Charging socket and high-power slotting terminal thereof and manufacturing method of slotting terminal

Abstract

The application relates to a charging socket and a split slot terminal and a manufacturing method of the split slot terminal. The split slot terminal comprises a tubular hollow terminal base body, a snap ring sleeved on the outer periphery of a plug-in end of the terminal base body, and a sealing ring accommodated in an inner cavity. The plug-in end is provided with an axial split slot to form a plurality of elastic contact springs, and the outer periphery is provided with a groove for assembling the snap ring; the inner cavity is provided with an inner sealing groove, and the sealing ring is assembled in the inner sealing groove and is in radial interference fit with the groove bottom; and the middle part of the terminal base body is provided with a convex structure which is integrally formed by local outward bulging of the pipe wall. The manufacturing method comprises the following steps: radially extruding a round pipe to make the pipe wall locally bulge to form a convex pipe blank, and then cutting, electroplating, assembling the sealing ring and the snap ring to obtain the split slot terminal. The split slot terminal uses a pipe material instead of a solid rod material, greatly improves the material utilization rate, and shortens the processing time; through the integrated high-strength convex structure and the inner interference sealing, high-reliability axial limiting and IP67-level protection are realized.

Description

Technical Field

[0001] This invention relates to the field of DC charging interface technology for new energy vehicles, specifically to a charging socket and its slotted terminals, and a method for manufacturing the slotted terminals. Background Technology

[0002] With the rapid evolution of high-voltage, high-current DC charging technology for electric vehicles, the high-power transmission terminals (such as DC+ / DC- terminals) in national standard DC charging sockets need to carry continuously increasing rated currents (typically exceeding 250A). Under high-current operating conditions, in order to strictly control the temperature rise of the terminals, reduce contact resistance, and improve resistance to thermal aging and repeated insertion and removal performance, slotted terminals with multi-lobed elastic contact structures have gradually become the preferred technical solution for high-power charging sockets.

[0003] In existing technologies, the aforementioned high-power slotted terminals are primarily manufactured using highly conductive copper alloy rods through integral machining. Because the rod itself is a solid structure, it possesses extremely high mechanical strength, facilitating the machining of radial protrusions for axial positioning on its outer periphery. Furthermore, it effectively prevents the penetration of moisture and impurities into the hollow channel, allowing for easy achievement of a high protection level after assembly. However, machining the slotted terminal integrally from the rod requires the removal of a significant amount of metal material to preserve the peripheral protrusions and the hollow cavity of the connector. This results in extremely high material waste, very low material utilization, and extremely long machining times for deep holes and the outer contour, leading to high manufacturing costs. Summary of the Invention

[0004] The purpose of this invention is to provide a charging socket and its slotted terminal, as well as a method for manufacturing the slotted terminal, to solve the technical problems of low material utilization, high cost, and low efficiency caused by the use of round bar cutting for slotted terminals in the prior art; the purpose of this invention is also to provide a slotted terminal for the charging socket; and the purpose of this invention is also to provide a method for manufacturing the slotted terminal.

[0005] The technical solution of the method for manufacturing the slotted terminal of the present invention is as follows:

[0006] The method for manufacturing slotted terminals includes the following steps: (1) Place the metal tube in the extrusion die for radial extrusion, so that the local tube wall expands and deforms outward to produce a tube blank with a convex structure. (2) Machining is performed on the pipe blank, a groove is machined on the outer front end, an inner sealing groove is machined on the inner side of the middle, and a split groove is machined along the axial direction at the front end to form an elastic contact spring, thus obtaining the terminal base; (3) Electroplating is performed on the terminal substrate; (4) Push the sealing ring into the inner sealing groove from the front opening of the terminal base and lock it in the inner sealing groove. Place the retaining ring in the groove to obtain the slotted terminal.

[0007] Furthermore, it also includes: To fabricate a metal stud, internal threads are machined on the inner side, and the outer diameter of the metal stud is machined to be larger than the rear inner diameter of the terminal base; a stud welding bevel is machined at the tail of the metal stud. In step (2), a terminal welding bevel is machined along the rear port edge of the terminal substrate; Before assembling the sealing ring in step (4), press the stud into the terminal block of the terminal body; A full-circle weld is performed at the junction of the terminal welding bevel of the terminal substrate and the stud welding bevel of the stud to form a weld seam.

[0008] Furthermore, prior to step (3), the rear end of the terminal substrate is axially flattened and compressed to form a flat welding plane with double-walled adhesion at the tail end of the terminal substrate.

[0009] The technical solution of the slotted terminal of the present invention is as follows: The slotted terminals include: The terminal base is integrally formed from a metal tube and has an internal cavity extending front and rear. Its front end is defined as the plug end. The outer periphery of the front end of the terminal base has a groove, and the tube wall of the terminal base has several slots extending rearward from its front end to form several inwardly converging elastic contact springs at the front end of the terminal base. The inner cavity wall of the terminal base has an inner sealing groove behind the slots. The outer periphery of the terminal base has a radially outward protruding convex structure behind the inner sealing groove. The convex structure is formed by locally radially extruding and expanding the tube wall of the terminal base into an integral structure. A retaining ring is fitted into the groove; The sealing ring is housed in the inner sealing groove.

[0010] Furthermore, the outer periphery of the sealing ring is provided with at least two annular waterproof ring ribs arranged side by side along the axial direction. The outer diameter of the waterproof ring ribs is larger than the inner diameter of the bottom of the inner sealing groove, so as to form a radial pressing fit with the bottom of the inner sealing groove.

[0011] Furthermore, it also includes a stud, which is interference-fitted into the hollow channel inside the rear end of the terminal base, and the stud has an axially extending internal thread; The outer diameter of the stud's outer side surface is larger than the inner diameter of the rear end of the terminal base. The tail end face of the stud is coplanar and flush with the terminal end face of the terminal base. The rear end of the terminal base and the tail end of the stud are sealed and fused together by a full-circular laser welding weld.

[0012] Furthermore, the rear end face of the terminal base is provided with an inwardly inclined terminal welding bevel, and the tail end of the stud is provided with an outwardly inclined stud welding bevel. The terminal welding bevel and the stud welding bevel are arranged opposite to each other and together form an annular welding groove, and the laser welding weld fills the annular welding groove.

[0013] Furthermore, the tubular structure at the rear end of the terminal base is axially compressed and flattened to form a flat welding plane with a double-walled structure that fits tightly at the rear end of the terminal base, or the rear end of the terminal base is a hollow tubular structure for inserting an external cable through its tail port and radially crimping the entire structure.

[0014] Furthermore, the inner and outer surfaces of the terminal substrate are entirely coated with an electroplated nickel underlayer, the outer surface of the elastic contact spring is provided with a silver plating layer with a thickness of a first preset thickness, and the other areas of the terminal substrate are provided with a silver plating layer with a thickness of a second preset thickness, wherein the first preset thickness is greater than the second preset thickness.

[0015] The technical solution of the charging socket of the present invention is as follows: The charging socket includes a socket housing and connecting terminals disposed within the socket housing, the connecting terminals including: The terminal base is integrally formed from a metal tube and has an internal cavity extending front and rear. Its front end is defined as the plug end. The outer periphery of the front end of the terminal base has a groove, and the tube wall of the terminal base has several slots extending rearward from its front end to form several inwardly converging elastic contact springs at the front end of the terminal base. The inner cavity wall of the terminal base has an inner sealing groove behind the slots. The outer periphery of the terminal base has a radially outward protruding convex structure behind the inner sealing groove. The convex structure is formed by locally radially extruding and expanding the tube wall of the terminal base into an integral structure. A retaining ring is fitted into the groove; The sealing ring is housed in the inner sealing groove.

[0016] Furthermore, the outer periphery of the sealing ring is provided with at least two annular waterproof ring ribs arranged side by side along the axial direction. The outer diameter of the waterproof ring ribs is larger than the inner diameter of the bottom of the inner sealing groove, so as to form a radial pressing fit with the bottom of the inner sealing groove.

[0017] Furthermore, it also includes a stud, which is interference-fitted into the hollow channel inside the rear end of the terminal base, and the stud has an axially extending internal thread; The outer diameter of the stud's outer side surface is larger than the inner diameter of the rear end of the terminal base. The tail end face of the stud is coplanar and flush with the terminal end face of the terminal base. The rear end of the terminal base and the tail end of the stud are sealed and fused together by a full-circular laser welding weld.

[0018] Furthermore, the rear end face of the terminal base is provided with an inwardly inclined terminal welding bevel, and the tail end of the stud is provided with an outwardly inclined stud welding bevel. The terminal welding bevel and the stud welding bevel are arranged opposite to each other and together form an annular welding groove, and the laser welding weld fills the annular welding groove.

[0019] Furthermore, the tubular structure at the rear end of the terminal base is axially compressed and flattened to form a flat welding plane with a double-walled structure that fits tightly at the rear end of the terminal base, or the rear end of the terminal base is a hollow tubular structure for inserting an external cable through its tail port and radially crimping the entire structure.

[0020] Furthermore, the inner and outer surfaces of the terminal substrate are entirely coated with an electroplated nickel underlayer, the outer surface of the elastic contact spring is provided with a silver plating layer with a thickness of a first preset thickness, and the other areas of the terminal substrate are provided with a silver plating layer with a thickness of a second preset thickness, wherein the first preset thickness is greater than the second preset thickness.

[0021] The beneficial effects of this application are as follows: A metal cylindrical tube is directly used as the base material, and radial extrusion in a mold causes the tube wall to expand locally outward, forming an integral convex structure. During this process, the tube not only retains its hollow flow channel, but the localized plastic rheology generated by radial extrusion also causes the metal grains to realign along the axial and radial directions. Without reducing the wall thickness in the non-convex region, the yield strength of the convex structure is increased, enabling the convex structure to withstand the axial limiting force required for high-power insertion and extraction.

[0022] The plastically deformed pipe blank is subjected to localized micro-turning to form grooves and inner sealing grooves, and axial grooving is also performed. Compared with traditional deep hole turning, this process has extremely low material removal and significantly reduces machining time, thereby greatly improving production efficiency and maximizing material utilization.

[0023] The sealing ring is pushed in from the front end and interference-fitted into the inner sealing groove in the middle, while the retaining ring is fitted onto the front groove. Because the grooved joint leaves the connector open, direct use of the pipe would lead to leakage due to the internal medium flowing through. This method, however, uses the inner sealing groove and the interference-fit sealing ring to construct a dense, airtight barrier inside the pipe cavity, solving the problem that tubular terminals cannot meet the high IP67 protection rating. By organically combining the plastic deformation of the outer bulge with the interference fit of the inner cavity seal, the tubular terminal achieves a synergistic effect of high-strength mechanical restraint and reliable inner cavity waterproofing, while reducing manufacturing costs and improving processing efficiency. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a specific embodiment of the slotted terminal of the present invention; Figure 2 for Figure 1 An exploded view of the structure of the slotted terminal; Figure 3 for Figure 1 A half-section view; Figure 4 for Figure 1 The rear view; Figure 5 This is a schematic diagram of the structure of a circular tube in a specific embodiment of the method for manufacturing the slotted terminal of the present invention; Figure 6 This is a schematic diagram of the structure of the convex tube blank in a specific embodiment of the method for manufacturing the slotted terminal of the present invention; In the diagram: 1-Terminal base; 11-Elastic contact spring; 12-Groove; 13-Inner sealing groove; 14-Terminal welding bevel; 15-Protrusion structure; 2-Snap ring; 3-Sealing ring; 31-Waterproof ring rib; 4-Stud; 41-Outer surface of stud; 42-Internal thread; 43-Stud welding bevel; 44-Laser welding weld. 5-Round tube; 6-Convex tube blank. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0027] It should be noted that relational terms such as "first" and "second" are used merely 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 a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0028] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0029] Specific embodiments of the slotted terminal of the present invention: as follows Figures 1 to 4 As shown, the slotted terminal is mainly used in new energy vehicle charging systems that carry high current transmission to achieve electrical contact connection, physical limiting, and airtight sealing of the electrical cavity. Specifically, the slotted terminal consists of a terminal base 1, a retaining ring 2 fitted onto the head of the terminal base 1, and a sealing ring 3 assembled in the inner cavity of the terminal base 1.

[0030] The terminal base 1 is an axially hollow tubular integrally formed structure. The front end of the terminal base 1 is defined as a plug end for physical insertion with the male pin of the charging plug, and the rear end of the terminal base 1 opposite to the plug end is defined as a wiring end for electrical and mechanical connection with external cables or copper busbars.

[0031] The outer peripheral surface of the insertion end of the terminal base 1 is provided with an inwardly recessed groove 12, and the insertion end is provided with a plurality of slots extending axially backward from the front end face of the terminal base 1. The slots are evenly distributed in the circumferential direction, preferably six slots, which evenly divide the tube wall at the insertion end to form six elastic contact springs 11 symmetrically arranged in the circumferential direction. The elastic contact springs 11 are arranged inward at a slight angle toward the central axis of the terminal in the axial direction, so that the six elastic contact springs 11 form a insertion cavity at the front end that is slightly smaller than the outer diameter of the mating male pin in the free state.

[0032] The retaining ring 2 is fitted into the groove 12. The outer diameter of the tube wall at the groove 12 is significantly smaller than the outer diameter of the foremost end of the insertion end, thus providing axial positioning constraint for the retaining ring 2. The retaining ring 2 has a radially elastically expandable open-loop ring structure. Its inner diameter in the absence of external force is slightly smaller than the bottom diameter of the groove 12, thus tightly clamping it inside the groove 12 and continuously applying an inward radial preload to the six elastic contact springs 11. When the external male needle is forcibly inserted axially into the insertion cavity of the elastic contact spring 11, the elastic contact spring 11 expands radially outward under the pressure of the male needle. At this time, the retaining ring 2 is simultaneously expanded outward, thereby generating a strong inward radial recovery force based on its elastic limit. This radial recovery force acts directly on the outer surface of the male needle through the elastic contact spring 11, increasing the radial positive pressure of the electrical contact surface. The high positive pressure can effectively penetrate the microscopic oxide film on the metal surface and significantly increase the contact area, keeping the contact resistance at a low level and effectively preventing abnormal temperature rise during high current transmission.

[0033] Within the inner cavity of the terminal base 1, at a position axially rearward of the elastic contact spring 11, an outwardly radially recessed inner sealing groove 13 is provided on the inner wall of the terminal base 1. The inner sealing groove 13 is axially located between the elastic slot and the rear terminal. The sealing ring 3 is housed within the inner sealing groove 13, and the outer periphery of the sealing ring 3 is provided with at least two axially arranged annular waterproof ring ribs 31. The outer diameter of these waterproof ring ribs 31 in the uncompressed state is larger than the inner diameter of the bottom of the inner sealing groove 13. When the sealing ring 3 is assembled, the waterproof ring ribs 31 are subjected to strong radial compression from the bottom of the inner sealing groove 13, thereby forming a high-pressure interference fit with the bottom of the groove and the two side walls of the groove. Through the tight fit between the multiple waterproof ring ribs 31 and the metal groove bottom, multiple continuous and dense annular interference sealing bands are formed in a localized area of ​​the inner cavity wall. Because the presence of the elastic slot causes the connector to be in an open state, external moisture, acid mist and dust can easily penetrate into the hollow cavity of the terminal along the slot. However, by setting an inner sealing groove 13 and a multi-ribbed sealing ring 3 in the middle of the cavity, an airtight isolation is formed in the hollow flow channel inside the terminal, blocking the path of water vapor and impurities to penetrate into the rear wiring area, so that the terminal can stably reach a high protection level and ensure the safety of the overall electrical system.

[0034] On the terminal base 1, located on the outer periphery of the middle portion axially rearward of the inner sealing groove 13, a radially outward protruding convex structure 15 with a specific stepped axial shape is provided. The convex structure 15 is a one-piece solid structure formed by locally radially bulging the tube wall of the terminal base 1, possessing extremely high and uniform tube wall thickness. Since the convex structure 15 is not formed by mechanically cutting away material from the tube, no stress concentration micro-tool marks caused by turning are generated in the transition areas on both sides of the convex structure 15, and its tube wall fiber structure remains continuous and unbroken. When the terminal is assembled into the socket assembly, this one-piece convex structure 15 provides strong axial mechanical limiting strength, capable of withstanding the high-frequency axial impact load generated by the male pin during insertion and removal cycles without bending, cracking, or limiting failure.

[0035] The slotted terminal also includes a separate metal stud 4. The stud 4 is housed in the internal channel at the rear end of the terminal base 1. The stud 4 has an axially extending internal thread 42 for connection with an external fastening bolt to fix the copper busbar. The outer diameter of the outer surface 41 of the stud 4 is slightly larger than the inner diameter of the terminal terminal of the terminal base 1, so that it is tightly fitted to the rear of the hollow channel of the terminal terminal by radial interference fitting, and the tail end face of the stud 4 is coplanar and flush with the end face of the terminal terminal of the terminal base 1.

[0036] To optimize the welding process, the terminal base 1 has an inwardly inclined terminal welding bevel 14 on its terminal end face, and the stud 4 has a corresponding outwardly inclined stud welding bevel 43 on its tail end. The two bevels are arranged opposite each other and together form a V-shaped annular welding groove that opens towards the tail end face of the terminal. The laser-welded weld 44 fills the annular welding groove, completely fusing the terminal base 1 and the stud 4 at the tail end contact point to form a seamless and high-strength closed weld. This weld not only seals the tiny assembly gap between the outer wall and the inner cavity wall of the stud 4 to achieve an airtight seal, but also provides strong torsional resistance to the stud 4, ensuring that the stud 4 will not rotate relative to the internal thread 42 under strong torque when the external copper busbar is tightened to the internal thread 42 with bolts.

[0037] In other embodiments, the stud 4 is omitted, and the tubular hollow structure at the rear end of the terminal base 1 is directly flattened by axial and radial compression without any external filler. This causes the inner wall of the terminal to tightly adhere under enormous pressure and undergo microscopic plastic rheological interlocking, thereby forming a flat welding plane at the rear end of the terminal base 1 with tightly fitted double-walled tubular surfaces and a solid, flat shape. This plane provides a wide, dense, and flat electrical contact surface, facilitating the direct welding of multiple copper cores of the external cable onto this flat welding plane using ultrasonic welding technology.

[0038] In other embodiments, the rear end of the terminal base 1 remains a hollow tubular segment structure, used directly as a crimping sleeve. During wiring, the exposed copper core after the external cable is stripped is directly inserted axially into the terminal tube. Subsequently, a huge radial compressive force is applied to the outer periphery of the terminal using an external crimping tool, causing the tube wall of the terminal to undergo radial plastic shrinkage deformation and forcefully bite and tighten the copper core inward, achieving a fast and firm electrical and mechanical crimp connection.

[0039] To achieve long-life resistance to electrochemical corrosion and optimal conductivity distribution, the inner and outer surfaces of the terminal substrate 1 are entirely covered with a nickel-plated underlayer. On this nickel underlayer, silver plating layers of varying thicknesses are selectively plated. Specifically, the outer surface of the elastic contact spring 11 at the terminal tip, which is prone to frequent friction and insertion / removal wear, is plated with a thick silver layer of a first preset thickness; while the other areas of the terminal substrate 1, excluding the elastic contact spring 11, are plated only with a thin silver layer of a second preset thickness, where the first preset thickness is significantly greater than the second preset thickness. This tiered plating design confines the expensive thick silver coating to the core electrical contact area requiring high-frequency insertion / removal and low contact resistance, while covering non-contact areas with a thin silver layer for corrosion protection. This approach minimizes the material cost of precious metals without compromising electrical contact performance and wear resistance life.

[0040] An embodiment of the method for manufacturing the slotted terminal involved in this invention includes the following specific process steps.

[0041] First, such as Figure 5 As shown, a copper alloy tube (such as high-purity copper or tellurium copper alloy tube) with high conductivity and good ductility is prepared as the original substrate. The inner diameter of the round tube 5 is preset to be smaller than the inner diameter of the finished terminal base 1, while the outer diameter is preset to be larger than the outer diameter of the finished terminal base 1. The entire round tube 5 is transversely cut using a tube cutting machine with high cutting precision to obtain a round tube fitting that meets the preset axial length.

[0042] Subsequently, as Figure 6 As shown, in order to form an axially limiting bulge structure 15 on the wall of a pipe with a uniform outer diameter, the cut circular pipe 5 is placed in a special extrusion molding die. The press head of the press applies extrusion force to both ends of the pipe in the die cavity, forcing the middle section of the pipe wall of the circular pipe 5 to radially expand outward under axial compression, thereby integrally forming a radially outward bulge structure 15 on the outer wall of the middle section of the circular pipe 5, producing a bulge pipe blank 6. In this extrusion molding process, the metal material undergoes plastic rheology, which keeps the internal grain fiber structure continuous and does not produce any cross-sectional cracking or micro-tool marks caused by cutting. At the same time, the intense plastic deformation caused by radial extrusion increases the yield strength and mechanical shear limit of the material in the bulge area, making it structurally stable when subjected to high-frequency insertion and extraction impacts.

[0043] Next, the prepared convex tube blank 6 is clamped on a high-precision CNC machine for local precision machining. First, a circumferential groove 12 is cut on the outer periphery of the front end of the convex tube blank 6. Then, the turning tool penetrates into the hollow tube and cuts an annular inner sealing groove 13 with a uniform depth and outward radial indentation in a local area of ​​its inner cavity wall. After that, six longitudinal slots that are symmetrical and evenly distributed in the circumferential direction are machined, thereby dividing the front end of the terminal into six inward elastic contact springs 11.

[0044] In the embodiment where the terminal is electrically connected by stud 4 at the rear end, the cutting tool also processes an inwardly inclined terminal welding bevel 14 on the edge of the tail end face of the terminal base 1. The above cutting process only involves a very small amount of mechanical material removal at both ends of the hollow tube, avoiding the high energy consumption and heavy material cutting process of traditionally hollowing out the hollow cavity from a solid bar. While ensuring processing accuracy, it maximizes the utilization rate of raw materials and shortens the cutting cycle by a factor of two.

[0045] Subsequently, the mechanically cut terminal substrate 1 is fed into the electroplating line, where it undergoes pretreatment steps such as chemical degreasing and acid pickling activation. In the electroplating tank, a uniformly thick nickel underlayer is first chemically plated or electroplated onto both the inner and outer surfaces of the terminal substrate 1 to serve as a physical protective barrier against copper ion diffusion and electrochemical corrosion. After the nickel underlayer, the surface of the terminal substrate 1 undergoes a selective silver plating process. Through current density control and local masking, a first silver plating layer is electroplated on the surface of the elastic contact spring 11 at the terminal tip, where high-frequency physical friction and contact electrical losses are prone to occur. Meanwhile, on other non-contact areas of the terminal substrate 1, only a second silver plating layer with a significantly thinner thickness than the first silver plating layer is electroplated. This process, through precise control of the plating layer thickness distribution, minimizes the consumption of expensive precious metals.

[0046] After the electroplating step is completed, the terminals are electrically connected according to different charging wiring requirements. In the embodiment using stud 4 welding connection, a stud 4 with axial internal thread 42 is first prepared, and an outwardly inclined stud welding bevel 43 is machined at the tail end of the stud 4. The outer diameter of the outer side 41 of the stud 4 is controlled to be slightly larger than the inner diameter of the rear end of the terminal base 1. Subsequently, the stud 4 is forcibly pressed into the rear end cavity of the terminal base 1 in a radial interference fit, and the pressing depth is adjusted so that the tail end face of the stud 4 is coplanar and flush with the terminal end face of the terminal base 1. At this time, the stud welding bevel 43 and the terminal welding bevel 14 are aligned at the tail joint and together form an annular V-shaped welding groove facing the tail. Laser welding is performed along the circumference of the annular welding groove. The laser beam instantly melts the metal of the bevel contact part to form a deep, closed annular molten pool. After cooling, it solidifies to form a closed laser welding weld 44, firmly fusing the stud 4 and the terminal base 1. The local overheating caused by laser welding will be rapidly conducted along the high thermal conductivity of the copper tube wall to the inner sealing groove 13 in the middle. If the rubber sealing ring 3 is installed in advance, the conducted high temperature will cause the sealing ring 3 to undergo thermal decomposition, melt and lose its elasticity, directly destroying its airtight sealing performance. Moreover, in the state where the sealing ring 3 is not installed, the elastic groove at the front end of the terminal base 1 forms a natural exhaust channel open to the atmosphere. During laser welding, the gas inside the hollow tube cavity that is rapidly heated and expanded can be discharged instantly from the front opening without obstruction, which completely solves the welding defects such as spatter, blowhole and pinhole caused by the thermal expansion of the sealed air in the molten weld pool.

[0047] In the embodiment where flattening and ultrasonic welding are used instead of stud welding, before the electroplating process, the terminal of the terminal base 1 is subjected to intense axial and radial compression by a hydraulic clamping fixture. This completely flattens the tubular hollow structure of the terminal, causing the opposing inner walls to fit tightly together under the huge extrusion pressure and produce microscopic plastic interlocking. This results in a flat welding plane with double-walled fitting and solid flatness at the tail of the terminal base 1, which can be directly used for ultrasonic welding of external multi-strand copper cables.

[0048] In the direct crimping implementation, the terminal maintains its original tubular hollow structure, and the cable core is inserted and radially clamped using crimping pliers only during field wiring.

[0049] Finally, after completing the above welding or deformation processing, the sealing and elastic pressure-increasing components are assembled. A rubber sealing ring 3 with several annular waterproof ribs 31 is pushed into the axial inner cavity of the terminal base 1 from the front insertion opening. A special guide shaft tool guides it to slide backward against the friction of the pipe wall until it is fully engaged in the inner sealing groove 13, forming an interference fit seal between the waterproof ribs 31 and the bottom of the inner sealing groove 13. Subsequently, a retaining ring 2 that can elastically expand radially is fitted into the groove 12 on the outer periphery of the elastic contact spring 11. After the retaining ring 2 springs back, it elastically tightens the elastic contact spring 11 inward.

[0050] An embodiment of the charging socket designed in this invention includes a socket housing and a connecting terminal disposed within the socket housing. The structure of the connecting terminal is consistent with the structure of the slotted terminal in any embodiment of the slotted terminal described above, and will not be described in detail.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a slotted terminal, characterized in that, Includes the following steps: (1) Place the metal tube in the extrusion die for radial extrusion, so that the local tube wall expands and deforms outward to produce a tube blank with a convex structure. (2) Machining is performed on the pipe blank, a groove is machined on the outer front end, an inner sealing groove is machined on the inner side of the middle, and a split groove is machined along the axial direction at the front end to form an elastic contact spring, thus obtaining the terminal base; (3) Electroplating is performed on the terminal substrate; (4) Push the sealing ring into the inner sealing groove from the front opening of the terminal base and lock it in the inner sealing groove. Place the retaining ring in the groove to obtain the slotted terminal.

2. The method for manufacturing a slotted terminal according to claim 1, characterized in that, Also includes: To fabricate a metal stud, internal threads are machined on the inner side, and the outer diameter of the metal stud is machined to be larger than the rear inner diameter of the terminal base; a stud welding bevel is machined at the tail of the metal stud. In step (2), a terminal welding bevel is machined along the rear port edge of the terminal substrate; Before assembling the sealing ring in step (4), press the stud into the terminal block of the terminal body; A full-circle weld is performed at the junction of the terminal welding bevel of the terminal substrate and the stud welding bevel of the stud to form a weld seam.

3. The method for manufacturing a slotted terminal according to claim 1, characterized in that, Before step (3), the rear end of the terminal base is axially flattened and squeezed to form a flat welding plane with double tube walls at the tail end of the terminal base.

4. A slotted terminal manufactured using the method of any one of claims 1-3, characterized in that, include: The terminal base is integrally formed from a metal tube and has an internal cavity extending front and rear. Its front end is defined as the plug end. The outer periphery of the front end of the terminal base has a groove, and the tube wall of the terminal base has several slots extending rearward from its front end to form several inwardly converging elastic contact springs at the front end of the terminal base. The inner cavity wall of the terminal base has an inner sealing groove behind the slots. The outer periphery of the terminal base has a radially outward protruding convex structure behind the inner sealing groove. The convex structure is formed by locally radially extruding and expanding the tube wall of the terminal base into an integral structure. A retaining ring is fitted into the groove; The sealing ring is housed in the inner sealing groove.

5. The slotted terminal according to claim 4, characterized in that, The outer periphery of the sealing ring is provided with at least two annular waterproof ring ribs arranged side by side along the axial direction. The outer diameter of the waterproof ring ribs is larger than the inner diameter of the bottom of the inner sealing groove, so as to form a radial pressing fit with the bottom of the inner sealing groove.

6. The slotted terminal according to claim 4, characterized in that, It also includes a stud, which is interference-fitted into the hollow channel inside the rear end of the terminal base, and the stud has an axially extending internal thread; The outer diameter of the stud's outer side surface is larger than the inner diameter of the rear end of the terminal base. The tail end face of the stud is coplanar and flush with the terminal end face of the terminal base. The rear end of the terminal base and the tail end of the stud are sealed and fused together by a full-circular laser welding weld.

7. The slotted terminal according to claim 6, characterized in that, The rear end face of the terminal base is provided with an inwardly inclined terminal welding bevel, and the tail end of the stud is provided with an outwardly inclined stud welding bevel. The terminal welding bevel and the stud welding bevel are arranged opposite to each other and together form an annular welding groove. The laser welding weld is filled in the annular welding groove.

8. The slotted terminal according to claim 4, characterized in that, The tubular structure at the rear end of the terminal base is axially compressed and flattened to form a flat welding plane with a double-walled structure that fits tightly at the rear end of the terminal base, or the rear end of the terminal base is a hollow tubular structure for inserting an external cable through its tail port and radially crimping the entire structure.

9. The slotted terminal according to claim 4, characterized in that, The inner and outer surfaces of the terminal substrate are entirely coated with an electroplated nickel underlayer. The outer surface of the elastic contact spring is provided with a silver plating layer with a thickness of a first preset thickness. Other areas of the terminal substrate are provided with a silver plating layer with a thickness of a second preset thickness, wherein the first preset thickness is greater than the second preset thickness.

10. A charging socket, comprising a socket housing and connecting terminals disposed within the socket housing, characterized in that, The connecting terminal is the slotted terminal as described in any one of claims 4-9.

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