Relay with high short circuit resistance

Abstract

The invention relates to the technical field of relays, and particularly discloses a relay with high short circuit resistance. The switch comprises a base, a magnetic circuit assembly and a movable contact assembly driven by a pushing sheet. The movable contact assembly is divided into a movable arcing contact and a movable current-carrying contact which are connected in parallel through a middle notch, and is provided with a U-shaped bending part; the pushing piece is of a step structure, so that time difference exists between opening and closing of the two contacts. The relay is further provided with a magnetic attraction sheet, an arc chute and an elastic speed reduction device. Through the synergistic effect of the structures, the anti-short-circuit capability, the electric service life and the working reliability of the relay are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of relay technology, and specifically relates to a relay with high short-circuit withstand capability. Background Technology

[0002] A relay is an electrical control device that causes a predetermined step change in the controlled quantity in the electrical output circuit when the change in the input quantity (such as the excitation quantity) reaches a specified requirement. It is widely used in automatic control, power protection, and communication equipment. Among them, relays with high short-circuit withstand capability, capable of withstanding large current surges and reliably disconnecting when a short circuit occurs in the load, are key components for ensuring circuit safety.

[0003] In existing technologies, common methods to improve the breaking capacity and electrical life of relays include using a double-contact structure to increase the contact area and employing arc-extinguishing devices such as arc-quenching grids. However, these conventional solutions still have significant drawbacks: First, conventional double contacts are mostly parallel contacts that operate synchronously. When subjected to abnormally large currents (such as short-circuit currents), huge electric repulsion forces are generated between the contacts, causing the contact pressure to decrease or even separate instantly, generating a strong electric arc. This can easily cause the contacts to weld or stick together, posing a risk of fire or even explosion.

[0004] Secondly, traditional contact material selection often struggles to balance arc erosion resistance and high conductivity. Using a single material cannot simultaneously optimize arc extinguishing performance and current carrying capacity, leading to unstable or even increased contact resistance in relays after frequent operation or prolonged use, affecting their long-term reliability and safety.

[0005] Furthermore, the existing relay's moving contact structure exhibits a relatively large reaction force from the moving spring during disconnection, resulting in insufficient disconnection speed, prolonged arc burning time, and exacerbated contact erosion. Simultaneously, the impact and bounce of the contacts at the moment of closure also generate an arc, similarly damaging contact life.

[0006] Therefore, there is an urgent need in this field for a relay solution that can effectively resist short-circuit current surges, significantly reduce arc erosion, and possess high reliability and long electrical life. Summary of the Invention

[0007] Based on the deficiencies of the prior art described in the background section, the present invention aims to solve one or more of the following technical problems: 1. How to effectively improve the repulsion and anti-welding ability of relays when subjected to abnormal short-circuit current, and prevent contact bonding failure.

[0008] 2. How to optimize the on / off timing and material usage of contacts to concentrate and efficiently extinguish electric arcs, thereby significantly extending the electrical life of relays.

[0009] 3. How to reduce the impact bounce and disconnection time when the contacts are closed, and reduce the erosion of the contacts by the electric arc energy.

[0010] 4. How to improve the stability and reliability of relays during long-term operation under harsh conditions.

[0011] To solve the above-mentioned technical problems, the present invention is implemented as follows: This invention provides a relay with high short-circuit withstand capability, comprising a base, a magnetic circuit assembly, an armature assembly, a moving contact assembly, a stationary contact assembly, and a drive piece, wherein: The moving contact assembly includes a moving arc contact and a moving current-carrying contact that are separated by a central slot and connected in parallel, and the moving spring of the moving contact assembly has a U-shaped bend. The static contact assembly includes a static arc contact corresponding to the dynamic arc contact and a static current-carrying contact corresponding to the dynamic current-carrying contact; The push plate has a stepped structure, which is configured such that, during operation, the dynamic arc contact closes with the corresponding stationary contact before the dynamic current-carrying contact closes with the corresponding stationary contact, and then opens with the dynamic current-carrying contact closes with the corresponding stationary contact. The relay also includes a short-circuit surge protection module, which includes: A magnetic sheet is disposed on the side opposite to the stationary contact assembly and the moving contact assembly, and is used to generate an attractive force on the moving contact assembly to resist the electro-repulsive force when an abnormally large current flows through the contact. An arc-extinguishing grid is disposed adjacent to the static arc contact to quickly extinguish the arc generated by the contact. The U-shaped bend, the stepped structure, the magnetic absorber, and the arc-extinguishing grid work together to enhance the relay's ability to withstand short-circuit current.

[0012] Furthermore, the anti-short-circuit impact module also includes an elastic deceleration device, which is disposed on the tail movement path of the push plate and is used to provide buffering at the end of the closing of the moving contact assembly to reduce the closing impact force.

[0013] Furthermore, the dynamic arc contact and the static arc contact are made of materials with strong resistance to arc erosion, and the dynamic current-carrying contact and the static current-carrying contact are made of materials with low resistivity and strong current-carrying capacity.

[0014] Furthermore, it also includes an auxiliary contact device, which is linked with the armature assembly and the push plate to detect the working status of the relay.

[0015] Furthermore, the stepped structure on the push plate includes a higher split step and a lower closed step.

[0016] Furthermore, the elastic deceleration device is a spring sheet, on which a positioning protrusion is stamped.

[0017] Furthermore, the arc-extinguishing grid is composed of multiple mutually insulated metal grid plates.

[0018] Furthermore, it also includes an auxiliary contact device, which is linked with the armature assembly or the push plate to detect and provide feedback on the operating status of the relay.

[0019] Compared with the prior art, the advantages of this invention are as follows: (1) High short-circuit resistance: The additional attraction provided by the magnetic sheet directly counteracts the short-circuit electric repulsion, greatly improving the stability of the relay in withstanding short-circuit current and fundamentally reducing the risk of contact welding.

[0020] (2) Long electrical life: Through the timing control of "first close then close", the electric arc is always guided to the dedicated arc-ignition contact, protecting the main current-carrying contact; combined with the arc-extinguishing grid and arc-resistant material, the electric arc is quickly controlled and the energy is efficiently dissipated, greatly reducing the erosion of the contact.

[0021] (3) Reliable operation and low impact: The U-shaped spring design reduces the reaction force when disconnecting and speeds up the breaking speed; the elastic deceleration device effectively buffers the closing impact and reduces closing bounce. The two work together to further shorten the total time of the arc and improve the reliability of the operation and mechanical life.

[0022] (4) High reliability: The groove in the middle of the moving contact allows the two contacts to operate independently. Even if one set of contacts becomes shorter due to ablation, the two sets of contacts can still ensure reliable contact, ensuring that the product can still work stably at the end of its life.

[0023] (5) Intelligent monitoring: Through the auxiliary contact device, the working status of the relay can be monitored in real time, which meets the needs of intelligent circuit control. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 A schematic diagram of the overall exploded structure of the relay with high short-circuit resistance provided by the present invention; Figure 2 This is a schematic diagram of the structure of the moving contact assembly provided by the present invention; Figure 3This is a schematic diagram of the structure of the static contact assembly provided by the present invention; Figure 4 This is a schematic diagram of the structure of the push plate provided by the present invention; Figure 5 for Figure 4 Enlarged view of section A; Figure 6 A top view of the high short-circuit withstand relay provided by the present invention after removing the top cover; Figure 7 for Figure 6 Enlarged view of section B; Figure 8 This is a schematic diagram of the structure of the elastic deceleration device provided by the present invention; Figure 9 This is a schematic diagram of the overall assembly structure of the relay with high short-circuit resistance provided by the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0027] like Figure 1 As shown, the present invention provides a relay with high short-circuit resistance, including a base 1, a magnetic circuit assembly 2, an armature assembly 3, a moving contact assembly 4, a stationary contact assembly 5, and a push plate 6.

[0028] The magnetic circuit assembly 2 and the armature assembly 3 constitute an electromagnetic drive system. When the coil is energized, the armature assembly 3 is driven, which in turn drives the connected push plate 6 to move.

[0029] See also Figure 2As shown, the moving contact assembly 4 includes a moving spring 41. A central slot 410 is formed on the moving spring 41 by stamping, dividing it into two arms that can move independently with small amplitudes. Each arm has a moving arc-ignition contact 42 and a moving current-carrying contact 43 riveted or welded to its end, forming a parallel double-contact structure. Furthermore, the moving spring 41 has a U-shaped bend 411 in the middle. This U-shaped bend 411 acts as an elastic hinge, increasing the flexibility of the moving spring 41, making it easier to pull when disconnected, and storing and releasing elastic potential energy at the moment of disconnection, thereby significantly reducing the reaction force during disconnection and shortening the overall disconnection time of the relay.

[0030] See also Figure 3 As shown, the stationary contact assembly 5 is fixed on the base 1, including a stationary arcing contact 51 corresponding to the dynamic arcing contact 42, and a stationary current-carrying contact 52 corresponding to the dynamic current-carrying contact 43. To achieve functional division, the stationary arcing contact 51 and the dynamic arcing contact 42 are preferably made of materials with strong resistance to arc erosion, such as silver tin oxide (AgSnO2); while the stationary current-carrying contact 52 and the dynamic current-carrying contact 43 are preferably made of materials with low resistivity and strong current-carrying capacity, such as silver-nickel alloy (AgNi). It should be noted that the materials used to manufacture the arcing contact and the current-carrying contact are not limited to silver tin oxide and silver-nickel alloy.

[0031] See also Figure 4 and Figure 5 As shown, the portion of the pusher 6 that acts on the moving contact assembly 4 is designed with a stepped structure, specifically including a higher breaking step 61 and a lower closing step 62. This structure is key to achieving the contact opening and closing time difference: Closing process: When the push plate 6 moves forward, the lower closing step 62 first contacts the arm containing the dynamic arc contact 42, causing it to close first; after the push plate 6 continues to move forward a small distance, the arm containing the dynamic current-carrying contact 43 then contacts the static current-carrying contact 52, achieving closure. Therefore, the dynamic arc contact 42 closes first.

[0032] Disconnection process: When the pusher plate 6 moves backward, the arm containing the moving current-carrying contact 43 first contacts the breaking step 61, thus disconnecting first; after the pusher plate 6 continues to move backward a small distance, the arm containing the moving arc-ignition contact 42 then contacts the pusher plate 6, achieving disconnection. Therefore, the moving arc-ignition contact 42 disconnects later. This "arc-ignition contact first closes then closes" sequence ensures that the arc generated during the switching process is always guided to the specially designed arc-ignition contact, protecting the main current-carrying contact and greatly improving the product's electrical life.

[0033] It should be noted that the "stepped structure" described in this invention is the core mechanical structure for realizing the timing difference between the opening and closing of the dynamic arcing contact and the dynamic current-carrying contact. Apart from the clearly defined high and low step forms such as the breaking step 61 and closing step 62 shown in the illustration, any structural modification that can achieve the function of the arcing contact closing before breaking by applying asynchronous driving forces to the two arms of the moving contact assembly 4, such as using a ramp, multi-level protrusions, or an asymmetrical contour pusher, should fall within the protection scope of this patent for the "stepped structure". The core design of this structure lies in creating a height difference or time difference in the driving stroke.

[0034] Combined Figure 9 As shown, the relay also includes a short-circuit surge protection module, which includes: The magnetic attracting sheet 7 is made of a magnetically conductive material (such as electrical pure iron) and is located on the side opposite to the stationary contact assembly 5 and the moving contact assembly 4. When the relay is connected to a large current, the current in the moving contact assembly 4 will generate a magnetic field (Lorentz force effect). At this time, the magnetic attracting sheet 7 will generate a strong attraction force to this magnetic field. The direction of this force is opposite to the direction of the electrical repulsion force generated between the contacts due to the large current, thereby effectively resisting the electrical repulsion force, preventing the contacts from being pushed apart and arcing, and significantly improving the relay's short-circuit withstand capability.

[0035] The arc-extinguishing grid 8 is composed of multiple mutually insulated metal grid plates and is installed near the static arc contact 51. When an electric arc is generated between the arc contacts, the arc is introduced into the grid plates and divided into multiple short arcs connected in series, thereby cooling and extinguishing it quickly and reducing the ablation of the contacts.

[0036] The U-shaped bend 411, the stepped structure, the magnetic absorber 7, and the arc-extinguishing grid 8 work together to enhance the relay's ability to withstand short-circuit current.

[0037] See further Figure 6 , Figure 7 , Figure 8 As shown, the relay also includes an elastic deceleration device 9, which in this embodiment is specifically a stamped deceleration spring. This spring is precisely positioned and fixed to the relay base 1 or related bracket by a positioning protrusion 91. The design of the positioning protrusion 91 makes it easier to mold the matching plastic parts during injection molding, avoiding excessively narrow slots, and also facilitating production and assembly. The elastic portion 92 of the deceleration spring is located on the movement path of the tail of the push plate 6. In the final stage of the contact closing action, the tail of the push plate 6 contacts and deforms the elastic portion 92, absorbing the closing kinetic energy through elastic buffering, effectively reducing the impact force when the moving and stationary contact assembly 4 closes, thereby significantly shortening the contact closing bounce time and reducing the arc that may be generated during closing.

[0038] See Figure 1 As shown, the relay also includes a mounting bracket 10 for securing the armature assembly 3 to the base 1.

[0039] In addition, the relay may be equipped with an auxiliary contact device 11. The auxiliary contact device 11 is linked with the armature assembly 3 and the push plate 6 to detect the operating status of the relay. When the main contact is activated, the auxiliary contact device 11 can switch synchronously, thereby providing real-time feedback on the operating status of the relay to the external control system.

[0040] The working principle of the high short-circuit withstand relay provided by this invention is as follows: When a forward closing voltage is applied to the coil, the armature assembly rotates clockwise, driving the pusher plate 6 to move. The pusher plate 6 first drives the moving arc contact 42 to close, and then drives the moving current-carrying contact 43 to close. At the end of the closing, the tail of the pusher plate 6 compresses the deceleration spring to achieve buffering. When a reverse breaking voltage is applied to the coil, the armature assembly rotates counterclockwise, and the pusher plate 6 retracts, first causing the moving current-carrying contact 43 to open, and then causing the moving arc contact 42 to open. During the breaking process, the U-shaped bend 411 assists in rapid breaking, and the arc is generated between the arc contacts and quickly extinguished by the arc-extinguishing grid 8. If a short-circuit current occurs during the process, the additional attraction provided by the magnetic plate 7 ensures stable contact of the contacts and resists electrical repulsion.

[0041] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0042] Furthermore, it should be noted that the scope of the methods and systems in the embodiments of the present invention is not limited to performing functions in the order shown or discussed, but also includes performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0043] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A relay with high short-circuit withstand capability, comprising a base (1), a magnetic circuit assembly (2), an armature assembly (3), a moving contact assembly (4), a stationary contact assembly (5), and a pusher plate (6), characterized in that: The moving contact assembly (4) includes a moving arc contact (42) and a moving current-carrying contact (43) that are separated and connected in parallel through a central slot (410), and the moving spring of the moving contact assembly (4) has a U-shaped bend (411). The stationary contact assembly (5) includes a stationary arc contact (51) corresponding to the dynamic arc contact (42) and a stationary current-carrying contact (52) corresponding to the dynamic current-carrying contact (43). The push plate (6) has a stepped structure, which is configured such that during operation, the dynamic arc contact (42) closes with the corresponding stationary contact before the dynamic current-carrying contact (43) and then opens with the corresponding stationary contact after the dynamic current-carrying contact (43). The relay also includes a short-circuit surge protection module, which includes: A magnetic sheet (7) is disposed on the side opposite to the stationary contact assembly (5) and the moving contact assembly (4) to generate an attraction force on the moving contact assembly (4) to resist the electro-repulsive force when an abnormally large current flows through the contact. An arc-extinguishing grid (8) is disposed adjacent to the static arc contact (51) for quickly extinguishing the arc generated by the contact; The U-shaped bend (411), the stepped structure, the magnetic absorber (7), and the arc-extinguishing grid (8) work together to enhance the relay's ability to withstand short-circuit current.

2. The relay with high short-circuit withstand capability according to claim 1, characterized in that, The anti-short-circuit impact module also includes an elastic deceleration device (9), which is disposed on the tail movement path of the push plate (6) and is used to provide buffering at the end of the closing of the moving contact assembly (4) to reduce the closing impact force.

3. The relay with high short-circuit withstand capability according to claim 1, characterized in that, The dynamic arc contact (42) and static arc contact (51) are made of materials with strong resistance to arc erosion, and the dynamic current-carrying contact (43) and static current-carrying contact (52) are made of materials with low resistivity and strong current-carrying capacity.

4. The relay with high short-circuit withstand capability according to claim 1, characterized in that, It also includes an auxiliary contact device (11), which is linked with the armature assembly (3) and the push plate (6) to detect the working status of the relay.

5. The relay with high short-circuit withstand capability according to claim 1, characterized in that, The stepped structure on the push plate (6) includes a higher split step (61) and a lower closed step (62).

6. The relay with high short-circuit withstand capability according to claim 2, characterized in that, The elastic deceleration device (9) is a spring sheet, on which a positioning protrusion (91) is stamped.

7. The relay with high short-circuit withstand capability according to claim 1, characterized in that, The arc-extinguishing grid (8) is composed of multiple mutually insulated metal grid sheets.

8. The relay with high short-circuit withstand capability according to claim 1, characterized in that, It also includes an auxiliary contact device (11), which is linked with the armature assembly (3) or the push plate (6) to detect and provide feedback on the working status of the relay.

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