Multi-contact composite contact for vacuum arc-extinguishing chamber

Abstract

A multi-contact composite contact for a vacuum arc-extinguishing chamber is of a circular layered structure and comprises a copper layer and a copper-chromium alloy layer fixedly connected with the copper layer into a whole, a circular sinking groove is concentrically formed in the center of the end face of the copper-chromium alloy layer, an annular groove is further concentrically formed in the end face of the copper-chromium alloy layer, and the circular sinking groove is communicated with the annular groove. The circular layered structure is provided with a plurality of vertically-through strip-shaped through grooves in the radial direction, the strip-shaped through grooves penetrate through the annular groove and then stretch into the circular sinking groove but do not penetrate through the circular sinking groove, the circular layered structure is divided into petal-shaped structures, and the end face of the copper-chromium alloy layer forms a plurality of contact faces which are relatively independent and connected together in parallel. According to the utility model, a plurality of independent contact surfaces are provided, when the moving contact and the static contact are contacted, multi-point contact can be formed through slight deformation of the copper layer, the contact area is increased, the electric repulsive force between the moving contact and the static contact is reduced, the contact resistance is reduced, fusion welding of the moving contact and the static contact is avoided, and the pressure of the contacts can be reduced by 30-50%.

Description

Technical Field

[0001] This utility model belongs to the field of vacuum circuit breaker technology, and in particular relates to a multi-contact composite contact for a vacuum interrupter. Background Technology

[0002] As a core component of vacuum circuit breakers, vacuum interrupters are electro-vacuum devices that use a pair of flat contacts sealed in a vacuum to connect and disconnect power circuits, using high vacuum as the insulating arc-extinguishing medium. Typically, the contacts are flat, and the material is a copper-chromium alloy. Due to the low conductivity of copper-chromium alloy (only about 1 / 3 that of oxygen-free copper), an oxygen-free copper sheet is welded between the contact and the contact base to improve conductivity. Simultaneously, to reduce eddy currents generated on the contact surface during vacuum interruption, which could affect the interruption function, 2-6 narrow slots are typically machined on both the contact and the copper sheet. During assembly, it is crucial to ensure that the narrow slots on the contact and the copper sheet are aligned.

[0003] The most recent prior art (CN203659743U) for copper-chromium composite contacts in vacuum interrupters has a planar butt joint structure. Although it has 2-6 narrow slots machined on it, when the contacts are closed, the moving and stationary contacts still have a single-point planar contact. When the current flowing through is large, the electrodynamic repulsion on its surface is large. Excessive electrodynamic repulsion may cause the contacts to break unexpectedly under short-circuit current, affecting the safe operation of the equipment. Secondly, the contact resistance between the moving and stationary contacts is large, which can easily cause the moving and stationary contacts to weld together. In addition, due to the single-point contact design of the moving and stationary contacts, the probability of arc reignition and overvoltage problems are prone to occur. Summary of the Invention

[0004] This invention provides a multi-contact composite contact for a vacuum interrupter to overcome the shortcomings of the prior art.

[0005] The technical solution adopted by this utility model is: a multi-contact composite contact for a vacuum interrupter, wherein the contact is a circular layered structure, including a copper layer and a copper-chromium alloy layer integrally bonded to the copper layer. A circular recessed groove is concentrically provided in the center of the end face of the copper-chromium alloy layer, and an annular groove is also concentrically provided on the end face of the copper-chromium alloy layer. The circular layered structure is provided with several vertically penetrating strip grooves along the radial direction, and the strip grooves penetrate the annular grooves and extend into the circular recessed grooves but do not penetrate them, dividing the circular layered structure into a petal-shaped structure, so that the end face of the copper-chromium alloy layer forms several relatively independent and parallel contact surfaces.

[0006] The depth of the annular groove is not less than two-thirds of the thickness of the copper-chromium alloy layer.

[0007] One or two annular grooves are provided.

[0008] A truncated cone protrudes from the center of the circular groove, flush with the end face of the copper-chromium alloy layer, and the inner end of the strip-shaped groove ends at the outer periphery of the truncated cone.

[0009] The strip-shaped through grooves are evenly distributed in 2-6 sections.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1. This utility model has multiple independent contact surfaces. When the moving and stationary contacts come into contact, the slight deformation of the copper layer can form multi-point contact, which increases the contact area, reduces the electro-repulsive force between the moving and stationary contacts, reduces the contact resistance, avoids welding between the moving and stationary contacts, and can also reduce the contact pressure by 30-50%.

[0012] 2. The multi-point contact of this utility model can compensate for single-point wear of the contact and extend the service life of the contact.

[0013] 3. This utility model has multiple independent contact surfaces connected in parallel. By dispersing the current density through multiple parallel contacts, the contact resistance is reduced by 30% to 50%, which reduces the risk of local overheating on the contact surface.

[0014] 4. The flexible contact of each contact point in this utility model ensures uniform arc distribution during the breaking process, thereby improving the reliability of short-circuit current breaking.

[0015] 5. The multi-point contact of this utility model increases the contact surface and reduces the probability of arc reignition, making it suitable for frequent operation scenarios of 10kV~35kV (such as energy storage power stations and rail transit).

[0016] 6. This utility model features multi-point contact, ensuring uniform arc distribution during the interruption process. This prevents a sharp drop in arc current that could lead to LC circuit resonance and generate overvoltage. Attached Figure Description

[0017] Figure 1 This is a cross-sectional schematic diagram of Embodiment 1 of this utility model;

[0018] Figure 2 This is a schematic diagram of the structure of Embodiment 1 of this utility model;

[0019] Figure 3 This is a cross-sectional schematic diagram of Embodiment 2 of this utility model;

[0020] Figure 4 This is a schematic diagram of the structure of Embodiment 2 of this utility model. Detailed Implementation

[0021] The following is in conjunction with the appendix Figure 1-4 The present invention will be described in detail with reference to specific embodiments.

[0022] Example 1, see Figure 1 , 2 .

[0023] A multi-contact composite contact for a vacuum interrupter, the contact having a circular layered structure, including a copper layer 1 and a copper-chromium alloy layer 2 integrally bonded to the copper layer 1. A circular recessed groove 5 is concentrically provided in the center of the end face of the copper-chromium alloy layer 2, and an annular groove 3 is also concentrically provided in the end face of the copper-chromium alloy layer 2. The circular layered structure has six vertically penetrating strip grooves 4 along the radial direction, and the strip grooves 4 penetrate the annular groove 3 and extend into the circular recessed groove 5 but do not penetrate it, dividing the circular layered structure into a six-petal structure, so that the end face of the copper-chromium alloy layer 2 forms 12 relatively independent contact surfaces 2-1.

[0024] To highlight the elasticity of the copper layer 1, the depth of the annular groove 3 is not less than two-thirds of the thickness of the copper-chromium alloy layer 2. When the moving and stationary contacts are in contact, the slight deformation of the copper layer 1 allows the 12 relatively independent contact surfaces 2-1 formed on the end face of the copper-chromium alloy layer 2 to form multi-point contact, increasing the contact area, reducing the electrodynamic repulsion between the moving and stationary contacts, lowering the contact resistance, preventing welding between the moving and stationary contacts, and reducing contact pressure by 30-50%. The copper layer 1 is preferably an oxygen-free copper layer 1.

[0025] Example 2, see Figure 3 , 4 Compared with the structure of Embodiment 1, the difference is that a frustum 2-2 protrudes from the center of the circular recess 5, which is flush with the end face of the copper-chromium alloy layer 2, and the inner end of the strip-shaped through groove 4 ends at the outer periphery of the frustum 2-2. This frustum 2-2 forms a relatively independent concentric contact surface, which adds one more contact surface compared to Embodiment 1 when the moving and stationary contacts are in contact.

[0026] Tests showed that the contact pressure required for a 12kV / 31.5KA vacuum interrupter in the background technology is 2800-3300N; while the contact pressure required in this application is 1650-2000N, a reduction of 30-50%.

[0027] In the specific manufacturing process, the copper layer 1 and the copper-chromium alloy layer 2 are first welded together to form a contact blank, and then the contact blank is processed into the multi-contact composite contact.

[0028] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of implementation of the present utility model. Therefore, all equivalent variations made based on the content described in the claims of the present utility model should be included within the scope of the claims of the present utility model.

Claims

1. A multi-contact composite contact for a vacuum interrupter, the contact having a circular layered structure, comprising a copper layer (1) and a copper-chromium alloy layer (2) integrally bonded to the copper layer (1), characterized in that: The copper-chromium alloy layer (2) has a concentric circular groove (5) at the center of its end face, and an annular groove (3) is also concentrically provided on the end face of the copper-chromium alloy layer (2). The circular layer structure has several vertically penetrating strip grooves (4) along the radial direction. The strip grooves (4) penetrate the annular groove (3) and extend into the circular groove (5) but do not penetrate it, dividing the circular layer structure into a petal-shaped structure, so that the end face of the copper-chromium alloy layer (2) forms several relatively independent and parallel contact surfaces (2-1).

2. The composite contact according to claim 1, characterized in that: The depth of the annular groove (3) is not less than two-thirds of the thickness of the copper-chromium alloy layer (2).

3. The composite contact according to claim 1 or 2, characterized in that: One or two annular grooves (3) are provided.

4. The composite contact according to claim 3, characterized in that: The circular groove (5) has a truncated cone (2-2) protruding from the center, which is flush with the end face of the copper-chromium alloy layer (2). The inner end of the strip groove (4) ends at the outer periphery of the truncated cone (2-2).

5. The composite contact according to claim 1, characterized in that: The strip-shaped through groove (4) is evenly distributed with 2-6 grooves.

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