Switching electrical equipment equipped with pyrotechnic excitation device

Abstract

The present invention provides a switching device equipped with a pyrotechnic excitation device. [Solution] The switching electrical device includes a switching electrical device body and a pyrotechnic excitation device. The switching electrical device body includes a fixed contact portion and a movable contact portion. The pyrotechnic excitation device has an independent modular structure and is fixedly attached to the switching electrical device body from the outside. Depending on the load condition of the switching electrical device body, it ignites a gunpowder to generate an explosive shock force that pushes the movable contact portion away from the fixed contact portion, thereby assisting in the rapid shutdown of the switching electrical device.

Description

Technical Field

[0001] The present invention claims the priority of Chinese patent applications with application numbers 202111682514.6, 202123431365.4, 202111658928.5, 202111658910.5, and 202111663554.6, filed on December 30, 2021, and incorporates the entire disclosure of the Chinese patent applications herein by reference.

[0002] The present invention relates to the field of switching electrical appliances, and particularly to a switching electrical appliance equipped with a pyrotechnic excitation device.

Background Art

[0003] Relays are widely used in remote control, telemetry, communications, automatic control, mechatronics, and power electronic devices, and are core components that control the state of switches in electrical circuits. With the continuous development and changes in electrical technology, the demands on the load of main circuits are increasing, and at the same time, the demands on the short-circuit resistance of relays are also increasing. In recent years, some manufacturers have proposed main circuit short-circuit resistance capacities of 20KA, and even 30KA. At such high short-circuit currents, the greatest possible short-circuit electric repulsion force appears between the relay contacts, repelling the movable contact and separating it from the fixed contact. In order to resist this short-circuit electric repulsion force and maintain the closed state between the movable and fixed contacts, it is necessary to increase the pressure of the contact spring or the closing magnetic attraction force of the movable contact (i.e., the magnetic attraction force that drives the movable contact to close by the electromagnetic drive mechanism) to resist this electric repulsion force. However, if the pressure of the contact spring or the magnetic attraction force of the movable contact becomes too large, it can affect the normal disconnection operation of the movable contact, and if the short-circuit current increases further, the circuit safety cannot be guaranteed if the disconnection is not fast enough. For this reason, some conventional technologies use a pyrotechnic actuator to assist in the rapid disconnection of the relay. When the system monitors that the short-circuit current has reached a threshold, it triggers the actuator to detonate explosives, and the explosive force of the explosives rapidly disconnects the movable contact, thereby providing protection to the circuit.

[0004] Conventional pyrotechnic excitation devices are typically integrated inside a relay, resulting in a large number of relay components, complex manufacturing and assembly processes, and high costs. Conventional pyrotechnic excitation devices are not replaceable; if the load current changes, the pyrotechnic excitation device cannot be replaced individually, and the entire relay must be replaced with one of a different specification, which is inconvenient. [Overview of the project]

[0005] The present invention provides a switching electric device equipped with a pyrotechnic excitation device with an optimized structure.

[0006] This invention provides the following technical solution.

[0007] The present invention provides a switching electrical device equipped with a pyrotechnic excitation device, the switching electrical device comprising a switching electrical device body and a pyrotechnic excitation device provided on the switching electrical device body, the switching electrical device body comprising a fixed contact portion and a movable contact portion for performing a switching function, the pyrotechnic excitation device having an independent modular structure, the pyrotechnic excitation device as an independent module fixedly attached to the switching electrical device body from the outside of the switching electrical device body, and can assist in the rapid shutdown of the switching electrical device by igniting explosives in accordance with the load condition of the switching electrical device body and generating an explosive impact force that pushes the movable contact portion away from the fixed contact portion.

[0008] In one embodiment, the switching device body includes a case body, the movable contact portion is provided inside the case body, and one end of the pyrotechnic excitation device enters the case body so as to be positioned directly facing one side of the movable contact portion.

[0009] Herein, from the standpoint of manufacturing and installation, in one embodiment, the pyrotechnic excitation device includes an exciter, a piston, and a bottom case, the exciter and the bottom case are joined and fixed to each other, the bottom case has a hollow structure, the piston is fitted and installed inside the bottom case, the bottom case enters the interior of the case body and faces the movable contact portion, and when the pyrotechnic excitation device is excited, the exciter ignites the gunpowder and pushes the piston with the fuel gas to break through the bottom case, the piston moves toward the movable contact portion by the guiding action of the bottom case, thereby pushing the movable contact portion away from the fixed contact portion.

[0010] In this embodiment, the bottom case has a structure that gradually contracts in the direction toward the movable contact portion, in order to concentrate the impact force when the pyrotechnic excitation device is detonated at the lower end of the bottom case and improve the piston's ability to break through the bottom case.

[0011] In this embodiment, the piston has a structure that gradually contracts in the direction toward the movable contact portion in order to break through the bottom case more quickly and rapidly advance the blocking of the movable contact.

[0012] In this embodiment, in order to improve the arc extinguishing capability of the switching device, an arc extinguishing medium is further stored in the piston or bottom case, and after the piston breaks through the bottom case, the arc extinguishing medium is released by the rupture of the piston or bottom case, thereby extinguishing the arc between the fixed contact part and the movable contact part.

[0013] Herein, from the viewpoint of manufacturing and installation, in one embodiment, the exciter includes a hollow exciter base, a first flange (burr) is provided at one end of the exciter base, and a second flange is provided at one end of the bottom case, and the exciter and the bottom case are joined and fixed together by the first flange and the second flange being fixed together with each other.

[0014] Herein, from the viewpoint of manufacturing and installation, in one embodiment, the second flange and the case body are fixed by welding, and the second flange is provided with annular ribs to enhance the stability of the welding.

[0015] Herein, from the viewpoint of manufacturing and installation, in one embodiment, the exciter further includes a connector fixedly mounted inside the exciter base, an igniter, and a seal ring, wherein the connector is fixed by engaging with the inner wall of the exciter base, the seal ring is press-fitted into the exciter base by interference fit, one end of the seal ring presses the igniter toward the connector, and the other end presses the piston toward the bottom case.

[0016] In order to improve electrical performance, in one embodiment, the switching electrical device body further includes a ceramic cover that covers the inside of the case body and covers the fixed contact portion, the movable contact portion, and the contact portion between the fixed contact portion and the movable contact portion, the ceramic cover is provided with an insertion hole, and one end of the pyrotechnic excitation device is fixed to the ceramic cover by welding through the insertion hole and sealing the insertion hole.

[0017] In this embodiment, in order to allow for rapid replacement of the pyrotechnic excitation device according to the load needs, the pyrotechnic excitation device is detachably and fixedly connected to the switching electrical unit.

[0018] In this embodiment, the switching device is a DC high-voltage relay.

[0019] The present invention offers the following beneficial effects. In this invention, the pyrotechnic excitation device has a modular structure, is independent of the relay body, and can be manufactured independently and then permanently attached to the relay. The manufacturing and transportation of the pyrotechnic excitation device are easy to manage, it has fewer parts, is easy to assemble, and it is easier to achieve standardization of parts, thus achieving the objectives of reducing weight, lowering costs, and improving performance. [Brief explanation of the drawing]

[0020] Exemplary embodiments will be described in detail with reference to the drawings, and the above content, other features and advantages of the present invention will become clearer. [Figure 1] It is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 1 (the relay is in the off state). [Figure 2] It is a schematic diagram in which the pyrotechnic excitation device in Example 1 is inserted into a ceramic cover and fixedly connected. [Figure 3] It is an exploded view of the structure of the pyrotechnic excitation device in Example 1. [Figure 4] It is a cross-sectional view of the pyrotechnic excitation device in Example 1. [Figure 5] It is an exploded view (front view) of the structure of the exciter in Example 1. [Figure 6] It is an exploded view (perspective view) of the structure of the exciter in Example 1. [Figure 7] It is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 1 (the relay is in the on state). [Figure 8] It is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 1 (excited by the pyrotechnic excitation device). [Figure 9(a)] It is a schematic diagram of the bottom case in Example 2. [Figure 9(b)] It is a cross-sectional view of the bottom case in Example 2. [Figure 10(a)] It is a schematic diagram of the bottom case in Example 3. [Figure 10(b)] It is a cross-sectional view of the bottom case in Example 3. [Figure 11] It is a schematic diagram of one feasible structure of the piston in Example 4. [Figure 12] It is a schematic diagram of another feasible structure of the piston in Example 4. [Figure 13] It is a schematic diagram in which the arc extinguishing medium in Example 5 is stored in the piston. [Figure 14]Cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 6 (relay in the interrupted state). [Figure 15] This is a schematic diagram showing how the pyrotechnic excitation device in Example 6 is inserted into and fixedly connected to the ceramic cover. [Figure 16] This is an exploded view of the pyrotechnic excitation device structure in Example 6. [Figure 17] This is a cross-sectional view of the pyrotechnic excitation apparatus in Example 6. [Figure 18] This is an exploded view (front view) of the structure of the exciter in Example 6. [Figure 19] This is an exploded view (perspective view) of the exciter structure in Example 6. [Figure 20] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 6 (with the relay in a conductive state). [Figure 21] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 6 (excited by a pyrotechnic excitation device). [Figure 22] This is a schematic diagram of the bottom case in Example 6. [Figure 23] This schematic diagram illustrates how the bottom case in Example 6 expands outward to form a pointed, toothed check valve, thereby limiting the piston's recoil. [Figure 24] This is a schematic perspective view of the push rod assembly in Example 6. [Figure 25] This is an exploded view of the structure of the push rod assembly in Example 6. [Figure 26] This is a schematic diagram (front view) showing how the limiting frame in Example 6 is crushed by the impact of the piston. [Figure 27] This is a schematic diagram (perspective view) showing how the limiting frame in Example 6 is crushed by the impact of the piston. [Figure 28] This is a schematic diagram of the piston in Example 7. [Figure 29]This is a schematic diagram illustrating how the bottom case in Example 7 expands outward to form a pointed, toothed check valve, thereby limiting the piston's recoil. [Figure 30] This is a schematic diagram of the piston in Example 8. [Figure 31] This is a schematic diagram of a feasible piston structure in Example 9. [Figure 32] This is a schematic diagram of another feasible piston structure in Example 9. [Figure 33] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 10 (with the relay in the interrupted state). [Figure 34] This is a schematic diagram showing the pyrotechnic excitation device in Example 10 being inserted into and fixedly connected to the ceramic cover. [Figure 35] This is an exploded view of the pyrotechnic excitation device structure in Example 10. [Figure 36] This is a cross-sectional view of the pyrotechnic excitation apparatus in Example 10. [Figure 37] This is an exploded view (front view) of the structure of the exciter in Example 10. [Figure 38] This is an exploded view (perspective view) of the exciter structure in Example 10. [Figure 39] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 10 (with the relay in a conductive state). [Figure 40] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 10 (excited by a pyrotechnic excitation device). [Figure 41] This is a schematic perspective view of the push rod assembly in Example 10. [Figure 42] This is an exploded view of the structure of the push rod assembly in Example 10. [Figure 43] This is a schematic diagram (front view) showing how the limiting frame in Example 10 is crushed by the impact of the piston. [Figure 44]This is a schematic diagram (perspective view) showing how the limiting frame in Example 10 is crushed by the impact of the piston. [Figure 45] This is a schematic diagram of the movable contact and magnetic guide ring assembly in Example 10. [Figure 46] This is a schematic diagram illustrating how an attractive force is generated in the magnetic guide ring assembly in Example 10 to resist the electric repulsive force caused by the short-circuit current. [Figure 47] This is a schematic diagram of the movable contact and magnetic guide ring assembly in Example 11. [Figure 48] This is a schematic diagram of the movable contact and magnetic guide ring assembly in Example 12. [Figure 49] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 13 (with the relay in the interrupted state). [Figure 50] This is a schematic diagram showing the pyrotechnic excitation device in Example 13 being inserted into and fixedly connected to the ceramic cover. [Figure 51] This is an exploded view of the pyrotechnic excitation device structure in Example 13. [Figure 52] This is a cross-sectional view of the pyrotechnic excitation device in Example 13. [Figure 53] This is an exploded view (front view) of the exciter structure in Example 13. [Figure 54] This is an exploded view (perspective view) of the exciter structure in Example 13. [Figure 55] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 13 (with the relay in a conductive state). [Figure 56] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 13 (excited by a pyrotechnic excitation device). [Figure 57] This is a schematic perspective view of the push rod assembly in Example 13. [Figure 58] This is an exploded view of the structure of the push rod assembly in Example 13. [Figure 59]This is a schematic diagram (front view) showing how the limiting frame in Example 13 is crushed by the impact of the piston. [Figure 60] This is a schematic diagram (perspective view) showing how the limiting frame in Example 13 is crushed by the impact of the piston. [Figure 61] This is a schematic diagram showing how the limiting frame in Example 14 is applied to a seesaw-type relay contact circuit. [Figure 62] This is a schematic diagram (perspective view) of the push rod assembly in Example 15. [Figure 63] This is a schematic diagram (front view) of the push rod assembly in Example 15. [Figure 64] A schematic perspective view (angle 1) showing the U-shaped bracket in Example 16. [Figure 65] A schematic perspective view (angle 2) showing the U-shaped bracket in Example 16. [Figure 66] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 17 (with the relay in the interrupted state). [Figure 67] This is a schematic diagram showing the pyrotechnic excitation device in Example 17 being inserted into and fixedly connected to the ceramic cover. [Figure 68] This is an exploded view of the pyrotechnic excitation device structure in Example 17. [Figure 69] This is a cross-sectional view of the pyrotechnic excitation device in Example 17. [Figure 70] This is an exploded view (front view) of the exciter structure in Example 17. [Figure 71] This is an exploded view (perspective view) of the exciter structure in Example 17. [Figure 72] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 17 (with the relay in a conductive state). [Figure 73] This is a cross-sectional view of a relay equipped with a pyrotechnic excitation device in Example 17 (excited by the pyrotechnic excitation device and releasing an arc-extinguishing medium). [Figure 74] This is a schematic diagram showing how the arc-extinguishing medium is stored in the piston in Example 18. [Figure 75(a)] This is a schematic diagram (front view) of the bottom case in Example 20. [Figure 75(b)] This is a cross-sectional view of the bottom case in Example 20. [Figure 76(a)] This is a schematic diagram (front view) of another viable bottom case modification in Example 20. [Figure 76(b)] This is a cross-sectional view of another viable bottom case variation in Example 20. [Figure 77] This is a schematic diagram of the piston in Example 21. [Figure 78] This is a schematic diagram of another viable alternative to the piston in Example 21. [Modes for carrying out the invention]

[0021] The exemplary embodiments will be described in more detail below with reference to the attached drawings. However, the exemplary embodiments can be carried out in multiple forms and are not limited to the embodiments described herein. In this specification, relative terms such as “top” and “bottom” are used to describe the relative relationship between one assembly and another shown in the drawings, but these terms are merely for convenience and, for example, due to the illustrative orientation shown in the drawings. If the device shown in the drawings is inverted and its top and bottom are reversed, it can be understood that the assembly located “top” becomes the assembly located “bottom.” Other relative terms, such as “top” and “bottom,” are said to have similar meanings. When one structure is located “top” another structure, it may mean that one structure is integrally formed on top of the other structure, one structure is “directly” positioned on top of the other structure, or one structure is “indirectly” positioned on the other structure by another structure.

[0022] The terms “one,” “one,” “that,” and “the aforementioned” are used to indicate the existence of one or more elements / components / etc. The terms “includes” and “have” are used to mean open inclusion and refer to elements / components / etc. that may exist in addition to the listed elements / components / etc. The terms “first,” “second,” etc. are used solely as markers and do not indicate a limit on the number of items they refer to.

[0023] Example 1: Referring to Figures 1 and 2, an embodiment of the present invention provides a relay equipped with a pyrotechnic excitation device, the relay comprising a relay body 100 and a pyrotechnic excitation device 5 attached to the relay body 100, the relay body 100 comprising a fixed contact 1 (as a fixed contact part) and a movable contact 2 (as a movable contact part) that realize conduction or interruption, the relay body 100 further comprising a case body 3, the fixed contact 1 having one end exposed from the case body 3 and electrically connected to an external load, and the other end extending into the interior of the case body 3, the movable contact 2 being provided inside the case body 3 and connected to an electromagnetic drive mechanism 4. Here, the fixed contact 1 is provided with a female screw used for fixing to an external terminal by screw connection. The movable contact 2 is a bridge-type movable contact, and by the action of the electromagnetic drive mechanism 4, the movable contact 2 can move relatively closer to or further away from the fixed contact 1, and when the movable contact 2 contacts the two fixed contacts 1 simultaneously, communication of the load is realized. For the sake of explanation, it is defined that the fixed contact 1 is located relatively above the movable contact 2, and the movable contact 2 is located relatively below the fixed contact 1.

[0024] The relay body 100 further includes a ceramic cover 6, which is fixedly installed inside the case body 3 and covers the lower end of the fixed contact 1 and the movable contact 2 (i.e., covers the fixed contact 1 and the movable contact 2 and their contacts), thereby forming a contact cavity. The ceramic cover 6 isolates the contacts between the fixed contact 1 and the movable contact 2 from the outside air, resulting in high pressure resistance and effectively ensuring low contact resistance, long life, and high reliability of the relay. In the event of a short circuit, the arc resistance and high temperature resistance characteristics of the ceramic material ensure the safety and reliability of the circuit in the event of a short-circuit arc.

[0025] The case body 3 further includes a base 32 and an upper cover 31 joined to each other, the ceramic cover 6 is provided inside the upper cover 31, the pyrotechnic excitation device 5 is inserted into the ceramic cover 6 from the outside and fixedly connected, the lower end of the pyrotechnic excitation device 5 extends into the contact cavity inside the ceramic cover 6 so as to face directly above the movable contact 2, and the upper cover 31 further covers the ceramic cover 6 and the pyrotechnic excitation device 5 to complete the assembly of the entire relay.

[0026] Referring to Figure 2, the pyrotechnic excitation device 5 is an independent modular structure, and its external shape is that of a roughly columnar rotating body. An insertion hole 61 is provided at the upper end of the ceramic cover 6, and the lower end of the pyrotechnic excitation device 5 extends through this insertion hole 61 into the contact cavity. The pyrotechnic excitation device 5 may be fixed to the ceramic cover 6 by welding, crimping, screwing, etc., but in this embodiment, the pyrotechnic excitation device 5 is fixed to the ceramic cover 6 by brazing.

[0027] In this embodiment, the upper cover 31 has through holes and a hollow cylindrical section on its upper surface that allow the two fixed contacts 1 and one pyrotechnic excitation device 5 to retract and align with it. This allows the tips of the two fixed contacts 1 to be exposed from the case body 3, while also covering and protecting the outside of the pyrotechnic excitation device 5. Furthermore, to enhance electrical safety, protective baffle plates extend from both sides of the outer wall of this hollow cylindrical section in a direction perpendicular to the plane of the drawing (not shown depending on the angle).

[0028] In other embodiments, the pyrotechnic excitation device 5 may be fixedly connected to the case body 3. However, in this embodiment, by configuring the pyrotechnic excitation device 5 to be fixedly connected to the ceramic cover 6, the assembly process can be simplified. At the time of final assembly, the pyrotechnic excitation device 5 and the fixed contact 1 are fixed to the ceramic cover 6 and then the upper cover 31 is placed over them.

[0029] Referring to Figures 3 to 6, the pyrotechnic excitation device 5 specifically includes an exciter 51, a piston 52, and a bottom case 53. The exciter 51 and the bottom case 53 are joined and fixed to each other from above and below, and the piston 52 is housed between the exciter 51 and the bottom case 53. Here, the exciter 51 further includes a hollow exciter base 512, a connector 511 fixedly mounted inside the exciter base 512, an igniter 513, and a seal ring 514. The exciter base 512 has a cylindrical structure and is provided with a first flange 510 at its lower end, and the bottom case 53 also has a hollow cylindrical structure and is provided with a second flange 532 at its upper end, and the first flange 510 and the second flange 532 are butted together and fixed (for example, by welding, crimping, or screwing) to achieve the joining and fixing of the exciter 51 and the bottom case 53. The lower end of the bottom case 53 enters the contact cavity of the ceramic cover 6, and the second flanging 532 is fixed to the ceramic cover 6 by brazing, thereby achieving a fixed connection between the pyrotechnic excitation device 5 and the ceramic cover 6.

[0030] As shown in Figure 4, an annular rib 531 is provided on the side of the second flanging 532 facing the ceramic cover 6, and this annular rib 531 can further improve the stability of the brazing between the second flanging 532 and the ceramic cover 6. In addition, the first flanging 510 and the second flanging 532 form an enlarged diameter portion that expands outward, further sealing the insertion hole 61 and thereby ensuring the airtightness of the ceramic cover 6.

[0031] In this embodiment, the exciter base 512 and the bottom case 53 are joined and fixed to each other to form the case body of the pyrotechnic type excitation device 5. The connector 511, igniter 513, seal ring 514, and piston 52 are sequentially installed inside the case body from top to bottom, and the connector 511 is connected to the lead 5131 of the igniter 513. Here, the connector 511 is engaged and fixed to the inner wall of the exciter base 512, the seal ring 514 is press-fitted into the exciter base 512 by interference fit and also presses the igniter 513 upward and fixes it, and the upper and lower ends of the piston 52 abut against the seal ring 514 and the bottom case 53, respectively. The seal ring 514 provides moisture-proof and hermetically sealed effects, and the slight deformation caused by the pressure on the seal ring 514 can further press the igniter 513 above it and the piston 52 below it, preventing loosening due to vibration.

[0032] Referring to Figures 7 and 8, the connector 511 is fixedly connected to the ignition lead of the monitoring-excitation circuit, thereby transmitting the excitation electrical signal emitted by the monitoring-excitation circuit to excite the igniter 513. The monitoring-excitation circuit monitors when the current value (or current rise rate) reaches a predetermined threshold, and then the emitted excitation electrical signal is transmitted downward through the connector 511, exciting the igniter 513 and causing ignition. A gap 50 is provided between the piston 52 and the igniter 513. After the igniter 513 ignites the gunpowder, high-pressure fuel gas is generated in this gap 50 (i.e., ignited), pushing the piston 52 and breaking through the bottom case 53 downwards. Furthermore, the piston 52 moves the movable contact 2 downwards, which helps the movable contact 2 disengage from contact with the fixed contact 1, enabling rapid tripping of the relay.

[0033] The bottom case 53 is a hollow cylindrical structure, and the piston 52 is a rotating body structure fitted into the inside of the bottom case 53 via an axial hole. Therefore, the bottom case 53 can act as a guide for the piston 52, and after the ignition device 513 is ignited, it moves the piston 52 downward along the axial direction of the inner lumen of the hollow cylindrical bottom case 53.

[0034] In this embodiment, the pyrotechnic excitation device 5 has a modular structure, is independent of the relay body, and can be manufactured separately and then permanently attached to the relay. This facilitates the management of the manufacturing and transportation of the pyrotechnic excitation device 5, reduces the number of parts, simplifies assembly, facilitates the standardization of parts, and achieves the objectives of reducing weight, lowering costs, and improving performance. Furthermore, the lead 5131 extending from the igniter 513 is connected to the ignition lead of the monitoring excitation circuit via the connector 511, so that the explosive in the igniter 513 is far from the lead end of the ignition lead, resulting in a smaller temperature rise and reduced temperature resistance requirements for the chemical agent.

[0035] The pyrotechnic excitation device 5 according to this embodiment is applied to a ceramic-sealed relay. Specifically, by welding the pyrotechnic excitation device 5 to the ceramic cover 3, the weld fastening performance is good, the sealing performance and vibration resistance of the pyrotechnic excitation device 5 are superior, and the molding of the case body of the pyrotechnic excitation device 5 is simpler, resulting in a lower product height.

[0036] In other embodiments, the pyrotechnic excitation device 5 may be attached to the relay by a fixed connection, provided with an insertion hole (for example, the insertion hole 61 in this embodiment) in the relay body for insertion of the pyrotechnic excitation device 5, and may be applied to relays having other structures. The pyrotechnic excitation device 5 may also be fixed to the relay body by a detachable connection (for example, screw fastening), so that the pyrotechnic excitation device 5 can be rapidly replaced in response to input demands.

[0037] As shown in Figure 8, the bottom case 53 of the pyrotechnic excitation device 5 is further provided with an arc-extinguishing medium 54. When the pyrotechnic excitation device 5 is excited, the piston 52 pierces the bottom case 53 downwards, releasing the arc-extinguishing medium 54 into the contact cavity of the ceramic cover 6. This extinguishes the contact gap between the fixed contact 1 and the movable contact 2, further accelerating the arc-extinguishing capability when the contacts are disconnected, and improving the short-circuit safety of the product.

[0038] In this embodiment, the arc extinguishing medium 54 is quartz sand. In this pyrotechnic excitation device 5, after ignition and explosion, the gas at its lower end expands rapidly, and the arc extinguishing medium 54 stored in the bottom case 53 or piston 52 can be dispersed very rapidly and uniformly into the contact cavity along with the explosion gas. This minimizes the limitations imposed by the external shapes of the fixed contactor 1 and the movable contactor 2 and the contour of the contact cavity, and allows for a direct arc extinguishing effect in a short time.

[0039] In this embodiment, the movable contact 2 is a bridge-type movable contact, the fixed contact 1 is provided at both ends of the bridge-type movable contact, and the pyrotechnic excitation device 5 is provided corresponding to one side of the middle position of the movable contact 2. As a result, the expanding gas after ignition explosion is blocked by the bridge-type movable contact, and the airflow is guided to both ends of the bridge-type movable contact, thereby allowing the arc extinguishing medium 54 to reach the region between the fixed contact 1 and the movable contact 2 more directly.

[0040] Referring to Figures 7 and 8, the electromagnetic drive mechanism 4 is used to move the movable contact 2. Specifically, the electromagnetic drive mechanism 4 includes a fixed core 41, a coil 42, a movable core 43, a push rod assembly 44, a return spring 45, a first yoke member 46, a second yoke member 47, and a magnetic guide tube 48 for transmitting magnetic field lines and improving the utilization rate of magnetic energy. The lower end of the push rod assembly 44 is fixedly connected to the movable core 43, and the upper end is connected in conjunction with the movable contact 2. One end of the return spring 45 acts on the fixed core 41, and the other end acts on the movable core 43. When the coil 42 is energized, the fixed core 41 attracts the movable core 43 and moves it upward, causing the push rod 44 to move the movable contact 2 upward. When the coil 42 is de-energized, the electromagnetic drive mechanism 4 returns to its original position due to the elastic force of the return spring 45. The electromagnetic drive mechanism 4 is a typical linear magnetic circuit structure, and its operating principle will not be explained in detail in this example.

[0041] This embodiment describes the function and effect of the pyrotechnic excitation device 5 using the structure of a relay, but a similar structure can be applied to other switching devices, such as contactors.

[0042] Example 2 This embodiment provides a relay whose structure is similar to that of Embodiment 1, the difference being that this embodiment uses a different pyrotechnic type bottom case structure for the excitation device. Referring to Figures 9(a) and 9(b), in this embodiment the bottom case 53A has a multi-stage stepped structure in which the radial dimension gradually contracts from top to bottom, and the lower end of the bottom case 53A is contracted so that the impact force during the explosion of the pyrotechnic type excitation device can be concentrated in the small stepped section at the lower end of the bottom case 53A, thereby improving localized capacity, which increases the ability of the piston to penetrate the bottom case 53A and accelerates the piston to push and shut off the movable contact 2, while simultaneously storing the arc extinguishing medium in the stepped section inside the bottom case 53A.

[0043] Example 3 This embodiment provides a relay whose structure is similar to that of the relay in Embodiment 2, the difference being that this embodiment uses a different pyrotechnic type bottom case structure for the excitation device. Referring to Figures 10(a) and 10(b), in this embodiment the bottom case 53B has a tapered structure in which the radial dimension gradually narrows from top to bottom (i.e., towards the movable contact). Similarly, because the lower end of the bottom case 53B is constricted, the impact force during the explosion of the pyrotechnic type excitation device can be concentrated at the lower end of the bottom case 53B, resulting in improved localized capability, thereby increasing the ability of the piston to penetrate the bottom case 53B and accelerating the piston to push and shut off the movable contact 2.

[0044] In both this embodiment and embodiment 2, the bottom case structure is designed so that the radial dimension gradually shrinks from top to bottom. In addition to the "stepwise shrinkage" and "tapered shrinkage" provided in this embodiment and embodiment 2, shrinkage may be achieved by combining "stepwise shrinkage" and "tapered shrinkage" in multiple stages in other embodiments, and any other regular or irregular shape for radial shrinkage is also feasible.

[0045] Example 4 This embodiment provides a relay with a structure similar to the relay of Embodiment 1, the difference being that this embodiment uses a different pyrotechnic type piston structure for the excitation device. In this embodiment, the piston is shaped to contract from top to bottom (i.e., towards the movable contact), which reduces its biasing area and increases the force acting on the bottom case and the movable contact, so that it can break through the bottom case more quickly and rapidly push the movable contact to shut it off. The contraction shape of the lower end of the piston may be specifically realized by a tapered contraction, a stepped contraction, or a contraction structure that combines tapered and stepped shapes, and the pistons with contracted lower ends shown in Figures 11 and 12 are all feasible.

[0046] Example 5 This embodiment provides a relay with a structure similar to the relay of Embodiment 1, the difference being that in this embodiment the arc-extinguishing medium is stored inside the piston. As shown in Figure 13, the piston 52C has a cylindrical structure with a hollow cavity, the arc-extinguishing medium 54A is stored inside the piston 52C, and the lower end 52C-1 of the piston 52C (i.e., the impact point of the piston 52C) has a thin and fragile structure. This lower end 52C-1 of the piston 52C is made of a fragile material such as bakelite or PBT plastic, and when the piston 52C impacts downwards, the lower end 52C-1 breaks due to the impact, causing cracks to form and releasing the arc-extinguishing medium 54A.

[0047] In addition to using the piston structure with an upward-facing opening as in this embodiment and Embodiment 1, the piston may also be a sealed structure with a sealed cavity. When such a piston structure with a sealed cavity is used, the arc extinguishing medium is stored inside the piston, resulting in good sealing performance. For this reason, the arc extinguishing medium can be other than quartz sand, such as gaseous sulfur hexafluoride or liquid transformer oil.

[0048] Furthermore, conventional pyrotechnic excitation devices generally include a piston. After ignition, the high-pressure fuel gas pushes the piston to operate it, and the piston then pushes a movable contact (movable contactor) to rapidly shut it off. However, conventional pyrotechnic excitation devices do not have a check valve for the piston, so the piston easily generates elastic repulsion after colliding with the movable contactor. This reduces the kinetic energy of the piston, which is unfavorable for rapidly shutting off the movable contactor.

[0049] Therefore, the present invention further provides a pyrotechnic excitation device with an optimized structure, and further provides a switching device equipped with this pyrotechnic excitation device.

[0050] This invention provides the following technical solution.

[0051] The present invention provides a pyrotechnic excitation device comprising an exciter, a piston, and a bottom case, wherein the bottom case has a hollow structure, the piston is fitted and mounted inside the bottom case, the exciter ignites gunpowder and pushes the piston with fuel gas to break through the bottom case, the bottom case is provided with a check valve structure, and after the piston breaks through the bottom case, the check valve structure prevents the piston from elastically rebounding due to the collision.

[0052] Here, the bottom of the bottom case is provided with a plurality of intersecting cracks, and after the piston breaks through the bottom case, the bottom of the bottom case expands outward from the intersection of the cracks to form a pointed, tooth-shaped check valve, so that the tip of the check valve presses against the piston and prevents the piston from recoiling.

[0053] Here, the crack forms a "rice" shape or a "cross" shape.

[0054] Here, the piston is provided with a radially stepped structure.

[0055] Here, the piston is provided with a reduced-diameter neck portion, and the tip of the check valve prevents the elastic rebound of the piston by pressing against the stepped portion at one end of the neck portion. Alternatively, the piston is divided into two independent stages, including an upper piston and a lower piston, and after the lower piston breaks through the bottom case, the upper piston remains inside the bottom case, and the tip of the check valve prevents the elastic rebound of the lower piston by pressing against the end of the lower piston.

[0056] Here, the piston has a structure that gradually contracts in the direction of piercing the bottom case.

[0057] The present invention further provides a switching electrical device equipped with a pyrotechnic excitation device, the switching electrical device comprising a switching electrical device body and a pyrotechnic excitation device provided on the switching electrical device body, the switching electrical device body comprising a fixed contact portion fixed to perform a switching function and a movable contact portion that is movable, the pyrotechnic excitation device can assist in the rapid shutdown of the switching electrical device by igniting a gunpowder in accordance with the load condition of the switching electrical device body to generate an explosive impact force that pushes the movable contact portion away from the fixed contact portion, and the pyrotechnic excitation device is the pyrotechnic excitation device described above.

[0058] Here, the switching electrical device equipped with a pyrotechnic excitation device further includes a limiting member, the limiting member being positioned where the piston penetrates the bottom case, the limiting member being able to restrict the movable contact portion from returning toward the fixed contact portion, and being configured to be assembled with the movable contact portion by coupling with, and the material of the limiting member being such that it does not recover from deformation even when subjected to impact from the piston.

[0059] Here, the limiting member is a limiting frame, and the limiting frame is crushed in such a way that it cannot recover from the deformation after being impacted by the piston, thereby restricting the movable contact portion from returning toward the fixed contact portion.

[0060] Here, the movable contact portion has a plate-like structure, and the limiting frame is provided across the plate-like movable contact portion, thereby restricting it from returning toward the fixed contact portion.

[0061] Here, the switching device is a DC high-voltage relay.

[0062] The present invention offers the following beneficial effects. By providing a piston check valve structure, the piston is pushed out from the bottom of the bottom case, but is stopped by the check valve structure and cannot bounce back. This allows the piston to be locked in real time, reducing energy loss due to the piston's elastic rebound.

[0063] The present invention will be further described below with reference to the drawings and specific embodiments.

[0064] Example 6 Referring to Figures 14 to 15, an embodiment of the present invention provides a relay equipped with a pyrotechnic excitation device, the relay comprising a relay body 100 and a pyrotechnic excitation device 5 attached to the relay body 100, the relay body 100 comprising a fixed contact 1 (as a fixed contact part) and a movable contact 2 (as a movable contact part) that realize conduction or interruption, the relay body 100 further comprising a case body 3, the fixed contact 1 having one end exposed from the case body 3 and electrically connected to an external load, and the other end extending into the interior of the case body 3, the movable contact 2 being provided inside the case body 3 and connected to an electromagnetic drive mechanism 4. Here, the fixed contact 1 is provided with a female screw used for fixing to an external terminal by screw connection. The movable contact 2 is a bridge-type movable contact, and through the action of the electromagnetic drive mechanism 4, the movable contact 2 can move closer to or further away from the fixed contact 1, and when the movable contact 2 contacts both fixed contacts 1 simultaneously, it achieves load communication. For the sake of explanation, it is defined that the fixed contact 1 is located relatively above the movable contact 2, and the movable contact 2 is located relatively below the fixed contact 1.

[0065] The relay body 100 further includes a ceramic cover 6, which is fixedly installed inside the case body 3 and covers the lower end of the fixed contact 1 and the movable contact 2 (i.e., covers the fixed contact 1 and the movable contact 2 and their contacts), thereby forming a contact cavity. The ceramic cover 6 isolates the contacts between the fixed contact 1 and the movable contact 2 from the outside air, resulting in high pressure resistance and effectively ensuring low contact resistance, long life, and high reliability of the relay. Furthermore, in the event of a short circuit, the arc resistance and high temperature resistance characteristics of the ceramic material ensure the safety and reliability of the circuit in the event of a short-circuit arc.

[0066] The case body 3 further includes a base 32 and an upper cover 31 which are joined together, the ceramic cover 6 is provided inside the upper cover 31, the pyrotechnic excitation device 5 is inserted into the ceramic cover 6 from the outside and fixedly connected, the lower end of the pyrotechnic excitation device 5 enters the contact cavity inside the ceramic cover 6 so as to face directly above the movable contact 2, and the upper cover 31 further covers the ceramic cover 6 and the pyrotechnic excitation device 5 to complete the assembly of the entire relay. Referring to Figure 15, the pyrotechnic excitation device 5 is an independent modular structure, its external shape is a substantially columnar rotating body structure, an insertion hole 61 is provided at the upper end of the ceramic cover 6, and the lower end of the pyrotechnic excitation device 5 enters the contact cavity through this insertion hole 61. The pyrotechnic excitation device 5 may be fixed to the ceramic cover 6 by welding, crimping, screwing, etc., but in this embodiment, the pyrotechnic excitation device 5 is fixed to the ceramic cover 6 by brazing. In this embodiment, the upper surface of the upper cover 31 has through holes and a hollow cylindrical section that retract and align with two fixed contacts 1 and one pyrotechnic excitation device 5, so that the tips of the two fixed contacts 1 are exposed from the case body 3, and the outside of the pyrotechnic excitation device 5 can be covered and protected. In addition, to enhance electrical safety, protective baffle plates extend from both sides of the outer wall of this hollow cylindrical section in a direction perpendicular to the plane of the drawing (not shown depending on the angle). In other embodiments, the pyrotechnic excitation device 5 may be fixedly connected to the case body 3. However, in this embodiment, by configuring the pyrotechnic excitation device 5 to be fixedly connected to the ceramic cover 6, the assembly process can be simplified. At the time of final assembly, the pyrotechnic excitation device 5 and the fixed contact 1 are fixed to the ceramic cover 6 and then the upper cover 31 is placed over them.

[0067] Referring to Figures 16 to 19, the pyrotechnic excitation device 5 specifically includes an exciter 51, a piston 52, and a bottom case 53. The exciter 51 and the bottom case 53 are joined and fixed to each other from top to bottom, and the piston 52 is housed between the exciter 51 and the bottom case 53. Here, the exciter 51 further includes a hollow exciter base 512, a connector 511 fixedly mounted inside the exciter base 512, an igniter 513, and a seal ring 514. The exciter base 512 and the bottom case 53 are joined and fixed to each other to form the case body of the pyrotechnic excitation device 5. The connector 511, igniter 513, seal ring 514, and piston 52 are sequentially installed inside this case body from top to bottom, and the connector 511 is connected to the lead 5131 of the igniter 513. Here, the connector 511 is engaged with and fixed to the inner wall of the exciter base 512, the seal ring 514 is press-fitted into the exciter base 512 by interference fit and also presses the igniter 513 upward to fix it, and both the upper and lower ends of the piston 52 are in contact with the seal ring 514 and the bottom case 53, respectively. The seal ring 514 provides moisture-proof and airtight sealing effects, and the slight deformation caused by the pressure on the seal ring 514 can further press the igniter 513 above it and the piston 52 below it, thereby preventing loosening due to vibration.

[0068] Referring to Figures 20 and 21, the connector 511 is fixedly connected to the ignition lead of the monitoring-excitation circuit, thereby transmitting the excitation electrical signal emitted by the monitoring-excitation circuit to excite the igniter 513. The monitoring-excitation circuit monitors when the current value (or current rise rate) reaches a predetermined threshold, and then the emitted excitation electrical signal is transmitted downward through the connector 511, exciting the igniter 513 and causing ignition. A gap 50 is provided between the piston 52 and the igniter 513. After the igniter 513 ignites the gunpowder, high-pressure fuel gas is generated in this gap 50 (i.e., ignited), pushing the piston 52 and breaking through the bottom case 53 downwards. Furthermore, the piston 52 moves the movable contact 2 downwards, which helps the movable contact 2 disengage from contact with the fixed contact 1, enabling rapid tripping of the relay.

[0069] Since the bottom case 53 is a hollow cylindrical structure and the piston 52 is a rotating body structure that fits into the inside of the bottom case 53 through an axial hole, the bottom case 53 can act as a guide for the piston 52, and after the ignition device 513 is ignited, the piston 52 moves downward along the axial direction of the hollow cylindrical lumen of the bottom case 53.

[0070] In this embodiment, the pyrotechnic excitation device 5 has a modular structure, is independent of the relay body, and can be manufactured separately and then permanently attached to the relay. This facilitates the management of the manufacturing and transportation of the pyrotechnic excitation device 5, reduces the number of parts, simplifies assembly, facilitates the standardization of parts, and achieves the objectives of reducing weight, lowering costs, and improving performance. Furthermore, the lead 5131 extending from the igniter 513 is connected to the ignition lead of the monitoring excitation circuit via the connector 511, so that the explosive in the igniter 513 is far from the lead end of the ignition lead, resulting in a smaller temperature rise and reduced temperature resistance requirements for the chemical agent.

[0071] Referring to Figures 22 and 23, in this embodiment, the bottom of the bottom case 53 is provided with intersecting "rice" shaped cracks. When the piston 52 impacts the bottom case 53 downwards, the bottom of the bottom case 53 expands outward from the intersection of the "rice" shaped cracks to form a pointed, tooth-shaped check valve 53-1. The check valve 53-1 presses against the circumferential surface or end of the piston 52 (if the piston 52 does not completely eject from the bottom case 53, the check valve 53-1 presses against the circumferential surface of the piston 52 to stop the piston 52. If the piston 52 completely ejects from the bottom case 53, the check valve 53-1 presses against the end of the piston 52 to stop the piston 52), thereby preventing the elastic rebound of the piston 52. In other words, the check valve structure of the intersecting, "rice" shaped cracks in this embodiment pushes the piston 52 out from the bottom of the bottom case 53, but is stopped by the check valve 53-1 and prevented from bouncing back. This allows the piston 52 to be locked in real time, reducing energy loss due to the elastic rebound of the piston 52. At the same time, after the piston 52 is locked, the head of the piston 52 firmly abuts against the movable contact, preventing the possibility of the movable contact and the fixed contact closing again.

[0072] The crack at the bottom of the bottom case 53 can be of other shapes, such as a cross shape, in addition to the "rice" shape used in this embodiment. Any crack shape that expands outward after the bottom of the bottom case 53 is subjected to impact is a feasible configuration.

[0073] Furthermore, the pyrotechnic excitation device having a check valve structure in this embodiment may be integrated with the relay, as in the prior art, rather than being attached to the relay body as an independent modular structure. The pyrotechnic excitation device having a check valve structure can significantly improve the electrical safety performance of the relay and is not necessarily related to the structure and mounting method of the pyrotechnic excitation device.

[0074] The pyrotechnic excitation device 5 according to this embodiment is applied to a ceramic-sealed relay. Specifically, by welding the pyrotechnic excitation device 5 to the ceramic cover 3, the weld fastening is good, the sealing and vibration resistance of the pyrotechnic excitation device 5 are superior, and the molding of the case body of the pyrotechnic excitation device 5 is simpler, resulting in a lower product height. In other embodiments, the pyrotechnic excitation device 5 may be attached to the relay by providing an insertion hole (for example, the insertion hole 61 in this embodiment) in the relay body for insertion of the pyrotechnic excitation device 5, and by a fixed connection. It may also be applied to relays with other structures. The pyrotechnic excitation device 5 may also be fixed to the relay body by a detachable connection (e.g., screw fastening), so that the pyrotechnic excitation device 5 can be rapidly replaced in response to input demands.

[0075] As shown in Figure 21, the bottom case 53 of the pyrotechnic excitation device 5 is further provided with an arc-extinguishing medium 54. When the pyrotechnic excitation device 5 is excited, the piston 52 pierces the bottom case 53 downwards, releasing the arc-extinguishing medium 54 into the contact cavity of the ceramic cover 6. This extinguishes the contact gap between the fixed contact 1 and the movable contact 2, further accelerating the arc-extinguishing ability when the contact is interrupted and improving the short-circuit safety of the product. In this embodiment, the arc-extinguishing medium 54 is quartz sand. In this pyrotechnic excitation device 5, after ignition and explosion, the gas at its lower end expands rapidly, allowing the arc-extinguishing medium 54 stored in the bottom case 53 or piston 52 to be dispersed very rapidly and uniformly into the contact cavity along with the explosion gas. This minimizes the limitations imposed by the external shapes of the fixed contact 1 and the movable contact 2 and the contour of the contact cavity, and directly achieves an arc-extinguishing effect in a short time. In this embodiment, the movable contact 2 is a bridge-type movable contact, the fixed contact 1 is provided at both ends of the bridge-type movable contact, and the pyrotechnic excitation device 5 is provided corresponding to one side of the middle position of the movable contact 2. As a result, the expanding gas after ignition explosion is blocked by the bridge-type movable contact, and the airflow is guided to both ends of the bridge-type movable contact, thereby allowing the arc extinguishing medium 54 to reach the region between the fixed contact 1 and the movable contact 2 more directly.

[0076] The electromagnetic drive mechanism 4 is used to move the movable contact 2. Referring to Figures 20-21, the electromagnetic drive mechanism 4 specifically includes a fixed core 41, a coil 42, a movable core 43, a push rod assembly 44, a return spring 45, and further includes a first yoke member 46, a second yoke member 47, and a magnetic guide tube 48 for transmitting magnetic field lines and improving the utilization rate of magnetic energy. The lower end of the push rod assembly 44 is fixedly connected to the movable core 43, and the upper end is connected in conjunction with the movable contact 2. One end of the return spring 45 acts on the fixed core 41, and the other end acts on the movable core 43. By energizing the coil 42, the fixed core 41 attracts the movable core 43 and moves it upward, causing the push rod 44 to move the movable contact 2 upward. If the coil 42 fails, the electromagnetic drive mechanism 4 returns to its original position by the elastic force of the return spring 45. The electromagnetic drive mechanism 4 is a typical linear magnetic circuit structure, and its operating principle will not be explained in detail in this example.

[0077] Referring to Figures 24 and 25, the push rod assembly 44 includes a push rod 441, a spring base 442, and a U-shaped bracket 443. The push rod 441 is used to output the driving force of the electromagnetic drive mechanism 4, with its lower end fixedly connected to the movable core 43 and its upper end fixedly connected to the spring base 442. The U-shaped bracket 443 is a sheet-like structure and includes a top plate 4431 positioned horizontally above the spring base 442, and two side plates 4432 connected to both ends of the top plate 4431 and extending downward. The lower ends of the two side plates 4432 are fixedly connected to both ends of the spring base 442, thereby connecting the spring base 442 and the U-shaped bracket 443 to form a rectangular hollow limiting frame 400. The lower end of the overtravel spring 445 abuts against the spring base 442, and the movable contact 2 penetrates the limiting frame 400 and abuts against the top plate 4431 by the elastic force of the overtravel spring 445. Thus, the overtravel spring 445 and the movable contact 2 are stably mounted within the limiting frame 400 by the elastic force of the overtravel spring 445. Furthermore, when the push rod assembly 44 pushes up and brings the movable contact 2 and the fixed contact 1 into contact, the spring base 442 can further compress the overtravel spring 445, enabling contact overtravel when the relay is in a conductive state.

[0078] Referring to Figures 26-27, this embodiment uses a spring base 442 and a U-shaped bracket 443 to form a limiting frame 400. When the pyrotechnic excitation device 5 is excited, the piston 52 strikes the limiting frame 400 downward, moving the push rod assembly 44 and the movable contact 2 downward. After the spring base 442 is stopped by the internal structure of the relay, the impact force of the piston 52 further compresses the overtravel spring 445, causing the two side plates 4432 of the U-shaped bracket 443 to bend under the force, generating plastic deformation and crushing the entire limiting frame 400, preventing it from recovering. This further reduces the overall height of the push rod assembly 44 and the movable contact 2. The U-shaped bracket 443, by being positioned above the plate-shaped movable contact 2, can limit the rebound recovery of the movable contact 2 to the fixed contact 1. Furthermore, when the piston 52 delivers a downward impact, the limiting frame 400 is crushed, which widens the contact gap between the movable contact 2 and the fixed contact 1, thereby improving short-circuit safety. From another perspective, in this embodiment, since the limiting frame 400 formed by the spring base 442 and the U-shaped bracket 443 can be crushed, compared to other configurations in which the push rod assembly is not crushed, when the push rod assembly 44 and the movable contact 2 in this embodiment are impacted by the piston 52, a sufficient contact gap can be ensured with only a shorter downward movement path (after the compression space due to the crushing of the limiting frame 400 is superimposed). For this reason, the height space of the contact cavity of the ceramic cover 6 can be set to an appropriate size, which can be adapted to the specifications of a relay that does not have a pyrotechnic excitation device 5 (conventional relays equipped with a pyrotechnic excitation device 5 require an increase in the height space of the contact cavity), thereby reducing the overall height and volume of the relay.

[0079] The U-shaped bracket 443 is made of a material that does not recover from distortion, such as stainless steel or low-carbon steel. In addition, in this embodiment, since the side plate 4432 has a thin, openwork structure, it becomes easier for the side plate 4432 to be bent when subjected to force.

[0080] In addition to using the limiting frame 400 of this embodiment to restrict the mounting position of the movable contact 2 and to restrict the rebound recovery of the movable contact 2 towards the fixed contact 1, other limiting members can be used instead of the limiting frame 400 in other embodiments. For example, the movable contact 2 is fixedly connected to the end of a rod, but the main body of this rod is designed to be compressed axially when subjected to impact and the deformation does not recover. This limiting member can be implemented as long as it can restrict the movable contact 2 from returning toward the fixed contact 1 and is assembled by coupling with the movable contact 2.

[0081] Furthermore, since a check valve structure is provided for the piston 52 in this embodiment, the check valve structure can lock the piston 52 in real time after it has been ejected from the bottom case 53, preventing the piston 52 from elastically rebounding upon impact. The limiting frame 400 can prevent the elastic rebound of the movable contact 2, and both have the effect of preventing the re-closing of the movable and fixed contacts, thereby ensuring double safety. On the other hand, since the check valve structure prevents the piston 52 from elastically rebounding and reduces the energy loss due to the elastic rebound of the piston 52, most of the kinetic energy of the piston 52 can act on the limiting frame 400, ensuring that the limiting frame 400 can be crushed by the impact. Since the energy loss due to the elastic rebound of the piston 52 is reduced, the demand for impact force on the piston 52 in this embodiment can be reduced, which in turn allows for a reduction in the amount of explosive in this embodiment, improving safety performance.

[0082] This embodiment describes the function and effect of the pyrotechnic excitation device 5 and pushrod assembly 44 using the structure of a relay, but a similar structure can be applied to other switching devices other than relays, such as contactors.

[0083] Example 7 This embodiment provides a relay whose structure is similar to that of the relay of Embodiment 6, and similarly includes a bottom case 53 with a "rice" shaped crack at the bottom, the difference being the piston structure of this embodiment. As shown in Figures 28 to 29, the piston 52A of this embodiment is provided with a reduced-diameter neck portion 52A-1, and when the piston 52A pierces the bottom case 53 downward, the bottom of the bottom case 53 expands outward from the intersection of the "rice" shaped crack to form a pointed, toothed check valve portion 53-1, so that when the piston 52A impacts the movable contact and elastically rebounds, the stepped portion at the lower end of the neck portion 52A-1 is stopped by the check valve portion 53-1 and its position is restricted.

[0084] In this embodiment, the piston 52A is provided with a reduced-diameter neck portion 52A-1. This allows the piston 52A to press against the stepped lower end of the neck portion 52A-1, thus providing a check valve effect. Therefore, even if the piston 52A in this embodiment has not fully protruded from the bottom case 53, it can be stably pressed against and stopped by the check valve portion 53-1. As a result, both the stroke and impact force requirements of the piston 52A in this embodiment can be reduced, thereby reducing the amount of explosive used and improving safety performance.

[0085] Example 8 This embodiment provides a relay whose structure is similar to that of the relay in Embodiment 6, and similarly includes a bottom case 53 with a bar-shaped crack at the bottom, the difference being the piston structure of this embodiment. Referring to Figure 30, in this embodiment the piston 52B is divided into two independent stages in the vertical direction, namely the upper piston 52B-1 and the lower piston 52B-2. When the pyrotechnic excitation device is not excited, the upper piston 52B-1 and the lower piston 52B-2 are stacked vertically. When the pyrotechnic excitation device is excited, the lower piston 52B-2 pops out of the bottom case 53C, while the upper piston 52B-1 remains inside the bottom case 53C, so that the check valve 53C-1 of the bottom case 53C stops the end of the lower piston 52B-2 and restricts its position. This embodiment, like Embodiment 7, forms a radially stepped structure on the piston. In Embodiment 7, the radially stepped section of the piston is formed at the reduced diameter portion, whereas in this embodiment, the piston is divided into two independent stages to form the radially stepped section. The effects of this can be seen by referring to Embodiment 7.

[0086] Example 9 This embodiment provides a relay whose structure is similar to that of the relay in Embodiment 8, and similarly includes a bottom case 53 with a "rice" shaped crack at the bottom and a piston divided into two stages, the difference being as follows: In this embodiment, the piston is shaped to contract from top to bottom (i.e., in the direction in which the piston breaks through the bottom case), which reduces the biasing area of ​​the piston in this embodiment and increases the force acting on the bottom case and the movable contact, so that it can break through the bottom case more quickly and rapidly push the movable contact to shut it off. Specifically, the contraction shape of the lower end of the piston may be realized by a tapered contraction, a stepped contraction, or a contraction structure that combines tapered and stepped shapes, and the pistons with contracted lower ends shown in Figures 31 and 32 are all feasible.

[0087] Furthermore, when conventional pyrotechnic excitation devices are applied to relays with high short-circuit resistance, the required explosive shock force also increases, resulting in a larger amount of explosives being carried, which is disadvantageous for safety management during the manufacturing and assembly process.

[0088] Therefore, the present invention further provides a switching electric device equipped with a pyrotechnic excitation device with an optimized structure.

[0089] This invention provides the following technical solution.

[0090] The present invention provides a switching electrical device comprising a pyrotechnic excitation device, the switching electrical device comprising a switching electrical device body and a pyrotechnic excitation device provided on the switching electrical device body, the switching electrical device body performing a switching function by comprising a linear electromagnetic drive mechanism, a fixedly provided fixed contact portion and a movable contact portion, the linear electromagnetic drive mechanism comprising a push rod assembly, the movable contact portion achieving contact with the fixed contact portion by being assembled to the push rod assembly via an elastic member, the switching electrical device further comprising at least one pair of conduit ring assemblies, the conduit ring assembly comprising an upper conduit and a lower conduit provided opposite each other, the upper conduit being fixedly connected to the upper end of the push rod assembly and the lower conduit being fixedly connected to the movable contact portion, the pyrotechnic excitation device comprising a push medium for performing downward movement, the push medium corresponding to the position above the push rod assembly.

[0091] Here, the push medium is a high-pressure fuel gas generated by the ignition of the pyrotechnic excitation device, or the push medium is a piston.

[0092] In this embodiment, in order to improve the short-circuit resistance of the switching device, n sets of the magnetic guide ring assemblies are provided, where n ≥ 2.

[0093] Herein, from the viewpoint of manufacturing and installation, in one embodiment, the upper conductor has a straight-line structure and is fixed horizontally above the movable contact portion, the lower conductor has a U-shaped structure, the lower conductor and the movable contact portion are fixedly connected such that the lower conductor surrounds at least a portion of the current-carrying conductor of the movable contact portion, and the opening of the U-shaped lower conductor is provided toward the upper conductor so that the upper conductor and the lower conductor form a magnetic circuit.

[0094] Herein, from the viewpoint of manufacturing and installation, in one embodiment, the push rod assembly includes a limiting frame, the movable contact portion penetrates the limiting frame, the elastic member is fixedly mounted inside the limiting frame and the elastic force of the elastic member presses the movable contact portion toward the upper end of the limiting frame, the upper conductor is fixedly connected to the inside of the tip of the limiting frame and is provided above the movable contact portion, the limiting frame moves upward to bring the movable contact portion and the fixed contact portion into contact, and the linear electromagnetic drive mechanism continues to move the limiting frame upward, compressing the elastic member and creating a certain magnetic gap between the upper conductor and the lower conductor.

[0095] Here, in order to reduce the demand for the elastic force of the overtravel elastic member and thereby reduce the amount of explosive in the pyrotechnic excitation device, in one embodiment, when the movable contact portion and the fixed contact portion are in contact, the elastic force of the elastic member is smaller than the maximum electric repulsive force between the movable contact portion and the fixed contact portion.

[0096] In this embodiment, in order to facilitate the manufacture, transport, and assembly of the pyrotechnic excitation device, the pyrotechnic excitation device has an independent modular structure, and the pyrotechnic excitation device as an independent module is fixedly attached to the switching electrical body from the outside of the switching electrical body, and the pyrotechnic excitation device rapidly shuts off the switching electrical body by igniting gunpowder and generating an explosive shock force, thereby separating the movable contact part from the fixed contact part.

[0097] Herein, from the viewpoint of manufacturing and installation, in one embodiment, the switching electrical body includes a ceramic cover, the ceramic cover forms a contact cavity surrounding at least the fixed contact portion, the movable contact portion and their contact portions, the ceramic cover is provided with an insertion hole, and one end of the pyrotechnic excitation device extends through the insertion hole into the contact cavity so as to be positioned directly facing one side of the movable contact portion.

[0098] Herein, from the standpoint of manufacturing and installation, in one embodiment, the pyrotechnic excitation device includes an exciter, a bottom case, and a piston as the push medium, the exciter and the bottom case are joined and fixed to each other, the bottom case has a hollow structure, the piston is fitted and installed inside the bottom case, the bottom case extends through the insertion hole to the contact cavity and faces the movable contact portion, and when the pyrotechnic excitation device is excited, the exciter ignites the gunpowder and pushes the piston with the fuel gas to break through the bottom case, the piston moves toward the movable contact portion by the guiding action of the bottom case, thereby pushing the movable contact portion and separating it from the fixed contact portion.

[0099] In this embodiment, in order to improve the arc extinguishing capability of the switching device, an arc extinguishing medium is further stored in the piston or bottom case, and after the piston breaks through the bottom case, the arc extinguishing medium is released into the contact cavity by the rupture of the piston or bottom case, thereby extinguishing the arc between the fixed contact part and the movable contact part.

[0100] Here, selectively, the switching device is a DC high-voltage relay.

[0101] The present invention offers the following beneficial effects. In addition to a switching device equipped with a pyrotechnic excitation device, the present invention further provides a magnetic guide ring assembly. Firstly, it can improve the short-circuit resistance of the switching device, allowing the switching device to be applied when high short-circuit resistance is required. Secondly, it can reduce the demand for the overtravel spring for the contact pressure of the movable contact. By using an overtravel elastic member with a small elastic modulus k value or by reducing the stroke amount of the overtravel elastic member, the amount of explosive required for the pyrotechnic excitation device can be reduced, improving the reliability of the pyrotechnic excitation device. Accordingly, the contact holding force of the movable core in the electromagnetic drive mechanism can also be reduced, and the diameter of the movable core, the elastic force of the return spring, the attractive force of the coil, etc., can be reduced. This further reduces the amount of explosive required for the pyrotechnic excitation device and improves the reliability of the pyrotechnic excitation device. Thirdly, it can accelerate the disconnection of the contacts and enhance electrical safety.

[0102] The present invention will be further described below with reference to the drawings and specific embodiments.

[0103] Example 10 Referring to Figures 33 to 34, an embodiment of the present invention provides a relay equipped with a pyrotechnic excitation device, the relay comprising a relay body 100 and a pyrotechnic excitation device 5 attached to the relay body 100, the relay body 100 comprising a fixed contact 1 (as a fixed contact part) and a movable contact 2 (as a movable contact part) that realize conduction or interruption, the relay body 100 further comprising a case body 3, the fixed contact 1 having one end exposed from the case body 3 and electrically connected to an external load, and the other end entering the interior of the case body 3, the movable contact 2 being provided inside the case body 3 and connected to an electromagnetic drive mechanism 4. Here, the fixed contact 1 is provided with a female screw used for fixing to an external terminal by screw connection. The movable contact 2 is a bridge-type movable contact, and through the action of the electromagnetic drive mechanism 4, the movable contact 2 can move closer to or further away from the fixed contact 1, and when the movable contact 2 contacts both fixed contacts 1 simultaneously, it achieves load communication. For the sake of explanation, it is defined that the fixed contact 1 is located relatively above the movable contact 2, and the movable contact 2 is located relatively below the fixed contact 1.

[0104] The relay body 100 further includes a ceramic cover 6, which is fixedly installed inside the case body 3 and covers the lower end of the fixed contact 1 and the movable contact 2 (i.e., covers the fixed contact 1 and the movable contact 2 and their contacts), thereby forming a contact cavity. The ceramic cover 6 isolates the contacts between the fixed contact 1 and the movable contact 2 from the outside air, resulting in high pressure resistance and effectively ensuring low contact resistance, long life, and high reliability of the relay. Furthermore, in the event of a short circuit, the arc resistance and high temperature resistance characteristics of the ceramic material ensure the safety and reliability of the circuit in the event of a short-circuit arc.

[0105] The case body 3 further includes a base 32 and an upper cover 31 which are joined together, the ceramic cover 6 is provided inside the upper cover 31, the pyrotechnic excitation device 5 is inserted into the ceramic cover 6 from the outside and fixedly connected, the lower end of the pyrotechnic excitation device 5 extends into the contact cavity inside the ceramic cover 6 so as to face directly above the movable contact 2, and the upper cover 31 further covers the ceramic cover 6 and the pyrotechnic excitation device 5 to complete the assembly of the entire relay. Referring to Figure 34, the pyrotechnic excitation device 5 is an independent modular structure, its external shape is a substantially columnar rotating structure, an insertion hole 61 is provided at the upper end of the ceramic cover 6, and the lower end of the pyrotechnic excitation device 5 penetrates this insertion hole 61 and enters the contact cavity. The pyrotechnic excitation device 5 may be fixed to the ceramic cover 6 by welding, crimping, screwing, etc., but in this embodiment, the pyrotechnic excitation device 5 is fixed to the ceramic cover 6 by brazing. In this embodiment, the upper surface of the upper cover 31 has through holes and a hollow cylindrical section that retract and align with two fixed contacts 1 and one pyrotechnic excitation device 5, so that the tips of the two fixed contacts 1 are exposed from the case body 3, and the outside of the pyrotechnic excitation device 5 can be covered and protected. In addition, to enhance electrical safety, protective baffle plates extend from both sides of the outer wall of this hollow cylindrical section in a direction perpendicular to the plane of the drawing (not shown depending on the angle). In other embodiments, the pyrotechnic excitation device 5 may be fixedly connected to the case body 3. However, in this embodiment, by configuring the pyrotechnic excitation device 5 to be fixedly connected to the ceramic cover 6, the assembly process can be simplified. At the time of final assembly, the pyrotechnic excitation device 5 and the fixed contact 1 are fixed to the ceramic cover 6 and then the upper cover 31 is placed over them.

[0106] Referring to Figures 35 to 38, the pyrotechnic excitation device 5 specifically includes an exciter 51, a piston 52 (as a push medium), and a bottom case 53. The exciter 51 and the bottom case 53 are joined and fixed to each other from above and below, and the piston 52 is housed between the exciter 51 and the bottom case 53. Here, the exciter 51 further includes a hollow exciter base 512, a connector 511 fixedly mounted inside the exciter base 512, an igniter 513, and a seal ring 514. The exciter base 512 has a cylindrical structure with a first flange 510 at its lower end, and the bottom case 53 also has a hollow cylindrical structure with a second flange 532 at its upper end, and the first flange 510 and the second flange 532 are butted together and fixed (for example, by welding, crimping, or screwing) to achieve the joint fixing of the exciter 51 and the bottom case 53. The lower end of the bottom case 53 enters the contact cavity of the ceramic cover 6, and the second flanging 532 is fixed to the ceramic cover 6 by brazing, thereby achieving a fixed connection between the pyrotechnic excitation device 5 and the ceramic cover 6. As shown in Figure 36, an annular rib 531 is provided on the side of the second flanging 532 facing the ceramic cover 6, and by providing this annular rib 531, the stability of the brazing between the second flanging 532 and the ceramic cover 6 can be further improved. In addition, the first flanging 510 and the second flanging 532 form an enlarged diameter portion that expands outward, further sealing the insertion hole 61, thereby ensuring the airtightness of the ceramic cover 6.

[0107] In this embodiment, the exciter base 512 and the bottom case 53 are joined and fixed to each other to form the case body of the pyrotechnic type excitation device 5. The connector 511, igniter 513, seal ring 514, and piston 52 are sequentially installed inside the case body from top to bottom, and the connector 511 is connected to the lead 5131 of the igniter 513. Here, the connector 511 is engaged and fixed to the inner wall of the exciter base 512, the seal ring 514 is press-fitted into the exciter base 512 by interference fit and also presses the igniter 513 upward and fixes it, and the upper and lower ends of the piston 52 abut against the seal ring 514 and the bottom case 53, respectively. The seal ring 514 provides moisture-proof and airtight sealing effects, and the slight deformation caused by the pressure on the seal ring 514 can further press the igniter 513 above it and the piston 52 below it, preventing loosening due to vibration.

[0108] Referring to Figures 39 to 40, the connector 511 is fixedly connected to the ignition lead of the monitoring-excitation circuit, thereby transmitting the excitation electrical signal emitted by the monitoring-excitation circuit to excite the igniter 513. The monitoring-excitation circuit monitors when the current value (or current rise rate) reaches a predetermined threshold, and then the emitted excitation electrical signal is transmitted downward through the connector 511, exciting the igniter 513 and causing ignition. A gap 50 is provided between the piston 52 and the igniter 513. After the igniter 513 ignites the gunpowder, high-pressure fuel gas is generated in this gap 50 (i.e., ignited), pushing the piston 52 and breaking through the bottom case 53 downwards. Furthermore, the piston 52 moves the movable contact 2 downwards, which helps the movable contact 2 disengage from contact with the fixed contact 1, enabling rapid tripping of the relay.

[0109] Since the bottom case 53 is a hollow cylindrical structure and the piston 52 is a rotating body structure that fits into the inside of the bottom case 53 through an axial hole, the bottom case 53 can act as a guide for the piston 52, and after the ignition device 513 is ignited, the piston 52 moves downward along the axial direction of the hollow cylindrical lumen of the bottom case 53.

[0110] In this embodiment, the pyrotechnic excitation device is moved downward using the piston 52. However, in other embodiments, the pyrotechnic excitation device can be made to ignite the gunpowder using only the igniter 513, generate high-pressure fuel gas to break through the bottom case 53 and push the movable contact 2, without providing a piston. In other words, the pushing medium for the pyrotechnic excitation device to push the movable contact 2 downward may be the high-pressure fuel gas itself or the piston 52.

[0111] In this embodiment, the pyrotechnic excitation device 5 has a modular structure, is independent of the relay body, and can be manufactured separately and then permanently attached to the relay. This facilitates the management of the manufacturing and transportation of the pyrotechnic excitation device 5, reduces the number of parts, simplifies assembly, facilitates the standardization of parts, and achieves the objectives of reducing weight, lowering costs, and improving performance. Furthermore, the lead 5131 extending from the igniter 513 is connected to the ignition lead of the monitoring excitation circuit via the connector 511, so that the explosive in the igniter 513 is far from the lead end of the ignition lead, resulting in a smaller temperature rise and reduced temperature resistance requirements for the chemical agent.

[0112] The pyrotechnic excitation device 5 according to this embodiment is applied to a ceramic-sealed relay. Specifically, by welding the pyrotechnic excitation device 5 to the ceramic cover 3, the weld fastening is good, the sealing and vibration resistance of the pyrotechnic excitation device 5 are superior, and the molding of the case body of the pyrotechnic excitation device 5 is simpler, resulting in a lower product height. In other embodiments, the pyrotechnic excitation device 5 may be attached to the relay by providing an insertion hole (for example, the insertion hole 61 in this embodiment) in the relay body for insertion of the pyrotechnic excitation device 5, and by a fixed connection. It may also be applied to relays with other structures. The pyrotechnic excitation device 5 may also be fixed to the relay body by a detachable connection (e.g., screw fastening), so that the pyrotechnic excitation device 5 can be rapidly replaced in response to input demands.

[0113] As shown in Figure 40, the bottom case 53 is further provided with an arc-extinguishing medium 54. When the pyrotechnic excitation device 5 is excited, the piston 52 pierces the bottom case 53 downwards, releasing the arc-extinguishing medium 54 into the contact cavity of the ceramic cover 6. This extinguishes the contact gap between the fixed contact 1 and the movable contact 2, further accelerating the arc-extinguishing ability when the contact is closed and improving the short-circuit safety of the product. In this embodiment, the arc-extinguishing medium 54 is quartz sand. In addition to storing the arc-extinguishing medium 54 in the bottom case 53, in other embodiments, the arc-extinguishing medium 54 may be stored in the piston 52. For example, the lower end (impact part) of the piston 52 may be provided as a fragile structure having a hollow cylinder, and when the piston 52 collides with the movable contact 2, the lower end of the piston 52 may break due to the impact, generating a crack and releasing the arc-extinguishing medium 54. In this pyrotechnic excitation device 5, after ignition and explosion, the gas at its lower end expands rapidly, allowing the arc-extinguishing medium 54 stored in the bottom case 53 or piston 52 to be dispersed very rapidly and uniformly into the contact cavity along with the explosion gas. This minimizes the limitations imposed by the external shapes of the fixed contact 1 and the movable contact 2 and the contour of the contact cavity, enabling a direct arc-extinguishing effect in a short time. In this embodiment, the movable contact 2 is a bridge-type movable contact, with the fixed contact 1 positioned at both ends of the bridge-type movable contact, and the pyrotechnic excitation device 5 positioned on one side of the middle position of the movable contact 2. As a result, the expanding gas after ignition and explosion is blocked by the bridge-type movable contact, guiding the airflow to both ends of the bridge-type movable contact, thereby allowing the arc-extinguishing medium 54 to reach the region between the fixed contact 1 and the movable contact 2 more directly.

[0114] Referring to Figures 39 to 40, the electromagnetic drive mechanism 4 is used to move the movable contact 2. Specifically, the electromagnetic drive mechanism 4 includes a fixed core 41, a coil 42, a movable core 43, a push rod assembly 44, a return spring 45, a first yoke member 46, a second yoke member 47, and a magnetic guide tube 48 for transmitting magnetic field lines and improving the utilization rate of magnetic energy. The lower end of the push rod assembly 44 is fixedly connected to the movable core 43, and the upper end is connected in conjunction with the movable contact 2. One end of the return spring 45 acts on the fixed core 41, and the other end acts on the movable core 43. By energizing the coil 42, the fixed core 41 attracts the movable core 43 and moves it upward, causing the push rod 44 to move the movable contact 2 upward. If the coil 42 is de-energized, the electromagnetic drive mechanism 4 returns to its original position due to the elastic force of the return spring 45. The electromagnetic drive mechanism 4 is a typical linear magnetic circuit structure, and its operating principle will not be explained in detail in this example.

[0115] Referring to Figures 41 and 42, the push rod assembly 44 includes a push rod 441, a spring base 442, and a U-shaped bracket 443. The push rod 441 is used to output the driving force of the electromagnetic drive mechanism 4, with its lower end fixedly connected to the movable core 43 (see Figure 40) and its upper end fixedly connected to the spring base 442. The U-shaped bracket 443 is a sheet-like structure and includes a top plate 4431 provided above the spring base 442, and two side plates 4432 connected to both ends of the top plate 4431 and extending downward. The lower ends of the two side plates 4432 are fixedly connected to both ends of the spring base 442, thereby connecting the spring base 442 and the U-shaped bracket 443 to form a rectangular hollow limiting frame 400. The lower end of the overtravel spring 445 (as an overtravel elastic member) abuts against the spring base 442, and the movable contactor 2 penetrates the limiting frame 400 and abuts against the top plate 4431 by the elastic force of the overtravel spring 445. Thus, the overtravel spring 445 and the movable contactor 2 are stably mounted within the limiting frame 400 by the elastic force of the overtravel spring 445.

[0116] Referring to Figures 43 and 44, this embodiment uses a spring base 442 and a U-shaped bracket 443 to form a limiting frame 400. When the pyrotechnic excitation device 5 is excited, the piston 52 strikes the limiting frame 400 downward, causing the push rod assembly 44 and the movable contact 2 to move downward. After the spring base 442 is stopped by the internal structure of the relay, the impact force of the piston 52 further compresses the overtravel spring 445, causing the two side plates 4432 of the U-shaped bracket 443 to bend under the force, generating plastic deformation and crushing the entire limiting frame 400, preventing it from recovering. This further reduces the overall height of the push rod assembly 44 and the movable contact 2. The U-shaped bracket 443, by being positioned over the plate-shaped movable contact 2, can limit the rebound recovery of the movable contact 2 to the fixed contact 1. Furthermore, when the piston 52 delivers a downward impact, the limiting frame 400 is crushed, which widens the contact gap between the movable contact 2 and the fixed contact 1, thereby improving short-circuit safety. From another perspective, in this embodiment, since the limiting frame 400 formed by the spring base 442 and the U-shaped bracket 443 can be crushed, compared to other configurations in which the push rod assembly is not crushed, when the push rod assembly 44 and the movable contact 2 in this embodiment are impacted by the piston 52, a shorter downward movement path is sufficient to ensure a sufficiently wide contact gap (after the compression space due to the crushing of the limiting frame 400 is superimposed). For this reason, the height space of the contact cavity of the ceramic cover 6 can be set to an appropriate size, which can be adapted to the specifications of a relay that does not have a pyrotechnic excitation device 5 (conventional relays equipped with a pyrotechnic excitation device 5 require an increase in the height space of the contact cavity), thereby reducing the overall height and volume of the relay.

[0117] Referring to Figures 41 to 46, the pushrod assembly 44 further includes at least one pair of magnetic ring assemblies, each pair of magnetic ring assemblies including an upper conductor 447 and a lower conductor 446, the upper conductor 447 and the lower conductor 446 forming a magnetic circuit that surrounds at least a portion of the current-carrying conductor of the movable contact 2, thereby resisting the electric repulsive force caused by the short-circuit current when a large short-circuit current flows through the movable contact 2 by the magnetic attractive force of the upper conductor 447 on the lower conductor 446 pushing the movable contact 2 upward. Specifically, in this embodiment, the upper conductor 447 has a straight-line structure, and the lower conductor 446 has a U-shaped structure. The upper conductor 447 is fixedly connected to the lower side of the top plate 4431 and is provided above the movable contact 2. The lower conductor 446 and the movable contact 2 are fixedly connected such that the lower conductor 446 partially surrounds a portion of the current-carrying conductor of the movable contact 2. The opening of the U-shaped lower conductor 446 faces the upper conductor 447, so that the upper conductor 447 and the lower conductor 446 form a magnetic circuit.

[0118] The upper conductor 447 is fixedly connected to the top plate 4431, while the lower conductor 446 is fixedly connected to the movable contact 2. Therefore, when the relay is in a conductive state, if the push rod assembly 44 pushes up the movable contact 2 and brings it into contact with the fixed contact 1, the stopper action of the fixed contact 1 prevents the lower conductor 446 from continuing to rise. However, the spring base 442 can further compress the overtravel spring 445, thereby allowing the limiting frame 400 to continue rising and creating a constant magnetic gap between the upper conductor 447 and the lower conductor 446. At the same time, further compression of the overtravel spring 445 enables contact overtravel when the relay is in a conductive state.

[0119] In this embodiment, a total of two magnetic guide ring assemblies are provided, and through holes 21 are opened at intermediate positions in the two width directions of the movable contact, separating the two current-carrying conductors in the two width directions of the movable contact through the through holes 21, and the two magnetic guide ring assemblies each surround the two current-carrying conductors to form independent magnetic guide circuits.

[0120] In addition to fixing the upper magnetic conductor 447 with the limiting frame 400 of this embodiment, other fixing structures may be used in other embodiments, for example, such as when a rod penetrates the movable contact 2 and the upper magnetic conductor is fixed to one end of the rod that exits the movable contact 2.

[0121] The “magnetic conduit ring assembly” provided in this embodiment means that the upper and lower conduits can form an annular magnetic conduit circuit. Specifically, one of the upper and lower conduits has a straight-line structure and the other has a U-shaped structure. In other embodiments, both the upper and lower conduits may have a straight-line structure, and such a structure can similarly form an annular magnetic conduit circuit (for example, a similar structure in Chinese patent CN103038851B), and also falls under the category of “magnetic conduit ring assembly” as defined in this embodiment.

[0122] As shown in Figure 46, in this embodiment, by providing two magnetic conduit circuits, the number of magnetic pole surfaces (a total of four) can be increased, improving magnetic efficiency and increasing the attractive force. When a large fault current occurs in the movable contact 2, an attractive force F is generated in the two independent magnetic conduit circuits, magnetic conduit circuit Φ1 and magnetic conduit circuit Φ2. By resisting the motorized repulsive force caused by the fault current between the movable contact and the fixed contact, resistance to short-circuit current is greatly improved. Furthermore, by dividing the movable contact 2 into two current-carrying conductors, current division can be achieved, and the divided current flowing through one current-carrying conductor is approximately half of the fault current. As a result, the magnetic conduit circuits do not become magnetically saturated, the magnetic flux increases, and the generated attractive force also increases.

[0123] For the structure and function of the magnetic guide ring assembly (upper guide 447 and lower guide 446), refer to Chinese utility model CN209000835U.

[0124] In this embodiment, a magnetic guide ring assembly is provided, which firstly improves the short-circuit resistance of the relay, allowing the relay to be used when high short-circuit resistance is required. Secondly, the reliability of the pyrotechnic excitation device 5 is improved by using an overtravel spring with a small elastic modulus k value or by reducing the compression amount of the overtravel spring. Thirdly, contact disconnection can be accelerated, thereby increasing electrical safety.

[0125] As described above, when a large fault current occurs in the movable contact 2, the magnetic guide ring assembly can generate an upward magnetic attractive force on the movable contact 2. This helps to resist the electric repulsion force caused by the large current in the load circuit between the movable contact 2 and the fixed contact 1 (the magnetic attractive force can increase synchronously with increasing electric repulsion force), significantly improving resistance to short-circuit current and thereby raising the upper limit of the excitation current setting for the pyrotechnic excitation device. In addition, in a typical relay without a magnetic guide ring assembly, the electric repulsion force is resisted only by the pressure on the movable contact 2 due to the elastic force of the overtravel spring. Since the electric repulsion force is large at the moment of short circuit (the short-circuit current has not yet reached the threshold to excite the pyrotechnic excitation device), it is necessary to set a large compression amount or elastic modulus of the overtravel spring to have sufficient elasticity to resist the electric repulsion force. The need to set a large compression amount or elastic modulus for the overtravel spring means that a larger external force is required to further compress the overtravel spring. Therefore, when the pyrotechnic excitation device 5 is excited, a large impact force is required to further compress the overtravel spring, further moving the movable contact 2 downwards. However, in this embodiment, because a magnetic conduit ring assembly is provided, when the load circuit current (or fault current) is large, the magnetic attraction force of the magnetic conduit ring assembly mainly resists the electric repulsion force, and the elastic force of the overtravel spring is smaller than the maximum electric repulsion force between the fixed contact 1 and the movable contact 2. As a result, the elastic force of the overtravel spring (contact pressure on the movable contact) can be set to a small value. In other words, an overtravel spring with a small elastic modulus k value can be used or the compression amount of the overtravel spring can be reduced. Therefore, it becomes easier to compress the overtravel spring, and the required impact force of the pyrotechnic excitation device 5 does not need to be so large. As a result, the amount of explosive in the pyrotechnic excitation device 5 can be reduced, and safety performance can be improved.Furthermore, the contact pressure of the overtravel spring on the movable contactor allows the contact holding force of the movable core 43 in the electromagnetic drive mechanism 4 to be reduced accordingly. In actual designs, this allows for reductions in the diameter of the movable core 43, the elastic force of the return spring 45, and the attractive force of the coil 42. This further reduces the amount of explosive required for the pyrotechnic excitation device, improving the reliability of the pyrotechnic excitation device. Additionally, since the piston 52 collides downward and crushes the limiting frame 400, it limits the rebound recovery of the movable contactor 2 against the fixed contactor 1, making it easier for the overtravel spring to be compressed. This increases the energy required for the piston 52 to impact the limiting frame 400, ensuring that the limiting frame 400 cannot recover from its deformation. Furthermore, if the short-circuit current is too high and triggers the predetermined monitoring current value of the monitoring excitation circuit, the attractive force of the lower conductor 446 on the upper conductor 447 increases, and an electric repulsive force is superimposed on the magnetic attractive force of the lower conductor 446 on the upper conductor 447. As a result, the magnetic attractive force of the fixed core 41 on the movable core 43 becomes insufficient to support the movable core 43 and the push rod assembly 44. At this time, the movable core 43 falls off first, pushing the push rod assembly 44 and the movable contact 2 downwards. As the piston 52 moves, the pyrotechnic excitation device 5 is excited, and the piston 52 collides downward against the U-shaped bracket 443 until the upper conductor 447 contacts the movable contact 2. The upper conductor 447, the movable contact 2, and the lower conductor 446 are integrated, and the magnetic attraction between the upper conductor 447 and the lower conductor 446 becomes an internal force. Finally, the movable contact 2 detaches from the fixed contact 1, and the magnetic attraction of the conductor ring assembly to resist the electric repulsion force is eliminated. In this process, the downward force of the electric repulsion force is superimposed on the thrust of the piston 52, pushing the movable contact 2 further downward and accelerating its movement, accelerating the disconnection of the contact, shortening the disconnection time, and further improving the electrical safety of the product.

[0126] This embodiment describes the function and effect of structures such as the pyrotechnic excitation device 5, magnetic guide ring assembly, and pushrod assembly 44 using the structure of a relay, but a similar structure can be applied to other switching devices other than relays, such as contactors.

[0127] Example 11 Referring to Figure 47, this embodiment provides a relay with a structure similar to the relay of Embodiment 10, the difference being that in this embodiment, the movable contact 2A is provided with only one set of conductor ring assemblies, including the upper conductor 447A and the lower conductor 446A. This embodiment is suitable for relays with a shorter short-circuit resistance than that of Embodiment 10, and using only one set of conductor ring assemblies simplifies the number and structure of parts, making manufacturing and assembly easier.

[0128] Example 12 Referring to Figure 48, this embodiment provides a relay with a structure similar to the relay of Embodiment 10, the difference being that in this embodiment the movable contact 2B is provided with three sets of magnetic guide ring assemblies, each set of magnetic guide ring assemblies including an upper guide body 447B and a lower guide body 446B. This embodiment is suitable for relays with a higher short-circuit resistance than that of Embodiment 10, as the short-circuit resistance of the relay can be improved by improving the magnetic attraction force of the magnetic guide ring assemblies.

[0129] Furthermore, since a pyrotechnic excitation device is used to rapidly shut off the movable contact by applying an impact, a larger space is required to accommodate the piston stroke of the pyrotechnic excitation device. In addition, because a pyrotechnic excitation device needs to be installed, the volume of the relay equipped with the pyrotechnic excitation device increases, which is disadvantageous for achieving miniaturization of the product.

[0130] Therefore, the present invention further provides a switching electric device equipped with a pyrotechnic excitation device with an optimized structure.

[0131] This invention provides the following technical solution.

[0132] The present invention provides a switching electrical device equipped with a pyrotechnic excitation device, the switching electrical device comprising a switching electrical device body and a pyrotechnic excitation device provided on the body, the switching electrical device body performing a switching function by comprising a linear electromagnetic drive mechanism, a fixedly provided fixed contact portion and a movable contact portion, the linear electromagnetic drive mechanism achieving conduction or interruption of a circuit by moving the movable contact portion closer to or further away from the fixed contact portion, the pyrotechnic excitation device comprising a push medium for performing downward movement, and after the push medium has moved downward, moving the movable contact portion away from the fixed contact portion, the switching electrical device further comprising a limiting member, the limiting member provided according to the position in which the piston moves downward and assembled by coupling with the movable contact portion, the limiting member configured to restrict the movable contact portion from returning toward the fixed contact portion. The material of the limiting member is a material that allows the deformation not to recover after being subjected to impact from the push medium.

[0133] Here, the push medium is a high-pressure fuel gas generated by the ignition of the pyrotechnic excitation device, or the push medium is a piston.

[0134] In one embodiment, the limiting member is a limiting frame, and the limiting frame is crushed so that the deformation cannot be recovered after being impacted by the push medium, thereby restricting the movable contact portion from returning toward the fixed contact portion.

[0135] In one embodiment, the limiting member was made of stainless steel or low-carbon steel.

[0136] Herein, from the viewpoint of manufacturing and installation, in one embodiment, the movable contact portion has a plate-like structure, and the limiting frame is provided across the plate-like movable contact portion, thereby restricting it from returning toward the fixed contact portion.

[0137] In one embodiment, the linear electromagnetic drive mechanism includes a push rod, the limiting frame is fixedly connected to the end of the push rod, the movable contact portion penetrates the limiting frame, and the overtravel elastic member is fixedly mounted inside the limiting frame. The elastic force of the overtravel elastic member presses the movable contact portion toward the upper end of the limiting frame, the limiting frame moves upward to bring the movable contact portion and the fixed contact portion into contact, and then the linear electromagnetic drive mechanism continues to move the push rod and the limiting frame upward, compressing the overtravel elastic member to achieve overtravel of the movable contact portion.

[0138] Herein, from the standpoint of manufacturing and installation, in one embodiment, the limiting frame includes an upper U-shaped bracket and a lower straight bottom frame, the U-shaped bracket includes a top plate and two side plates extending downward from both ends of the top plate, the two side plates are fixedly connected to both ends of the bottom frame to form a rectangular frame-shaped limiting frame, and after the limiting frame is subjected to impact from the push medium, the side plates are bent, causing the limiting frame to be crushed in a way that the distortion cannot be recovered. Alternatively, in another embodiment, the limiting frame includes a lower U-shaped bottom frame and an upper straight top plate, the bottom frame includes a base and two side plates extending upward from both ends of the base, the two side plates are fixedly connected to both ends of the top plate to form a rectangular frame-shaped limiting frame, and after the limiting frame is subjected to impact from the push medium, the side plates are bent, causing the limiting frame to be crushed in a way that the distortion cannot be recovered.

[0139] In one embodiment, to facilitate the bending of the side panels, the side panels have a perforated and / or flaky structure.

[0140] In this embodiment, the side panels are folded in a corrugated shape to facilitate their bending.

[0141] Here, the switching device is a DC high-voltage relay.

[0142] The present invention offers the following beneficial effects. By providing a limiting member that does not recover from deformation even when subjected to impact from the piston, the present invention restricts the movable contact from elastically rebounding and returning to the fixed contact when a pyrotechnic excitation device is excited. At the same time, the overall height of the push rod assembly and the movable contact is further reduced, further widening the contact gap between the movable and fixed contacts and improving short-circuit safety. The present invention ensures that a sufficient contact gap can be widened with only a shorter downward movement path, thereby appropriately reducing the height space of the contact cavity of the switching device, and thus reducing the overall height and volume of the switching device.

[0143] The present invention will be further described below with reference to the drawings and specific embodiments.

[0144] Example 13 Referring to Figures 49 to 50, an embodiment of the present invention provides a relay equipped with a pyrotechnic excitation device, the relay comprising a relay body 100 and a pyrotechnic excitation device 5 attached to the relay body 100, the relay body 100 comprising a fixed contact 1 (as a fixed contact part) and a movable contact 2 (as a movable contact part) that realize conduction or interruption, the relay body 100 further comprising a case body 3, the fixed contact 1 having one end exposed from the case body 3 and electrically connected to an external load, and the other end extending into the interior of the case body 3, the movable contact 2 being provided inside the case body 3 and connected to an electromagnetic drive mechanism 4. Here, the fixed contact 1 is provided with a female screw used for fixing to an external terminal by screw connection. The movable contact 2 is a bridge-type movable contact, and through the action of the electromagnetic drive mechanism 4, the movable contact 2 can move closer to or further away from the fixed contact 1, and when the movable contact 2 contacts both fixed contacts 1 simultaneously, it achieves load communication. For the sake of explanation, it is defined that the fixed contact 1 is located relatively above the movable contact 2, and the movable contact 2 is located relatively below the fixed contact 1.

[0145] The relay body 100 further includes a ceramic cover 6, which is fixedly installed inside the case body 3 and covers the lower end of the fixed contact 1 and the movable contact 2 (i.e., covers the fixed contact 1 and the movable contact 2 and their contacts), thereby forming a contact cavity. The ceramic cover 6 isolates the contacts between the fixed contact 1 and the movable contact 2 from the outside air, resulting in high pressure resistance and effectively ensuring low contact resistance, long life, and high reliability of the relay. Furthermore, in the event of a short circuit, the arc resistance and high temperature resistance characteristics of the ceramic material ensure the safety and reliability of the circuit in the event of a short-circuit arc.

[0146] The case body 3 further includes a base 32 and an upper cover 31 joined to each other, the ceramic cover 6 is provided inside the upper cover 31, the pyrotechnic excitation device 5 is inserted into the ceramic cover 6 from the outside and fixedly connected, the lower end of the pyrotechnic excitation device 5 extends into the contact cavity inside the ceramic cover 6 so as to face directly above the movable contact 2, and the upper cover 31 further covers the ceramic cover 6 and the pyrotechnic excitation device 5 to complete the assembly of the entire relay. Referring to Figure 50, the pyrotechnic excitation device 5 is an independent modular structure, its external shape is a substantially columnar rotating body structure, an insertion hole 61 is provided at the upper end of the ceramic cover 6, and the lower end of the pyrotechnic excitation device 5 extends through this insertion hole 61 into the contact cavity. The pyrotechnic excitation device 5 may be fixed to the ceramic cover 6 by welding, crimping, screwing, etc., but in this embodiment, the pyrotechnic excitation device 5 is fixed to the ceramic cover 6 by brazing. In this embodiment, the upper surface of the upper cover 31 has through holes and a hollow cylindrical section that retract and align with two fixed contacts 1 and one pyrotechnic excitation device 5, so that the tips of the two fixed contacts 1 are exposed from the case body 3, and the outside of the pyrotechnic excitation device 5 can be covered and protected. In addition, to enhance electrical safety, protective baffle plates extend from both sides of the outer wall of this hollow cylindrical section in a direction perpendicular to the plane of the drawing (not shown depending on the angle). In other embodiments, the pyrotechnic excitation device 5 may be fixedly connected to the case body 3. However, in this embodiment, by configuring the pyrotechnic excitation device 5 to be fixedly connected to the ceramic cover 6, the assembly process can be simplified. At the time of final assembly, the pyrotechnic excitation device 5 and the fixed contact 1 are fixed to the ceramic cover 6 and then the upper cover 31 is placed over them.

[0147] Referring to Figures 51 to 54, the pyrotechnic excitation device 5 specifically includes an exciter 51, a piston 52 (as a push medium), and a bottom case 53. The exciter 51 and the bottom case 53 are joined and fixed to each other from top to bottom, and the piston 52 is housed between the exciter 51 and the bottom case 53. Here, the exciter 51 further includes a hollow exciter base 512, a connector 511 fixedly mounted inside the exciter base 512, an igniter 513, and a seal ring 514. The exciter base 512 and the bottom case 53 are joined and fixed to each other to form the case body of the pyrotechnic excitation device 5. The connector 511, igniter 513, seal ring 514, and piston 52 are sequentially installed inside this case body from top to bottom, and the connector 511 is connected to the lead 5131 of the igniter 513. Here, the connector 511 is engaged with and fixed to the inner wall of the exciter base 512, the seal ring 514 is press-fitted into the exciter base 512 by interference fit and also presses the igniter 513 upward to fix it, and both the upper and lower ends of the piston 52 are in contact with the seal ring 514 and the bottom case 53, respectively. The seal ring 514 provides moisture-proof and airtight sealing effects, and the slight deformation caused by the pressure on the seal ring 514 can further press the igniter 513 above it and the piston 52 below it, thereby preventing loosening due to vibration.

[0148] Referring to Figures 55 and 56, the connector 511 is fixedly connected to the ignition lead of the monitoring-excitation circuit, thereby transmitting the excitation electrical signal emitted by the monitoring-excitation circuit to excite the igniter 513. The monitoring-excitation circuit monitors when the current value (or current rate of increase) reaches a predetermined threshold, and then the emitted excitation electrical signal is transmitted downward through the connector 511, exciting the igniter 513 and causing ignition. A gap 50 is provided between the piston 52 and the igniter 513. After the igniter 513 ignites the gunpowder, high-pressure fuel gas is generated in this gap 50 (i.e., ignited), pushing the piston 52 and breaking through the bottom case 53 downwards. Furthermore, the piston 52 moves the movable contact 2 downwards, which helps the movable contact 2 disengage from contact with the fixed contact 1, enabling rapid tripping of the relay.

[0149] The bottom case 53 of the pyrotechnic excitation device 5 is a hollow cylindrical structure, and the piston 52 is a rotating body structure that fits inside the bottom case 53 through an axial hole. Therefore, the bottom case 53 can act as a guide for the piston 52, and after the ignition device 513 is ignited, the piston 52 moves downward along the axial direction of the hollow cylindrical lumen of the bottom case 53.

[0150] In this embodiment, the pyrotechnic excitation device is moved downward using the piston 52. However, in other embodiments, the pyrotechnic excitation device can be made to ignite the gunpowder using only the igniter 513, generate high-pressure fuel gas to break through the bottom case 53 and push the movable contact 2, without providing a piston. In other words, the pushing medium for the pyrotechnic excitation device to push the movable contact 2 downward may be the high-pressure fuel gas itself or the piston 52.

[0151] Referring to Figures 55 and 56, the electromagnetic drive mechanism 4 is used to move the movable contact 2. In Figure 55, the electromagnetic drive mechanism 4 specifically includes a fixed core 41, a coil 42, a movable core 43, a push rod assembly 44, a return spring 45, a first yoke member 46, a second yoke member 47, and a magnetic guide tube 48 for transmitting magnetic field lines and improving the utilization rate of magnetic energy. The lower end of the push rod assembly 44 is fixedly connected to the movable core 43, and the upper end is connected in conjunction with the movable contact 2. One end of the return spring 45 acts on the fixed core 41, and the other end acts on the movable core 43. By energizing the coil 42, the fixed core 41 attracts the movable core 43 and moves it upward, causing the push rod 44 to move the movable contact 2 upward. If the coil 42 fails, the electromagnetic drive mechanism 4 returns to its original position due to the elastic force of the return spring 45. The electromagnetic drive mechanism 4 is a typical linear magnetic circuit structure, and its operating principle will not be explained in detail in this example.

[0152] Referring to Figures 57-58, the pushrod assembly 44 includes a pushrod 441, a spring base 442 (as a bottom frame), and a U-shaped bracket 443. The pushrod 441 is used to output the driving force of the electromagnetic drive mechanism 4, with its lower end fixedly connected to the movable core 43 (see Figure 56) and its upper end fixedly connected to the spring base 442. The U-shaped bracket 443 is a sheet-like structure and includes a top plate 4431 positioned horizontally above the spring base 442, and two side plates 4432 connected to both ends of the top plate 4431 and extending downward. The lower ends of the two side plates 4432 are fixedly connected to both ends of the spring base 442, thereby connecting the spring base 442 and the U-shaped bracket 443 to form a rectangular hollow limiting frame 400. The lower end of the overtravel spring 445 abuts against the spring base 442, and the movable contact 2 penetrates the limiting frame 400 and abuts against the top plate 4431 by the elastic force of the overtravel spring 445. Thus, the overtravel spring 445 and the movable contact 2 are stably mounted within the limiting frame 400 by the elastic force of the overtravel spring 445. Furthermore, when the push rod assembly 44 pushes up and brings the movable contact 2 and the fixed contact 1 into contact, the spring base 442 can further compress the overtravel spring 445, enabling contact overtravel when the relay is in a conductive state.

[0153] Referring to Figures 56 and 59-60, this embodiment uses a spring base 442 and a U-shaped bracket 443 to form a limiting frame 400. When the pyrotechnic excitation device 5 is excited, the piston 52 strikes the limiting frame 400 downward, causing the push rod assembly 44 and the movable contact 2 to move downward. After the spring base 442 is locked into the internal structure of the relay, the impact force of the piston 52 further compresses the overtravel spring 445, causing the two side plates 4432 of the U-shaped bracket 443 to bend under the force, generating plastic deformation and crushing the entire limiting frame 400, preventing it from recovering. This further reduces the overall height of the push rod assembly 44 and the movable contact 2. The U-shaped bracket 443, by being positioned over the plate-shaped movable contact 2, can limit the rebound recovery of the movable contact 2 to the fixed contact 1. Furthermore, when the piston 52 delivers a downward impact, the limiting frame 400 is crushed, which widens the contact gap between the movable contact 2 and the fixed contact 1, thereby improving short-circuit safety. From another perspective, in this embodiment, since the limiting frame 400 formed by the spring base 442 and the U-shaped bracket 443 can be crushed, compared to other configurations in which the push rod assembly is not crushed, when the push rod assembly 44 and the movable contact 2 in this embodiment are impacted by the piston 52, a shorter downward movement path is sufficient to ensure a sufficiently wide contact gap (after the compression space due to the crushing of the limiting frame 400 is superimposed). For this reason, the height space of the contact cavity of the ceramic cover 6 can be set to an appropriate size, which can be adapted to the specifications of a relay that does not have a pyrotechnic excitation device 5 (conventional relays equipped with a pyrotechnic excitation device 5 require an increase in the height space of the contact cavity), thereby reducing the overall height and volume of the relay.

[0154] In some embodiments, the U-shaped bracket 443 was manufactured from a material that does not recover from distortion, such as stainless steel or low-carbon steel. Also in this embodiment, since the side plate 4432 has a thin, openwork structure, it becomes easier for the side plate 4432 to be bent when subjected to force.

[0155] In addition to using the limiting frame 400 of this embodiment to restrict the mounting position of the movable contact 2 and to restrict the rebound recovery of the movable contact 2 towards the fixed contact 1, other limiting members can be used instead of the limiting frame 400 in other embodiments. For example, the movable contact 2 is fixedly connected to the end of a rod, but the main body of this rod is designed to be compressed axially when subjected to impact and the deformation does not recover. This limiting member can be implemented as long as it can restrict the movable contact 2 from returning toward the fixed contact 1 and is assembled by coupling with the movable contact 2.

[0156] This embodiment describes the function and effect of the pyrotechnic excitation device 5 and pushrod assembly 44 using the structure of a relay, but a similar structure can be applied to other switching devices other than relays, such as contactors.

[0157] Example 14 Referring to Figure 61, this embodiment provides a relay including a fixed contact portion 1A and a movable contact portion 2A, wherein the movable contact portion 2A has a seesaw structure and is driven by an electromagnetic drive mechanism 4A to contact or disengage from the fixed contact portion 1A. The relay further includes a pyrotechnic excitation device, which includes a piston 52A, and after the piston 52A moves downward, the movable contact portion 2A can be separated from the fixed contact portion 1A. A limiting frame 400A is provided correspondingly below the piston 52A, and the limiting frame 400A is provided across the seesaw-type movable contact portion 2A, and the limiting frame 400A restricts the movable contact portion 2A from returning toward the fixed contact portion 1A by being crushed so that the deformation cannot be recovered after being struck by the piston 52A.

[0158] In other words, the limiting member (limiting frame 400A) can be applied not only to the linear contact circuit of Example 13, but also to the seesaw contact circuit of this embodiment. However, any contact circuit structure that limits the movable contact portion by utilizing the characteristic that the distortion of the limiting member cannot be recovered is feasible.

[0159] Example 15 This embodiment provides a relay whose structure is similar to that of the relay of Embodiment 13, the difference being the structure of the limiting frame of the pushrod assembly. Referring to Figures 62-63, in this embodiment the limiting frame includes a U-shaped spring base 442A (as the bottom frame) and a top plate 443A. The spring base 442A includes a base 442A-2 and side plates 442A-1 extending upward from both ends of the base 442A-2. The side plates 442A-1 are fixedly connected to the top plate 443A, so that the spring base 442A is connected to the top plate 443A and forms the limiting frame. When subjected to impact from the piston, the side plates 442A-1 bend and the entire limiting frame is crushed.

[0160] The difference between this embodiment and Embodiment 13 is that in Embodiment 13, the structure of the limiting frame 400 is realized by fitting and connecting an inverted U-shaped U-shaped bracket 443 to a straight spring base 442 below it, whereas in this embodiment, the structure of the limiting frame 400 is realized by fitting and connecting a U-shaped spring base 442A to a top plate 443A above it. Although this example has a different structure from Embodiment 13, it has similar technical effects.

[0161] In this embodiment and embodiment 13, the side plates may be integrally connected to the spring base (i.e., the structure of the U-shaped spring base 442A) or integrally connected to the top plate (i.e., the structure of the U-shaped bracket 443). In other embodiments, the side plates can be made as an independent structure, and both ends of the side plates can be fixedly connected to the top plate and the spring base, respectively, during assembly to obtain a limiting frame.

[0162] Example 16 This embodiment provides a relay whose structure is similar to that of the relay in Embodiment 13, the difference being the structure of the U-shaped bracket. Referring to Figures 64-65, in this embodiment, the side plate 4432B of the U-shaped bracket 443B is corrugated, not flat like in Embodiment 13. The corrugated structure of the side plate 4432B in this embodiment makes it easier for the side plate 4432B to bend under force, thereby adaptively reducing the explosive force of the pyrotechnic excitation device.

[0163] Furthermore, conventional relays equipped with pyrotechnic excitation devices often lack an arc extinguishing system because they require separate space for the pyrotechnic excitation device. This results in poor arc extinguishing capabilities and insufficient re-ignition prevention performance.

[0164] Therefore, the present invention further provides a switching electric device equipped with a pyrotechnic excitation device with an optimized structure.

[0165] This invention provides the following technical solution.

[0166] The present invention provides a switching electrical device equipped with a pyrotechnic excitation device, the switching electrical device comprising a switching electrical device body and a pyrotechnic excitation device provided on the body, the switching electrical device body performing a switching function by including a fixed contact portion and a movable contact portion, the pyrotechnic excitation device rapidly shutting off the switching electrical device by igniting gunpowder and generating an explosive shock force, thereby separating the movable contact portion from the fixed contact portion. The pyrotechnic excitation device includes an exciter, a piston, and a bottom case, wherein the exciter ignites gunpowder and uses fuel gas to push the piston, causing it to break through the bottom case, and the piston again impacts the movable contact portion, separating it from the fixed contact portion, and the switching device further includes an arc-extinguishing medium, which is provided inside the bottom case or the piston, and after the bottom case or the piston breaks, the arc-extinguishing medium is released into the space between the contact point of the movable contact portion and the fixed contact portion, thereby extinguishing the arc generated between the contact point of the movable contact portion and the fixed contact portion.

[0167] Herein, from the viewpoint of manufacturing and installation, in one embodiment, the switching electrical unit body includes a case body and a ceramic cover provided inside the case body, the ceramic cover covers the fixed contact portion and the movable contact portion and their contact portions to form a contact cavity, the contact between the movable contact portion and the fixed contact portion is provided in the contact cavity, and the arc generated between the contact between the movable contact portion and the fixed contact portion is extinguished by scattering the arc extinguishing medium into the contact cavity by the explosive impact force of the pyrotechnic excitation device.

[0168] In one embodiment, the piston is provided with a groove that opens toward the exciter, and the arc-extinguishing medium is solid and stored in the groove.

[0169] In one embodiment, the arc-extinguishing medium is stored within the piston, and at least the impact portion of the piston is made of a brittle material.

[0170] In this embodiment, the arc-extinguishing medium is quartz sand.

[0171] In one embodiment, the piston has a sealed seal cavity, and the arc extinguishing medium is a gas or a liquid and is sealed in the seal cavity.

[0172] In one embodiment, the arc extinguishing medium is sulfur hexafluoride gas or transformer oil.

[0173] In one embodiment, the piston or bottom case has a structure that gradually contracts in the direction toward the movable contact portion.

[0174] In one embodiment, the switching device body includes a case body, the movable contact portion is provided inside the case body, and the pyrotechnic excitation device enters the inside of the case body so as to face the movable contact portion.

[0175] In one embodiment, the movable contact portion is a bridge-type movable contact, the fixed contact portion is two fixed contacts provided at both ends of the bridge-type movable contact, the pyrotechnic excitation device is provided corresponding to one side of the middle position of the bridge-type movable contact, and after the piston penetrates the bottom case, the fuel gas generated by the ignition explosion of the pyrotechnic excitation device is guided to both ends of the bridge-type movable contact by the piston and the bottom case, and rapidly reaches the space between the contact points of the bridge-type movable contact and the fixed contacts.

[0176] Here, the switching device is a DC high-voltage relay.

[0177] The present invention offers the following beneficial effects. The present invention uses a piston in a pyrotechnic excitation device to penetrate the bottom case downwards, releasing the arc-extinguishing medium into the contact cavity of the switching device, performing arc extinguishing, further accelerating the arc-extinguishing capability when the contacts are disconnected, and improving the short-circuit safety of the product.

[0178] The present invention will be further described below with reference to the drawings and specific embodiments.

[0179] Example 17 Referring to Figures 66 to 67, an embodiment of the present invention provides a relay equipped with a pyrotechnic excitation device, the relay comprising a relay body 100 and a pyrotechnic excitation device 5 attached to the relay body 100, the relay body 100 comprising a fixed contact 1 (as a fixed contact part) and a movable contact 2 (as a movable contact part) that realize conduction or interruption, the relay body 100 further comprising a case body 3, the fixed contact 1 having one end exposed from the case body 3 and electrically connected to an external load, and the other end extending into the interior of the case body 3, the movable contact 2 being provided inside the case body 3 and connected to an electromagnetic drive mechanism 4. Here, the fixed contact 1 is provided with a female screw used for fixing to an external terminal by screw connection. The movable contact 2 is a bridge-type movable contact, and through the action of the electromagnetic drive mechanism 4, the movable contact 2 can move closer to or further away from the fixed contact 1, and when the movable contact 2 contacts both fixed contacts 1 simultaneously, it achieves load communication. For the sake of explanation, it is defined that the fixed contact 1 is located relatively above the movable contact 2, and the movable contact 2 is located relatively below the fixed contact 1.

[0180] The relay body 100 further includes a ceramic cover 6, which is fixedly installed inside the case body 3 and covers the lower end of the fixed contact 1 and the movable contact 2 (i.e., covers the fixed contact 1 and the movable contact 2 and their contacts), thereby forming a contact cavity. The ceramic cover 6 isolates the contacts between the fixed contact 1 and the movable contact 2 from the outside air, resulting in high pressure resistance and effectively ensuring low contact resistance, long life, and high reliability of the relay. In the event of a short circuit, the arc resistance and high temperature resistance characteristics of the ceramic material ensure the safety and reliability of the circuit in the event of a short-circuit arc.

[0181] The case body 3 further includes a base 32 and an upper cover 31 joined to each other, the ceramic cover 6 is provided inside the upper cover 31, the pyrotechnic excitation device 5 is inserted into the ceramic cover 6 from the outside and fixedly connected, the lower end of the pyrotechnic excitation device 5 enters the contact cavity inside the ceramic cover 6 so as to face directly above the movable contact 2, and the upper cover 31 further covers the ceramic cover 6 and the pyrotechnic excitation device 5 to complete the assembly of the entire relay. Referring to Figure 67, the pyrotechnic excitation device 5 is an independent modular structure, its external shape is a substantially columnar rotating body structure, an insertion hole 61 is provided at the upper end of the ceramic cover 6, and the lower end of the pyrotechnic excitation device 5 extends through this insertion hole 61 into the contact cavity. The pyrotechnic excitation device 5 may be fixed to the ceramic cover 6 by welding, crimping, screwing, etc., but in this embodiment, the pyrotechnic excitation device 5 is fixed to the ceramic cover 6 by brazing. In this embodiment, the upper surface of the upper cover 31 has through holes and a hollow cylindrical section that retract and align with two fixed contacts 1 and one pyrotechnic excitation device 5, so that the tips of the two fixed contacts 1 are exposed from the case body 3, and the outside of the pyrotechnic excitation device 5 can be covered and protected. In addition, to enhance electrical safety, protective baffle plates extend from both sides of the outer wall of this hollow cylindrical section in a direction perpendicular to the plane of the paper shown in the figure. In other embodiments, the pyrotechnic excitation device 5 may be fixedly connected to the case body 3. However, in this embodiment, by configuring the pyrotechnic excitation device 5 to be fixedly connected to the ceramic cover 6, the assembly process can be simplified. At the time of final assembly, the pyrotechnic excitation device 5 and the fixed contact 1 are fixed to the ceramic cover 6 and then the upper cover 31 is placed over them.

[0182] Referring to Figures 68 to 71, the pyrotechnic excitation device 5 specifically includes an exciter 51, a piston 52, and a bottom case 53. The exciter 51 and the bottom case 53 are joined and fixed to each other from above and below, and the piston 52 is housed between the exciter 51 and the bottom case 53. Here, the exciter 51 further includes a hollow exciter base 512, a connector 511 fixedly mounted inside the exciter base 512, an igniter 513, and a seal ring 514. The exciter base 512 has a cylindrical structure with a first flange 510 at its lower end, and the bottom case 53 also has a hollow cylindrical structure with a second flange 532 at its upper end, and the first flange 510 and the second flange 532 are butted together and fixed (for example, by welding, crimping, or screwing) to achieve the joint fixing of the exciter 51 and the bottom case 53. The lower end of the bottom case 53 enters the contact cavity of the ceramic cover 6, and the second flanging 532 is fixed to the ceramic cover 6 by brazing, thereby achieving a fixed connection between the pyrotechnic excitation device 5 and the ceramic cover 6. As shown in Figure 69, an annular rib 531 is provided on the side of the second flanging 532 facing the ceramic cover 6, and by providing this annular rib 531, the stability of the brazing between the second flanging 532 and the ceramic cover 6 can be further improved. In addition, the first flanging 510 and the second flanging 532 form an enlarged diameter portion that expands outward, further sealing the insertion hole 61, thereby ensuring the airtightness of the ceramic cover 6.

[0183] In this embodiment, the exciter base 512 and the bottom case 53 are joined and fixed to each other to form the case body of the pyrotechnic type excitation device 5. The connector 511, igniter 513, seal ring 514, and piston 52 are sequentially installed inside the case body from top to bottom, and the connector 511 is connected to the lead 5131 of the igniter 513. Here, the connector 511 is engaged and fixed to the inner wall of the exciter base 512, the seal ring 514 is press-fitted into the exciter base 512 by interference fit and also presses the igniter 513 upward and fixes it, and the upper and lower ends of the piston 52 abut against the seal ring 514 and the bottom case 53, respectively. The seal ring 514 provides moisture-proof and hermetically sealed effects, and the slight deformation caused by the pressure on the seal ring 514 can further press the igniter 513 above it and the piston 52 below it, preventing loosening due to vibration.

[0184] Referring to Figures 72 and 73, the connector 511 is fixedly connected to the ignition lead of the monitoring-excitation circuit, thereby transmitting the excitation electrical signal emitted by the monitoring-excitation circuit to excite the igniter 513. The monitoring-excitation circuit monitors when the current value (or current rate of increase) reaches a predetermined threshold, and then the emitted excitation electrical signal is transmitted downward through the connector 511, exciting the igniter 513 and causing ignition. A gap 50 is provided between the piston 52 and the igniter 513. After the igniter 513 ignites the gunpowder, high-pressure fuel gas is generated in this gap 50 (i.e., ignited), pushing the piston 52 and breaking through the bottom case 53 downwards. Furthermore, the piston 52 moves the movable contact 2 downwards, which helps the movable contact 2 disengage from contact with the fixed contact 1, enabling rapid tripping of the relay.

[0185] The bottom case 53 of the pyrotechnic excitation device 5 is a hollow cylindrical structure, and the piston 52 is a rotating body structure that fits inside the bottom case 53 through an axial hole. Therefore, the bottom case 53 can act as a guide for the piston 52, and after the ignition device 513 is ignited, the piston 52 moves downward along the axial direction of the hollow cylindrical lumen of the bottom case 53.

[0186] In this embodiment, the pyrotechnic excitation device 5 has a modular structure, is independent of the relay body, and can be manufactured separately and then permanently attached to the relay. This facilitates the management of the manufacturing and transportation of the pyrotechnic excitation device 5, reduces the number of parts, simplifies assembly, facilitates the standardization of parts, and achieves the objectives of reducing weight, lowering costs, and improving performance. Furthermore, the lead 5131 extending from the igniter 513 is connected to the ignition lead of the monitoring excitation circuit via the connector 511, so that the explosive in the igniter 513 is far from the lead end of the ignition lead, resulting in a smaller temperature rise and reduced temperature resistance requirements for the chemical agent.

[0187] As an example, the pyrotechnic excitation device 5 according to this embodiment is applied to a ceramic-sealed relay. Specifically, by welding the pyrotechnic excitation device 5 to the ceramic cover 3, the weld fastening is good, the sealing and vibration resistance of the pyrotechnic excitation device 5 are superior, and the molding of the case body of the pyrotechnic excitation device 5 is simpler, resulting in a lower product height. In other embodiments, the pyrotechnic excitation device 5 may be attached to the relay by providing an insertion hole (for example, the insertion hole 61 in this embodiment) in the relay body for insertion of the pyrotechnic excitation device 5, and by a fixed connection. It may also be applied to relays with other structures. The pyrotechnic excitation device 5 may also be fixed to the relay body by a detachable connection (e.g., screw fastening), so that the pyrotechnic excitation device 5 can be rapidly replaced in response to input demands.

[0188] As shown in Figure 73, the bottom case 53 is further provided with an arc-extinguishing medium 54. When the pyrotechnic excitation device 5 is excited, the piston 52 pierces the bottom case 53 downwards, releasing the arc-extinguishing medium 54 into the contact cavity of the ceramic cover 6. This extinguishes the contact gap between the fixed contact 1 and the movable contact 2, further accelerating the arc-extinguishing capability when the contact is interrupted and improving the short-circuit safety of the product. In this embodiment, the arc-extinguishing medium 54 is quartz sand. In this pyrotechnic excitation device 5, after ignition and explosion, the gas at its lower end expands rapidly, and the arc-extinguishing medium 54 stored in the bottom case 53 is dispersed very rapidly and uniformly into the contact cavity along with the explosion gas. This minimizes the limitations imposed by the external shapes of the fixed contact 1 and the movable contact 2 and the contour of the contact cavity, allowing for a direct arc-extinguishing effect in a short time. In this embodiment, since the movable contact 2 is a bridge-type movable contact, the fixed contact 1 is provided at both ends of the bridge-type movable contact, and the pyrotechnic excitation device 5 is provided corresponding to one side of the middle position of the movable contact 2. As a result, the expanding gas after ignition and explosion is guided by the bottom case 53 and piston 52, and the airflow is guided to both ends of the bridge-type movable contact, thereby allowing the arc extinguishing medium 54 to reach the region between the fixed contact 1 and the movable contact 2 more directly.

[0189] In this embodiment, by storing the arc-extinguishing medium 54 in the bottom case 53, the internal space of the pyrotechnic excitation device 5 can be effectively utilized, which is advantageous for miniaturizing the pyrotechnic excitation device 5. Furthermore, since a seal ring 514 is provided inside the exciter 51, a moisture-proof effect can be achieved for the arc-extinguishing medium 54. The lower end of the pyrotechnic excitation device 5 in this embodiment extends into the inside of the case body 3 and faces directly above the movable contact 2. This allows the piston 52 of this embodiment to be brought even closer to the movable contact 2, shortening the distance of the piston 52 to the movable contact 2 and shortening the stroke of the piston 52. As a result, the piston 52 penetrates the bottom case 53 more quickly, releasing the arc-extinguishing medium 54 and achieving a rapid arc-extinguishing effect.

[0190] Referring to Figures 72-73, the electromagnetic drive mechanism 4 is used to move the movable contact 2. Specifically, the electromagnetic drive mechanism 4 includes a fixed core 41, a coil 42, a movable core 43, a push rod assembly 44, a return spring 45, and further includes a first yoke member 46, a second yoke member 47, and a magnetic guide tube 48 for transmitting magnetic field lines and improving the utilization rate of magnetic energy. The lower end of the push rod assembly 44 is fixedly connected to the movable core 43, and the upper end is connected in conjunction with the movable contact 2. One end of the return spring 45 acts on the fixed core 41, and the other end acts on the movable core 43. By energizing the coil 42, the fixed core 41 attracts the movable core 43 and moves it upward, causing the push rod 44 to move the movable contact 2 upward. If the coil 42 fails, the electromagnetic drive mechanism 4 returns to its original position by the elastic force of the return spring 45. The electromagnetic drive mechanism 4 is a typical linear magnetic circuit structure, and its operating principle will not be explained in detail in this example.

[0191] This embodiment describes the function and effect of the pyrotechnic excitation device 5 using the structure of a relay, but a similar structure can be applied to other switching devices, such as contactors.

[0192] Example 18 This embodiment provides a relay with a structure similar to the relay of Embodiment 17, the difference being that in this embodiment the arc-extinguishing medium is stored inside the piston. As shown in Figure 74, the piston 52A is provided with an upwardly open groove, and the arc-extinguishing medium 54A is stored inside the groove of the piston 52A. Furthermore, the lower end 52A-1 of the piston 52A (i.e., the impact point of the piston 52A) has a thin and fragile structure, and when the piston 52A impacts downward, the lower end 52A-1 breaks due to the impact and generates cracks, thereby releasing the arc-extinguishing medium 54A. In addition, this lower end 52A-1 may be made of a fragile material such as bakelite or PBT plastic.

[0193] In addition to the piston structure with an upward-facing opening in this embodiment and Embodiment 17, in other embodiments, the central cavity of the piston may be a sealed cavity, and other arc-extinguishing media such as gaseous sulfur hexafluoride or liquid transformer oil may be sealed in this seal cavity. That is, in addition to solid quartz sand, the arc-extinguishing media of this embodiment can also be realized using other gaseous or liquid arc-extinguishing media to ensure sealing performance. The arc-extinguishing media may be stored in the piston or in the bottom case of the pyrotechnic excitation device, but both methods of releasing the arc-extinguishing media by the explosive impact force of the pyrotechnic excitation device are feasible, and the specific storage location of the arc-extinguishing media can be determined according to the properties of the arc-extinguishing media in accordance with the actual demand.

[0194] Example 19 This embodiment provides a relay with a structure similar to the relay of Embodiment 17, the difference being that in this embodiment, arc extinguishing medium is provided in both the piston and the bottom case, and by storing the arc extinguishing medium in both the piston and the bottom case in this embodiment, the amount of arc extinguishing medium can be increased and the arc extinguishing capacity can be improved.

[0195] Example 20 This embodiment provides a relay whose structure is similar to that of the relay in Embodiment 17, the difference being that this embodiment uses a different pyrotechnic type bottom case structure for the excitation device. Referring to Figures 75(a) and 75(b), in this embodiment the bottom case 53A has a multi-stage stepped structure in which the radial dimension gradually contracts from top to bottom, and the lower end of the bottom case 53A is contracted so that the impact force during the explosion of the pyrotechnic type excitation device can be concentrated on the small stepped section at the lower end of the bottom case 53A, thereby improving localized performance, which increases the ability of the piston to penetrate the bottom case 53A and accelerates the injection of the arc-extinguishing medium.

[0196] As a variation of this embodiment, Figures 76(a) and 76(b) show other feasible bottom case 53B structures, in which the bottom case 53B has a tapered structure in which the radial dimension gradually narrows from top to bottom (i.e., towards the movable contact). Similarly, since the lower end of the bottom case 53B is constricted, the impact force during the explosion of the pyrotechnic excitation device can be concentrated at the lower end of the bottom case 53B, resulting in improved localized performance, thereby increasing the ability of the piston to penetrate the bottom case 53B and accelerating the injection of the arc-extinguishing medium.

[0197] Both "stepwise shrinkage" and "tapered shrinkage" result in a bottom case structure in which the radial dimension gradually shrinks from top to bottom. In addition to the "stepwise shrinkage" and "tapered shrinkage" provided in this embodiment, shrinkage may be achieved by combining "stepwise shrinkage" and "tapered shrinkage" in multiple stages in other embodiments, and any other regular or irregular shape for radial shrinkage is also a feasible form.

[0198] Example 21 This embodiment provides a relay whose structure is similar to that of the relay in Embodiment 17, the difference being that this embodiment uses a different piston structure for a pyrotechnic excitation device. In this embodiment, the piston is shaped to contract from top to bottom (i.e., towards the movable contact), which reduces its biasing area and increases the force acting on the bottom case and the movable contact. This allows it to break through the bottom case more quickly, rapidly push and shut off the movable contact, and accelerate the injection of the arc-extinguishing medium. The contraction shape of the lower end of the piston may be specifically realized by a tapered contraction, a stepped contraction, or a contraction structure combining tapered and stepped shapes, and the pistons with contracted lower ends shown in Figures 77 and 78 are all feasible.

[0199] It should be understood that the present invention is not limited to the detailed structure and arrangement of the components proposed herein. The present invention may have other embodiments and can be realized and carried out in various ways. The above-mentioned variations and modifications are within the scope of the present invention. Notwithstanding that the present invention disclosed and limited herein extends to all substitutable combinations of two or more distinct features mentioned or expressed herein and / or in the drawings. All these different combinations constitute multiple substitutable aspects of the present invention. The embodiments described herein illustrate the most preferred known modes for realizing the present invention and enable those skilled in the art to utilize the present invention.

Claims

1. A switching electrical device comprising a switching electrical device body and a pyrotechnic type excitation device provided on the switching electrical device body, wherein the switching electrical device body performs a switching function by including a linear electromagnetic drive mechanism, a fixed contact portion that is permanently provided, and a movable contact portion that is movable, the linear electromagnetic drive mechanism includes a push rod assembly, and the movable contact portion is assembled to the push rod assembly via an elastic member, thereby enabling contact with the fixed contact portion, the switching electrical device comprising a pyrotechnic type excitation device, The pyrotechnic excitation device further includes at least one set of magnetic conduit ring assemblies, the magnetic conduit ring assemblies including an upper conduit and a lower conduit provided opposite each other, the upper conduit being fixedly connected to the upper end of the push rod assembly, the lower conduit being fixedly connected to the movable contact portion, and the pyrotechnic excitation device includes a push medium for performing downward movement, the push medium corresponding to the position above the push rod assembly. A switching electrical device equipped with a pyrotechnic excitation device characterized by the following features.

2. The push medium is either a high-pressure fuel gas generated by ignition of the pyrotechnic excitation device, or the push medium is a piston. A switching electric device comprising a pyrotechnic excitation device as described in claim 1.

3. The magnetic guide ring assemblies are provided in n sets, where n ≥ 2. A switching electric device comprising a pyrotechnic excitation device as described in claim 1.

4. The upper magnetic conductor has a straight-line structure and is fixed horizontally above the movable contact portion, the lower magnetic conductor has a U-shaped structure, the lower magnetic conductor and the movable contact portion are fixedly connected such that the lower magnetic conductor surrounds at least half of a portion of the current-carrying conductor of the movable contact portion, and the opening of the U-shaped lower magnetic conductor is provided toward the upper magnetic conductor so that the upper magnetic conductor and the lower magnetic conductor form a magnetic circuit. A switching electric device comprising a pyrotechnic excitation device as described in claim 1.

5. The push rod assembly includes a limiting frame, the movable contact portion penetrates the limiting frame, the elastic member is fixedly mounted inside the limiting frame and the elastic force of the elastic member presses the movable contact portion toward the upper end of the limiting frame, the upper conduit is fixedly connected to the inside of the tip of the limiting frame and is provided above the movable contact portion, the limiting frame moves upward to bring the movable contact portion and the fixed contact portion into contact, and the linear electromagnetic drive mechanism continues to move the limiting frame upward, compressing the elastic member and creating a constant magnetic gap between the upper conduit and the lower conduit. A switching electric device comprising a pyrotechnic excitation device as described in claim 1.

6. When the movable contact portion and the fixed contact portion are in contact, the elastic force of the elastic member is less than the maximum electric repulsive force between the movable contact portion and the fixed contact portion. A switching electric device comprising a pyrotechnic excitation device as described in claim 5.

7. The pyrotechnic excitation device has an independent modular structure, and as an independent module, the pyrotechnic excitation device is fixedly attached to the switching electrical unit from the outside of the switching electrical unit. The pyrotechnic excitation device ignites gunpowder to generate an explosive shock force, which separates the movable contact part from the fixed contact part and rapidly shuts off the switching electrical unit. A switching electric device comprising a pyrotechnic excitation device as described in claim 1.

8. The switching electrical body includes a ceramic cover, the ceramic cover forming a contact cavity surrounding at least the fixed contact portion, the movable contact portion and their contact portions, the ceramic cover is provided with an insertion hole, and one end of the pyrotechnic excitation device extends through the insertion hole into the contact cavity so as to be positioned directly facing one side of the movable contact portion. A switching electric device comprising a pyrotechnic excitation device as described in claim 7.

9. The pyrotechnic excitation device includes an exciter, a bottom case, and a piston as the pushing medium, wherein the exciter and the bottom case are joined and fixed to each other, the bottom case has a hollow structure, the piston is fitted and mounted inside the bottom case, the bottom case extends through the insertion hole into the contact cavity and faces the movable contact portion, and when the pyrotechnic excitation device is excited, the exciter ignites the gunpowder and pushes the piston with the fuel gas to break through the bottom case, the piston moves toward the movable contact portion by the guiding action of the bottom case, thereby pushing the movable contact portion and separating it from the fixed contact portion. A switching electric device comprising a pyrotechnic excitation device as described in feature 8.

10. An arc-extinguishing medium is further stored in the piston or the bottom case, and after the piston breaks through the bottom case, the arc-extinguishing medium is released into the contact cavity by the rupture of the piston or the bottom case, thereby extinguishing the arc between the fixed contact portion and the movable contact portion. A switching electric device comprising a pyrotechnic excitation device as described in feature 9.

11. The aforementioned switching device is a DC high-voltage relay. A switching electric device comprising a pyrotechnic excitation device according to any one of claims 1 to 10.

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