Switch for increasing short-time withstand current

Abstract

The invention provides a switch for increasing short-time withstand current, which comprises an insulating shell, a moving contact device, a static contact device, an operating mechanism and a wiring terminal, and is characterized in that the moving contact device at least comprises a first moving contact and a contact support; the static contact device at least comprises a first static contact conductor, a magnet yoke sleeved on the static contact conductor, and an armature which is arranged above the magnet yoke and forms a closed magnetic circuit with the magnet yoke and can rotate; the first moving contact rotates along with the contact support, the static contact device is arranged in front of the moving contact device, the outer diameter R1 of the rotating motion of the first moving contact and the outer diameter R2 of the rotating motion of the armature have two intersection points P1 and P2, and when the first moving contact is in contact with the first static contact conductor, the intersection point P1 is located above the first moving contact. According to the invention, the damage effect caused by the reliable contact of the moving contact and the static contact which are repelled by the electric repulsive force and the Hemm force when the short-circuit current occurs can be effectively suppressed, the safety of a power distribution system is ensured, and the economical efficiency is very high.

Description

Technical Field

[0001] The present invention relates to the field of low-voltage electrical appliances, and particularly to a switch for increasing the short-time withstand current. Background Art

[0002] With the implementation of the national new energy strategy and the iterative update of battery technology, the advantages of energy storage in aspects such as power peak shaving, improving the operation stability of the system, and improving the power supply quality in the power system are becoming increasingly obvious.

[0003] As the capacity of the energy storage system becomes larger and larger, the short-circuit current that may be generated by the batteries or battery clusters of the BMU (battery module unit), BCU (battery cluster unit), and BAU (battery array unit) in the energy storage system is getting larger and larger. The energy storage system puts forward higher and higher protection requirements for electrical protection equipment: it is required that the electrical equipment in the circuit has a small rated current, a high and stable peak short-circuit current, so higher and higher requirements are put forward for the short-time withstand performance of electrical components under short-circuit conditions;

[0004] In order to improve the short-circuit withstand ability of electrical components when the short-circuit current occurs in the low-voltage electrical appliance industry, the conventional and common method is to press the reaction forces of the electro-dynamic repulsive force and the Holm force generated by the short circuit with a large final contact pressure to ensure the reliable connection of the electrical contacts under short-circuit conditions; the commonly adopted technical solution is to increase the force values of the operating mechanism spring and the contact spring to form a large final contact pressure. Obviously, this method has more stringent requirements for technology and materials, will increase the production and manufacturing costs, and this final contact pressure still exists when there is no short-circuit current in the circuit. During the opening and closing operations under non-short-circuit conditions, the force values of the mechanism spring and the contact spring are very large, which will generate a large impact stress and cause great wear on the contacts and the mechanism, affecting the service life of the electrical components.

[0005] In addition, because the implementation structure of the final contact pressure of the traditional circuit breaker is a laborious lever, the effect of improving the final contact pressure by the traditional method of increasing the force values of the mechanism spring and the contact spring is not very obvious;

[0006] In summary, a switch solution for increasing the short-time withstand current with low cost and high efficiency has become an urgent need to break through the technical bottleneck of the industry. Summary of the Invention

[0007] Based on the above background, the present invention provides a switch for increasing the short-time withstand current, which improves the short-time withstand performance index of the electrical switch in a low-cost and high-efficiency manner without affecting the mechanical life of the product.

[0008] The present application discloses a switch for increasing the short-time withstand current, including an insulating housing and components arranged inside. The components inside at least include: a moving contact device, a static contact device, an operating mechanism, a first terminal, and a second terminal. The moving contact device at least includes a moving contact and a contact support. The static contact device at least includes a static contact conductor, a magnetic yoke sleeved on the static contact conductor, and an armature that can perform rotational movement and is arranged above the magnetic yoke to form a closed magnetic circuit with the magnetic yoke. The moving contact device rotates under the operation of the operating mechanism to make contact with and disconnect from the static contact conductor. The moving contact rotates with the contact support. The static contact device is arranged in front of the moving contact device. There are two intersection points P1 and P2 between the outer diameter R1 of the rotational movement of the moving contact and the outer diameter R2 of the rotational movement of the armature. When the moving contact is in contact with the static contact conductor, the contact position between the armature and the moving contact is located between the intersection points P1 and P2.

[0009] In the above embodiment, the magnetic yoke sleeved on the static contact conductor is in a fixed state. The armature arranged above the magnetic yoke and the magnetic yoke can form a closed magnetic circuit. The armature can perform rotational movement relative to the magnetic yoke. When a short-circuit current appears in the static contact conductor passing through the centers of the armature and the magnetic yoke, the armature will be attracted to the magnetic yoke under the action of a strong magnetic field. Thus, the armature applies an external force to the contact finger of the moving contact, increasing the pressure of the moving contact and preventing the electro-dynamic repulsive force generated by the moving and static contacts and the Holm force generated by the moving and static contacts from repelling the contacts under high-current conditions.

[0010] In some embodiments, when the moving contact and the static contact conductor are disconnected, and when the moving contact and the static contact conductor are in contact and there is no short-circuit current in the circuit, the armature is in an open state. When the moving contact and the static contact conductor are in contact and a short-circuit current appears in the circuit, a closed magnetic circuit is formed by the armature and the magnetic yoke, generating magnetic suction force. The armature performs rotational movement relative to the magnetic yoke, and the armature pressurizes the moving contact.

[0011] In the above embodiment, there are two intersection points P1 and P2 between the outer diameter R1 of the rotational movement of the moving contact and the outer diameter R2 of the rotational movement of the armature. After the moving contact and the static contact conductor are in contact and conduct electricity, a short-circuit current appears in the circuit. The short circuit generates a strong magnetic field. The armature rotates and presses on the upper end of the contact finger of the moving contact. The armature only operates when the moving and static contacts are closed and a short-circuit current appears in the circuit. The contact position between the armature and the contact finger of the moving contact is located between the intersection points P1 and P2.

[0012] In some embodiments, the armature is limited by a rotating shaft on a bracket. Under the action of electromagnetic suction force, the armature rotates along the rotating shaft.

[0013] In the above embodiment, the armature performs a rotational snapping motion along a fixed rotating shaft under the action of the magnetic field. The rotational snapping motion of the armature component is conducive to the opening of the moving and static contacts, and presents an open state, ensuring that the moving and static parts maintain a reliable isolation electrical gap, or the moving and static contacts are in a closed state, but the loop current is small, the magnetic attraction is small, and the armature is in an open state, ensuring that the moving and static parts can be opened and closed normally.

[0014] In some embodiments, the yoke sleeved on the static contact conductor and the armature arranged above the yoke are stacked by at least one magnetic conductive sheet.

[0015] In the above embodiment, the yoke sleeved under the static contact busbar and the armature arranged above the yoke are U-shaped, which is conducive to magnetic conduction. The superposition of multiple yokes is conducive to increasing the magnetic field strength. The armature and the yoke cooperate in rotational motion under the action of the magnetic field. By increasing the magnetic field strength, it is conducive to increasing the suction force of the yoke and the armature, thereby increasing the pressure applied by the armature on the contact, thereby improving the short-time tolerance of the circuit.

[0016] In some embodiments, the armature includes an armature magnetic conductive component, at least one gasket is arranged below the armature magnetic conductive component, at least one spring sheet is arranged below the gasket, and the spring sheet, gasket, and armature magnetic conductive component are connected by fasteners.

[0017] In the above embodiment, the magnetic armature arranged above the magnetic yoke is U-shaped, which is conducive to magnetic conduction. A gasket is arranged under the magnetic conductive component of the armature to increase the elastic deformation of the spring sheet, thereby improving the short-time tolerance of the circuit. The added gasket and spring sheet can effectively improve the reliability of the armature in applying pressure to the moving contact finger.

[0018] In some embodiments, a spring sheet is arranged on the armature, one end of the spring sheet is a multi-finger structure, and the other end is arranged with a mounting hole, and the moving contact row is pressurized by the multi-finger structure.

[0019] In the above embodiment, a comb-shaped multi-finger structure is arranged at one end of the leaf spring for applying pressure. The multi-finger structure can increase the deformation amount and reliability of the leaf spring in applying pressure to multiple contact pieces. The conductive contacts are pressurized separately by the multi-finger spring pieces, and the problem of inconsistent contact heights between the armature and each conductive contact is automatically adjusted, so that each conductive contact is subjected to pressure from the armature, thereby increasing the contact pressure.

[0020] In some embodiments, a spring is arranged below the armature, the spring is fixed on the rotating shaft, one end of the spring is arranged on the limiting holes on both sides of the yoke, and the other end is arranged below the armature.

[0021] In the above embodiments, the spring drives the armature to be in an open state when there is no magnetic suction force formed by the short-circuit current. When there is a magnetic field suction force generated by the short-circuit current, under the action of the magnetic field, the armature forms a magnetic suction force with the yoke. This magnetic suction force cancels the action of the spring, driving the armature to close. The leaf spring on the armature component applies a pressure to the contact, and the reaction force value of the spring can be flexibly set to adjust the short-duration magnetic enhancement pressure value and the short-duration value.

[0022] In some embodiments, under the action of the spring, the lower edge of the armature contacts and is limited by one side of the mounting bracket to position / limit the opening angle of the armature.

[0023] In the above embodiments, the spring drives the armature component to rotate clockwise along the rotating shaft on the bracket. The lower edge of the armature is limited by contacting one side of the bracket to limit the rotation angle of the armature and the opening angle of the armature component, ensuring that the armature will not have problems such as insufficient magnetic suction force or incorrect magnetic suction force direction due to too large an opening angle, approaching or being greater than 90 degrees. At the same time, the initial included angle between the armature component and the moving contact can be adjusted to position the electrical clearance and ensure the insulation distance.

[0024] In some embodiments, the spring is a torsion spring with single-leg or double-leg support, or a compression spring.

[0025] In the above embodiments, the spring is a torsion spring with double-leg support. The spring is positioned on the rotating shaft and is limited to the two side yokes through the two support legs of the torsion spring, improving the installation stability and reliability of the spring and the stability and reliability of the force on the armature.

[0026] In some embodiments, the armature is limited by the rotating shaft on the bracket, and both sides outside the bracket limit both sides inside the armature.

[0027] In the above embodiments, the armature is limited in one dimension by the rotating shaft on the bracket, and the armature can rotate around the rotating shaft; both sides outside the bracket limit both sides inside the armature, limiting the space for the armature to move left and right and improving the stability and reliability of the armature rotation.

[0028] In some embodiments, a first moving contact, a contact support, and a second moving contact are provided on the moving contact device. The second moving contact is longer than the first moving contact. The static contact device is also provided with a second static contact conductor, and a contact corresponding to the second moving contact is provided on the static contact conductor. An arc extinguishing chamber is provided on the static contact conductor. The second moving contact and the first moving contact are provided on the same contact support or different contact supports. The first moving contact, the second moving contact, and the first static contact conductor and the second static contact conductor are of the same polarity or in the same phase.

[0029] In the above embodiments, the moving contacts of the same polarity or the same phase are provided with a first moving contact and a second moving contact with different structural characteristics, and the first moving contact and the second moving contact are arranged on one contact support or different contact supports. By setting the contact fingers of the second moving contact to be longer than those of the first moving contact, the first stationary contact and the second stationary contact with different structural characteristics are provided for the moving contacts of the same polarity or the same phase, and parameters such as the opening distance, overtravel, and final pressure between different contacts are differentially set. Different combinations of moving contacts and stationary contacts of the same polarity or the same phase realize their respective electrical functions.

[0030] In some embodiments, the second moving contact closes and separates before the first moving contact, and the second moving contact bears the arc breaking, while the first moving contact bears the short-circuit repulsive force.

[0031] In the above embodiments, for the moving contacts and stationary contacts of the same polarity or the same phase, through the design of the closing-first-and-separating-later structure, one moving contact undertakes the function of arc breaking, and the other moving contact undertakes the function of short-circuit withstand, so as to achieve the technical purpose that the moving and stationary contacts of the same polarity or the same phase satisfy both arc breaking and high short-circuit withstand performance.

[0032] In some embodiments, the first moving contact, the second moving contact, the first stationary contact conductor, and the second stationary contact conductor are arranged in the same cavity or different cavities.

[0033] In the above embodiments, arranging different moving contacts and stationary contacts in different cavities can improve the isolation effect of the arc extinguishing and short-circuit withstand functions, with no interference with each other, and improve the functional stability and reliability of the product. Arranging different moving contacts and stationary contacts in the same cavity can improve the structural compactness of the product and reduce the volume of the product.

[0034] The beneficial effects of the present invention are as follows:

[0035] 1. In this application, a switch for increasing the short-time withstand current can effectively suppress the destructive effect caused by the electromagnetic repulsive force and the Holm force generated when a short-circuit current occurs, which repel the reliable contact between the moving and stationary contacts of the electrical switch.

[0036] 2. Since both the moving contact and the armature in the switch for increasing the short-time withstand current adopt a rotary motion fit, only when a short-circuit current occurs, the armature will apply an additional pressure to the moving contact, improving the short-circuit withstand performance of the switch. In the open state and the closed state without a short-circuit current, the armature is in an open state, which does not affect the normal opening and closing operations of the switch.

[0037] 3. Since the switch for increasing the short-time withstand current does not involve the optimization and improvement of the force values of the mechanism spring and the contact spring, and there is no need to further increase the mechanical strength of the mechanism parts, the process manufacturing cost for improving the short-circuit withstand performance is reduced. It is easy to install, operates reliably, and has universal promotion significance. Brief Description of the Drawings

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 Structural schematic diagram of a switch for increasing short-time withstand current disclosed in this embodiment;

[0040] Figure 2 Another perspective structural schematic diagram of a switch for increasing short-time withstand current disclosed in this embodiment;

[0041] Figure 3 Another perspective structural schematic diagram of a switch for increasing short-time withstand current disclosed in this embodiment;

[0042] Figure 4 Structural schematic diagram of the armature in a switch for increasing short-time withstand current disclosed in this embodiment;

[0043] Figure 5 Schematic diagram of another support structure of a switch for increasing short-time withstand current disclosed in this embodiment;

[0044] Figure 6 Schematic diagram of the intersection point of the outer diameter R1 of the moving contact finger rotation and the outer diameter R2 of the armature rotation in a switch for increasing short-time withstand current disclosed in this embodiment;

[0045] Figure 7 Schematic diagram of the force analysis of a switch for increasing short-time withstand current disclosed in this embodiment;

[0046] Figure 8 Schematic diagram of the magnetic enhancement, pressure application and arc extinguishing structure of a switch for increasing short-time withstand current disclosed in this embodiment. Detailed Embodiments

[0047] To make the purpose, technical solutions and advantages of the implementation of the present invention clearer, the following will describe the technical solutions in the embodiments of the present invention in more detail with reference to the drawings in the embodiments of the present invention. In the drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of the present invention.

[0048] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0049] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0050] Please refer to Figures 1 to 8 , this embodiment discloses a switch for increasing the short-time withstand current, including an insulating housing and components arranged inside. The components inside at least include: a moving contact device 1, a static contact device 2, an operating mechanism 3, a first terminal 4, and a second terminal 5. The moving contact device 1 at least includes a first moving contact 11 and a contact support 12. The static contact device 2 at least includes a first static contact conductor 21, a magnetic yoke 22 sleeved on the static contact conductor 21, and an armature 23 that can perform rotational movement and forms a closed magnetic circuit with the magnetic yoke 22 above the magnetic yoke 22. The moving contact device 1 rotates under the operation of the operating mechanism 3 to make contact with and break away from the first static contact conductor 21. The first moving contact 11 rotates with the contact support 12. The static contact device 2 is arranged in front of the moving contact device 1. There are two intersection points P1 and P2 between the outer diameter R1 of the rotational movement of the first moving contact 11 and the outer diameter R2 of the rotational movement of the armature 23. When the first moving contact 11 is in contact with the first static contact conductor 21, the contact position between the armature 23 and the first moving contact 11 is located between the intersection points P1 and P2. The switch of this embodiment improves the short-time withstand current performance index in a low-cost and high-efficiency manner without affecting the mechanical life of the product.

[0051] There are two intersection points P1 and P2 between the rotational outer diameter R1 of the first moving contact 11 and the rotational outer diameter R2 of the armature 23. The intersection point P1 is arranged above the moving contact device 1 in the closing state, and the intersection point P2 is located below the intersection point P1. After the moving contact and the static contact are closed, a short-circuit current appears in the circuit. The short-circuit current generates a strong magnetic field, forming a strong suction force between the magnetic yoke 22 and the armature 23. The multi-finger 2331 at the upper end of the spring piece 233 on the armature 23 exerts pressure on the front end position 11b of the first moving contact 11. The position point where the armature 23 exerts pressure on the first moving contact 11 is located below the intersection point P1 between the rotational outer diameter R1 of the first moving contact 11 and the rotational outer diameter R2 of the armature 23 and above the point P2.

[0052] The lever arm of the electric repulsive force and the reaction force F1 of the Holm force acting on the silver point 11a of the first moving contact 11 is R3, and the lever arm of the pressure F2 applied by the pressing armature 23 at the front end position 11b of the moving contact is R4. According to the torque balance formula: F1×R3 = F2×R4. Since R4 > R3, a smaller pressure F2 can balance the contact repulsive force F1, indicating that the structure has an obvious pressurizing effect on the moving contact;

[0053] In other embodiments, such as Figure 5 As shown, for a switch of the present invention that increases the short-time withstand current, the bracket 24 can also be arranged below the first static contact conductor 21 as needed. The bracket 24 is in contact with the yoke 22, limited by the groove feature on the first static contact conductor 21, and then fastened to the first static contact conductor 21 together with the yoke 22.

[0054] Preferably, the armature 23 is limited to the inner side of the bracket 24 by the rotating shaft 25, and both sides of the rotating shaft 25 are limited by the inner wall of the base cavity. Further, a positioning arm 241 for limiting the rotation position of the armature 23 can be derived from the bracket 24, and the armature 23 is driven by the spring 26 to rotate to be limited by the positioning arm 241 on the bracket 24.

[0055] Preferably, the yoke 22 and the armature 23 are at least composed of a stack of magnetic conductive sheets. The armature 23 moves in a rotational manner relative to the yoke 22. The yoke 22 arranged below the static contact conductor 21 and the armature 23 arranged above the yoke 22 are in a U shape, which is beneficial for magnetic conduction. The stacking of multiple yokes 22 is beneficial for increasing the magnetic field strength, and the armature 23 and the yoke 22 perform rotational movement cooperation under the action of the magnetic field force.

[0056] In other embodiments, the yoke 22 and the armature 23 in the present invention patent can also be magnetic conductive coils spirally wound on the magnetic conductive sheets.

[0057] Preferably, the armature 23 moves in a reciprocating slapping manner relative to the yoke 22. At least one gasket 232 is arranged below the magnetic conductive part 231 of the armature 23, and at least one spring sheet 233 is arranged below the gasket 232 to increase the deformation amount of the spring sheet 233 through the gasket 232. The spring sheet 233, the gasket 232, and the magnetic conductive part 231 of the armature are fastened and connected by rivets 234. The stacking of multiple gaskets 232 is beneficial for increasing the magnetic field strength and the elastic deformation amounts of the spring sheet 233 and the gasket 232. By increasing the magnetic field strength, the short-time withstand capacity of the circuit is improved, and the added gaskets 232 and spring sheets 233 can also effectively improve the reliability of the armature 23 pressing the contact finger 11b of the first moving contact 11.

[0058] Preferably, one end of the spring piece 233 where the finger 11b of the first moving contact 11 applies pressure is a comb-shaped multi-finger structure 2331. The multi-finger structure 2331 is used to increase the deviation correction margin of the pressure applied by a single finger to a single moving contact finger.

[0059] In other embodiments, for the armature 23 of the present invention, the spring piece 233 used to apply pressure can also be arranged at the upper end of the point magnetic conduction component of the armature 23. Further, the spring piece 233, the gasket 232, and the armature magnetic conduction component 231 can also be fixed by welding or screws and nuts.

[0060] Preferably, the end of the spring piece 233 applying pressure can be in surface contact, or line contact, or point contact to apply pressure to the contact piece of the first moving contact 11.

[0061] Preferably, the armature 23 is limited by the rotating shaft 25 on the bracket 24. Under the strong magnetic field suction force generated by the short-circuit current, the armature 23 rotates along the rotating shaft 25 to form a rotary clapper type action with the fixed yoke 22. When the moving and static contacts are opened, there is no suction force on the armature 23, or when the moving and static contacts are in the closed state, but the loop current is small and the magnetic suction force is small, and the suction force of the armature 23 is less than the reaction force of the spring 26. Under the action of the spring 26, the armature 23 rotates and is limited at a certain angle to maintain a reliable isolation electrical gap between the moving and static contacts; when the moving and static contacts are closed and a large short-circuit current appears in the loop, after the suction force of the armature 23 cancels the reaction force of the spring 26, the suction force can also drive the armature 23 to quickly attract to the yoke 22. This clapper type movement is beneficial to the spatial arrangement of the components of the magnetic field increasing and pressure applying structure.

[0062] Preferably, in other embodiments, the armature 23 can also be an energized screw type structure. When a short-circuit current is generated at the static contact 11, a strong magnetic field suction force is generated on the energized screw type armature, and the screw type armature drives the spring piece 233 to apply a final pressure to the finger of the first moving contact 11. Further, the screw type armature can perform a reciprocating suction movement.

[0063] Preferably, the spring 26 is fixed on the rotating shaft 25. One end 26a is arranged in the limiting holes on both sides of the yoke 22, and the other end 26b is arranged below the armature 23. By driving the armature 23 with the spring 26, when there is no magnetic suction force formed by the short-circuit current, it presents an open state. When there is a magnetic suction force generated by the short-circuit current, under the magnetic field action, the armature 23 forms a magnetic suction force with the yoke 22, and this magnetic suction force cancels the action of the spring 26 and drives the armature 23 to attract.

[0064] Preferably, in this embodiment, the trigger force value of the spring 26 can be flexibly set to adjust the pressure value of the short-circuit withstand and magnetic field increasing and pressure applying, adjust the short-circuit withstand value, or adjust the short-circuit current threshold of the short-circuit withstand and pressure applying action.

[0065] In other embodiments, the initial opening angle of the spring 26 can also be flexibly set to adjust the opening angle of the armature 23 so as to cooperate with the first moving contact 11's contact piece and adjust the electrical insulation gap.

[0066] Preferably, one end of the spring piece 233 has a multi-finger structure 2331 in the shape of a comb, and an installation through-hole 2332 is arranged at the other end. The spring piece 233 and the gasket 232 are fixed below the armature magnetic conductive component 231 by screws or rivets 234. It should be noted that the gasket 232 can increase the elastic deformation amount of the leaf spring, and the comb-shaped structure arranged at the pressure-applying end of the spring piece 233 can increase the deformation amount of the spring piece 233 applying pressure to multiple contact pieces, improve the reliability of pressurization, and increase the final pressure of the contact.

[0067] Preferably, under the action of the spring 26, the lower edge 231a of the armature 23 contacts and limits the position with one surface 24a of the bracket to position / limit the opening angle of the armature 23.

[0068] It should be noted that limiting the opening angle of the armature ensures that the armature will not have too large an opening angle. When it is close to and less than 90°, the magnetic attraction force is close to perpendicular to the yoke 22, resulting in a slow rotation speed of the armature 23; when it is greater than 90°, the suction direction is incorrect, resulting in an incorrect rotation direction of the armature 23.

[0069] Preferably, the spring 26 is a torsion spring supported by a single leg or two legs, or a compression spring.

[0070] Preferably, the armature 23 is limited by the rotating shaft 25 on the bracket 24, and both sides outside the bracket 24 limit both sides inside the armature 23.

[0071] Preferably, the armature 23 is limited by the rotating shaft 25 on the bracket 24. At the same time, both side walls outside the bracket 24 limit both side walls inside the armature 23. The lateral limitation or positioning of the bracket 24 and the armature 23 can ensure the alignment of the magnetic fields of the armature 23 and the yoke 22 and improve the effect of the magnetic attraction force.

[0072] Preferably, the moving contact device 1 further includes a second moving contact 13, the length of the second moving contact 13 being longer than that of the first moving contact 11. The static contact device 2 further includes a second static contact conductor 27, on which a contact corresponding to the second moving contact 13 is provided. An arc extinguishing chamber 28 is provided above the second static contact conductor 27. The second moving contact 13 and the first moving contact 11 are arranged on the same contact support or different contact supports. The first moving contact 11, the second moving contact 13, the first static contact conductor 21, and the second static contact conductor 27 are of the same polarity or phase. By respectively arranging moving contacts and static contacts of two different structures on the same polarity or phase, wherein the fingers of the second moving contact are longer than those of the first moving contact, and armatures, yokes and other magnetic enhancement and pressure application structures are arranged on the first moving contact and the first static contact conductor, and an arc extinguishing chamber device is arranged above the second moving contact and the second static contact, the short withstand performance and the breaking and arc extinguishing performance are respectively improved.

[0073] Preferably, the second moving contact 13 closes and opens before the first moving contact 11, and the second moving contact 13 bears the arc breaking, while the first moving contact 11 bears the short-circuit repulsion force. The design of closing and opening first and then closing and opening enables the second moving contact to be solely used to undertake the function of arc breaking or extinguishing that appears in the execution loop during the energized closing and opening; no arc appears during the closing and opening process of the first moving contact, so there is no need to set an arc extinguishing chamber, and the space left around the first moving contact and the first static contact can be used to arrange structures such as armatures and yokes for magnetic enhancement and pressure application. By means of magnetic enhancement and pressure application, the short withstand performance of this loop is improved.

[0074] Preferably, the first moving contact 11, the second moving contact 13, the first static contact conductor 21, and the second static contact conductor 27 are arranged in the same cavity or different cavities. Arranging different moving contacts and static contacts in different cavities can improve the isolation effect of the arc extinguishing and short withstand functions, with no interference with each other, and improve the functional stability and reliability of the product. Arranging different moving contacts and static contacts in the same cavity can improve the structural compactness of the product and reduce the volume of the product.

[0075] The present invention can be implemented in other specific forms without departing from its spirit and essential features. The current embodiments are regarded as exemplary in all aspects rather than restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and all changes falling within the meaning and equivalents of the claims are thus included in the scope of the present invention.

Claims

1. A switch for increasing the short-time withstand current, comprising an insulating housing and components arranged inside, wherein the components inside at least include: Moving contact device, static contact device, operating mechanism, first terminal, second terminal. The moving contact device at least includes a first moving contact and a contact support. The static contact device at least includes a first static contact conductor, a yoke sleeved on the first static contact conductor, and an armature that can rotate and is arranged above the yoke to form a closed magnetic circuit with the yoke. The moving contact device rotates under the operation of the operating mechanism to contact and disconnect from the first static contact conductor. The moving contact rotates with the contact support. The static contact device is arranged in front of the moving contact device. There are two intersection points P1 and P2 between the outer diameter R1 of the rotation movement of the first moving contact and the outer diameter R2 of the rotation movement of the armature. When the first moving contact contacts the first static contact conductor, the contact position between the armature and the first moving contact is located between the intersection points P1 and P2.

2. The switch for increasing the short-time withstand current according to claim 1, wherein: When the first moving contact disconnects from the first static contact conductor, or when the first moving contact contacts the first static contact conductor and there is no short-circuit current in the circuit, the armature is in an open state. When the first moving contact contacts the first static contact conductor and a short-circuit current appears in the circuit, a closed magnetic circuit is formed by the armature and the yoke, generating a magnetic suction force. The armature makes a rotary motion relative to the yoke, and the armature presses the moving contact.

3. The switch for increasing the short-time withstand current according to claim 2, characterized in that: The armature is limited by a rotating shaft on the bracket. Under the action of electromagnetic suction, the armature rotates along the rotating shaft.

4. The switch for increasing the short-time withstand current according to claim 1, wherein: The yoke sleeved on the first static contact conductor and the armature arranged above the yoke are stacked by one or at least two magnetic conductive sheets.

5. The switch for increasing the short-time withstand current according to claim 1, characterized in that: The armature includes an armature magnetic conductive component. At least one gasket is arranged below the armature magnetic conductive component, and at least one spring sheet is arranged below the gasket. The spring sheet, gasket, and armature magnetic conductive component are connected by fasteners.

6. The switch for increasing the short-time withstand current according to claim 5, wherein: One end of the spring sheet is a multi-finger structure, and the other end is provided with a mounting through hole. The moving contact is pressed by the multi-finger structure.

7. The switch for increasing the short-time withstand current according to claim 1, characterized in that: A spring is arranged below the armature. The spring is fixed on the rotating shaft. One end of the spring is arranged in the limit holes on both sides of the yoke, and the other end is arranged below the armature.

8. The switch for increasing the short-time withstand current according to claim 7, wherein: Under the action of the spring, the lower edge of the armature contacts and is limited by one side of the bracket, positioning / limiting the opening angle of the armature.

9. The switch for increasing the short-time withstand current according to claim 8, wherein: The spring is a torsion spring with single-leg or double-leg support, or a compression spring.

10. The switch for increasing the short-time withstand current according to claim 7, characterized in that: The armature is limited by a rotating shaft on the bracket, and both sides outside the bracket limit both sides inside the armature.

11. The switch for increasing the short-time withstand current according to claim 1, characterized in that: The moving contact device is provided with a first moving contact, a contact support, and a second moving contact. The second moving contact is longer than the first moving contact. The static contact device is also provided with a second static contact conductor. A contact corresponding to the second moving contact is arranged on the static contact conductor. An arc extinguishing chamber is arranged on the static contact conductor. The second moving contact and the first moving contact are arranged on the same contact support or different contact supports. The first moving contact, the second moving contact, the first static contact conductor, and the second static contact conductor are of the same polarity or the same phase.

12. The switch for increasing the short-time withstand current according to claim 11, wherein: The second moving contact closes and disconnects before the first moving contact. The second moving contact bears the arc disconnection, and the first moving contact bears the short-circuit repulsive force.

13. The switch for increasing the short-time withstand current according to claim 11, characterized in that: The first moving contact, the second moving contact, the first static contact conductor, and the second static contact conductor are arranged in the same cavity or different cavities.

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