A large-current electrically conductive connector production process

Abstract

The application discloses a large-current electric conduction joint production process. The electric conduction joint produced by the process comprises a plate part, a cylindrical part integrally connected with the plate part, a number of wire grooves formed in one end of the plate part away from the cylindrical part, a number of thread holes formed in the outer end of the cylindrical part and a light hole formed in the plate part. The production process at least comprises the following steps: forging forming, surface oxide layer cleaning, mechanical processing and silver plating. A fine pressing process is further arranged. The wire groove position is formed with a sink groove on the forging and the fine pressing blank, and the sink groove is located at the tool withdrawing side when the wire groove is mechanically processed.

Description

Technical Field

[0001] This application relates to the field of electrical components technology, specifically a manufacturing process for a high-current conductive connector. Background Technology

[0002] Large air circuit breakers are one of the core components of switchgear or ring main units, mainly used for the on / off control of power circuits. The conductive joints are key components connecting the moving / stationary contacts to the external circuit. These conductive joints are typically made of copper using a casting process. However, due to the characteristics of casting, the conductivity is low, and they are prone to overheating under high current operating conditions. Therefore, a forging process using copper (commonly grade T2) has been developed to produce these conductive joints. This involves hot forging to create forgings, surface cleaning, and then machining to produce the finished product. Conductive joints produced using this process have the advantage of high conductivity; however, if… Figure 7 As shown, existing conductive connector products produced by hot forging process have low hardness after hot forging. When machining the wire groove, sharp protrusions are easily formed at the edge of the cutter. Although the protrusions are effectively removed by machining chamfering and deburring, the plate surface around the wire groove is uneven, which affects the installation and fixation of the subsequent copper braided flexible connection wire. Therefore, after testing, the applicant proposes this case to solve the above problems. Summary of the Invention

[0003] The purpose of this application is to provide a manufacturing process for high-current conductive connectors to solve the problems in the prior art.

[0004] To achieve the above objectives, this application provides the following technical solution: a manufacturing process for a high-current conductive connector, the conductive connector comprising a plate portion, a cylindrical portion integrally connected to the plate portion, several grooves formed on the plate portion away from the cylindrical portion, several threaded holes formed on the outer end of the cylindrical portion, and a light hole formed on the plate portion; the manufacturing process includes at least the following steps:

[0005] S10: Forging process, which involves hot forging, trimming, and cooling to form the forging of the conductive connector;

[0006] S20: Surface oxide layer cleaning, used to clean the oxide layer on the surface of the forging;

[0007] S30: Machining, used to complete the machining of the cylindrical portion, the groove, the threaded hole and the smooth hole to form a machined finished product; wherein, the groove is used to accommodate the welding target copper braided flexible connector wire;

[0008] S40: Silver plating, used to electroplate the machined finished product to form a silver plating layer;

[0009] Between steps S20 and S30, there is also a step:

[0010] S21: Precision pressing process, used to perform cold precision pressing on the forging to form a precision pressed blank; wherein, the groove is located on both the forging and the precision pressed blank, and the groove is located on the exit side when machining the groove in step S30;

[0011] The bottom width F of the settling tank is the same in steps S20 and S21;

[0012] Let the sidewall of the settling tank in step S20 be sidewall one, and the angle between sidewall one and the bottom surface of the settling tank be angle E; let the sidewall of the settling tank in step S21 be sidewall two, and the angle between sidewall two and the bottom surface of the settling tank be angle D. Then, angle E - angle D = 4°~8°, which is used to form a hardened layer in a set area in sidewall two in step S21.

[0013] After the machining of the groove is completed in step S30, the second sidewall has at least some residue.

[0014] Furthermore, during the process of welding the target copper braided flexible connector wire into the groove, the hardness of the hardened layer is reduced to the hardness of the forging state.

[0015] Furthermore, in step S10, the conductive connector is also formed with a first connecting rib and a second connecting rib connected to the adjacent surfaces of the plate portion and the cylindrical portion. The width of the first connecting rib is greater than the width of the second connecting rib, and the center plane of the first connecting rib is coplanar with the axis of the cylindrical portion and the center plane of the width direction of the plate portion.

[0016] Furthermore, the angle D is 43°~47°.

[0017] Furthermore, the plate portion is 0.1 to 0.2 mm thicker in the forging than in the precision-pressed blank, and the forging and the precision-pressed blank have the same diameter cylindrical portion.

[0018] Furthermore, the two sides of the second connecting rib extend to the outer circular surface of the cylindrical portion and are coplanar with the outer circular surface of the cylindrical portion.

[0019] Furthermore, the threaded hole formed in step S30 is a press-fit threaded hole.

[0020] The beneficial effects of this application are as follows: The high-current conductive connector manufacturing process provided by this application forms a groove structure in the forging step, wherein the groove is located on the exit side of the cutting tool during machining, and the sidewall of the groove is cold-pressed and hardened in the cold finishing step, thereby forming a locally hardened layer in the sidewall area. On the one hand, due to the increased hardness, the strength of the substrate to resist cutting deformation during machining of the groove is increased, significantly reducing the deformation of the substrate towards the exit side of the cutting tool. On the other hand, since the sidewall is a sloping structure, it not only improves the deformation resistance but also has a counteracting effect on slight deformation. Therefore, the combined effect of these two factors ensures the flatness of the groove opening along the plate surface after the groove is machined. This process ensures the flatness of the plate surface and eliminates the need for machining steps such as chamfering and deburring around the groove. It also saves raw materials and guarantees the reliability of the target copper braided flexible connector during subsequent assembly and welding. Because the hardened area is only localized and remains at the edge after groove machining to form a chamfer, the overall conductive joint retains the high conductivity of the forging. A silver plating process is used to plate a silver layer of a predetermined thickness onto the surface of the conductive joint, ensuring low resistance between the conductive joint and the target copper braided flexible connector after welding. Therefore, conductive joints produced using this process have high conductivity and a larger rated current for the same specifications, far superior to existing technologies. Attached Figure Description

[0021] Figure 1 A front view of a conductive connector manufactured using the high-current conductive connector manufacturing process of this application.

[0022] Figure 2 A side view of a conductive connector manufactured using the high-current conductive connector manufacturing process of this application.

[0023] Figure 3 A bottom view of the conductive connector produced using the high-current conductive connector manufacturing process of this application.

[0024] Figure 4 A front view of the precision-pressed blank of the conductive connector produced by the high-current conductive connector manufacturing process of this application;

[0025] Figure 5 for Figure 4 Sectional view of AA;

[0026] Figure 6 This is a partial schematic diagram of the cross-sectional view of the settling tank structure of this application;

[0027] Figure 7 A schematic diagram illustrating the defects of existing conductive connectors formed by machining grooves;

[0028] In the figure: 1. Plate part; 2. Cylindrical part; 3. Threaded hole; 4. Plain hole; 5. Wire groove; 6. First connecting rib; 7. Second connecting rib; 8. Slot; 801. Side wall one; 802. Side wall two; 9. Sharp convex angle. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] Please see Figure 1-6 A manufacturing process for a high-current conductive connector, wherein the conductive connector produced by this process includes a plate portion 1, a cylindrical portion 2 integrally connected to the plate portion 1, several grooves 5 formed at one end of the plate portion 1 away from the cylindrical portion 2, several threaded holes 3 formed at the outer end of the cylindrical portion 2, and a smooth hole 4 formed in the plate portion 1; the manufacturing process includes at least the following steps:

[0031] S10: Forgings formed by hot forging, trimming, and cooling to form conductive connectors;

[0032] S20: Surface oxide layer cleaning, used to clean the oxide layer on the surface of forgings;

[0033] S30: Machining, used to complete the machining of the cylindrical part 2, the groove 5, the threaded hole 3, and the smooth hole 4 to form a finished machined product; wherein, the groove 5 is used to accommodate the copper braided flexible connecting wire to be welded; in this embodiment, as a preferred machining process, firstly, using the front end, the plate surface, and one side edge of the plate part 1 as references, an automatic centering hydraulic fixture is used to complete the machining of the outer circle, end face, and threaded hole 3 of the cylindrical part 2 in one clamping on the machining center; secondly, using the machined end face of the cylindrical part 2 and the two threaded holes 3 as positioning references, and the front end of the plate part 1 as the clamping edge, the smooth hole 4 is machined on the machining center; finally, using the end face of the cylindrical part 2 and the two threaded holes 3 as positioning references, and the end face of the cylindrical part 2 facing the plate part 1 as the clamping edge, a disc milling cutter is used on a milling machine to complete the milling of the groove 5, and the exit side described later is the side on which the chips are discharged with the disc milling cutter when machining the groove 5;

[0034] S40: Silver plating, used for electroplating finished machined products to form a silver plating layer;

[0035] Between steps S20 and S30, there is also a step:

[0036] S21: Precision pressing process, used to cold precision press the forging to form a precision pressed blank; wherein, groove 8 is formed on both the forging and the precision pressed blank at the location of groove 5, and groove 8 is located on the exit side when machining groove 5 in step S30.

[0037] In steps S20 and S21, the bottom width F of the settling tank 8 is the same;

[0038] Let the sidewall of the sink 8 in step S20 be sidewall one 801, and the angle between sidewall one 801 and the bottom surface of the sink 8 be angle E; let the sidewall of the sink 8 in step S21 be sidewall two 802, and the angle between sidewall two 802 and the bottom surface of the sink 8 be angle D. Then, angle E - angle D = 4°~8°, which is used to form a hardened layer in a set area on sidewall two 802 in step S21. It can be understood that in this embodiment, both the forging process in S10 and the precision pressing process in S21 are completed using molds. The molds can adopt the open mold structure in this technical field, namely, a forging mold and a cold precision pressing mold, respectively. In this way, since the forging... The angle E between the sidewall 801 of the sinker 8 and the bottom surface of the sinker 8 is large, meaning the opening of the sinker 8 on the plate 1 surface is small, and its perimeter has more solid material. When the forging is placed into the cold pressing die, because the angle D is smaller than the angle E, the cold pressing die will compress the material in the area of ​​sidewall 801 towards the solid interior until sidewall 802 is formed. This process results in work hardening, thereby increasing the hardness of the area of ​​sidewall 802. Furthermore, since the width F of the forging and the pressing blank at the bottom of the sinker 8 is the same, the compression is greatest at the edge of the sinker 8 and least at the bottom. Therefore, the hardness of the area of ​​sidewall 802 shows a gradual increasing trend from the bottom to the edge. Figure 5 The hardness is lowest at position B and highest at position C. This facilitates machining while improving the substrate's resistance to cutting deformation. In this embodiment, the preferred angle E-angle D is 5°, which gives the forging optimal cold pressing allowance on the sidewall of the groove 8.

[0039] After the machining of the groove 5 is completed in step S30, the second sidewall 802 will have at least some residue, so that the slight deformation generated during machining will be absorbed and offset by the second sidewall 802.

[0040] According to the structure provided in this embodiment, the high-current conductive connector manufacturing process provided in this application forms a groove structure in the forging step. The groove 8 is located on the exit side of the cutting tool when forming the groove 5 during machining. The sidewall of the groove 8 is cold-pressed and hardened in the cold pressing step, thereby forming a locally hardened layer in the sidewall area. On the one hand, the increased hardness increases the strength of the substrate against cutting deformation during machining of the groove 5, significantly reducing the deformation of the substrate towards the cutting tool exit side. On the other hand, since the sidewall 802 is a sloping structure, it not only improves the resistance to deformation but also has a counteracting effect on slight deformation. Therefore, the combined effect of both ensures the flatness of the groove 5 edge plate surface after machining, thus ensuring the flatness of the plate 1 surface and saving the need for chamfering and deburring along the perimeter of the groove 5. In the machining process, minor burrs generated during machining can be removed by light scraping with hand tools. This saves raw materials and ensures the reliability of subsequent assembly and welding of the target copper braided flexible connector. Since the hardened area is only localized and remains at the edge after the groove 5 is machined, forming a chamfer, the overall conductive joint retains the high conductivity of the forging. A silver layer of a set thickness is plated onto the surface of the conductive joint through a silver plating process, ensuring low resistance between the conductive joint and the target copper braided flexible connector after welding. It can be understood that the welding process of the target copper braided flexible connector is located after the silver plating process. Therefore, the conductive joint produced by this process has high conductivity and a larger rated current under the same specifications, which is far superior to the existing technology. In this embodiment, the silver plating process adopts the existing electroplating process.

[0041] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 6 During the welding of the target copper braided flexible connector in the wire groove 5, the hardness of the hardened layer is reduced to that of the forging state. This process is equivalent to annealing and softening the conductive connector, restoring the distorted crystal lattice during cold pressing, thus improving conductivity. In other words, this process cold-works the solid on the cutting side before machining the wire groove 5 to increase its strength and improve its resistance to cutting deformation. The hardened layer is then annealed and softened using the high temperature during the installation and welding of the target copper braided flexible connector in the wire groove 5, thereby restoring the conductivity to the level of the forging and improving the conductivity of the finished conductive connector. Here, the installation and welding of the target copper braided flexible connector in the wire groove 5 can be carried out using existing technologies such as brazing and pressure welding.

[0042] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 6In step S10, the conductive connector is further formed with a first connecting rib 6 and a second connecting rib 7 connecting the adjacent surfaces of the plate portion 1 and the cylindrical portion 2. The width of the first connecting rib 6 is greater than the width of the second connecting rib 7, and the center plane of the first connecting rib 6 is coplanar with the axis of the cylindrical portion 2 and the center plane of the plate portion 1 in the width direction. In this way, on the one hand, it is beneficial to the flow of material in the forging mold during forging, ensuring the mold filling and ensuring the quality of the conductive connector forging. On the other hand, in step S30, i.e., the machining process, the outer circle, end face and threaded hole 3 of the cylindrical portion 2 are machined with the plate portion 1 as the reference, which has better support strength. At the same time, the current cross-sectional area between the plate portion 1 and the cylindrical portion 2 is increased, which can carry a larger rated current.

[0043] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 6 The angle D is 43°~47°, and is preferably 45° in this embodiment. This minimizes the burrs generated during cutting while maintaining the best anti-cutting deformation performance, making it easier to deburr in the subsequent process, saving processing time and improving processing efficiency.

[0044] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 6 The plate portion 1 is 0.1-0.2 mm thicker in the forging process than in the precision-pressed blank. Both the forging and the precision-pressed blank have cylindrical portions 2 with the same diameter. Thus, in step S21, when the conductive connector forging is cold-pressed using a mold, the cylindrical portion 2 only contacts the corresponding cavity wall of the cold-pressing mold when the plate portion 1 is pressed to the set size. This allows for precision pressing correction of the relative dimensions of the plate portion 1 and the cylindrical portion 2. Since the cylindrical portion 2 does not undergo compression during the precision pressing process and only participates in correction, the required pressure is low. Therefore, a small-tonnage hydraulic device can be used to complete the cold-pressing operation. As a specific embodiment, the thickness of the precision-pressed blank plate portion 1 after cold-pressing is required to be 10 mm-10.2 mm. The outer diameter of the cylindrical part 2 is 62mm~63mm. Considering the elastic recovery of the copper material, the total thickness of the cavity of the plate part 1 in the cold precision pressing die can be designed to be 10mm, and the inner diameter of the cavity of the cylindrical part 2 is 62.5mm. Then the thickness of the plate part 1 of the forging can be designed to be 10.1mm~10.2mm, while the outer diameter of the cylindrical part 2 is still designed to be 62.5mm. In this way, when the forging is placed into the cold precision pressing die for cold precision pressing, when the thickness of the plate part 1 is pressed to 10mm~10.2mm, the outer surface of the cylindrical part 2 will be in complete contact with the corresponding cavity surface of the cold precision pressing die and be corrected. It is understandable that the design parameters such as the shrinkage of the hot forging forming die used for forging can adopt existing technology.

[0045] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 6The second connecting rib 7 extends to the outer circular surface of the cylindrical part 2 on both sides and is coplanar with the outer circular surface of the cylindrical part 2. In this way, while increasing the connection strength between the plate part 1 and the cylindrical part 2, the conductive cross-sectional area is increased, which is beneficial for passing large currents, reducing heat generation, and improving the conductivity of the conductive joint.

[0046] In another embodiment of this application, please refer to [the relevant document / reference]. Figures 1 to 6 The threaded hole 3 formed in step S30 is a extruded threaded hole processed by an extrusion tap. In this way, the material of the inner wall of the threaded hole 3 is extruded and cold-worked hardened by the action of the extrusion tap, so that the thread of the threaded hole 3 has a stronger connection strength, which is beneficial to the installation stability of the conductive connector.

[0047] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0048] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0049] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0050] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manufacturing process for a high-current conductive connector, the conductive connector comprising a plate portion (1), a cylindrical portion (2) integrally connected to the plate portion (1), several grooves (5) formed at one end of the plate portion (1) away from the cylindrical portion (2), several threaded holes (3) formed at the outer end of the cylindrical portion (2), and a light hole (4) formed in the plate portion (1); the manufacturing process includes at least the following steps: S10: Forging process, which involves hot forging, trimming, and cooling to form the forging of the conductive connector; S20: Surface oxide layer cleaning, used to clean the oxide layer on the surface of the forging; S30: Machining, used to complete the machining of the cylindrical part (2), the groove (5), the threaded hole (3), and the smooth hole (4) to form a machined finished product; wherein, The groove (5) is used to accommodate the copper braided flexible connecting wire to be welded; S40: Silver plating, used to electroplate the machined finished product to form a silver plating layer; The feature is that a further step is provided between steps S20 and S30: S21: Precision pressing process, used to cold precision press the forging to form a precision pressed blank; wherein, the groove (5) is located on both the forging and the precision pressed blank, and the groove (8) is located on the exit side when machining the groove (5) in step S30; The bottom width F of the settling tank (8) is the same in steps S20 and S21; Let the sidewall of the settling tank (8) in step S20 be sidewall one (801), and the angle between sidewall one (801) and the bottom surface of the settling tank (8) be angle E; let the sidewall of the settling tank (8) in step S21 be sidewall two (802), and the angle between sidewall two (802) and the bottom surface of the settling tank (8) be angle D. Then, angle E - angle D = 4°~8°, which is used to form a hardened layer of a set area on sidewall two (802) in step S21. After the machining of the groove (5) is completed in step 30, the second sidewall (802) has at least some residue; During the welding of the target copper braided flexible connecting wire in the groove (5), the hardness of the hardened layer is reduced to the hardness of the forging state, so as to restore the distorted lattice in the cold precision pressing. The plate portion (1) is 0.1 to 0.2 mm thicker in the forging than in the precision blank, and the cylindrical portion (2) of the forging and the precision blank have the same diameter.

2. The manufacturing process for high-current conductive connectors according to claim 1, characterized in that: In step S10, the conductive connector is further formed with a first connecting rib (6) and a second connecting rib (7) connected to the adjacent surfaces of the plate portion (1) and the cylindrical portion (2). The width of the first connecting rib (6) is greater than the width of the second connecting rib (7), and the center plane of the first connecting rib (6) is coplanar with the axis of the cylindrical portion (2) and the center plane of the width direction of the plate portion (1).

3. The manufacturing process for high-current conductive connectors according to claim 1, characterized in that: The angle D is 43°~47°.

4. The manufacturing process for high-current conductive connectors according to claim 2, characterized in that: The second connecting rib (7) extends to the outer circular surface of the cylindrical part (2) on both sides and is coplanar with the outer circular surface of the cylindrical part (2).

5. The manufacturing process for high-current conductive connectors according to claim 1, characterized in that: The threaded hole (3) formed in step S30 is a press-fit threaded hole.

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