Ceramic arc-isolating cover for small-sized high-voltage direct-current relay

Abstract

The invention relates to a ceramic arc-isolating cover for a small-sized high-voltage direct-current relay, which is integrally formed by ceramic and is divided into an arc extinguishing cavity and an arc blowing magnetic steel assembling cavity part, the ceramic is the ceramic with the alumina content of 99%; the arc blowing magnetic steel assembly cavity is arranged below the arc extinguishing cavity; the number of the arc blowing magnetic steel assembling cavities is two. In order to prevent short circuit caused by contact and connection between the blown arc and the metal part, the arc is controlled in the arc extinguishing cavity of the ceramic arc-isolating cover, the ceramic arc-isolating cover and the arc-blowing magnetic steel form an arc extinguishing device, and the arc extinguishing device completely separates the arc from the metal part to form physical insulation, so that the arc is extinguished in the arc cavity. The high-voltage direct-current relay avoids high-voltage breakdown short circuit among metal parts, and solves the technical problems that the product performance is affected and the use requirement cannot be met due to the fact that the arc extinguishing effect of a small-size high-voltage direct-current relay is not ideal.

Description

Technical Field

[0001] This invention relates to a ceramic arc shield for a small high-voltage DC relay, belonging to the field of relay technology. Background Technology

[0002] To meet market demands and develop small-volume high-voltage DC relays, while meeting usage requirements, the size and weight of the relays should be reduced to broaden their application scenarios. Due to the small size and high voltage, the arc extinguishing space is limited. Currently widely used metal grid arc extinguishing and insulating material slot arc extinguishing structures are difficult to apply under the small volume constraints, resulting in unsatisfactory arc extinguishing effects, which affect product performance and fail to meet usage requirements. Summary of the Invention

[0003] The present invention aims to solve the technical problem that the arc extinguishing effect of small-volume high-voltage DC relays is not ideal, which affects the product performance and fails to meet the usage requirements.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A ceramic arc-blocking cover for a small high-voltage DC relay is integrally formed from ceramic and consists of two parts: an arc-extinguishing cavity and an arc-blowing magnet assembly cavity. The ceramic is selected from ceramics with an alumina content of 99%. The arc-blowing magnet assembly cavity is located below the arc-extinguishing cavity. There are two arc-blowing magnet assembly cavities.

[0005] The beneficial effects of adopting the above technical solution are: To prevent short circuits caused by contact between the arc blower and metal parts, this invention controls the arc within the arc-extinguishing cavity of a ceramic arc-isolating cover. The ceramic arc-isolating cover and the arc-blowing magnet constitute an arc-extinguishing device, which completely isolates the arc from the metal parts, creating physical insulation and extinguishing the arc within the arc cavity. This avoids high-voltage breakdown and short circuits between metal parts, solving the technical problem of unsatisfactory arc-extinguishing performance in small-volume high-voltage DC relays, which affects product performance and fails to meet usage requirements. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the ceramic arc-blocking structure of the present invention used in a small high-voltage DC relay.

[0007] Figure 2 for Figure 1 Rear view.

[0008] Figure 3 for Figure 1 Left sectional view.

[0009] Figure 4 A schematic diagram illustrating the application of a ceramic arc shield combined with magnetic blowout technology, showing the arc being blown outwards.

[0010] Figure 5 This is a schematic diagram illustrating the application of a ceramic arc shield combined with magnetic blowout technology, where the electric arc is blown inward.

[0011] In the diagram: 1-arc extinguishing cavity, 2-arc blowing magnet assembly cavity. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0013] A ceramic arc-extinguishing cover for a small high-voltage DC relay is integrally molded from ceramic and consists of two parts: an arc-extinguishing cavity 1 and an arc-blowing magnet assembly cavity 2. The ceramic is selected with an alumina content of 99%, possessing extremely high melting point and stability, with a maximum melting point of 2050℃. It can maintain the integrity of the overall structure at high temperatures and also has good insulation properties, with a volume resistivity at room temperature exceeding 10¹⁴ Ω·cm. This makes it difficult for an arc to continuously and stably form and spread on the surface of the arc-extinguishing cavity; the arc is forced to move rapidly or extinguish within a very small area, avoiding concentrated arc erosion of the contacts per unit time. With high wear resistance and chemical inertness, the ceramic arc shield, when assembled into the relay, is less likely to rub against the internal parts of the relay and generate excess material. It will not react with gases generated by other internal parts of the relay under high-temperature conditions. Specifically, it is made of ceramic with 99% alumina content, resulting in a stable ceramic arc shield with strong resistance to high-voltage arc erosion. The arc-blowing magnet assembly cavity 2 is located below the arc-extinguishing cavity 1. There are two arc-blowing magnet assembly cavities 2. In addition to the arc-extinguishing ability of the material itself, the structural design incorporates magnetic blowout arc-extinguishing technology to enhance the arc-extinguishing effect of the ceramic arc shield.

[0014] A pre-reserved cavity 2 for assembling the arc-blowing magnet is provided in the ceramic arc-isolating cover and placed directly below the moving and stationary contacts. Each set of contacts uses a separate magnet. The surface of the magnet perpendicular to the contact is the direction of the magnetic field, and the outward-facing surface is the N pole. When the contacts are disconnected, the arc is subjected to force in the magnetic field generated by the magnet, which blows the arc laterally to both sides (outer or inner sides) of the contacts. The arc column is lengthened, and the arc voltage increases. When the arc voltage is lower than the arc volt-ampere characteristic curve, the arc is extinguished.

[0015] Limited by the size of the relay, there is not a large enough arc cavity volume and cooling area when the electric arc is blowing horizontally. Therefore, by combining ceramic materials, the electric arc can be partially stretched into the inner wall of the ceramic arc extinguishing chamber by the magnetic field of the magnet to help extinguish the arc.

[0016] Meanwhile, to prevent the arc from coming into contact with and short-circuiting the metal parts, the arc is controlled within the arc-extinguishing chamber of the ceramic arc-isolating cover. The ceramic arc-isolating cover and the arc-blowing magnet constitute an arc-extinguishing device. This device completely isolates the arc from the metal parts, forming physical insulation, thus extinguishing the arc within the arc chamber. This avoids high-voltage breakdown and short circuits between the metal parts.

[0017] The main performance indicators of the ceramic arc shield for a small high-voltage DC relay described in this invention are shown in Table 1.

[0018] Table 1 Application of Ceramic Arc Isolation Covers Application Scope of the Normally Closed Bidirectional High Voltage Relay of the Present Invention The ceramic arc shield for small high-voltage DC relays described in this invention has been successfully applied in 540V and 270V high-voltage DC relays and has been verified through testing and in power supply and distribution systems.

Claims

1. A ceramic arc-shielding cover for a small high-voltage DC relay, characterized in that: It is integrally formed from ceramic and is divided into two parts: an arc-extinguishing cavity (1) and an arc-blowing magnet assembly cavity (2); the ceramic is selected with an alumina content of 99%; the arc-blowing magnet assembly cavity (2) is located below the arc-extinguishing cavity (1); there are two arc-blowing magnet assembly cavities (2).

2. The ceramic arc shield for a small high-voltage DC relay according to claim 1, characterized in that: The arc-blowing magnet assembly cavity (2) is placed directly below the moving and stationary contacts, and each of the two sets of contacts uses a separate magnet. The magnetic field direction is the surface of the magnet perpendicular to the contact, and the outward-facing surface is the N pole. When the contact is broken, the arc is subjected to force in the magnetic field generated by the magnet, which blows the arc horizontally to both sides of the contact. The arc column is stretched, and the arc voltage increases. When the arc voltage is lower than the arc voltage-current characteristic curve, the arc is extinguished.

Images