected to one end of each of the two conductive contacts 5 passing through the arc-extinguishing chamber. The other end of the conductive contact 5 passes through the arc-extinguishing chamber, the second housing, and the first housing, entering the cavity of the first housing. The conductive contact end 50 of the conductive contact 5 makes conductive contact with the conductive element 21 located on the side of the impact end of the impact device, above the spring sheet structure 21a. The conductive contact end 50 is an elastic sheet structure, bent in the cavity of the first housing before contacting the conductive element 21, increasing the contact area. When the conductive contact end 50 contacts the conductive element, it is in a compressed state to ensure tight contact. Within the housing, the conductive contact element has a three-dimensional geometric shape and is offset from the conductor, not in contact with it.

[0042] The workflow and principle of this embodiment are as follows: The excitation source activates upon receiving the excitation signal, releasing high-pressure gas to drive the impact device to overcome the limiting structure and move along the guide groove. During this displacement, the spring-loaded structure 21a at the end of the conductive element extending from the impact end face of the impact device first makes conductive contact with the conductors on both sides of the weak point of the break. Since the conductive contact is still in conductive contact with the conductive element at this time, the melt in the arc-extinguishing chamber is connected in parallel with the conductor. As the impact device continues to move, it breaks the conductor at the weak point, forming a break in the conductor. At this time, the melt is still in conductive contact with the conductor portions on both sides of the conductor break. Simultaneously, as the impact device continues to move, the spring-loaded structure at the end of the conductive element extending from the impact end of the impact device bends under the resistance of the conductor. The conductive element on the impact device disengages from the conductive contact, thereby separating the melt from the conductor portions on both sides of the conductor break. This continues until the bottom dead point of the impact device's moving cavity is reached. By breaking the conductor and separating the melt from the conductive connection, the circuit is cut off, achieving circuit protection. Regardless of whether the melt melts or not, the current is ultimately cut off and the circuit is disconnected. When the current is small, the molten element does not melt and the current is cut off and the circuit is broken by the separation of the conductor and the molten element from the conductive contact. When the current is large, the molten element melts quickly and the circuit is broken. Then, the good insulation performance after the break is ensured by the separation of the conductor and the molten element from the conductive contact.

[0043] Example 2

[0044] The difference between this embodiment and Embodiment 1 is that a conductive element 21 is provided on the side of the impact end of the impact device, see [reference]. Figures 4 to 6 One of the conductive contacts 5 is in conductive contact with the conductive component, and the other conductive contact 51 passes through the arc-extinguishing chamber and the second housing and is conductively connected to the conductor.

[0045] The impact end face of the impact device has a blade structure, with a break weak point and a rotation weak point on the conductor. A conductive contact that is electrically connected to the conductor is located on one side of the conductor break weak point, and the end of the conductive contact that is electrically connected to the other conductive contact extends out of the impact end face and is located on the other side of the conductor break weak point. This ensures that after the impact device is activated, both sides of the conductor break weak point are connected to the melt through one conductive contact, one conductive contact, and another conductive contact, respectively.

[0046] A groove is provided at the bottom of the second housing cavity at the position corresponding to the impact end face of the impact device, and the shape of the groove matches the shape of the impact end face of the impact device.

[0047] The workflow and principle of Example 2 are the same as those of Example 1.

[0048] Example 3

[0049] The biggest difference from Example 1 is that the arc-extinguishing chamber is located on the impact device. See also Figures 7 to 9 The impact device 6 has a constricted end face, similar to an inverted trapezoid in this embodiment. The part of the impact device located above the end face is in sealed contact with the cavity it contains. An arc-extinguishing chamber 60 is provided in the impact device 6 above the end face. The arc-extinguishing chamber 60 can be achieved by opening a cavity in the impact device and then sealing it with a sealing cover. The molten material 40 passes through the arc-extinguishing chamber 60. After the two ends of the molten material pass through the arc-extinguishing chamber 60 and the through holes on the end face of the impact device that communicate with the arc-extinguishing chamber, it extends out of the end face of the impact device and then bends to both sides of the impact end in a trumpet shape. In the initial position, the trumpet-shaped end of the molten material is kept at a certain distance from the conductor. The purpose is to ensure that the end of the molten material extending from the end face of the impact device makes sufficient contact with the conductor during the movement of the impact device. In this embodiment, the molten material structure extending out of the arc-extinguishing chamber replaces the conductive element, that is, the conductive element and the molten material are an integral structure. The molten material part located in the arc-extinguishing chamber is provided with a weak point for melting.

[0050] Grooves 61 are provided on both ends of the impact end, and the grooves 61 are located on the outer side of the end of the melt that extends out of the impact end. Corresponding protrusions 12a are provided at the bottom of the cavity of the second housing 12 at the position corresponding to the grooves 61.

[0051] The working principle of this embodiment is as follows: The excitation source receives an excitation signal and releases high-pressure gas, driving the impact device to operate. The two ends of the molten material first contact the conductor, achieving parallel connection between the molten material and the conductor. The impact device continues to move, breaking the conductor and forming a break. The two ends of the molten material are located on either side of the conductor break, connecting the circuit. The impact device continues to move to the dead point position, and the two ends of the molten material lose contact with the conductor. The impact end of the impact device is interference-fitted with the groove at the bottom of the second housing. By squeezing the electric arc generated when the molten material separates from the conductor, it elongates, cools, and extinguishes the arc, breaking the circuit. Under the drive of the impact device, the two ends of the molten material bend and fit between the impact device and the bottom of the cavity of the second housing. Simultaneously, the groove of the impact device and the protrusion at the bottom of the second housing form an insulating barrier, squeezing the electric arc while improving the insulation performance after the break. Regardless of whether the molten material melts or not, the current is ultimately cut off and the circuit is broken. When the current is small, the molten material does not melt; the current is cut off and the circuit is broken directly by the separation of the conductor and the molten material. When the current is large, the molten material melts rapidly, at which point the circuit is broken, and the good insulation performance after the break is ensured by the separation of the conductor and the molten material.

[0052] Example 4

[0053] Based on the structure of Embodiment 3, several arc-extinguishing grids 12b are provided at the bottom of the cavity of the second housing 12. The shape of the arrangement of the arc-extinguishing grids matches the shape of the impact end face of the impact device. (See Figure 3) Figure 10 After the impact device reaches the dead point, the impact end face of the impact device approaches the arc-extinguishing grid with a small gap. When the melt separates from the conductor, the electric arc generated enters the arc-extinguishing grid in segments, is stretched and cooled, and is quickly extinguished. The arc-extinguishing grid improves the arc-extinguishing capability.

Claims

1. A staged excitation and protection device for molten metal, comprising a housing, a conductor passing through the housing, an excitation source and an impact device located within the housing, wherein both ends of the conductor are located outside the housing, and the excitation source receives an excitation signal and drives the impact device to disconnect the conductor; characterized in that, A conductive element is provided on the impact device, with one end of the conductive element extending out of the impact end face of the impact device. In the initial position, the conductive element is not in contact with the conductor. The molten material passes through the shell or the arc-extinguishing chamber in the impact device, and both ends of the molten material are electrically connected to the conductive element or electrically connected to the conductive element through conductive contacts. During the process of the impact device displacing under the excitation of the excitation source and breaking the conductor to form a fracture and reaching the dead point position, the relationship between the conductive element, the molten material, and the conductor is as follows: at least one end of the conductive element and the molten material after being electrically connected is not connected to the conductor; the conductor is connected in parallel with the conductive element and the molten material; both sides of the conductor fracture are connected in series with the conductive element and the molten material; at least one end of the conductive element and the molten material is disconnected from the conductor; or, the molten material is disconnected from the conductive element, and at least one end of the molten material is not connected to the conductor; or, the conductive element, the molten material, and the conductor are disconnected from each other.

2. The excitation protection device according to claim 1, characterized in that, The melt is electrically connected to a conductive contact at each end, and the conductive contact passes through the arc-extinguishing chamber and is located outside the arc-extinguishing chamber; at least one of the conductive contacts is in conductive contact with the conductive element. During the process of the impact device displacing under the excitation of the excitation source and breaking the conductor to form a fracture and reaching the dead point position, the conductive element and the conductive contact remain in conductive contact until the conductor breaks and then the conductive contact is released.

3. The excitation protection device according to claim 2, characterized in that, A conductive element is provided on the side of the impact end of the impact device, one of the conductive contacts being in conductive contact with the conductive element, and the other conductive contact being in conductive connection with a conductor.

4. The excitation protection device according to claim 2, characterized in that, Two mutually insulated conductive elements are provided on opposite sides of the impact end of the impact device, and the two conductive contacts are in conductive contact with one of the conductive elements respectively.

5. The excitation protection device according to claim 1, characterized in that, The portion of the conductive element extending beyond the impact end face of the impact device is a spring-loaded structure.

6. The excitation protection device according to claim 2, characterized in that, The end of the conductive contact that contacts the conductive element has an elastic structure.

7. The excitation protection device according to claim 1, characterized in that, When the arc-extinguishing chamber is located inside the impact device, through holes are provided on both sides of the impact end of the impact device, near the side position, and the conductive element passes through the through holes and is connected to both ends of the melt.

8. The excitation protection device according to claim 7, characterized in that, The impact device has a mating insulating structure at the outer side of the through hole through which the two conductive components pass and at the corresponding bottom position of the housing cavity.

9. The excitation protection device according to claim 8, characterized in that, The insulating structure includes mutually nested and sealed grooves and protrusions. The grooves or protrusions are respectively disposed on the outer side of the through hole through which the two conductive components pass in the impact device, and at the corresponding position at the bottom of the shell cavity.

10. The excitation protection device according to claim 1, characterized in that, The arc-extinguishing chamber is located on the housing on one side of the dead point position of the impact device displacement.

11. The excitation protection device according to claim 1, characterized in that, The impact end of the impact device has an inverted trapezoidal structure, a conical structure, or a blade-like structure.

12. The excitation protection device according to claim 1, characterized in that, The upper part of the impact device is in sealed contact with the cavity inside the housing, and a guide device is provided in the cavity inside the housing to provide displacement guidance for the impact device.

13. The excitation protection device according to claim 1, characterized in that, When the arc-extinguishing chamber is the impact device, the melt passing through the arc-extinguishing chamber is integrally connected with the conductive element.

14. The excitation protection device according to any one of claims 1 to 13, characterized in that, Several arc-extinguishing grids are provided on the housing at the dead point of the displacement of the impact device.

15. The excitation protection device according to claim 14, characterized in that, The end face shape formed by the arc-extinguishing grids matches the impact end face shape of the impact device.

Images