Copper-aluminum composite busbar electric connection wire clamp and preparation method thereof

Abstract

The invention relates to the technical field of overhead line system electrified railways, in particular to a copper-aluminum composite busbar electric connection wire clamp and a preparation method thereof.The copper-aluminum composite busbar electric connection wire clamp comprises a wire clamp body, a first clamping block, a second clamping block and a wiring terminal, and the wire clamp body comprises an integrally-formed aluminum alloy body and a copper contact layer arranged on the upper side of the aluminum alloy body; the wiring terminal is connected to the upper side of the copper contact layer, the first clamping block and the second clamping block are connected to the lower side of the aluminum alloy body, a busbar installation groove is formed in the lower surface of the aluminum alloy body, the first clamping block and the second clamping block are symmetrically arranged on the two sides of the busbar installation groove, and busbar clamping grooves are formed in the sides, close to each other, of the first clamping block and the second clamping block. According to the copper-aluminum composite busbar electric connection wire clamp and the preparation method thereof, the problem that a traditional wire clamp is prone to oxidation and electrocorrosion is solved, and the connection reliability is improved.

Description

Technical Field

[0001] This invention relates to the field of overhead contact line electrification railway technology, and in particular to a copper-aluminum composite busbar electrical connection clamp and its preparation method. Background Technology

[0002] Busbar electrical connectors are key components in power transmission systems, enabling connections between busbars and cables. They are widely used in high-voltage, high-current applications such as subways, rail transit, and substations. However, traditional electrical connectors often use pure aluminum or simple copper-aluminum composite structures, with aluminum alloy as the primary contact surface. Aluminum is chemically reactive and easily oxidizes in humid environments (such as the perpetually dark and damp conditions of subway tunnels), forming a high-resistivity oxide film (Al2O3). This leads to increased resistance and overheating at the connector. Furthermore, under prolonged exposure to high-power currents, the aluminum alloy contact surface undergoes electrolytic corrosion due to electrolysis, further deteriorating connection performance and potentially posing safety hazards.

[0003] Furthermore, traditional electrical connection clamps have a small contact surface between the terminals and the clamp body, resulting in concentrated current density and accelerated aging of local materials. In addition, copper and aluminum components are mostly mechanically spliced, resulting in low interface bonding strength and easy gaps, which leads to increased contact resistance and increased power loss.

[0004] Based on the above problems, subway operators have reported that traditional wire clamps frequently fail after long-term use. Therefore, there is an urgent need for a new type of electrical connection wire clamp that combines high conductivity, corrosion resistance, and structural stability. Summary of the Invention

[0005] The purpose of this invention is to provide a copper-aluminum composite busbar electrical connection clamp and its preparation method, which solves the problems of easy oxidation and electro-corrosion of traditional clamps and improves connection reliability.

[0006] To achieve the above objectives, the present invention provides a copper-aluminum composite busbar electrical connection clamp, comprising a clamp body, clamp block one, clamp block two, and terminals. The clamp body comprises an integrally formed aluminum alloy body and a copper contact layer disposed on the upper side of the aluminum alloy body. The terminals are connected to the upper side of the copper contact layer. Clamp block one and clamp block two are connected to the lower side of the aluminum alloy body. A busbar mounting groove is provided on the lower surface of the aluminum alloy body. Clamp block one and clamp block two are symmetrically arranged on both sides of the busbar mounting groove. A busbar clamping groove is provided on the side of clamp block one and clamp block two that are close to each other.

[0007] Preferably, the terminal block includes a connecting plate and a terminal post. The connecting plate is connected to one end of the clamp body by a bolt assembly. The width of the connecting plate is equal to the width of the clamp body. The terminal post is connected to the outward side of the connecting plate. Both the connecting plate and the terminal post are made of copper.

[0008] Preferably, clamping block one is connected to one side below the clamping body via bolt assembly one, and clamping block two is connected to the other side below the clamping body via bolt assembly two.

[0009] Preferably, the clamp body is provided with a limiting protrusion symmetrically on both sides of the busbar mounting groove, and a limiting step is provided on the side of the limiting protrusion away from the busbar mounting groove.

[0010] Preferably, clamping block one and clamping block two have the same structure. Clamping block one and clamping block two are provided with a limiting step two on one side of the busbar clamping groove. The limiting step two is abutted and connected with the limiting protrusion one. The limiting step two is provided with a limiting protrusion two on the side away from the busbar clamping groove. The limiting protrusion two is abutted and connected with the limiting step one.

[0011] Preferably, the transitions between the first limiting protrusion and the first limiting step, between the busbar clamping groove and the second limiting step, and between the second limiting step and the second limiting protrusion are all circular arc transitions.

[0012] Preferably, the clamp body is provided with symmetrical limiting grooves on two sides of the busbar mounting groove, and the limiting groove has an inclined surface on the outward side.

[0013] Preferably, clamping block one and clamping block two have the same structure. Clamping block one and clamping block two are provided with a limiting protrusion three on one side of the busbar clamping groove. The limiting protrusion three is inserted and connected to the limiting groove. The limiting protrusion three is provided with an inclined surface two on the side away from the busbar clamping groove. The inclined surface two is abutted and connected to the inclined surface one.

[0014] This invention also provides a method for preparing a copper-aluminum composite busbar electrical connection clamp, comprising the following steps: S1. Select copper T2 as the copper contact layer material and aluminum alloy 1050A as the aluminum alloy body material. Make copper billets and aluminum billets respectively from the copper contact layer material and the aluminum alloy body material. S2. After mechanically grinding and chemically cleaning the surfaces of the copper and aluminum billets, dry them; use the aluminum billet as a base, lay the copper billet flat on the top of the aluminum billet, and fix it with a clamp to form a layered combination; S3. The layered combination of S2 is heated and extruded, then air-cooled and annealed, and then machined to obtain the wire clamp body. S4. Select T2 copper as the raw material for the terminal block, and make the connecting plate and terminal block through an integrated forging process. After forming, mill the plane and drill the hole to make the width of the connecting plate match the body of the clamp. S5. Select aluminum alloy 1050A as the raw material for clamping block one and clamping block two. Forge the raw material into a plate-shaped billet. Machining the plate-shaped billet into clamping block one and clamping block two. S6. Connect the connecting plate of the S4 terminal block to the upper side of the copper contact layer of the S3 clamp body by means of bolt assembly one, and connect the S5 clamp block one and clamp block two symmetrically to the lower side of the aluminum alloy body of clamp block one and clamp block two by means of bolt assembly two, thereby obtaining a copper-aluminum composite busbar electrical connection clamp.

[0015] Preferably, in S2, the chemical cleaning is performed using dilute hydrochloric acid, and the drying is performed at 120°C for 300 minutes.

[0016] Preferably, in S3, induction heating is used, with the aluminum billet heated to 400~450℃ and the copper billet heated to 650~700℃, and the annealing treatment is held at 250℃ for 1 hour.

[0017] The beneficial effects of this invention are: (1) By using a copper contact layer to replace the traditional aluminum alloy contact surface, the present invention has higher chemical stability, and the oxidation rate is only 1 / 10 of that of aluminum. Moreover, its oxidation product (Cu2O) still has good conductivity, which can effectively avoid the contact resistance from rising sharply due to oxidation. The copper-aluminum composite interface achieves metallurgical bonding through extrusion process, eliminating the gaps of mechanical splicing and reducing the electro-corrosion caused by electrolyte penetration. It is especially suitable for humid environments such as subway tunnels.

[0018] (2) The width of the terminal block connecting plate of the present invention is equal to the width of the clamp body, which increases the contact area between the terminal block and the clamp body, reduces the current density, reduces local heating, and the copper contact layer has excellent conductivity. Combined with the low interface resistance of the metallurgical bond, it significantly reduces power loss.

[0019] (3) The present invention improves the stability of the connection between the clamp and the clamp body by setting corresponding limiting protrusions, limiting steps, limiting grooves and inclined surfaces on the clamp body, clamp block one and clamp block two, avoiding poor contact caused by vibration and improving long-term safety.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a copper-aluminum composite busbar electrical connection clamp according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the wire clamp body of Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of clamping block one in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of a copper-aluminum composite busbar electrical connection clamp according to Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the wire clamp body in Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of clamping block one in Embodiment 2 of the present invention.

[0022] Figure label: 1. Cable clamp body; 11. Aluminum alloy body; 12. Copper contact layer; 13. Busbar mounting groove; 14. Limiting protrusion one; 15. Limiting step one; 16. Limiting groove; 17. Inclined surface one; 2. Clamping block one; 21. Busbar clamping groove; 22. Limiting step two; 23. Limiting protrusion two; 24. Limiting protrusion three; 25. Inclined surface two; 3. Clamping block two; 4. Terminal block; 41. Connecting plate; 42. Terminal post. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should be understood in their ordinary sense by those skilled in the art. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.

[0024] Example 1 like Figure 1 As shown, this invention provides a copper-aluminum composite busbar electrical connection clamp, including a clamp body 1, a first clamp block 2, a second clamp block 3, and a terminal block 4. The clamp body 1 includes an integrally formed aluminum alloy body 11 and a copper contact layer 12 disposed on the upper side of the aluminum alloy body 11, utilizing the high conductivity of copper to reduce contact resistance. The aluminum alloy body 11 serves as the base, balancing structural strength and lightweight requirements. The copper contact layer 12 is composited onto the aluminum alloy body 11, forming a low-resistance, high-stability transition layer, which effectively reduces electro-corrosion and ensures the reliability and durability of the electrical connection clamp.

[0025] Terminal 4 is connected to the upper side of the copper contact layer 12. Terminal 4 includes a connecting plate 41 and a terminal 42. The connecting plate 41 is connected to one end of the clamp body 1 by a bolt assembly. The width of the connecting plate 41 is equal to the width of the clamp body 1, which increases the contact area between the terminal 4 and the clamp body 1, improves conductivity, and ensures the stability of current transmission. The terminal 42 is connected to the outward side of the connecting plate 41. Both the connecting plate 41 and the terminal 42 are made of copper, further improving conductivity.

[0026] Clamping block 2 and clamping block 3 are connected to the lower side of the aluminum alloy body 11. The lower surface of the aluminum alloy body 11 is provided with a busbar mounting groove 13. Clamping blocks 2 and 3 are symmetrically arranged on both sides of the busbar mounting groove 13. Each clamping block 2 and clamping block 3 has a busbar clamping groove 21 on its closest side. Clamping block 2 is connected to one side below the clamping body 1 via bolt assembly 1, and clamping block 3 is connected to the other side below the clamping body 1 via bolt assembly 2 (both bolt assemblies 1 and 2 are combinations of bolts, nuts, and washers, which are prior art and not shown in the accompanying drawings). The busbar clamping groove 21 and the busbar mounting groove 13 cooperate to form a stable clamping and positioning structure for the busbar, effectively limiting the horizontal and vertical displacement of the busbar and ensuring the reliability and stability of the electrical connection.

[0027] like Figures 2 to 3 As shown, the clamp body 1 has symmetrically arranged limiting protrusions 14 on both sides of the busbar mounting groove 13, and a limiting step 15 on the side of the limiting protrusions 14 away from the busbar mounting groove 13. Clamping blocks 2 and 3 have the same structure. Clamping blocks 2 and 3 have a limiting step 22 on the side of the busbar clamping groove 21, which abuts against the limiting protrusions 14. A limiting protrusion 23 is arranged on the side of the limiting step 22 away from the busbar clamping groove 21, which abuts against the limiting step 15. This forms a double limiting structure, enhancing the connection stability between clamping blocks 2 and 3 and the clamp body 1, preventing clamping blocks 2 and 3 from shifting under force, and improving clamping stability.

[0028] The transitions between the first limiting protrusion 14 and the first limiting step 15, between the busbar clamping groove 21 and the second limiting step 22, and between the second limiting step 22 and the second limiting protrusion 23 are all rounded. Rounded transitions can reduce stress concentration, improve the strength and service life of components, and also facilitate processing and manufacturing.

[0029] During installation, the mounting part of the busbar is embedded into the busbar mounting groove 13 on the lower surface of the aluminum alloy body 11, ensuring that the busbar fits tightly against the groove. Then, the clamping blocks 1 2 and 2 3 are symmetrically fixed to both sides of the busbar mounting groove 13 by bolt assembly one and bolt assembly two, respectively, so that the busbar clamping grooves 21 on the inner side of clamping blocks 1 2 and 2 3 tightly wrap around the side of the busbar. Through the cooperation of clamping blocks 1 2, clamping blocks 2 3 and wire clamp body 1, the busbar is stably fixed and electrically connected.

[0030] Example 2 like Figure 4As shown, this invention provides a copper-aluminum composite busbar electrical connection clamp, including a clamp body 1, a first clamp block 2, a second clamp block 3, and a terminal block 4. The clamp body 1 includes an integrally formed aluminum alloy body 11 and a copper contact layer 12 disposed on the upper side of the aluminum alloy body 11, utilizing the high conductivity of copper to reduce contact resistance. The aluminum alloy body 11 serves as the base, balancing structural strength and lightweight requirements. The copper contact layer 12 is composited onto the aluminum alloy body 11, forming a low-resistance, high-stability transition layer, which effectively reduces electro-corrosion and ensures the reliability and durability of the electrical connection clamp.

[0031] Terminal 4 is connected to the upper side of the copper contact layer 12. Terminal 4 includes a connecting plate 41 and a terminal 42. The connecting plate 41 is connected to one end of the clamp body 1 by a bolt assembly. The width of the connecting plate 41 is equal to the width of the clamp body 1, which increases the contact area between the terminal 4 and the clamp body 1, improves conductivity, and ensures the stability of current transmission. The terminal 42 is connected to the outward side of the connecting plate 41. Both the connecting plate 41 and the terminal 42 are made of copper, further improving conductivity.

[0032] Clamping block 2 and clamping block 3 are connected to the lower side of the aluminum alloy body 11. The lower surface of the aluminum alloy body 11 is provided with a busbar mounting groove 13. Clamping block 2 and clamping block 3 are symmetrically arranged on both sides of the busbar mounting groove 13. Each side of clamping block 2 and clamping block 3 that is close to each other is provided with a busbar clamping groove 21. Clamping block 2 is connected to one side of the lower part of the clamping body 1 by bolt assembly 1, and clamping block 3 is connected to the other side of the lower part of the clamping body 1 by bolt assembly 2. The busbar clamping groove 21 and the busbar mounting groove 13 cooperate to form a stable clamping and positioning structure for the busbar, which can effectively limit the displacement of the busbar in the horizontal and vertical directions and ensure the reliability and stability of the electrical connection.

[0033] like Figures 5 to 6 As shown, the clamp body 1 has symmetrically arranged limiting grooves 16 on both sides of the busbar mounting groove 13, and an inclined surface 17 on the outward side of the limiting groove 16. Clamping block 2 and clamping block 3 have the same structure. Clamping block 2 and clamping block 3 have limiting protrusions 24 on one side of the busbar clamping groove 21. The limiting protrusions 24 are inserted into the limiting grooves 16. An inclined surface 25 is provided on the side of the limiting protrusions 24 away from the busbar clamping groove 21, and the inclined surface 25 abuts against the inclined surface 17. Through the insertion and engagement of the limiting protrusions 24 and the limiting grooves 16, and the abutting connection of the inclined surface 25 and the inclined surface 17, the connection strength between clamping blocks 2 and 3 and the clamp body 1 is further enhanced, making it suitable for scenarios with frequent vibration.

[0034] During installation, the mounting part of the busbar is embedded into the busbar mounting groove 13 on the lower surface of the aluminum alloy body 11, ensuring that the busbar fits tightly against the groove. Then, the clamping blocks 1 2 and 2 3 are symmetrically fixed to both sides of the busbar mounting groove 13 by bolt assembly one and bolt assembly two, respectively, so that the busbar clamping grooves 21 on the inner side of clamping blocks 1 2 and 2 3 tightly wrap around the side of the busbar. Through the cooperation of clamping blocks 1 2, clamping blocks 2 3 and wire clamp body 1, the busbar is stably fixed and electrically connected.

[0035] Example 3 Both the copper-aluminum composite busbar electrical connection clamps in Examples 1 and 2 are prepared by the following method, including the following steps: S1. Select copper T2 as the raw material for the copper contact layer 12 to ensure high conductivity, and select aluminum alloy 1050A as the raw material for the aluminum alloy body 11 to balance strength and lightweight. The copper contact layer 12 raw material and the aluminum alloy body 11 raw material are respectively made into copper billets and aluminum billets.

[0036] S2. Mechanically grind the surfaces of copper and aluminum billets to remove the oxide film, use dilute hydrochloric acid for chemical cleaning to remove residual impurities, and then dry at 120℃ for 300 minutes to avoid interface inclusions.

[0037] Using an aluminum billet as a base, a copper billet is laid flat on top of the aluminum billet and fixed with a clamp to prevent misalignment during extrusion, forming a layered combination.

[0038] S3. Heat the layered combination of S2 using induction heating. The heating temperature is 400~450℃ for aluminum billet and 650~700℃ for copper billet to ensure that both are in a highly ductile state and to avoid overheating and melting of aluminum.

[0039] After heating, it is extruded and formed. The extrusion forming adopts forward extrusion. The extrusion die is designed according to the cross section of the wire clamp body. The extrusion ratio is 20~30 and the extrusion speed is 5~8mm / s.

[0040] After extrusion molding, air cooling is used to avoid stress concentration caused by rapid cooling. Then, annealing is performed at 250°C for 1 hour to eliminate extrusion stress. The wire clamp body 1 is obtained by machining (machined by existing technologies such as milling and grinding, which will not be described in detail).

[0041] S4. Select copper T2 as the raw material for terminal 4, and make connecting plate 41 and terminal 42 through integrated forging process. After forming, mill the plane and drill holes on the connecting plate 41 and terminal 42 so that the width of the connecting plate 41 matches the wire clamp body 1. Polish the surface to reduce contact resistance.

[0042] S5. Select aluminum alloy 1050A as the raw material for clamping block 1 2 and clamping block 2 3. Forge the raw material into plate blanks. Machining the plate blanks into clamping block 1 2 and clamping block 2 3. Anodize the surface to enhance corrosion resistance.

[0043] S6. Connect the connecting plate 41 of the S4 terminal 4 to the upper side of the copper contact layer 12 of the S3 clamp body 1 using bolt assembly one. Connect the S5 clamp 1 2 and clamp 2 3 symmetrically to the lower side of the aluminum alloy body 11 of clamp 1 2 and clamp 2 3 using bolt assembly two. Adjust the position to make the limiting structure (such as the limiting step 22 and the limiting protrusion 14) fit precisely to ensure that the force is uniform when clamping the busbar, and obtain the copper-aluminum composite busbar electrical connection clamp.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A copper-aluminum composite busbar electrical connection clamp, characterized in that: The device includes a clamp body, clamp block one, clamp block two, and terminals. The clamp body includes an integrally formed aluminum alloy body and a copper contact layer disposed on the upper side of the aluminum alloy body. The terminals are connected to the upper side of the copper contact layer. Clamp block one and clamp block two are connected to the lower side of the aluminum alloy body. The lower surface of the aluminum alloy body is provided with a busbar mounting groove. Clamp block one and clamp block two are symmetrically arranged on both sides of the busbar mounting groove. Each side of clamp block one and clamp block two that is close to each other is provided with a busbar clamping groove.

2. The copper-aluminum composite busbar electrical connector clamp according to claim 1, characterized in that: The terminal block includes a connecting plate and a terminal post. The connecting plate is connected to one end of the clamp body by a bolt assembly. The width of the connecting plate is equal to the width of the clamp body. The terminal post is connected to the outward side of the connecting plate. Both the connecting plate and the terminal post are made of copper.

3. The copper-aluminum composite busbar electrical connector clamp according to claim 2, characterized in that: Clamping block one is connected to one side of the clamp body below the clamp body via bolt assembly one, and clamping block two is connected to the other side of the clamp body below the clamp body via bolt assembly two.

4. The copper-aluminum composite busbar electrical connector clamp according to claim 1, characterized in that: The clamp body is provided with a limiting protrusion symmetrically on both sides of the busbar mounting groove, and a limiting step is provided on the side of the limiting protrusion away from the busbar mounting groove.

5. The copper-aluminum composite busbar electrical connector clamp according to claim 4, characterized in that: Clamping block one and clamping block two have the same structure. Clamping block one and clamping block two are provided with a limiting step two on one side of the busbar clamping groove. The limiting step two is connected to the limiting protrusion one. The limiting step two is provided with a limiting protrusion two on the side away from the busbar clamping groove. The limiting protrusion two is connected to the limiting step one.

6. The copper-aluminum composite busbar electrical connector clamp according to claim 5, characterized in that: The transitions between the first limiting protrusion and the first limiting step, between the busbar clamping groove and the second limiting step, and between the second limiting step and the second limiting protrusion are all circular arc transitions.

7. The copper-aluminum composite busbar electrical connector clamp according to claim 1, characterized in that: The clamp body has symmetrical limiting grooves on two sides of the busbar mounting groove, and the limiting groove has an inclined surface on the outward side.

8. The copper-aluminum composite busbar electrical connector clamp according to claim 7, characterized in that: Clamping block one and clamping block two have the same structure. Clamping block one and clamping block two are provided with a limiting protrusion three on one side of the busbar clamping groove. The limiting protrusion three is connected to the limiting groove. The limiting protrusion three is provided with an inclined surface two on the side away from the busbar clamping groove. The inclined surface two is connected to the inclined surface one.

9. A method for preparing a copper-aluminum composite busbar electrical connection clamp as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Select copper T2 as the copper contact layer material and aluminum alloy 1050A as the aluminum alloy body material. Make copper billets and aluminum billets respectively from the copper contact layer material and the aluminum alloy body material. S2. After mechanically grinding and chemically cleaning the surfaces of the copper and aluminum billets, dry them; use the aluminum billet as a base, lay the copper billet flat on the top of the aluminum billet, and fix it with a clamp to form a layered combination; S3. The layered combination of S2 is heated and extruded, then air-cooled and annealed, and then machined to obtain the wire clamp body. S4. Select T2 copper as the raw material for the terminal block, and make the connecting plate and terminal block through an integrated forging process. After forming, mill the plane and drill the hole to make the width of the connecting plate match the body of the clamp. S5. Select aluminum alloy 1050A as the raw material for clamping block one and clamping block two. Forge the raw material into a plate-shaped billet. Machining the plate-shaped billet into clamping block one and clamping block two. S6. Connect the connecting plate of the S4 terminal block to the upper side of the copper contact layer of the S3 clamp body by means of bolt assembly one, and connect the S5 clamp block one and clamp block two symmetrically to the lower side of the aluminum alloy body of clamp block one and clamp block two by means of bolt assembly two, thereby obtaining a copper-aluminum composite busbar electrical connection clamp.

10. The method for preparing a copper-aluminum composite busbar electrical connection clamp according to claim 9, characterized in that: In S3, induction heating is used for heating. The heating temperature is 400~450℃ for aluminum billets and 650~700℃ for copper billets. The annealing process is to hold at 250℃ for 1 hour.

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