High voltage dc contactor and moving contact assembly therefor

Abstract

The application discloses a high-voltage direct-current contactor and a moving contact assembly thereof, and belongs to the technical field of high-voltage direct-current contactors. The moving contact assembly comprises a fixed support, moving pieces and independent elastic pieces. The fixed support is provided with a mounting groove and a buckle hole. A lower armature is fixedly connected below the moving piece. The two side walls of the lower armature are provided with convex blocks. The moving piece is clamped and limited with the fixed support through the convex blocks embedded in the buckle hole. The independent elastic pieces are arranged in the mounting groove of the fixed support. The independent elastic pieces comprise two elastic pieces arranged in a symmetrical manner. One end of each elastic piece is fixedly connected with the fixed support, and the other end is elastically pressed against the bottom of the moving piece, so as to apply contact pressure to the moving piece. The independent elastic pieces are used for independently applying pressure to each moving piece, the elastic pieces do not interfere with each other, and self-adaptive pressure compensation can be realized. The symmetrical arrangement of each group of elastic pieces balances the stress of the moving piece and avoids additional bending moments. The moving piece is embedded in the buckle hole through the convex blocks, so that fast plug-in assembly and bidirectional limiting can be realized.

Description

Technical Field

[0001] This invention belongs to the field of high voltage DC contactor technology, specifically relating to a high voltage DC contactor and its moving contact assembly. Background Technology

[0002] In existing high-voltage DC contactor moving contact assemblies, contact pressure is typically provided by cylindrical springs. Long-term operation of cylindrical springs can lead to plastic deformation and elastic fatigue, resulting in decreased contact pressure, increased contact resistance, and intensified heating. The single-spring overall pressure application method lacks unilateral adaptive adjustment capability. When machining tolerances or unilateral wear occur, pressure deviations on both sides of the moving contact can cause poor contact, localized heating, and arcing. Furthermore, the single-spring structure lacks pressure redundancy, meaning a single point of failure can render the entire unit inoperable.

[0003] Chinese patent CN106158517A discloses a moving contact structure for a high-voltage DC sealed contactor. It employs a double "J"-shaped structure formed by a first moving contact piece and a second moving contact piece located below it, stacked vertically. This, combined with two nested contact springs, constitutes a two-path, double-break structure. The "J"-shaped structure with double moving contact pieces accelerates arc movement and extinguishing, while the moving contact pieces and contact springs reduce arcing time and contact wear between the main contacts. However, this solution still uses a spring-linked pressure application method, failing to achieve independent adaptive adjustment of each contact.

[0004] Chinese patent CN106098477A discloses a high-voltage DC contactor with a magnetic coil for arc extinguishing. Its moving contact is driven by a rocker arm, and a cylindrical spring provides contact pressure. This solution relates to an improvement in the arc extinguishing system and does not involve an independent pressure-applying structure for the leaf spring.

[0005] Chinese patent CN215527615U discloses a moving piece positioning structure for a high-voltage DC relay. This structure utilizes a locking groove at the upper end of a push rod and protruding locking pieces on both sides of the moving piece that engage with locking holes on the side walls of the mounting bracket to achieve moving piece positioning. While this solution involves a moving piece locking and limiting structure, it is only used for the assembly and positioning of the moving piece with the push rod and mounting bracket. Its compressible elastic element is used for positioning and engagement, and it does not involve a contact pressure system.

[0006] Therefore, it is necessary to improve the pressure system of the moving contact assembly so that each contact can apply pressure independently and has adaptive adjustment capabilities. Summary of the Invention

[0007] The purpose of this invention is to provide a high-voltage DC contactor and its moving contact assembly to solve the technical problems mentioned in the background art, such as easy pressure decay, inability to adaptively adjust, and lack of independent pressure redundancy in existing single-spring pressure structures.

[0008] To achieve the above objectives, the present invention provides a moving contact assembly for a high-voltage DC contactor, employing the following technical solution:

[0009] A moving contact assembly of a high-voltage DC contactor includes a fixed bracket, a moving piece, and an independent spring. The fixed bracket has a mounting groove and a snap-fit ​​hole. A lower armature is fixedly connected below the moving piece. The lower armature has protrusions on both sides of its side walls. The moving piece is engaged with the fixed bracket by the snap-fit ​​hole through the protrusions. The independent spring is disposed in the mounting groove of the fixed bracket. The independent spring includes a set of two symmetrically arranged springs. One end of each spring is fixedly connected to the fixed bracket, and the other end elastically presses against the bottom of the moving piece. The independent spring is used to apply contact pressure to the moving piece.

[0010] By adopting the above technical solution, the moving piece and the lower armature are fixed together, and the protrusions on both sides of the lower armature are embedded in the snap-fit ​​holes of the fixing bracket. The snap-fit ​​holes limit the movement of the moving piece to the left and right to prevent it from shaking, and leave a slight movement space at the top and bottom to ensure that the spring clip presses the moving piece firmly. The protrusions slide into the snap-fit ​​holes along the bent arc guide structure to achieve quick-connect assembly.

[0011] The spring is a cantilever beam leaf spring, with one end fixed to the bracket and the other end pressed against the bottom of the moving plate. Each spring corresponds to one moving plate, and they do not interfere with each other. When the moving plate changes position due to tolerance or wear, the spring compensates by changing its deformation. When the moving plate moves downward, the spring deformation increases and the pressure increases slightly, unlike a cylindrical spring which becomes looser with use. This ensures stable pressure at each contact point during long-term use.

[0012] Compared to cylindrical springs, leaf springs have a more uniform stress distribution along their length, resulting in lower maximum stress under the same load and a longer fatigue life. Cylindrical springs maintain constant pressure on both sides, failing to compensate for unilateral wear; independent leaf springs, on the other hand, apply pressure to each contact point independently, automatically adjusting for tolerances and wear to ensure consistent pressure across all groups.

[0013] Preferably, the lower armature has a U-shaped structure, with both side walls of the U-shaped structure extending upward beyond the upper surface of the moving piece, and the convex bulge is disposed on the side wall.

[0014] By adopting the above technical solution, the U-shaped armature is wrapped around the outside of the moving piece, and the protrusions on both sides of the wall cooperate with the snap-fit ​​holes to achieve snap-fit ​​and limit, resulting in a compact structure and reliable limit.

[0015] Preferably, there are multiple moving pieces, lower armatures, and independent spring pieces, each of which corresponds to a moving piece, and each of which independently applies contact pressure to the corresponding moving piece.

[0016] When the number of moving pieces is N, the number of independent spring pieces is N, and each independent spring piece includes a set of two spring pieces arranged symmetrically.

[0017] By adopting the above technical solution, each moving piece obtains independent and uniform pressure, and the failure of a single spring does not affect the operation of other contacts, resulting in high system fault tolerance and safety.

[0018] Preferably, the independent spring is a cantilever beam leaf spring, and the end of the independent spring that contacts the moving piece has an arc-shaped contact surface.

[0019] By adopting the above technical solution, the cantilever beam structure is simple and reliable, and the arc contact surface reduces the frictional resistance between the spring and the moving plate, avoiding jamming during relative sliding.

[0020] Preferably, the top of the fixed bracket is provided with a bent arc guide structure.

[0021] By adopting the above technical solution, the bent arc guide structure facilitates the rapid assembly and insertion of the moving piece, thereby improving assembly efficiency.

[0022] On the other hand, the present invention also provides a high-voltage DC contactor, including a housing, an electromagnetic drive mechanism disposed within the housing, a stationary contact and a moving contact assembly, wherein the moving contact assembly is any of the moving contact assemblies described above; the fixed bracket of the moving contact assembly is drively connected to the output end of the electromagnetic drive mechanism, and the fixed bracket, driven by the electromagnetic drive mechanism, drives the moving contact to move closer to or away from the stationary contact, so as to realize the closing or opening of the contactor.

[0023] In summary, the present invention has the following beneficial technical effects:

[0024] This invention employs independent springs to apply pressure to each moving piece independently, with no interference between the springs, enabling adaptive pressure compensation; the symmetrical arrangement of each group of springs ensures balanced force on the moving pieces, avoiding additional bending moments; the moving pieces are quickly assembled and bidirectionally limited by being embedded into snap-fit ​​holes via convex bulges; the failure of a single group of springs does not affect the operation of other contacts, resulting in high system fault tolerance and safety; the leaf springs exhibit excellent fatigue resistance and minimal pressure decay over long-term operation. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the moving contact assembly in Embodiment 1 of the present invention.

[0026] Figure 2 This is an exploded structural diagram of the moving contact assembly in Embodiment 1 of the present invention.

[0027] Figure 3 This is a schematic diagram of the overall structure of the moving contact assembly in Embodiment 2 of the present invention.

[0028] Figure 4 This is a schematic diagram illustrating the connection relationship between the three sets of moving plates and the fixed bracket in Embodiment 2 of the present invention.

[0029] Figure 5 This is an exploded structural diagram of the moving contact assembly in Embodiment 2 of the present invention.

[0030] Figure 6 This is a schematic diagram of the overall disassembled structure of the high-voltage DC contactor of the present invention.

[0031] Explanation of reference numerals in the attached drawings: 1. Fixed bracket; 11. Mounting groove; 12. Snap-in hole; 2. Moving piece; 3. Lower armature; 31. Protrusion; 4. Independent spring. Detailed Implementation

[0032] The following is in conjunction with the appendix Figure 1-6 The present invention will be described in further detail below.

[0033] Example 1

[0034] Reference Figure 1-2 The moving contact assembly in this embodiment includes a fixed bracket 1, a moving piece 2, a lower armature 3, and an independent spring piece 4.

[0035] The fixed bracket 1 has a mounting groove 11, which is a rectangular groove with a width that matches the width of the independent spring piece. The top of the fixed bracket 1 has a bent arc guide structure to facilitate the quick assembly and insertion of the moving piece 2. The fixed bracket 1 also has a snap-fit ​​hole 12.

[0036] The movable piece 2 is mounted on the fixed bracket 1, and a lower armature 3 is fixedly connected below the movable piece 2. The lower armature 3 has a U-shaped structure, and the two side walls of the U-shaped structure extend upward beyond the upper surface of the movable piece 2. The two side walls are provided with protrusions 31. The movable piece 2 is inserted into the snap-fit ​​holes 12 on the fixed bracket 1 through the protrusions 31 on the two side walls, and is snapped and limited with the fixed bracket 1. The snap-fit ​​holes 12 form a bidirectional limit on the protrusions 31 to prevent the movable piece 2 from wobbling left and right.

[0037] An independent spring 4 is disposed within the mounting groove 11 of the fixed bracket 1. The independent spring 4 is a cantilever beam leaf spring. The independent spring 4 includes a set of two symmetrically arranged springs, which are respectively disposed on both sides of the moving plate 2 and symmetrically press against the bottom ends of the moving plate 2. One end of each spring is fixed to the mounting groove 11 by riveting, and the other end elastically presses against the bottom of the moving plate 2, applying contact pressure to the moving plate 2. The end of the independent spring 4 that contacts the moving plate 2 has an arc-shaped contact surface to avoid jamming during relative sliding.

[0038] In this embodiment, the number of moving piece 2, lower armature 3 and independent spring piece 4 is one, that is, the fixed bracket 1 is provided with a set of moving pieces and a corresponding set of independent spring pieces (two symmetrical spring pieces in each set), which constitute a single-channel contact control system.

[0039] The fixed bracket 1 is positioned above the push rod assembly, and the push rod assembly drives the fixed bracket 1 and the moving plate 2 assembly to move as a whole.

[0040] As a preferred embodiment, the moving piece 2 in this embodiment is wide at both ends and narrow in the middle. This shape helps to reduce the stiffness of the middle area of ​​the moving piece, allowing the moving piece to adapt to deformation during spring pressure transmission, and further improving the uniformity of contact pressure.

[0041] Example 2

[0042] The difference between this embodiment and Embodiment 1 is that the number of moving piece 2, lower armature 3 and independent spring piece 4 are all three.

[0043] Reference Figure 3-5 The fixed bracket 1 has three mounting grooves 11 and three snap-fit ​​holes 12. Each mounting groove 11 contains a movable piece 2 and a set of independent spring pieces 4 (i.e., two symmetrical spring pieces per set), with each independent spring piece 4 corresponding to each movable piece 2. The three movable pieces 2 are arranged side by side on the fixed bracket 1, and each movable piece 2 is inserted into the corresponding snap-fit ​​hole 12 through the protrusions 31 on both sides of its lower armature 3, thus engaging and limiting its position with the fixed bracket 1.

[0044] Each independent spring 4 applies contact pressure independently to its corresponding moving piece 2. The independent springs 4 do not interfere with each other, forming three independent contact pressure systems. The three sets of moving pieces correspond to the three channels of the three-phase circuit, realizing three-way synchronous control.

[0045] Those skilled in the art will understand that the number of moving piece 2, lower armature 3 and independent spring piece 4 is not limited to one or three, and can be set to two or more according to actual working conditions, all of which can realize the inventive concept of the present invention.

[0046] Example 3

[0047] Reference Figure 6 This embodiment provides a high-voltage DC contactor, including a housing, an electromagnetic drive mechanism disposed within the housing, a stationary contact, and a moving contact assembly. The moving contact assembly adopts the moving contact assembly described in Embodiment 1 or Embodiment 2.

[0048] The fixed bracket 1 of the moving contact assembly is connected to the output end of the electromagnetic drive mechanism. Specifically, the output end of the electromagnetic drive mechanism can be a push rod, and the fixed bracket 1 is mounted on the push rod. When the electromagnetic drive mechanism is energized, the push rod drives the fixed bracket 1 and the moving piece 2 to move towards the stationary contact, so that the moving piece 2 contacts the stationary contact, and the contactor closes; when the electromagnetic drive mechanism is de-energized or reversed, the push rod drives the fixed bracket 1 and the moving piece 2 away from the stationary contact, and the contactor opens.

[0049] The independent spring 4 applies contact pressure to the moving piece 2, ensuring reliable contact between the moving piece 2 and the stationary contact. Figure 6 The diagram shows the moving piece 2 and the independent spring piece 4. The housing, electromagnetic drive mechanism, stationary contact, etc., can adopt conventional structures in the art, as long as they can drive the fixed bracket 1 to move the moving piece 2 closer to or away from the stationary contact.

[0050] Implementation Principles

[0051] During assembly, each moving piece 2 is inserted into the corresponding snap-fit ​​hole 12 of the fixed bracket 1 through the protrusions 31 on both sides of the lower armature 3 along the bent arc guide structure, realizing quick-connect assembly. The snap-fit ​​hole 12 forms a bidirectional limit on the protrusions 31. A set of symmetrical springs of each independent spring piece 4 presses against the bottom ends of the corresponding moving piece 2, independently providing contact pressure. The symmetrical arrangement ensures that each moving piece 2 is subjected to balanced force.

[0052] During operation, when the position of a moving piece 2 changes due to machining tolerances or contact wear, the corresponding independent spring piece 4 compensates by changing its elastic deformation. If the moving piece 2 moves downward, the spring piece deformation increases, and the pressure slightly increases; if the moving piece 2 moves upward, the spring piece deformation decreases, maintaining a stable contact pressure and achieving adaptive pressure compensation. In the embodiment using three moving pieces, if the elasticity of one of the individual independent spring pieces 4 decreases, the other symmetrical spring piece in the same group can still provide a certain contact pressure; a complete failure of a single independent spring piece 4 does not affect the contact pressure of other moving pieces 2, demonstrating the system's fault tolerance and redundancy safety.

[0053] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A moving contact assembly for a high-voltage DC contactor, comprising a fixed bracket, a moving contact, and an independent spring contact, characterized in that: The fixed bracket is provided with a mounting groove and a snap-fit ​​hole. A lower armature is fixedly connected below the moving piece. The lower armature has protrusions on both sides. The moving piece is engaged with the fixed bracket by inserting the protrusions into the snap-fit ​​hole. The independent spring is disposed in the mounting groove of the fixed bracket. The independent spring includes a set of two springs arranged symmetrically. One end of each spring is fixedly connected to the fixed bracket, and the other end is elastically pressed against the bottom of the moving piece. The independent spring is used to apply contact pressure to the moving piece.

2. The moving contact assembly of the high-voltage DC contactor according to claim 1, characterized in that: The lower armature has a U-shaped structure, with the two side walls of the U-shaped structure extending upward beyond the upper surface of the moving piece, and the convex bulge is disposed on the side wall.

3. The moving contact assembly of the high-voltage DC contactor according to claim 1, characterized in that: The number of the moving piece, the lower armature, and the independent spring pieces are all multiple, and each independent spring piece corresponds one-to-one with each moving piece. Each independent spring piece independently applies contact pressure to the corresponding moving piece. When the number of moving pieces is N, the number of independent spring pieces is N, and each independent spring piece includes a set of two spring pieces arranged symmetrically.

4. The moving contact assembly of the high-voltage DC contactor according to claim 1, characterized in that: The spring is a cantilever beam leaf spring, and the end of the spring that contacts the moving piece has an arc-shaped contact surface.

5. The moving contact assembly of the high-voltage DC contactor according to claim 1, characterized in that: The top of the fixed bracket is provided with a bent arc guide structure.

6. A high-voltage DC contactor, comprising a housing, an electromagnetic drive mechanism disposed within the housing, a stationary contact, and a moving contact assembly, characterized in that: The moving contact assembly is the moving contact assembly according to any one of claims 1 to 5; The fixed bracket of the moving contact assembly is connected to the output end of the electromagnetic drive mechanism. Under the drive of the electromagnetic drive mechanism, the fixed bracket moves the moving piece closer to or away from the stationary contact to realize the closing or opening of the contactor.

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