Plum blossom contact connecting device

Abstract

The invention provides a tulip contact connecting device, a tulip contact comprises a moving contact and a static contact, the moving contact is provided with a first contact surface, the static contact is provided with a second contact surface corresponding to the first contact surface, and the tulip contact connecting device is characterized in that at least two contact elements are distributed on the first contact surface; the contact piece is provided with at least two contact arms, and an elastic transition part is arranged between two adjacent contact arms on the same contact piece; the second contact surface is provided with connecting grooves which are in one-to-one correspondence with the contact pieces and are matched with the contact pieces in shape and size; when the first contact surface is attached to the second contact surface, the contact arm is attached to the connecting groove, and the elastic transition part is attached to the connecting groove. When the first contact surface is attached to the second contact surface, the contact arms and the elastic transition parts of the contact pieces are attached to the connecting grooves respectively, so that multi-point coplanar contact is achieved, the actual conductive area and pressure uniformity are greatly improved, and the conductive stability and thermal reliability after connection and use are improved.

Description

Technical Field

[0001] This invention relates to the field of electrical connection technology, and in particular to a plum blossom contact connection device. Background Technology

[0002] In 10 kV metal-enclosed switchgear handcart circuit breakers, the moving and stationary clover contacts transmit current through fixed connectors (such as bolts or inserts). Copper alloys or other highly conductive materials are commonly used to make the contacts to ensure low contact resistance and reliable current carrying capacity under high current.

[0003] However, current switchgear circuit breakers use a bolt-tight planar contact design for the moving and stationary contacts, supplemented by a high-strength spring to achieve electrical connection. The limited contact area between the moving and stationary contacts leads to pressure concentration at a few contact points, generating high localized thermal stress and resistance. The adverse consequences of this structure include plastic deformation in the thermal stress concentration area, uneven contact surfaces, further exacerbating resistance increases and heat generation, creating a vicious cycle and reducing thermal reliability.

[0004] Furthermore, during the installation of the handcart switch, it is difficult to ensure a high degree of alignment for all six moving and stationary contacts simultaneously. Traditionally, this is done by visually determining the alignment manually, relying on factors such as the lack of interference fit between the bolt holes and the contact backplate. The accuracy of the guide groove in the insert-type structure is also relatively limited. The resulting adverse consequences are that repeated insertion and removal, or low-frequency vibrations caused by electrical stress, lead to misalignment of the center lines of the moving and stationary contacts, reduced overlap of the contact surfaces, uneven contact resistance, and even "point contact," severely affecting conductivity stability. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a plum blossom contact connection device to improve the conductivity stability and thermal reliability after connection and use.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A plum blossom contact connection device, wherein the plum blossom contact includes a moving contact and a stationary contact, the moving contact has a first contact surface, and the stationary contact has a second contact surface corresponding to the first contact surface, characterized in that at least two contact elements are distributed on the first contact surface; The contact member has at least two contact arms, and an elastic transition portion is provided between two adjacent contact arms on the same contact member; The second contact surface is provided with connecting grooves that correspond one-to-one with the contact elements and are adapted in shape and size; When the first contact surface and the second contact surface are in contact, the contact arm is in contact with the connecting groove and the elastic transition portion is in contact with the connecting groove.

[0007] The beneficial effects of the present invention are as follows: a plum blossom contact connection device is provided, wherein at least two contact elements are distributed on the moving contact, and each contact element has at least two contact arms; an elastic transition portion is provided between two adjacent contact arms on the same contact element, and when the first contact surface and the second contact surface are in contact, the contact arms of the contact element and the elastic transition portion are respectively in contact with the connecting groove, thereby realizing multi-point coplanar contact, greatly improving the actual conductive area and pressure uniformity, and at the same time, the elastic transition portion can effectively release local stress under thermal load or mechanical impact, reduce the risk of breakage, and improve the conductive stability and thermal reliability after connection and use. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the moving contact and stationary contact of a plum blossom contact connection device according to the present invention; Figure 2 This is a front view of the first contact surface of the moving contact of a plum blossom contact connection device according to the present invention; Figure 3 This is a front view of the second contact surface of the stationary contact of a plum blossom contact connection device according to the present invention; Figure 4 This is a schematic diagram of the contact element of a plum blossom contact connection device according to the present invention; Figure 5 This is a finite element mesh structure diagram of a plum blossom contact connection device of the present invention during stress simulation; Figure 6 This is a stress cloud diagram of the interface of a plum blossom contact connection device of the present invention during stress simulation.

[0009] Label Explanation: 1. Moving contact; 2. Stationary contact; 3. First contact surface; 4. Second contact surface; 5. Contact element; 6. Contact arm; 7. Elastic transition part; 8. First protrusion; 9. First limiting groove; 10. Second protrusion; 11. Second limiting groove; 12. Connecting part; 13. Contact piece; 14. Support frame. Detailed Implementation

[0010] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0011] Please refer to Figures 1 to 4 A plum blossom contact connection device, wherein the plum blossom contact includes a moving contact 1 and a stationary contact 2, the moving contact 1 has a first contact surface 3, the stationary contact 2 has a second contact surface 4 corresponding to the first contact surface 3, and at least two contact elements 5 are distributed on the first contact surface 3. The contact member 5 has at least two contact arms 6, and an elastic transition portion 7 is provided between two adjacent contact arms 6 on the same contact member 5. The second contact surface 4 is provided with connecting grooves that correspond one-to-one with the contact elements 5 and are adapted in shape and size; When the first contact surface 3 and the second contact surface 4 are in contact, the contact arm 6 is in contact with the connecting groove, and the elastic transition portion 7 is in contact with the connecting groove.

[0012] As can be seen from the above description, the beneficial effects of the present invention are as follows: at least two contact elements 5 are distributed on the moving contact 1, and the contact element 5 has at least two contact arms 6; an elastic transition portion 7 is provided between two adjacent contact arms 6 on the same contact element 5; when the first contact surface 3 and the second contact surface 4 are in contact, the contact arms 6 of the contact element 5 and the elastic transition portion 7 respectively fit into the connecting groove, thereby achieving multi-point coplanar contact, greatly improving the actual conductive area and pressure uniformity; at the same time, the elastic transition portion 7 can effectively release local stress under thermal load or mechanical impact, reduce the risk of breakage, and improve the conductive stability and thermal reliability after connection and use.

[0013] Furthermore, the moving contact 1 is provided with a contact piece 13, and the contact piece 13 is provided with a first protrusion 8; The stationary contact 2 is provided with a first limiting groove 9 that is aligned and connected with the first protrusion 8.

[0014] As can be seen from the above description, the moving contact 1 and the stationary contact 2 are respectively provided with a first protrusion 8 and a first limiting groove 9, so as to achieve precise pre-positioning during the docking process of the moving and stationary contacts 2, avoid the contact piece 13 from shifting or misaligning when it is attached, ensure that the contact piece 5 and the connecting groove can be accurately aligned, and reduce the problem of poor local contact caused by misalignment.

[0015] Furthermore, the moving contact 1 is provided with a support frame 14, and the first contact surface 3 is the annular surface of the support frame 14 used to press against the second contact surface 4. At least two second protrusions 10 are distributed on the annular surface. The stationary contact 2 is provided with a second limiting groove 11 that is aligned and connected with the second protrusion 10.

[0016] As can be seen from the above description, the second protrusion 10 and the second limiting groove 11 can cooperate with the first protrusion 8 and the first limiting groove 9 to achieve dual positioning. This not only further enhances the overall docking accuracy of the moving and stationary contacts 2, but also fills the tiny gaps between the contact surfaces through the tight cooperation between the protrusion and the limiting groove, reducing the impact of air gaps on conductivity. At the same time, it enhances the pull-out resistance of the connection device and improves the overall structural reliability.

[0017] Furthermore, at least two of the second protrusions 10 are evenly distributed circumferentially on the annular surface.

[0018] As described above, the circumferentially continuous and uniformly distributed second protrusion 10 ensures that the limiting force during the mating of the moving and stationary contacts 2 is evenly distributed along the circumference of the annular surface, preventing deformation or damage to the contact surface caused by localized concentration of limiting force. Furthermore, the uniformly distributed structure ensures consistent contact pressure at all points on the annular surface, allowing the conductive current to be uniformly conducted in the circumferential direction, reducing heat generation caused by excessive localized current, and improving the thermal stability of the device.

[0019] Furthermore, the stationary contact 2 is provided with a connecting portion 12 corresponding to the contact piece 13; The first limiting groove 9 is located on the circumferential side of the connecting part 12; When the first contact surface 3 and the second contact surface 4 are in contact, the first protrusion 8 is snapped into the first limiting groove 9.

[0020] As can be seen from the above description, the first limiting groove 9 located on the circumferential side of the connecting part 12 and the first protrusion 8 form a snap-fit ​​connection, which can realize the bidirectional limiting and fixing of the moving and stationary contacts 2. It not only restricts radial displacement, but also prevents axial separation through the clamping force of the snap-fit. It is especially suitable for equipment that needs to be frequently plugged and unplugged or in a vibrating environment, which greatly improves the firmness and service life of the connection.

[0021] Furthermore, all the contact arms 6 on the same contact member 5 are distributed in a petal-like pattern along the circumference of the contact member 5.

[0022] As described above, the petal-shaped distribution of contact element 5 significantly increases the actual contact points between contact arm 6 and connecting groove, further expanding the conductive area and reducing contact resistance. Simultaneously, the petal-shaped structure, through the independent elastic deformation of each contact arm 6 during bonding, adapts to minute dimensional deviations in the connecting groove, ensuring that each contact arm 6 fits tightly against the connecting groove. This avoids localized contact failures caused by processing errors, improving the reliability and fault tolerance of conductivity.

[0023] Furthermore, all of the contact elements 5 are symmetrically distributed on the first contact surface 3.

[0024] As described above, the symmetrically distributed contact elements 5 enable the current to be evenly distributed along the axis of symmetry on the first contact surface 3, avoiding current concentration caused by uneven distribution of contact elements 5 and reducing the risk of local overheating. In addition, the symmetrical structure can also keep the force on the moving contact 1 balanced during docking, preventing contact tilting or poor contact surface fit caused by excessive force on one side, and ensuring that all contact elements 5 can fit synchronously and evenly with the corresponding connecting groove.

[0025] Furthermore, both the contact element 5 and the contact arm 6 are copper alloy parts, and the surfaces of the contact element 5 and the contact arm 6 are provided with a nickel-tin double electroplating layer.

[0026] As can be seen from the above description, copper alloy material itself has excellent electrical conductivity and mechanical strength, which can meet the requirements of long-term conductivity and mechanical impact resistance of plum blossom contacts; while the nickel-tin double electroplating layer can play a dual protective role - the nickel layer can enhance the corrosion resistance and wear resistance of the substrate, and prevent the conductivity of contact 5 from decreasing due to oxidation or wear during long-term use.

[0027] Furthermore, the elastic transition portion 7 is a rounded corner with a radius of R4-R6mm.

[0028] As can be seen from the above description, the rounded corner transition structure with R4-R6mm can effectively avoid the risk of fracture caused by stress concentration between adjacent contact arms 6. Compared with sharp transition, rounded corners can evenly distribute the local stress generated by thermal load or mechanical impact to the transition area, improve the fatigue resistance of the elastic transition part 7, and extend the service life of the contact part 5.

[0029] Furthermore, the end of the contact arm 6 is provided with a rounded chamfer, the radius of which is R2-R3mm.

[0030] As described above, the R2-R3mm rounded corners at the ends serve as a guide during the mating of the moving and stationary contacts 2, preventing the sharp ends of the contact arm 6 from scratching the inner wall of the connecting groove and reducing mechanical damage during mating. Secondly, the rounded corners increase the contact area between the end of the contact arm 6 and the connecting groove, making the contact pressure more uniform and reducing local contact resistance. Finally, the rounded corners of this size can improve the wear resistance of the end without affecting the rigidity of the contact arm 6, preventing deformation or wear of the end due to long-term insertion and removal, and ensuring that the contact arm 6 always maintains good fit and conductivity.

[0031] Please refer to Figures 1 to 6 Embodiment 1 of the present invention is as follows: A plum blossom contact connection device, such as Figure 1 As shown, the plum blossom contact includes a moving contact 1 and a stationary contact 2. The moving contact 1 has a first contact surface 3, and the stationary contact 2 has a second contact surface 4 corresponding to the first contact surface 3. At least two contact elements 5 are distributed on the first contact surface 3. Each contact element 5 has at least two contact arms 6, and an elastic transition portion 7 is provided between two adjacent contact arms 6 on the same contact element 5. The second contact surface 4 is provided with connecting grooves that correspond one-to-one with the contact elements 5 and are adapted in shape and size. When the first contact surface 3 and the second contact surface 4 are in contact, the contact arms 6 of the contact elements 5 and the elastic transition portions 7 are respectively in contact with the connecting grooves.

[0032] like Figure 2The moving contact 1 shown typically consists of a contact piece 13, a support frame 14, and a tension spring. The support frame 14 is annular, and several contact pieces 13 are assembled on the support frame 14 to form an annular body, which is bound together by a non-magnetic stainless steel annular tension spring. The contact pieces 13 are generally made of precision-stamped copper plate, with a thick silver plating and anti-discoloration treatment to enhance wear resistance and oxidation resistance.

[0033] In this embodiment, during connection, the first contact surface 3 and the second contact surface 4 are pressed together, and each contact arm 6 of each contact member 5 and the elastic transition portion 7 are fitted with the connecting groove to achieve multi-point contact and increase the conductive area. The end of the contact arm 6 is provided with a rounded chamfer with a radius of R2-R3mm.

[0034] And, as Figure 4 As shown, all contacts 5 are symmetrically distributed on the first contact surface 3. All contact arms 6 on the same contact 5 are distributed in a petal shape along the circumference of the contact 5. Specifically, as shown in the figure, all contact arms 6 on the same contact 5 adopt a "cross" type contact piece 13 design. The four symmetrically distributed contact arms 6 extend outward like plum petals. Each contact arm 6 has an independent elastic transition part 7. The elastic transition part 7 is a rounded corner with a radius of R4-R6mm.

[0035] Furthermore, both contact element 5 and contact arm 6 are made of copper alloy, and both surfaces are coated with a nickel-tin double electroplating layer. The bottom layer is nickel-plated (30μm thick) to enhance corrosion resistance and adhesion, while the top layer is tin-plated (5μm thick) to reduce contact resistance and the coefficient of friction. High-precision polishing followed by electroplating is employed, ensuring the final contact surface roughness is controlled to Ra≤0.4μm, guaranteeing the actual contact point density and mechanical meshing force. The fixing plate and locating pin area undergo rust-proof zinc plating or anodizing treatment to ensure long-term weather resistance.

[0036] In this embodiment, M8 high-strength bolts are used between the first contact surface 3 and the second contact surface 4, along with elastic washers and limiting baffles. The preload is controlled by a torque wrench, with a set torque value of 30±2 N·m, corresponding to a contact pressure of approximately 8~10 MPa, which can meet the requirements for stable contact under high loads. The bolt mounting holes adopt a step-limiting design to prevent bolt loosening due to long-term thermal expansion. Stress diffusion grooves are provided around the preload area to reduce shear stress caused by concentrated tightening.

[0037] To verify the performance of the plum blossom contact connection device in this embodiment, stress and thermo-mechanical multiphysics simulation analysis were first performed as follows: First, such as Figure 5As shown, finite element modeling and mesh generation establish a complete 3D structural model on the finite element platform, including all key components such as the contact, contact piece 13, connecting plate, bolts, and locating pins. Fine meshing (mesh size ≤ 0.3mm) is used at the contact interface and transition arc region to ensure accurate result convergence and local response. Boundary condition equations are established as follows: ; Stress boundary conditions (if) ): .in, The surface traction force vector, Let n be the projection direction, and n be the normal vector of the contact surface e (i.e., the perpendicular direction of the interface). This represents the gradient vector of the plastic potential function (potential energy density) on the contact surface.

[0038] Set initial conditions: ; At the initial time t=0, the velocity / displacement field u is zero everywhere. This represents the initiation condition of transient flow or dynamics (such as fluid flow or structural vibration starting from rest).

[0039] Simulation load settings: Mechanical load: Set insertion and extraction force to 250N, contact surface friction force to 0.3×normal force; Electrothermal load: Set heat source model with current flow of 1250A and ambient temperature of 25℃, with a temperature rise target of 150℃; Constraints: Positioning pin fixed constraint, bolt preload is simulated in the form of tension.

[0040] The simulated load equation is: ; In the formula: It is an inertial force; This refers to the momentum change caused by the migration of fluid particles; For pressure gradient ( ); This is the contribution of viscous force to the corresponding shear stress; External volume force; This represents the divergence of the viscous stress tensor, and the result is a vector (force density). It is a second-order tensor matrix, and its component form is: .

[0041] Reference Figure 6 The final analysis results are as follows: Stress analysis: The maximum stress in the new structure is 8.5 × 10⁻⁶. 7 Pa is reduced by about 20% compared to the traditional structure; Maximum displacement analysis: The displacement of the new structure is 0.12 mm, while that of the traditional structure is 0.25 mm; Contact pressure distribution: The pressure difference between contact arms is less than 8%, significantly better than the maximum difference of 30% in traditional designs. Thermal expansion coupling stress: After 10 thermal cycles, the structural deformation remains within ±0.05mm. Simulation results show that the contacts can maintain high alignment and stable electrical contact performance under actual operating conditions.

[0042] Please refer to Figure 2 and Figure 3 Embodiment two of the present invention is as follows: A plum blossom contact connection device is provided, wherein each contact piece 13 of the moving contact 1 is provided with a first protrusion 8; the stationary contact 2 is provided with a first limiting groove 9 that is aligned and connected to the first protrusion 8. The first contact surface 3 is a support frame 14 used to press against the annular surface of the second contact surface 4, and at least two second protrusions 10 are distributed on the annular surface; the stationary contact 2 is provided with a second limiting groove 11 that is aligned and connected to the second protrusion 10.

[0043] In this embodiment, at least two second protrusions 10 are evenly distributed circumferentially on the annular surface.

[0044] like Figure 1 As shown, the stationary contact 2 is provided with a connecting part 12 corresponding to the contact piece 13; the first limiting groove 9 is located on the circumferential side of the connecting part 12; when the first contact surface 3 and the second contact surface 4 are in contact, the first protrusion 8 is snapped into the first limiting groove 9.

[0045] In summary, the present invention provides a plum blossom contact connection device, wherein at least two contact elements are distributed on the moving contact, and each contact element has at least two contact arms. An elastic transition portion is provided between adjacent contact arms on the same contact element. When the first contact surface and the second contact surface are in contact, the contact arms of the contact element and the elastic transition portion respectively fit into the connecting groove, thereby achieving multi-point coplanar contact, significantly improving the actual conductive area and pressure uniformity. Simultaneously, the elastic transition portion can effectively release local stress under thermal load or mechanical impact, reducing the risk of breakage and improving the conductive stability and thermal reliability after connection. Furthermore, the petal-shaped distribution of the contact elements significantly increases the actual contact points between the contact arms and the connecting groove, further expanding the conductive area and reducing contact resistance. At the same time, the petal-shaped structure can adapt to the slight dimensional deviations of the connecting groove through the independent elastic deformation of each contact arm during fitting, ensuring that each contact arm fits tightly into the connecting groove, avoiding local contact failure due to processing errors, and improving the reliability and fault tolerance of conductivity. Meanwhile, the contact itself has excellent conductivity and mechanical strength, which can meet the requirements of long-term conductivity and mechanical shock resistance of the plum blossom contact; while the nickel-tin double electroplating layer can play a dual protective role - the nickel layer can enhance the corrosion resistance and wear resistance of the substrate, and prevent the conductivity of the contact from decreasing due to oxidation or wear during long-term use.

[0046] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A plum blossom contact connection device, characterized in that, The plum blossom contact includes a moving contact and a stationary contact. The moving contact has a first contact surface, and the stationary contact has a second contact surface corresponding to the first contact surface. The first contact surface is provided with at least two contact elements. The contact member has at least two contact arms, and an elastic transition portion is provided between two adjacent contact arms on the same contact member; The second contact surface is provided with connecting grooves that correspond one-to-one with the contact elements and are adapted in shape and size; When the first contact surface and the second contact surface are in contact, the contact arm is in contact with the connecting groove, and the elastic transition portion is in contact with the connecting groove.

2. The plum blossom contact connection device according to claim 1, characterized in that, The moving contact is provided with a contact piece, and the contact piece is provided with a first protrusion; The stationary contact head is provided with a first limiting groove that is aligned and connected to the first protrusion.

3. The plum blossom contact connection device according to claim 2, characterized in that, The moving contact is provided with a support frame, and the first contact surface is an annular surface of the support frame used to press against the second contact surface. At least two second protrusions are distributed on the annular surface. The stationary contact head is provided with a second limiting groove that is aligned and connected with the second protrusion.

4. The plum blossom contact connection device according to claim 3, characterized in that, At least two of the second protrusions are evenly distributed circumferentially on the annular surface.

5. The plum blossom contact connection device according to claim 2, characterized in that, The stationary contact head is provided with a connecting part corresponding to the contact piece; The first limiting groove is located on the circumferential side of the connecting part; When the first contact surface and the second contact surface are in contact, the first protrusion is snapped into place by the first limiting groove.

6. The plum blossom contact connection device according to claim 1, characterized in that, All the contact arms on the same contact element are distributed in a petal-like pattern along the circumference of the contact element.

7. The plum blossom contact connection device according to claim 1, characterized in that, All of the contacts are symmetrically distributed on the first contact surface.

8. The plum blossom contact connection device according to claim 1, characterized in that, Both the contact element and the contact arm are copper alloy parts, and the surfaces of the contact element and the contact arm are provided with a nickel-tin double electroplating layer.

9. A plum blossom contact connection device according to claim 1, characterized in that, The elastic transition section is a rounded corner, and the radius of the rounded corner is R4-R6mm.

10. A plum blossom contact connection device according to claim 1, characterized in that, The end of the contact arm is provided with a rounded chamfer, the radius of which is R2-R3mm.

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