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EP-4372922-B1 - CYLINDRICAL TERMINAL, PLUG-IN CONNECTION STRUCTURE, AND METHOD FOR MACHINING CYLINDRICAL TERMINAL

EP4372922B1EP 4372922 B1EP4372922 B1EP 4372922B1EP-4372922-B1

Inventors

  • WANG, CHAO

Dates

Publication Date
20260506
Application Date
20220715

Claims (15)

  1. A machining method for manufacturing a cylindrical terminal which comprises a contact section (10), a fixing section (20) and a connecting section (30); wherein the fixing section (20) comprises an extension section (201) and an assembly portion (202) disposed on the extension section (201); the contact section (10), the extension section (201) and the connecting section (30) are integrally formed as a cylindrical tube; the contact section (10) is provided with at least two axial slots (102), which divide a side wall of the contact section (10) into at least two contact elastic sheets (103); the contact section (10) is provided with a depression that is recessed radially inward, such that the contact elastic sheets (103) form arc-shaped structures; and the connecting section (30) is electrically connectable to a wire; the machining method comprises: step S10: preparing a cylindrical tube; characterized in that the machining method further comprises: step S20: preparing an extruder and a mold that comprises an inner mold and an outer mold, wherein the inner mold is provided with arc-shaped recesses (101) and first grooves (203), and the outer mold is provided with arc-shaped convexes and cutting blocks; step S30: placing the inner mold into the cylindrical tube, and then putting them together into the outer mold; step S40: starting the extruder, wherein the arc-shaped convexes of the outer mold move to the arc-shaped recesses (101) of the inner mold, and extrude the contact section (10) of the cylindrical tube to make it concave inwardly; step S50: driving, by the extruder, the cutting blocks of the outer mold to continue to move, so that the cutting blocks cooperate with the first grooves (203) of the inner mold to extrude the contact section (10) of the cylindrical tube to form axial slots (102); a step S57 after the step S50: extruding or rolling the extension section (201) to make it in a corrugated shape; step S60: driving, by the extruder, the outer mold back to its original position, taking the extruded cylindrical tube and the inner mold out of the outer mold, and taking out the inner mold; and a step S70 after the step S60: placing the cylindrical tube that has been extruded or rolled into an injection molding machine to form the assembly portion (202) by injection molding.
  2. The machining method of a cylindrical terminal according to claim 1, wherein the extruder in the steps S20, S40, S50 and S60 is a rolling machine.
  3. The machining method of a cylindrical terminal according to claim 1 or 2, wherein the method comprises one of the following steps: (i) the step S50 comprises: shearing or cutting the contact section (10) of the cylindrical tube to form axial slots (102); (ii) after the step S40, the machining method further comprises a step S45 of moving the outer mold to the inner mold to extrude the extension section (201) of the cylindrical tube to form the assembly portion (202); (iii) after the step S50, the machining method further comprises a step S56 of shearing the extension section (201) to obtain an opening (206); (vi) after the step S50, the machining method further comprises a step S58 of extruding or rolling the contact section (10) to form a second groove (104), and after the step S60, the machining method further comprises a step S100 of assembling the elastic ferrule (105) in the second groove (104); (vii) after the step S50, the machining method further comprises a step S59 of extruding or rolling the connecting section (30) to reduce its diameter; (viii) after the step S60, the machining method further comprises a step S66 of providing a plating layer on at least the contact section (10) and/or the connecting section (30); (ix) after the step S60, the machining method further comprises a step S80 of placing the cylindrical tube that has been extruded or rolled into an injection molding machine to form a sealing ring by injection molding; and (x) after the step S60, the machining method further comprises a step S90 of assembling the sealing ring in the first groove (203).
  4. A cylindrical terminal, wherein the cylindrical terminal is machined by the machining method according to any one of claims 1 to 3, wherein the cylindrical terminal comprises a contact section (10), a fixing section (20) and a connecting section (30); wherein the fixing section (20) comprises an extension section (201) and an assembly portion (202) disposed on the extension section (201); the contact section (10), the extension section (201) and the connecting section (30) are integrally formed as a cylindrical tube; the contact section (10) is provided with at least two axial slots (102), which divide a side wall of the contact section (10) into at least two contact elastic sheets (103); the contact section (10) is provided with a depression that is recessed radially inward, such that the contact elastic sheets (103) form arc-shaped structures; the connecting section (30) is electrically connectable to a wire; characterized in that the assembly portion (202) is made of a plastic material, and the assembly portion (202) is formed on the extension section (201) by injection molding; and a side wall of the extension section (201) is in a corrugated shape, and the assembly portion (202) is formed at a periphery of the extension section (201) and in contact with an entire corrugated outer side surface of the extension section (201).
  5. The cylindrical terminal according to claim 4, wherein, the slots (102) penetrate through one end of the contact section (10) that is away from the fixing section (20), and one end of each contact elastic sheet (103) is a free end; or, both ends of each slot (102) are closed, and both ends of each contact elastic sheet (103) are fixed.
  6. The cylindrical terminal according to claim 4, wherein, a width of one end of each slot (102) that is close to the fixing section (20) is greater than or equal to a width of one end of the slot (102) that is away from the fixing section (20); or, the slots (102) are arranged inclinedly with respect to an axis of the cylindrical terminal; or, the assembly portion (202) is formed by extruding the extension section (201).
  7. The cylindrical terminal according to claim 4, wherein, an opening (206) is provided in the extension section (201) to enable the assembly portion (202) to be formed integrally inside and outside the cylindrical tube.
  8. The cylindrical terminal according to claim 4, wherein, the cylindrical tube is a seamless tube, or a seamed tube rolled from a sheet material; preferably wherein, when the cylindrical tube is a seamed tube, there is no seam on the contact elastic sheets (103).
  9. The cylindrical terminal according to claim 4, wherein, distances between inner surfaces of the arc-shaped structures and an axis of the cylindrical terminal are the same; or, a diameter of the connecting section (30) is smaller than or equal to a diameter of the contact section (10) or the extension section (201). or, an outward expanding chamfer is provided at one end of the contact section (10) that is away from the fixing section (20) and has an angle of 17° to 178°.
  10. The cylindrical terminal according to claim 4, wherein, the cylindrical tube is made of copper or copper alloy, or aluminum or aluminum alloy; preferably wherein, when the cylindrical tube is made of copper alloy, the copper alloy contains copper material containing tellurium material, and the cylindrical tube has a content of tellurium of 0.1% to 5%.
  11. The cylindrical terminal according to claim 4, wherein, a first groove (203) is provided at a periphery of the assembly portion (202), the cylindrical terminal further comprises a sealing ring that is sleeved on the first groove (203) and made of a rubber material; or, an outer side of the contact section (10) is provided with a second groove (104) arranged in a circumferential direction, the cylindrical terminal further comprises an elastic ferrule that is sleeved on the second groove (104) and made of a rubber material.
  12. The cylindrical terminal according to claim 4, wherein, a plating layer is provided on at least part of the contact section (10) and/or the connecting section (30); preferably wherein, the plating layer comprises a bottom layer and a surface layer; the bottom layer is made of one or more selected from the group consisting of gold, silver, nickel, tin, tin-lead alloy and zinc; and the surface layer is made of one or more selected from the group consisting of gold, silver, nickel, tin, tin-lead alloy, zinc, silver-antimony alloy, palladium, palladium-nickel alloy, graphite-silver, graphene-silver and silver-gold-zirconium alloy.
  13. The cylindrical terminal according to claim 12, wherein, the bottom layer has a thickness of 0.01 µm to 15 µm, preferably the bottom layer has a thickness of 0.1 µm to 9 µm; or, the surface layer has a thickness of 0.5 µm to 55 µm, preferably the surface layer has a thickness of 1 µm to 35 µm.
  14. A plug-in connection structure, comprising the cylindrical terminal according to any one of claims 4 to 13 and a plug-in terminal (40), wherein the plug-in terminal (40) is inserted into the contact section (10), an outer side wall of the plug-in terminal (40) is closely fitted with inner side walls of the contact elastic sheets (103).
  15. The plug-in connection structure according to claim 14, wherein, a positioning pin (207) is provided in the assembly portion (202) of the cylindrical terminal, a front end of the plug-in terminal (40) is provided with a positioning hole (402), and the positioning pin (207) is inserted into the positioning hole (402).

Description

RELATED APPLICATION The present application claims priority to Chinese Invention Patent Application No. 202110803204.9 filed on July 15, 2021, and Chinese Utility Model Patent Application No. 202121613435.5 filed on July 15, 2021. TECHNICAL FIELD The present application relates to the field of electrical connection, in particular to a cylindrical terminal, a plug-in connection structure and a method for machining the cylindrical terminal. BACKGROUND In the field of electrical connection, there are many electrical circuits that require plug-in terminals for connection. At present, a male terminal and a female terminal are usually used to realize plug-in connection, especially in a harness with high current and large wire diameter. For example, in the new energy automobiles that are developing rapidly, the charging gun head and the charging base for charging the battery are internally provided with male terminals and female terminals that plugged with each other. Because the carrying current is large, the cross-sectional area of the plug-in terminal is required to be large. The existing commonly used plug-in terminals are all obtained by performing a turning process on copper rods, which has a low material utilization rate, adopts a complex machining process and takes a long machining time, especially the processing of female terminals, the waste of copper is more, resulting in the cost of the charging system cannot be reduced. In addition, in order to realize the assembly and sealing of the terminal on an electrical device, it is necessary to provide an assembling area and a sealing area in addition to the electrical function area of the terminal, which also requires a complicated processing process and will lose part of raw materials, leading to an even lower material utilization rate. Chinese patent specification CN107394445A discloses a conductive connector for a charging gun, which includes a sleeve and a contact piece. The contact piece is integrally formed with multiple contact arms, a connecting portion, and a wiring portion. The connecting portion is cylindrical in shape, and the multiple contact arms extend forward from the connecting portion and are arranged to form a cylindrical structure. Chinese patent specification CN108616004A discloses a connector terminal, which includes a terminal body, a terminal protective sleeve, and a waterproof plug. The terminal body comprises a sealing waterproof section, a terminal plug-in section extending forward from the sealing waterproof section, and a conductor clamping section extending backward from the sealing waterproof section. Chinese patent specification CN207743426U discloses a cylindrical terminal, which includes a main body portion. The main body portion is rolled and bent along a corresponding direction to form two arc-shaped side walls, with a gap between the two arc-shaped side walls. The front end of the main body portion extends to form a contact portion that makes conductive contact with a mating male terminal, while the rear end of the main body portion extends to form a shaping portion. Chinese patent specification CN110024235A discloses a socket contact and a method for manufacturing the socket contact from a round rod. The method includes the following steps: producing a hollow cylindrical contact region on the first end of the round rod by means of flow pressing; and adjusting the first section with the thicker wall thickness inward, wherein the second section with the thinner wall thickness bends or folds outward. Therefore, there is an urgent need for a new solution to solve the above problems in the prior art. SUMMARY The present application provides a cylindrical terminal, a plug-in connection structure and a method for machining the cylindrical terminal, which improve the utilization rate of machining materials of the terminal, adopt a simple machining process, take short time and greatly reduce the production cost of the terminal. The present application provides the technical solution as below. An embodiment of the first aspect of the present application provides a cylindrical terminal according to claim 4 including a contact section, a fixing section and a connecting section. The fixing section includes an extension section and an assembly portion that is disposed on the extension section. The contact section, the extension section and the connecting section are integrally formed as a cylindrical tube. The contact section is provided with at least two axial slots, which divide a side wall of the contact section into at least two contact elastic sheets. The contact section is recessed radially inward, such that the contact elastic sheets are arc-shaped structures. The connecting section is electrically connected with a wire. An embodiment of the second aspect of the present application provides a plug-in connection structure, according to claim 14, including the cylindrical terminal as described in the embodiment of the first aspect