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CN-120772270-B - Preparation process of copper wire

CN120772270BCN 120772270 BCN120772270 BCN 120772270BCN-120772270-B

Abstract

The application relates to a preparation process of a copper wire, which belongs to the technical field of wire production and comprises the following steps of S1, preparing an oxygen-free copper rod by an upward drawing method, S2, cleaning the surface of the oxygen-free copper rod, S3, processing the oxygen-free copper rod after surface cleaning into a copper flat wire by a continuous extruder, wherein the continuous extruder comprises a forming cavity and an extrusion die detachably fixed in the forming cavity, the extrusion die is provided with an integrally formed die opening structure, the die opening structure comprises a gradual change forming section and an equal section forming section, the geometric outline of the gradual change forming section is formed by axially lofting an inlet end circular section to an outlet end target rectangular section, the equal section forming section is connected with the outlet end of the gradual change forming section, and the section shape of the equal section forming section is consistent with the target rectangular section. The application can inhibit edge skin tilting and cracks, avoid abrupt pressure change of the die during extrusion, prolong the service life of the die, and ensure the high-efficiency production requirement of the copper wire without deliberately slowing down the production speed to relieve the pressure.

Inventors

  • YUAN YAYA
  • ZHANG WEI
  • SU BAOXIN

Assignees

  • 铜陵精达特种电磁线股份有限公司

Dates

Publication Date
20260508
Application Date
20250808

Claims (7)

  1. 1. The preparation process of the copper wire is characterized by comprising the following steps of: S1, preparing an oxygen-free copper rod by adopting an upward-guiding method; S2, cleaning the surface of the oxygen-free copper rod; s3, processing the oxygen-free copper rod with the surface cleaned into a copper flat wire through a continuous extruder; The continuous extrusion machine comprises a forming cavity (1) and an extrusion die (2) which is detachably fixed in the forming cavity (1), wherein the extrusion die (2) is provided with an integrally formed die opening structure (21), the die opening structure (21) comprises a gradual change forming section (211) and an equal section shaping section (212), the geometric outline of the gradual change forming section (211) is formed by axially lofting an inlet end circular section to an outlet end target rectangular section, the equal section shaping section (212) is connected with the outlet end of the gradual change forming section (211), and the section shape of the equal section shaping section is consistent with the target rectangular section; The outlet end of the molding cavity (1) is provided with a mounting groove (14), the extrusion die (2) is inserted into the mounting groove (14) in an adapting way, the section of the mounting groove (14) is non-circular, the side wall of the extrusion die (2) is provided with a clamping groove (22), and the inner wall of the mounting groove (14) is provided with a clamping unit (15) which is matched with the clamping groove (22); the clamping unit (15) comprises a containing groove (151) arranged on the inner wall of the mounting groove (14) and a clamping block (152) arranged in the containing groove (151) in a sliding manner, wherein the containing groove (151) is arranged corresponding to the clamping groove (22), the clamping block (152) is matched with the clamping groove (22), a pressure spring (153) is connected between the clamping block (152) and the bottom wall of the containing groove (151), one side of the clamping block (152) facing the opening of the mounting groove (14) is provided with a guide inclined surface (1521), when the pressure spring (153) is in a natural state, the guide inclined surface (1521) is at least partially positioned in the containing groove (151) or just stretches out of the containing groove (151), and when the pressure spring (153) is in a compression limit, the clamping block (152) is completely positioned in the containing groove (151); One end of the clamping block (152) close to the bottom wall of the accommodating groove (151) is connected with a pull rod (154), a through hole (16) for the pull rod (154) to penetrate out is formed in the forming cavity (1), the pull rod (154) is in clearance fit with the through hole (16), a pull buckle part (1541) is arranged at one end of the pull rod (154) penetrating out of the through hole (16), the through hole (16) is communicated with the accommodating groove (151), an external thread (1542) is arranged on the pull rod (154), the external thread (1542) is in threaded connection with a lock nut (155), and the lock nut (155) is located outside the forming cavity (1).
  2. 2. A process for producing a copper wire according to claim 1, wherein step S1 comprises: S11, smelting an electrolytic copper raw material in a closed smelting furnace, wherein a smelting environment is covered with a reducing medium; S12, transferring the molten copper to an upper continuous casting furnace, and drawing by a crystallizer to form an oxygen-free copper rod with pitch lines.
  3. 3. The process for preparing a copper wire according to claim 1, wherein in step S2, the surface cleaning is performed by using a rotary wire brush to remove dirt and a slight oxide layer on the surface of the oxygen-free copper rod, and a dust collecting device is arranged to collect cleaning residues.
  4. 4. The preparation process of the copper wire, which is characterized in that the continuous extrusion machine further comprises an extrusion wheel (3) arranged at the inlet side of the forming cavity (1), a wheel groove (31) for an oxygen-free copper rod to pass through is formed in the wheel surface of the extrusion wheel (3), a compression wheel (4) used for compressing the oxygen-free copper rod on the wall of the wheel groove (31) is arranged at one side of the extrusion wheel (3), an arc surface (11) tightly attached to the extrusion wheel (3) is arranged at one side of the forming cavity (1) close to the extrusion wheel (3), a material guide channel (12) opposite to the wheel groove (31) in position is arranged on the arc surface (11), the material guide channel (12) is communicated with the mounting groove (14), a stop block (13) is further arranged on the arc surface (11), and the stop block (13) is arranged at the lower side of the material guide channel (12).
  5. 5. The process for preparing the copper wire according to claim 1, wherein the step S3 is followed by the step S4, and the step S4 is to spray-cool the copper flat wire extruded by the continuous extruder.
  6. 6. A process for producing a copper wire according to claim 1, wherein the constant section forming section (212) has a length longer than that of the gradual change forming section (211).
  7. 7. A process for producing a copper wire according to claim 1, wherein the inlet end of the taper molding section (211) is provided with an lead-in taper angle (2111).

Description

Preparation process of copper wire Technical Field The application relates to the field of wire production, in particular to a preparation process of a copper wire. Background The driving motor of the new energy automobile is one of core components of the new energy automobile, and compared with the traditional industrial motor, the driving motor of the new energy automobile has the characteristics of high integration level, high working condition efficiency, high power density, high safety level, high cost performance and low noise. The drive motor is a core component of an automobile, and the enameled rectangular wire is a key raw material of the drive motor, so that higher requirements on a copper conductor of the enameled rectangular wire, an accurate rectangular section, a defect-free surface and excellent dimensional stability are correspondingly provided. The traditional process adopts an upward continuous casting method to prepare an oxygen-free copper rod as a raw material, and pitch lines on the surface of the oxygen-free copper rod need to be eliminated by mechanical cleaning. The copper rod is pretreated and then enters a continuous extrusion process, namely, the copper rod plastically flows in a forming cavity at high temperature and high pressure, a die is assembled in the forming cavity, and a copper conductor with a rectangular section (namely, an enamelled flat wire base material) is directly obtained through continuous extrusion molding of a die opening of the die. However, this process has significant drawbacks in preparing high aspect ratio flat wires. Because the deformation from the circular section to the rectangular section completely depends on single-die extrusion, the stress distribution of the metal flow in the bearing area is uneven, so that the defects of skin warping, burrs and the like are generated at the edge of the finished product, and the size fluctuation in the thickness direction is aggravated. In order to compensate for the lack of precision, the prior art is generally provided with a separate rolling shaping line after extrusion, and a plurality of groups of press rolls are used for secondary processing of the flat wire. The process needs to be provided with additional rolling mill equipment, so that the line of a production line is obviously prolonged, the process connection is interrupted and the equipment layout is redundant, meanwhile, the capacity of correcting the rectangular edge profile by rolling is limited, and the severe requirement of the enamelled wire on the conductor surface quality is difficult to meet. In addition, the cavity pressure is increased rapidly when the flat wire with high aspect ratio is extruded, the die loss is accelerated, and the flat wire is forced to be produced at a low speed to relieve the pressure, so that the production efficiency is severely restricted. Disclosure of Invention In order to solve the problems of edge defects, size fluctuation and low process efficiency in the production of high-aspect-ratio copper flat wires in a single-die continuous extrusion process, the application provides a preparation process of a copper wire. The application provides a preparation process of a copper wire, which adopts the following technical scheme: A preparation process of a copper wire comprises the following steps: S1, preparing an oxygen-free copper rod by adopting an upward-guiding method; S2, cleaning the surface of the oxygen-free copper rod; s3, processing the oxygen-free copper rod with the surface cleaned into a copper flat wire through a continuous extruder; The continuous extrusion machine comprises a forming cavity and an extrusion die which is detachably fixed in the forming cavity, wherein the extrusion die is provided with an integrally formed die orifice structure, the die orifice structure comprises a gradual change forming section and a constant section shaping section, the geometric outline of the gradual change forming section is formed by axially lofting a circular section of an inlet end to a target rectangular section of an outlet end, the constant section shaping section is connected with the outlet end of the gradual change forming section, and the section shape of the constant section shaping section is consistent with that of the target rectangular section. Optionally, the step S1 includes: S11, smelting an electrolytic copper raw material in a closed smelting furnace, wherein a smelting environment is covered with a reducing medium; S12, transferring the molten copper to an upper continuous casting furnace, and drawing by a crystallizer to form an oxygen-free copper rod with pitch lines. Optionally, in step S2, the surface cleaning uses a rotating steel wire brush to remove dirt and slight oxide layer on the surface of the oxygen-free copper rod, and a dust collecting device is configured to collect cleaning residues. Optionally, the exit end of shaping cavity is equipped with the mounting groove, extrusion d