WO2024125001A1

WO2024125001A1 - Cathode roller for electrolytic copper foil production, and manufacturing method for cathode roller

Info

Publication number: WO2024125001A1
Application number: PCT/CN2023/118243
Authority: WO
Inventors: 李学雷; 蔡瑞; 杨东海; 殷凯; 高世凯; 田俍媛; 李养宁; 邓爽; 王向明; 许俊如; 王朝晖; 任发民; 阎阳天
Original assignee: 西安航天动力机械有限公司
Priority date: 2022-12-12
Filing date: 2023-09-12
Publication date: 2024-06-20
Also published as: CN116240592B; CN116240592A

Abstract

A cathode roller for electrolytic copper foil production, and a manufacturing method for cathode roller. The cathode roller is of a three-layer titanium-copper-steel composite structure, and a conductive path is completely made of copper. There is a V-shaped slot in a contact surface between a copper cylinder and a titanium cylinder, such that the fitting rate between the titanium cylinder and the copper cylinder is increased, thereby improving the uniformity of roller-surface currents of the cathode roller. The roller-surface currents are uniformly conducted inside the cathode roller by using a conductive copper plate and a current equalizing cylinder, conductive paths passed by the currents are substantially the same, thereby reducing the problem of the roller-surface currents being non-uniform caused by the conductive paths, and avoiding the situation where a copper foil produced by a large-breadth cathode roller being thinned in the middle; and the weight deviation per unit area, in the breadth and circumferential direction, of produced lithium battery copper foils of 4.5 μm and 6 μm is less than or equal to 1%, such that more than 50000 m can be stably rolled at a time. The present invention meets the requirements of the static balance deviation of a cathode roller being less than or equal to 3 Nm, the circle run-out and straightness of roll-surface precision being less than or equal to 0.05 mm and the roughness Ra of a roller surface being less than or equal to 0.2 μm, and realizes a simple and economic manufacturing process, and a cathode roller manufactured thereby works stably, and thus can be used for producing copper foils for a long time.

Description

Cathode roller for electrolytic copper foil production and manufacturing method thereof

Technical Field

The invention relates to the field of electrolytic copper foil equipment manufacturing, in particular to a cathode roller with a diameter of ≥3000mm and a width of ≥1650mm for electrolytic copper foil production and a manufacturing method thereof.

Background technique

Lithium battery copper foil is the negative electrode current collector material of lithium batteries and the conductive substrate of the negative electrode of lithium batteries. Its weight accounts for about 10% to 15% of the total weight of lithium batteries. As lithium batteries develop towards high energy density, reducing the thickness of lithium battery copper foil can directly increase the energy density of lithium batteries. Compared with 8μm lithium battery copper foil, 6μm and 4.5μm lithium battery copper foil can increase the energy density of lithium batteries by 5% and 9% respectively. In the future, lithium battery copper foil will develop towards thinner and thinner. Lithium battery copper foil is produced by electrolysis. Under the action of an external DC electric field, copper ions in the copper sulfate electrolyte inside the anode tank are continuously deposited onto the surface of the uniformly rotating cathode roller. After deposition to a certain thickness, it is peeled off, surface treated, and rolled up to continuously produce lithium battery copper foil.

The cathode roller is the carrier for the production of electrolytic copper foil. Its diameter, width, conductivity, and roller surface current uniformity directly determine the quality and production efficiency of the copper foil. At present, the cathode roller is mainly Φ2700mm, and its conductivity and production efficiency are basically close to the theoretical design value. The manufacture of cathode rollers with larger diameters and wider widths is more critical for the manufacture of electrolytic copper foil. At present, the cathode roller has a conductive structure at both ends. When used to manufacture cathode rollers with a diameter ≥3000mm and a width ≥1650mm, there are problems such as poor uniformity of copper foil thickness, decreasing thickness of copper foil at both ends toward the center, excessive weight per unit area of copper foil, and substandard length of copper foil. The problem is more serious when producing extremely thin lithium battery copper foil. This shows that the conductive structure at both ends of the cathode roller currently used cannot be applied to cathode rollers with larger diameters and wider widths, which will result in poor uniformity of roller surface current and substandard thickness performance of the copper foil produced. The roller surface current uniformity of the cathode roller is expressed by detecting the thickness consistency of the copper foil produced by it. The thickness consistency of the copper foil is measured by taking samples of the same size on the surface of the copper foil and weighing them. The weight deviation per unit area of each copper foil sample is calculated. The smaller the deviation, the better the roller surface current uniformity.

Summary of the invention

In order to overcome the problems in the prior art that the cathode roller with a diameter of ≥3000 mm and a width of ≥1650 mm has insufficient conductivity uniformity and poor thickness uniformity of the produced copper foil, the present invention provides a cathode roller for electrolytic copper foil and a manufacturing method thereof.

The cathode roller for producing electrolytic copper foil provided by the present invention comprises a steel shaft, a copper sleeve, a conductive ring, a bearing, a titanium sleeve, a titanium Sheath, titanium cylinder, copper cylinder, steel cylinder, center steel plate, support ring, conductive copper plate, titanium plate, insulating ring, titanium ring, titanium cover, reinforcement ring, current collecting copper plate and current equalizing cylinder.

Wherein: both ends of the steel shaft are respectively covered with titanium sleeves; on each titanium sleeve, a copper sleeve, a conductive ring, a titanium sleeve, a bearing and a titanium sleeve are sequentially covered from the outside to the inside; the copper sleeve is interference-connected with the steel shaft, and the rest are tight-fitting connections.

The steel cylinder, copper cylinder and titanium cylinder are nested with each other to form a titanium-copper-steel three-layer composite structure of the cathode roller. The steel cylinder is sleeved on the steel shaft; the copper cylinder is sleeved on the outer circumferential surface of the steel cylinder, and the inner circumferential surface of the copper cylinder is fitted with the outer circumferential surface of the steel cylinder; the titanium cylinder is sleeved on the outer circumferential surface of the copper cylinder, and the silver-plated inner circumferential surface of the titanium cylinder is interference-fitted with the silver-plated outer circumferential surface of the copper cylinder.

The flow balancing tube is mounted on the steel shaft and distributed at both ends of the central steel plate. The outer circle of the outer end of the flow balancing tube is fixedly connected to the end plate, and the outer circle of the inner end of the flow balancing tube is fixedly connected to the central steel plate. The inner surface of the flow balancing tube is spaced 600 to 800 mm from the outer surface of the steel shaft, and the outer surface of the flow balancing tube is spaced 500 to 600 mm from the outer surface of the steel tube.

There are eight support rings axially arranged between the current equalizing cylinder and the steel cylinder, which are divided into four groups. There is a ring-shaped conductive copper plate between the two support rings in each group. The outer circumferential surface of each conductive copper plate is respectively fixedly connected to the copper cylinder; the inner circumferential surface of each conductive copper plate is respectively fixedly connected to the outer circumferential surface of the current equalizing cylinder.

Two current collecting copper plates are symmetrically distributed along the axial direction between the inner surface of the current equalizing cylinder and the steel shaft. The outer circumferential surfaces of the current collecting copper plates at both ends are respectively fixedly connected to the inner circumferential surface of the current equalizing cylinder, and the inner circumferential surface is fixedly connected to the outer circumferential surface of the copper sleeve.

The steel cylinder is composed of a plurality of small steel cylinders connected together, and the two ends of the steel cylinder are respectively located at the inner end of the titanium sleeve at one end; the outer circumferential surface of the copper cylinder has a "V"-shaped groove,

The outer circumferential surface of each group of support rings is fixed to the inner surface of the steel cylinder, so that the inner circumferential surface of each group of support rings is fixed to the outer inner surface of the flow equalizing cylinder.

There is a reinforcement ring between each of the current collecting copper plates, and the outer circumferential surface of the reinforcement ring is fixedly connected to the inner circumferential surface of the current equalizing cylinder. The inner circumferential surface of the reinforcement ring is fixedly connected to the circumferential surface of the steel shaft or the outer circumferential surface of the copper sleeve according to its position.

The cathode roller has a diameter of 3000 mm and a length of 2000 mm. To ensure the uniformity of the roller surface current, the cathode roller is divided into five equal sections along the axial direction by four groups of conductive copper plates located inside the cathode roller.

The specific process of manufacturing the cathode roller for producing electrolytic copper foil proposed by the present invention is:

Step 1, titanium cylinder preparation: cold spinning process is used to spin-form seamless titanium cylinder; the titanium cylinder composition satisfies the H content ≤ 0.01%; the structure is equiaxed α structure, the grain size grade is 11 to 12, and the twin content is less than 10%.

Step 2, heat-fit copper sleeves at both ends of the steel shaft: heat-fit copper sleeves at both ends of the steel shaft; the assembly interference between the copper sleeves at both ends and the steel shaft must meet 0.2mm.

Step 3, assemble and weld the center steel plate: Assemble and weld the center steel at the center position inside the width of the cathode roller.

Step 4, welding the current equalizing tube: use MIG welding to weld the reinforcing ring on the inner position corresponding to the conductive copper plate on the outside of the current equalizing tube; weld the inner circle of the current equalizing tube at both ends to the boss of the center steel plate.

Step 5, welding the current collecting copper plate: weld the current collecting copper plate at the axial center position of the current balancing tube at both ends, and weld the current collecting copper plate to the copper sleeve.

Step 6, welding each steel cylinder, conductive copper plate, and support ring: weld the steel cylinder from the center to both ends, weld the support ring and the conductive copper plate, weld the triangular reinforcement ribs between the support ring and the steel cylinder, and connect and fix the two support rings and one conductive copper plate. MIG welding is used for copper-copper and copper-steel welding, and _CO2 gas shielded welding is used for steel welding.

Step 7, welding the end plates at both ends: weld the outer circle of the end plate to the stopper of the steel cylinder end of the steel cylinder, weld the inner circle to the copper sleeve, weld the outer circle of the current equalizer to the end plate, weld the end plate to the current equalizer and the steel cylinder respectively through triangular reinforcement ribs, and weld the end plate to the copper sleeve through large triangular reinforcement ribs. MIG welding is used for copper-copper and copper-steel welding.

Step 8, welding the axial horizontal ribs inside the steel cylinder: divide the circumference of the steel cylinder into 4 parts, and use CO2 gas shielded welding to connect the 4 horizontal ribs evenly distributed circumferentially inside the steel cylinder to the support ring, center steel plate, and end plate respectively.

Step 9, heat treatment of the steel cylinder: There are multiple welds on the steel cylinder. In order to reduce the later deformation of the cathode roller caused by welding stress, a heat treatment heating track is used to cover the outer circle of the steel cylinder and keep it at 620±10℃ for 1.5h for stress relief annealing.

Step 10, machining the outer surface of the steel cylinder: In order to ensure the uniformity of the thickness of the additional copper cylinder, the outer surface of the steel cylinder is machined by CNC machine to a roughness Ra ≤ 1.6 μm, a circular runout and a straightness ≤ 0.05 mm, and the conductive copper plate is ensured to be more than 10 mm higher than the steel cylinder.

Step 11, prepare the copper cylinder: wrap a layer of copper tape on the surface of the machined steel cylinder; the copper tape is 10 mm thick and 16 mm wide, weld the two ends of the copper tape to the two ends of the steel cylinder, and weld the copper tape to the conductive copper plate used.

Step 12, machining the outer surface of the copper cylinder: Use CNC machine to machine the copper cylinder surface to achieve surface roughness Ra ≤ 1.6μm, circular runout and straightness ≤ 0.05mm, ensure the copper cylinder thickness is 8mm, and the thickness deviation is ≤ 0.15mm. Add a forming tool and machine a "V"-shaped groove on the outer surface of the copper sleeve to ensure that the "V"-shaped groove angle α is 35-45°, the depth is 2-2.5mm, the distance between the two grooves is 4-5mm, and the "V"-shaped grooves are spirally distributed on the copper cylinder.

Step 13, initial static balance test: In order to ensure that the cathode roller rotates stably and evenly, the rolling static balance test method is used to perform the initial static balance test, and the static balance torque is ensured to be ≤3Nm by welding a counterweight block on the internal end plate.

Step 14, machining the inner surface of the titanium cylinder: use CNC to machine the outer surface of the copper cylinder and the inner surface of the titanium cylinder in sequence, so that the inner diameter of the titanium cylinder is 3.5mm smaller than the outer diameter of the copper cylinder, and the inner surface roughness Ra≤1.6μm, circular runout and straightness≤0.05mm.

Step 15, silver plating: In order to increase conductivity, reduce contact resistance and reduce energy consumption, the brush plating process is used to plate silver on the outer circumference of the copper cylinder and the inner circumference of the titanium cylinder after machining; the coating thickness is 5 to 8 μm and the thickness is uniform and firmly attached.

Step 16, hot assembly: keep the inner circle of the silver-plated titanium cylinder at 450°C for 1.5 hours, and use argon gas for protection during the heating process; after the insulation is completed, insert the outer circle of the silver-plated copper cylinder into the titanium cylinder, and assemble it using the principle of thermal expansion and contraction.

Step 17, titanium welding: assemble the titanium plate and titanium sleeve at one end in sequence, and use TIG welding to complete the welding of the titanium plate to the inner wall of the titanium tube and the titanium plate to the titanium sleeve; assemble the titanium ring and titanium sleeve, ensure that the outer end face of the titanium ring is 5mm lower than the end face of the titanium tube, and use TIG welding to complete the welding of the titanium ring to the inner wall of the titanium tube, the titanium sleeve and the titanium plate; then assemble and weld the titanium plate, titanium sleeve, titanium tube, titanium ring and other titanium welding at the other end. After the titanium welding is completed, all titanium welds are subjected to surface coloring inspection.

Step 18, heat treatment of the titanium cylinder: The titanium cylinder is subjected to stress relief heat treatment. The outer circle of the titanium cylinder is covered with a heat treatment heating track and kept at 520±10℃ for 1.5 hours for stress relief annealing treatment to eliminate the residual stress on the surface of the cathode roller titanium cylinder and overcome the problems of collapse, stress corrosion and easy oxidation of the roller surface during the use of the cathode roller.

Step 19, machining the outer circle of the titanium cylinder and the outer circle of the copper sleeve: Use CNC machining to complete the processing of the outer circle of the cathode roller titanium cylinder and the outer circle of the copper sleeve, ensuring that the outer circle diameter of the cathode roller is Φ3000mm and the width is 2000mm, the wall thickness of the titanium cylinder is 10mm~10.5mm, the end of the titanium cylinder is right-angled, the end of the titanium cylinder is 5mm higher than the outer end of the titanium ring, the roller surface roughness is Ra1.6, and the straightness and circular runout are ≤0.05mm.

Step 20, static balancing test: To ensure that the final static balancing torque of the cathode roller is ≤3Nm, static balancing weights are applied to the counterweight holes of the titanium plates at both ends of the cathode roller. The length of the counterweight rod is adjusted according to the counterweight weight so that the final static balancing torque of the cathode roller is ≤3Nm. After the counterweight is completed, the counterweight hole is blocked with a titanium cover, and the titanium cover is welded to the titanium plate, and the weld is subjected to surface coloring inspection.

Step 21, airtight test: install a pressure gauge at one end of the airtight hole of the cathode roller steel shaft, pass compressed nitrogen at one end, maintain the pressure at 0.04 MPa for 2 hours, and check the overall sealing performance of the cathode roller.

Step 22, polishing the outer circumferential surface of the titanium cylinder: on the cathode roller polishing grinder, use 40#, 80#, 120#, 220#, 320#, and 600# PVA grinding wheels to polish the roller surface in sequence, so that the roller surface roughness Ra ≤ 0.2μm, the circular runout and straightness ≤ 0.05mm, and the surface has no color difference, spots, and pinhole defects.

When polishing the outer circumference of the titanium cylinder:

When using 40# PVA grinding wheel, the grinding wheel speed is 400-450r/min, the grinding wheel longitudinal feed is 30-40mm/min, the pressure is 0.25-0.3MPa, the cathode roller speed is 4.0-4.5r/min, and the grinding wheel consumption is 2.

When using 80# PVA grinding wheel, the grinding wheel speed is 450-500r/min, the grinding wheel longitudinal feed is 25-30mm/min, the pressure is 0.2-0.25MPa, the cathode roller speed is 4.5-5r/min, and the grinding wheel consumption is 1.5.

When using 120# PVA grinding wheel, the grinding wheel speed is 450-500r/min, the longitudinal feed of the grinding wheel is 25-30mm/min, the pressure is 0.2-0.25MPa, the cathode roller speed is 4.5-5r/min, and the grinding wheel consumption is 1.5.

When using 220#PVA grinding wheel, the grinding wheel speed is 500-550r/min, the longitudinal feed of the grinding wheel is 20-25mm/min, the pressure is 0.15-0.2MPa, the cathode roller speed is 5.5-6r/min, and the grinding wheel consumption is 1.

When using 320#PVA grinding wheel, the grinding wheel speed is 500-550r/min, the grinding wheel longitudinal feed is 20-25mm/min, the pressure is 0.15-0.2MPa, the cathode roller speed is 5.5-6r/min, and the grinding wheel consumption is 0.5.

When using 600# PVA grinding wheel, the grinding wheel speed is 550-600r/min, the grinding wheel longitudinal feed is 15-20mm/min, the pressure is 0.1-0.15MPa, the cathode roller speed is 6-6.5r/min, and the grinding wheel consumption is 0.5.

Step 23, accessories installation: install the insulating rings, titanium screws, bearings and conductive rings at both ends of the cathode roller in sequence.

At this point, the cathode roller is manufactured.

The cathode roller proposed in the present invention adopts a titanium-copper-steel three-layer composite structure, and the conductive path is entirely made of copper material, which has relatively low energy consumption. The contact surface between the copper cylinder and the titanium cylinder has a "V"-shaped groove, which greatly improves the fitting rate between the titanium cylinder and the copper cylinder, thereby improving the current uniformity of the cathode roller surface. At the same time, the cathode roller invented in the present invention adopts an internal center conductive method, and adopts multiple groups of conductive copper plates and two current equalizing cylinders to evenly conduct the roller surface current. The conduction paths through which the current passes are basically the same, which reduces the problem of uneven roller surface current caused by the conductive path, and avoids the copper foil thinning in the middle of the copper foil produced by the wide cathode roller. The unit area weight deviation of the produced 4.5μm and 6μm lithium copper foil in the width and circumferential direction is ≤1%, and it can be stably rolled up for more than 50,000m at a time, and the S surface and M surface of the copper foil meet the requirements of the negative electrode of the lithium battery. The manufacturing method of the cathode roller invented in the present invention ensures that the key parameters that affect the conductive uniformity of the cathode roller, such as the titanium cylinder thickness deviation of 0 to 0.5mm, the copper cylinder thickness deviation of 0 to 0.15mm, and the interference amount ≥3.5mm, realize the static cathode roller. The balance deviation is ≤3Nm, the roller surface accuracy circular runout and straightness is ≤0.05mm, and the roller surface roughness Ra is ≤0.2μm. The manufacturing process is simple and economical, the manufactured cathode roller works stably, and can be used for long-term production of copper foil.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an appearance diagram of a cathode roller, wherein FIG. 1a is a front view and FIG. 1b is a left view.

FIG. 2 is a schematic structural diagram of a cathode roller.

Fig. 3a is a view in the direction of A-A in Fig. 2; Fig. 3b is a view in the direction of B-B in Fig. 2; and Fig. 3c is a partial enlarged view of portion I in Fig. 2.

Fig. 4 is a schematic diagram of the structure of the central steel plate; wherein Fig. 4a is a C-C cross-sectional view in Fig. 4b, and Fig. 4b is a main view.

Figure 5 is a schematic diagram of the structure of the end plate; Figure 5a is a D-D cross-sectional view in Figure 5b, and Figure 5b is a main view.

FIG6 is a schematic diagram of the copper cylinder inside the cathode roller; FIG6a is a schematic diagram of the distribution of the "V"-shaped grooves on the copper cylinder, and FIG6b is a partial enlarged view of the part II in FIG6a.

FIG. 7 is a SEM image of copper foil produced by the cathode roller of the present invention: FIG. 7a is a SEM image of the M surface of the copper foil, and FIG. 7b is a SEM image of the S surface of the copper foil.

In the figure:

1. Steel shaft; 2. Copper sleeve; 3. Conductive ring; 4. Bearing; 5. Titanium sleeve; 6. Titanium sleeve; 7. Titanium cylinder; 8. Copper cylinder; 9. Steel cylinder; 10. Center steel plate; 11. Reinforcement ribs; 12. Support ring; 13. Conductive copper plate; 14. End plate; 15. Titanium plate; 16. Insulation ring; 17. Titanium screw; 18. Titanium ring; 19. Titanium cover; 20. Counterweight rod; 21. Horizontal ribs; 22. Bolts; 23. Reinforcement ring; 24. Current collecting copper plate; 25. Current equalizing cylinder.

Detailed ways

This embodiment is a cathode roller with a diameter of 3000mm and a width of 2000mm, including a steel shaft 1, a copper sleeve 2, a conductive ring 3, a bearing 4, a titanium sleeve 5, a titanium sleeve 6, a titanium cylinder 7, a copper cylinder 8, a steel cylinder 9, a central steel plate 10, a reinforcing rib 11, a support ring 12, a conductive copper plate 13, an end plate 14; a titanium plate 15; an insulating ring 16; a titanium screw 17, a titanium ring 18, a titanium cover 19, a counterweight bar 20, a horizontal rib 21, a bolt 22, a reinforcing ring 23, a current collecting copper plate 24, and a current equalizing cylinder 25. Wherein: the two ends of the steel shaft are respectively covered with a titanium sleeve 6; the copper sleeve 2, the conductive ring 3, the titanium sleeve 5, the bearing 4 and the titanium sleeve 5 are sequentially covered on each of the titanium sleeves from the outside to the inside, the copper sleeve 2 is connected with the steel shaft 1 by interference, and the rest are connected by tight fit.

The steel cylinder 9, the copper cylinder 8 and the titanium cylinder 7 are nested with each other to form a titanium-copper-steel three-layer composite structure of the cathode roller. The steel cylinder 9 is sleeved on the steel shaft 1 and is composed of a plurality of small steel cylinders connected together, and the two ends of the steel cylinder are respectively located at the inner end of the titanium sleeve 5 at one end; a copper cylinder 8 is sleeved on the outer circumferential surface of the steel cylinder, and the inner circumferential surface of the copper cylinder is fitted with the outer circumferential surface of the steel cylinder; a "V"-shaped groove is provided on the outer circumferential surface of the copper cylinder, and a titanium cylinder 7 is sleeved on the outer circumferential surface of the copper cylinder, and the silver-plated inner circumferential surface of the titanium cylinder is interference-fitted with the silver-plated outer circumferential surface of the copper cylinder.

The flow equalizing tube 25 is sleeved on the steel shaft 1 and distributed at both ends of the central steel plate 10. The outer circle of the outer end of the flow equalizing tube is fixedly connected to the end plate 14, and the outer circle of the inner end of the flow equalizing tube is fixedly connected to the central steel plate. The inner surface of the flow equalizing tube is spaced 600 to 800 mm from the outer surface of the steel shaft 1, and the outer surface of the flow equalizing tube is spaced 500 to 600 mm from the outer surface of the steel tube 9.

There are eight support rings 12 along the axial direction between the current equalizing cylinder 25 and the steel cylinder 9, which are divided into four groups, and the outer circumferential surface of each group of support rings is fixed to the inner surface of the steel cylinder, and the inner circumferential surface of each group of support rings is fixed to the outer inner surface of the current equalizing cylinder. There is a ring-shaped conductive copper plate 13 between the two support rings of each group. The outer circumferential surface of each conductive copper plate is fixedly connected to the copper cylinder 8; the inner circumferential surface of each conductive copper plate is fixedly connected to the outer circumferential surface of the current equalizing cylinder 25.

Two current collecting copper plates 24 are symmetrically distributed along the axial direction between the inner surface of the current equalizing cylinder 25 and the steel shaft 1. The outer circumferential surfaces of the current collecting copper plates at both ends are respectively fixedly connected to the inner circumferential surface of the current equalizing cylinder 25, and the inner circumferential surface is fixedly connected to the outer circumferential surface of the copper sleeve 2.

There is a reinforcement ring 23 between each of the current collecting copper plates 24, and the outer circumferential surface of the reinforcement ring is fixedly connected to the inner circumferential surface of the current equalizing cylinder 25. The inner circumferential surface of the reinforcement ring is fixedly connected to the circumferential surface of the steel shaft 1 or the outer circumferential surface of the copper sleeve 2 according to its position.

In this embodiment, the cathode roller has a diameter of 3000 mm and a length of 2000 mm. To ensure the uniformity of the roller surface current, there are 4 groups of conductive copper plates 13 inside the cathode roller, and the cathode roller is equally divided into 5 sections along the axial direction.

In order to make the rated raw foil current of the cathode roller reach 80kA, the thickness of the shell of the conductive copper cylinder 8 is 8mm. The thickness of the conductive copper plate 13 is 8mm, the outer diameter is consistent with the conductive copper cylinder, and the inner diameter is 1602mm. The outer diameter of the current equalizing cylinder 29 is 1600mm, the inner diameter is 1576mm, and the axial length is 944mm. The outer diameter of the current collecting copper plate 28 is 1576mm, the inner diameter is 400mm, and the thickness is 45mm. The outer end of the copper sleeve 2 is a small diameter section, the outer diameter of the small diameter section is 380mm, the inner diameter is 260mm, and the axial length is 600mm; the inner end of the copper sleeve is a large diameter section, the outer diameter of the large and small diameter sections is 400mm, the inner diameter is 260mm, and the axial length is 780mm;

In this embodiment, all copper materials are annealed oxygen-free copper T2 with a purity greater than 99.95%, and all copper and copper The contact parts of the components are connected by welding.

The steel shaft 1 is made of Q355 alloy steel, with a small diameter of 260 mm at both ends and a large diameter of 280 mm in the middle. The small diameters at both ends are heat-fitted with copper sleeves 2, and the assembly interference of the copper sleeve sections is 0.2-0.3 mm.

The material of the center steel plate 10 is Q235, with an outer diameter of 2922mm, an inner diameter of 282mm and a thickness of 16mm; the bosses at both ends of the center steel plate are 10mm high and have an outer diameter of 1574mm. The center steel plate 10 is welded to the outer circle of the steel shaft 1, and medium triangular reinforcement ribs are evenly distributed between the center steel plate and the steel shaft 1.

The reinforcing ring 23 is made of Q235, with an outer diameter of 1574mm, an inner diameter of 1474mm and a thickness of 10mm. The inner circle of the flow-equalizing cylinder at both ends is welded to the boss of the central steel plate 10, and the uniformly distributed middle triangular reinforcing ribs between the central steel plate and the flow-equalizing cylinder are welded. The support ring 12 is made of Q235, with a wall thickness of 10mm, an outer diameter of 2934mm, an inner diameter of 1602mm, and an outer circumferential surface is welded to the steel cylinder 9, and an inner circumferential surface is welded to the flow-equalizing cylinder 25.

The outer diameter of the current collecting copper plate 24 is 1576 mm, the inner diameter is 400 mm, and the thickness is 45 mm. The current collecting copper plate 24 is welded at the axial center of the current equalizing tube 25 at both ends, and the current collecting copper plate is welded to the copper sleeve 2.

The steel cylinder 9 is composed of multiple short steel cylinders made of Q235, with an outer diameter of 2964 mm, an inner diameter of 2924 mm, a length of 385 mm, and a stopper of 12 mm×12 mm on the inner surface of both ends. The segmented steel cylinder 9 is welded from the center to both ends, and the support ring 12 and the conductive copper plate 13 are welded, the triangular reinforcement rib 11 between the support ring and the steel cylinder is welded, and the two support rings 12 and the one conductive copper plate 13 are connected and fixed with bolts.

The end plate 14 is made of Q235, with an outer diameter of 2934mm, an inner diameter of 380mm, and a boss outer diameter of 1574mm. There are 16 threaded through holes evenly distributed on the Φ2300mm dividing circle. The outer circumferential surface of the welded end plate 14 is welded to the stopper at the end of the steel cylinder 9, and the inner circumferential surface is welded to the outer circumferential surface of the copper sleeve 2.

The outer circle of the current-equalizing copper cylinder 25 is welded to the end plate, and the end plate is welded to the current-equalizing cylinder 25 and the steel cylinder 9 respectively through the triangular reinforcing ribs 11, and the end plate is welded to the copper sleeve 2 through the large triangular reinforcing ribs. The reinforcing ribs 21 are made of Q235 with a wall thickness of 10 mm.

Width 100mm, 4 pieces are 383mm long, 2 pieces are 190mm long, and the circumference of the steel cylinder is evenly divided into 4 parts. The reinforcing ribs are axially welded inside the steel cylinder 9, and the 4 horizontal ribs 21 evenly distributed circumferentially inside the steel cylinder are welded to the support ring 12, the center steel plate 10, and the end plate 14. The copper cylinder 8 is made of T2 material, and a copper strip with a thickness of 10mm and a width of 16mm is wound around the steel cylinder 9, and the copper strip is welded to the steel cylinders 9 at both ends and the conductive copper plate 13; the surface of the machined copper cylinder is machined to achieve a surface roughness Ra≤1.6μm, circular runout and straightness≤0.05mm, and the copper cylinder thickness is guaranteed to be 8mm, and the thickness deviation is ≤0.15mm. The "V"-shaped groove on the outer surface of the formed copper cylinder is ensured to have a "V"-shaped groove angle α of 35～45°, depth 2～2.5mm, the spacing between the two grooves is 4～5mm, and the "V"-shaped grooves are spirally distributed on the copper cylinder. The titanium cylinder 7 is made of TA1 and is formed by spinning or coil welding. The content of component H is ≤0.01%, the organization is equiaxed α organization, the grain size grade is 11～12, and the twin content is less than 10%; according to the outer diameter size of the copper cylinder 8 after machining, the inner surface of the titanium cylinder 7 is machined to ensure that the inner diameter of the titanium cylinder is 3.5mm smaller than the outer diameter of the copper cylinder, and the inner surface roughness Ra≤1.6μm, the circular runout and straightness ≤0.05mm. The outer circle of the copper cylinder 8 and the inner circle of the titanium cylinder 9 after machining are silver-plated to ensure that the coating thickness is 5～8μm. The inner circle of the titanium cylinder with silver plating is kept at 450℃ for 1.5 hours, and argon is used for protection during the heating process; after the insulation is completed, the outer circle of the silver-plated copper cylinder 8 is inserted into the titanium cylinder 7, and the assembly is achieved by using the principle of thermal expansion and contraction. The material of titanium plate 15, titanium ring 18, titanium sleeve 5, titanium sheath 6, titanium cover 19 and titanium screw 17 is TA2. The outer diameter of the titanium plate is Φ2978mm, the inner diameter is Φ396mm, and the wall thickness is 6mm. There are 16 Φ40 through holes evenly distributed on the Φ2300mm dividing circle on the titanium plate; the outer diameter of the titanium sleeve 5 is Φ394mm, the inner diameter is Φ380mm, and the length is 400mm; the outer diameter of the titanium ring 18 is Φ2978mm, the inner diameter is Φ2878mm, and the thickness is 25mm. M is evenly distributed on the Φ2940mm dividing circle on it. 10 The threaded hole is 15mm deep; the outer diameter of the titanium sheath 6 is Φ496mm, the inner diameter is Φ296mm, and the thickness is 8mm; the titanium plate 15 and the titanium sleeve 5 at one end are assembled in sequence, the Φ40 through holes of the titanium plate 16 are in the same position as the M36 on the end plate 14, and TIG welding is used to complete the welding of the titanium plate to the inner wall of the titanium cylinder 7 and the titanium plate to the titanium sleeve 5; the titanium ring 18 and the titanium sheath 6 are assembled to ensure that the outer end face of the titanium ring is 5mm lower than the end face of the titanium cylinder 7, and TIG welding is used to complete the welding of the titanium ring 18 to the inner wall of the titanium cylinder 7, and the titanium sheath 6 to the titanium plate 15. The outer circle of the machined titanium cylinder and the outer circle of the copper sleeve are processed on the lathe to ensure that the outer diameter of the cathode roller is Φ3000mm and the width is 2000mm, the wall thickness of the titanium cylinder is 10mm~10.5mm, the end of the titanium cylinder is right angle, the end of the titanium cylinder is 5mm higher than the outer end of the titanium ring, the roller surface roughness is Ra1.6, and the straightness and circular runout are ≤0.05mm. Static balancing weights are carried out on the counterweight holes of the titanium plates 15 at both ends of the cathode roller. The counterweight rod 20 is an M36 screw made of Q235. The length of the counterweight rod is adjusted according to the counterweight weight so that the final static balancing torque of the cathode roller is ≤3Nm. After the counterweight is completed, the counterweight hole is blocked with a titanium cover 19, and the titanium cover is welded to the titanium plate 15, and the weld is subjected to surface color flaw detection. On a special grinding machine for cathode roller polishing, a PVA grinding wheel is used to polish the roller surface, so that the roller surface roughness Ra≤0.2μm, the circular runout and straightness ≤0.05mm, and the surface has no defects such as color difference, spots, pinholes, etc. The insulating rings 16 at both ends of the cathode roller are installed in sequence. The insulating ring material is CPVC, with an outer diameter of Φ3000mm and an inner diameter of Φ2880mm. The stepped through holes are evenly distributed on the Φ2940mm dividing circle: Φ20mm deep 20mm, Φ12mm through hole; titanium screws 17 are used to install the insulating ring 16 on the titanium rings at both ends. The conductive ring 3 is made of T2, with an inner diameter of Φ380mm, an outer diameter of Φ520mm, and a thickness of 120mm. The distance between adjacent conductive rings is 60mm, and the installation center distance is 2830mm. The inner circle of the sleeve contact and the outer circle of the copper sleeve 2 are silver-plated with 5-8μm. The installation center distance of the bearing 4 is 2320mm.

This embodiment also proposes a method for manufacturing a cathode roller for electrolytic copper foil production. The specific process of manufacturing the above-mentioned Φ3000mm×2000mm cathode roller is as follows:

Step 1, titanium cylinder preparation: adopt conventional cold spinning process to spin-form seamless titanium cylinder, the titanium cylinder composition satisfies H content ≤ 0.01%; the structure is equiaxed α structure, the grain size grade is 11-12, and the twin content is less than 10%.

Step 2, heat-fit the copper sleeves at both ends of the steel shaft: Check that the interference fit between the copper sleeve 2 and the steel shaft 1 meets 0.2 mm, use conventional heat-fitting method, heat the copper sleeve to 300°C, and heat-fit the copper sleeves at both ends separately.

Step 3, welding the center steel plate: assemble the center steel plate 10 at the center position inside the width of the cathode roller, weld the center steel plate and the steel shaft 1 using conventional _CO2 gas shielded welding, and weld reinforcing ribs at the connection between the center steel plate and the steel shaft.

Step 4, welding the current equalizing tube: use conventional MIG welding to weld the reinforcing ring 23 on the inner position corresponding to the conductive copper plate 13 on the outside of the current equalizing tube 25; weld the inner circle of the current equalizing tube at both ends to the boss of the central steel plate 10, and weld the evenly distributed middle triangular reinforcing ribs between the central steel plate and the current equalizing tube.

Step 5, welding the current collecting copper plate: conventional MIG welding is used to weld the current collecting copper plate 24 at the axial center position of the current equalizing tube 25 at both ends, and the current collecting copper plate is welded to the copper sleeve 2.

Step 6, welding each steel cylinder, conductive copper plate, and support ring: weld the steel cylinder 9 from the center to both ends, weld the support ring 12 and the conductive copper plate 13, weld the triangular reinforcing rib 11 between the support ring and the steel cylinder, and use bolts 22 to connect and fix the two support rings 12 and the one conductive copper plate 13. Conventional MIG welding is used for copper-copper and copper-steel welding, and conventional CO2 gas shielded welding is used for steel welding.

Step 7, welding the end plates at both ends: weld the outer circle of the end plate 14 to the stopper of the steel cylinder 9, weld the inner circle to the copper sleeve 2, weld the outer circle of the current equalizer 25 to the end plate, and weld the end plate to the current equalizer 29 and the steel cylinder 9 through the triangular reinforcement ribs 11, and weld the end plate to the copper sleeve 2 through the large triangular reinforcement ribs 26. Conventional MIG welding is used for copper-copper and copper-steel welding, and conventional CO2 gas shielded welding is used for steel welding.

Step 8, welding the axial horizontal ribs inside the steel cylinder: divide the circumference of the steel cylinder into 4 parts, and use conventional CO2 gas shielded welding to connect the 4 horizontal ribs 21 evenly distributed circumferentially inside the steel cylinder with the support ring 12, the center steel plate 10, and the end plate 14 respectively.

Step 9, heat treatment of the steel cylinder: There are multiple welds on the steel cylinder 9. In order to reduce the later deformation of the cathode roller caused by welding stress, a conventional heat treatment heating track is used to cover the outer circle of the steel cylinder, and the stress relief annealing treatment is carried out at 620±10℃ for 1.5h.

Step 10, machining the outer surface of the steel cylinder: In order to ensure the uniformity of the thickness of the additional copper cylinder, the outer surface of the steel cylinder 9 is machined by conventional CNC machining to a roughness Ra ≤ 1.6 μm, a circular runout and a straightness ≤ 0.05 mm, and to ensure that the guide The electric copper plate 13 is higher than the steel cylinder 9 by more than 10 mm.

Step 11, prepare the copper cylinder 8: wrap a layer of copper tape on the surface of the machined steel cylinder 9; the copper tape is 10 mm thick and 16 mm wide, weld the two ends of the copper tape to the two ends of the steel cylinder 9, and weld the copper tape to the conductive copper plate 13 used.

Step 12, machining the outer surface of the copper cylinder: using conventional CNC machine to machine the surface of the copper cylinder 8, reaching the surface roughness Ra≤1.6μm, circular runout and straightness≤0.05mm, ensuring the thickness of the copper cylinder 8mm, thickness deviation≤0.15mm. And using a machine forming tool, the "V"-shaped groove on the outer surface of the copper sleeve is machined to ensure that the "V"-shaped groove angle α is 35-45°, the depth is 2-2.5mm, the spacing between the two grooves is 4-5mm, and the "V"-shaped groove is spirally distributed on the copper cylinder.

Step 13, initial static balance test: In order to ensure that the cathode roller rotates stably and evenly, the initial static balance test is carried out using a conventional rolling static balance test method, and a counterweight is welded on the internal end plate to ensure that the static balance torque is ≤3Nm.

Step 14, machining the inner surface of the titanium cylinder: use conventional CNC to machine the outer surface of the copper cylinder 8 and the inner surface of the titanium cylinder 7 in sequence, so that the inner diameter of the titanium cylinder is 3.5mm smaller than the outer diameter of the copper cylinder, and the inner surface roughness Ra≤1.6μm, circular runout and straightness≤0.05mm.

Step 15, silver plating: In order to increase conductivity, reduce contact resistance and reduce energy consumption, the outer circumferential surface of the machined copper cylinder 8 and the inner circumferential surface of the titanium cylinder 9 are silver plated using a conventional brush plating process; the coating thickness is 5 to 8 μm and the thickness is uniform and firmly attached.

Step 16, hot assembly: keep the inner circle of the silver-plated titanium cylinder at 450°C for 1.5 hours, and use argon gas for protection during the heating process; after the insulation is completed, insert the outer circle of the silver-plated copper cylinder 8 into the titanium cylinder 7, and assemble it using the principle of thermal expansion and contraction.

Step 17, titanium welding: assemble the titanium plate 15 and the titanium sleeve 5 at one end in sequence, and use conventional TIG welding to complete the welding of the titanium plate and the inner wall of the titanium tube 7 and the titanium plate and the titanium sleeve 5; assemble the titanium ring 18 and the titanium sleeve 6, ensure that the outer end face of the titanium ring is 5 mm lower than the end face of the titanium tube 7, and use TIG welding to complete the welding of the titanium ring 18 and the inner wall of the titanium tube 7, and the titanium sleeve 6 and the titanium plate 15; then assemble and weld the titanium plate, titanium sleeve, titanium tube, titanium ring and other titanium welding at the other end. After the titanium welding is completed, all titanium welds are subjected to surface coloring inspection.

Step 18, heat treatment of the titanium cylinder: stress relief heat treatment of the titanium cylinder, use conventional heat treatment heating tracks to cover the outer circle of the titanium cylinder, keep it at 520±10℃ for 1.5 hours for stress relief annealing treatment to eliminate residual stress on the surface of the cathode roller titanium cylinder, and overcome the collapse, stress corrosion and easy oxidation problems of the roller surface during the use of the cathode roller.

Step 19, machining the outer circle of the titanium cylinder and the outer circle of the copper sleeve: conventional CNC machining is used to complete the outer circle of the cathode roller titanium cylinder 7 And the outer circle of the copper sleeve 2 is processed to ensure that the outer circle diameter of the cathode roller is Φ3000mm and the width is 2000mm, the wall thickness of the titanium cylinder is 10mm~10.5mm, the end of the titanium cylinder is right-angled, the end of the titanium cylinder is 5mm higher than the outer end of the titanium ring, the roller surface roughness is Ra1.6, and the straightness and circular runout are ≤0.05mm.

Step 20, static balancing test: To ensure that the final static balancing torque of the cathode roller is ≤3Nm, static balancing weights are applied to the counterweight holes of the titanium plates at both ends of the cathode roller. The length of the counterweight rod 20 is adjusted according to the counterweight weight so that the final static balancing torque of the cathode roller is ≤3Nm. After the counterweight is completed, the counterweight hole is blocked with a titanium cover 19, and the titanium cover is welded to the titanium plate 15, and the weld is subjected to surface coloring inspection.

Step 22, polishing the outer circumferential surface of the titanium cylinder: on the cathode roller polishing grinder, use 40#, 80#, 120#, 220#, 320#, and 600# PVA grinding wheels to polish the roller surface in sequence. The polishing parameters are shown in the following table, so that the roller surface roughness Ra ≤ 0.2μm, circular runout and straightness ≤ 0.05mm, and there are no defects such as color difference, spots, pinholes, etc. on the surface.

Step 23, accessories installation: install the insulating rings 16, titanium screws 17, bearings 4, and conductive rings 3 at both ends of the cathode roller in sequence.

At this point, the cathode roller is manufactured.

Claims

A cathode roller for producing electrolytic copper foil, characterized in that it comprises a steel shaft (1), a copper sleeve (2), a conductive ring 3, a bearing 4, a titanium sleeve (5), a titanium sheath (6), a titanium cylinder (7), a copper cylinder (8), a steel cylinder (9), a central steel plate (10), a support ring (12), a conductive copper plate (13), a titanium plate (15), an insulating ring (16), a titanium ring (18), a titanium cover (19), a reinforcement ring (23), a current collecting copper plate (24) and a current equalizing cylinder (25);

Wherein: both ends of the steel shaft are respectively covered with titanium sleeves (6); on each of the titanium sleeves, from outside to inside, a copper sleeve (2), a conductive ring 3, a titanium sleeve (5), a bearing 4 and a titanium sleeve (5) are sequentially covered; the copper sleeve (2) and the steel shaft (1) are connected by interference fit, and the rest are connected by tight fit;

The steel cylinder (9), the copper cylinder (8) and the titanium cylinder (7) are nested with each other to form a titanium-copper-steel three-layer composite structure of the cathode roller; wherein the steel cylinder (9) is sleeved on the steel shaft (1); the copper cylinder (8) is sleeved on the outer circumferential surface of the steel cylinder, and the inner circumferential surface of the copper cylinder is fitted with the outer circumferential surface of the steel cylinder; the titanium cylinder (7) is sleeved on the outer circumferential surface of the copper cylinder, and the silver-plated inner circumferential surface of the titanium cylinder is interference-fitted with the silver-plated outer circumferential surface of the copper cylinder;

The flow equalizing tube (25) is sleeved on the steel shaft (1) and distributed at both ends of the central steel plate (10). The outer circle of the outer end of the flow equalizing tube is fixedly connected to the end plate (14), and the outer circle of the inner end of the flow equalizing tube is fixedly connected to the central steel plate. The inner surface of the flow equalizing tube is spaced 600 to 800 mm from the outer surface of the steel shaft (1), and the outer surface of the flow equalizing tube is spaced 500 to 600 mm from the outer surface of the steel cylinder (9).

There are eight support rings (12) axially arranged between the current equalizing cylinder (25) and the steel cylinder (9), which are divided into four groups. There is a ring-shaped conductive copper plate (13) between the two support rings in each group. The outer circumferential surface of each conductive copper plate is fixedly connected to the copper cylinder (8). The inner circumferential surface of each conductive copper plate is fixedly connected to the outer circumferential surface of the current equalizing cylinder (25).

Two current collecting copper plates (24) are symmetrically distributed along the axial direction between the inner surface of the current balancing tube (25) and the steel shaft (1); the outer circumferential surfaces of the current collecting copper plates at both ends are respectively fixedly connected to the inner circumferential surface of the current balancing tube (25), and the inner circumferential surfaces are fixedly connected to the outer circumferential surface of the copper sleeve (2).
The cathode roller for producing electrolytic copper foil as described in claim 1 is characterized in that the steel cylinder (9) is composed of a plurality of small steel cylinders connected together, and the two ends of the steel cylinder are respectively located at the inner end of the titanium sleeve (5) at one end; and there is a "V"-shaped groove on the outer circumferential surface of the copper cylinder.
The cathode roller for producing electrolytic copper foil as described in claim 1 is characterized in that the outer circumferential surface of each group of support rings is fixed to the inner surface of the steel cylinder, so that the inner circumferential surface of each group of support rings is fixed to the outer inner surface of the flow equalizing cylinder.
The cathode roller for producing electrolytic copper foil as described in claim 1 is characterized in that there is a reinforcement ring (23) between each of the current collecting copper plates (24), and the outer circumferential surface of the reinforcement ring is fixedly connected to the inner circumferential surface of the current equalizing cylinder (25), and the inner circumferential surface of the reinforcement ring is fixedly connected to the circumferential surface of the steel shaft (1) or the outer circumferential surface of the copper sleeve (2) according to its position.
The cathode roller for producing electrolytic copper foil as described in claim 1 is characterized in that the diameter of the cathode roller is 3000 mm and the length is 2000 mm; in order to ensure the uniformity of the roller surface current, the cathode roller is divided into 5 equal sections along the axial direction through 4 groups of conductive copper plates (13) located inside the cathode roller.
A method for manufacturing a cathode roller for producing electrolytic copper foil according to claim 1, characterized in that the specific process is:

Step 1, titanium cylinder preparation: cold spinning process is adopted to spin-form a seamless titanium cylinder; the titanium cylinder composition satisfies that the H content is ≤0.01%; the structure is equiaxed α structure, the grain size grade is 11-12, and the twin content is less than 10%;

Step 2, heat-fitting the copper sleeves at both ends of the steel shaft: heat-fitting the copper sleeves at both ends of the steel shaft; the interference fit between the copper sleeves (2) at both ends and the steel shaft must meet 0.2mm;

Step 3, welding the center steel plate: assemble the center steel plate (10) at the center position inside the width of the cathode roller;

Step 4, welding the current equalizing tube: welding the corresponding reinforcing ring (23) inside the conductive copper plate (13) on the outside of the current equalizing tube (25); welding the inner circle of the current equalizing tube at both ends to the boss of the central steel plate (10);

Step 5, welding the current collecting copper plate: welding the current collecting copper plate (24) at the axial center position of the current equalizing tube (25) at both ends, and welding the current collecting copper plate to the copper sleeve (2);

Step 6, welding each steel cylinder, conductive copper plate, and support ring: sequentially welding the steel cylinder (9) from the center to both ends, and welding the support ring (12) and the conductive copper plate (13), welding the reinforcing ribs between the support ring and the steel cylinder, and connecting and fixing the two support rings (12) and one conductive copper plate (13); wherein copper-copper and copper-steel welding adopts MIG welding, and steel welding adopts CO2 gas shielded welding;

Step 7, welding the end plates at both ends: weld the outer circle of the end plate (14) to the stopper of the steel cylinder end of the steel cylinder (9), weld the inner circle to the copper sleeve (2), weld the outer circle of the current equalizing cylinder (25) to the end plate, respectively weld the end plate to the current equalizing cylinder (29) and the steel cylinder (9) through the triangular reinforcing ribs 11, and weld the end plate to the copper sleeve (2) through the large triangular reinforcing ribs; wherein copper-copper and copper-steel welding adopts MIG welding;

Step 8, welding the axial horizontal ribs inside the steel cylinder: divide the circumference of the steel cylinder into four parts, and use CO2 gas shielded welding to respectively connect the four horizontal ribs (21) evenly distributed in the circumferential direction inside the steel cylinder with the support ring (12), the center steel plate (10), and the end plate (14);

Step 9, heat treatment of the steel cylinder: The steel cylinder (9) has multiple welds. In order to reduce the negative pressure caused by welding stress, The pole roller is deformed in the later stage, and the heat treatment heating crawler is used to cover the outer circle of the steel cylinder, and the stress relief annealing treatment is carried out at 620±10℃ for 1.5h;

Step 10, machining the outer surface of the steel cylinder: In order to ensure the uniformity of the thickness of the additional copper cylinder, the outer surface of the steel cylinder (9) is machined by CNC machining to a roughness Ra ≤ 1.6 μm, a circular runout and a straightness ≤ 0.05 mm, and the conductive copper plate (13) is ensured to be 10 mm higher than the steel cylinder;

Step 11, preparing a copper cylinder (8): wrapping a layer of copper tape on the surface of the machined steel cylinder (9); the copper tape has a thickness of 10 mm and a width of 16 mm, welding the two ends of the copper tape to the two ends of the steel cylinder, and welding the copper tape to the conductive copper plate (13);

Step 12, machining the outer surface of the copper tube: using CNC machine to machine the surface of the copper tube (8) to achieve a surface roughness Ra ≤ 1.6 μm, a circular runout and a straightness ≤ 0.05 mm, and to ensure that the thickness of the copper tube is 8 mm and the thickness deviation is ≤ 0.15 mm; and using a machine forming tool to machine a "V"-shaped groove on the outer surface of the copper sleeve, ensuring that the "V"-shaped groove angle α is 35 to 45°, the depth is 2 to 2.5 mm, the distance between the two grooves is 4 to 5 mm, and the "V"-shaped grooves are spirally distributed on the copper tube;

Step 13, initial static balance test: In order to ensure that the cathode roller rotates stably and evenly, the rolling static balance test method is used to perform the initial static balance test, and the static balance torque is ensured to be ≤3Nm by welding a counterweight block on the internal end plate;

Step 14, machining the inner surface of the titanium cylinder: using numerical control to sequentially machine the outer surface of the copper cylinder (8) and the inner surface of the titanium cylinder (7), so that the inner diameter of the titanium cylinder is 3.5 mm smaller than the outer diameter of the copper cylinder, and the inner surface roughness Ra is ≤ 1.6 μm, and the circular runout and straightness are ≤ 0.05 mm;

Step 15, silver plating: in order to increase conductivity, reduce contact resistance and reduce energy consumption, the outer circumferential surface of the machined copper cylinder (8) and the inner circumferential surface of the titanium cylinder (9) are silver plated by brush plating; the plating thickness is 5 to 8 μm and the thickness is uniform and firmly attached;

Step 16, hot assembly: heat the inner circle of the silver-plated titanium cylinder at 450° C. for 1.5 hours, and use argon gas for protection during the heating process; after the heat insulation is completed, insert the outer circle of the silver-plated copper cylinder (8) into the titanium cylinder (7), and assemble it by using the principle of thermal expansion and contraction;

Step 17, titanium welding: sequentially assemble the titanium plate (15) and the titanium sleeve (5) at one end, and use TIG welding to complete the welding of the titanium plate and the inner wall of the titanium tube (7) and the titanium plate and the titanium sleeve (5); assemble the titanium ring (18) and the titanium sleeve (6), ensure that the outer end face of the titanium ring is 5 mm lower than the end face of the titanium tube (7), and use TIG welding to complete the welding of the titanium ring (18) and the inner wall of the titanium tube (7), and the titanium sleeve (6) and the titanium plate (15); then assemble and weld the titanium plate, titanium sleeve, titanium tube, titanium ring and other titanium welding at the other end, and after the titanium welding is completed, all titanium welds are subjected to surface coloring flaw detection;

Step 18, heat treatment of the titanium cylinder: stress relief heat treatment of the titanium cylinder, using a heat treatment heating track to cover the outer circle of the titanium cylinder, and heat preservation at 520±10℃ for 1.5 hours to perform stress relief annealing treatment to eliminate the residual stress on the surface of the cathode roller titanium cylinder, and overcome the collapse, stress corrosion, and easy oxidation problems of the roller surface during the use of the cathode roller;

Step 19, machining the outer circle of the titanium cylinder and the outer circle of the copper sleeve: CNC machining is used to complete the machining of the outer circle of the cathode roller titanium cylinder (7) and the outer circle of the copper sleeve (2), ensuring that the outer circle diameter of the cathode roller is Φ3000mm and the width is 2000mm, the wall thickness of the titanium cylinder is 10mm-10.5mm, the end of the titanium cylinder is right-angled, the end of the titanium cylinder is 5mm higher than the outer end of the titanium ring, the roller surface roughness is Ra1.6, and the straightness and circular runout are ≤0.05mm;

Step 20, static balance test: To ensure that the final static balance moment of the cathode roller is ≤3Nm, static balance weights are applied to the weight holes of the titanium plates at both ends of the cathode roller, and the length of the weight rod 920 is adjusted according to the weight of the weight, so that the final static balance moment of the cathode roller is ≤3Nm. After the weight is balanced, the weight hole is blocked with a titanium cover (19), and the titanium cover is welded to the titanium plate (15), and the weld is subjected to surface color flaw detection;

Step 21, airtight test: install a pressure gauge at one end of the airtight hole of the cathode roller steel shaft, pass compressed nitrogen at one end, maintain the pressure at 0.04 MPa for 2 hours, and check the overall sealing performance of the cathode roller;

Step 22, polishing the outer circumferential surface of the titanium cylinder: on a cathode roller polishing grinder, use 40#, 80#, 120#, 220#, 320#, and 600# PVA grinding wheels to polish the roller surface in sequence, so that the roller surface roughness Ra ≤ 0.2μm, the circular runout and straightness ≤ 0.05mm, and the surface has no color difference, spots, or pinhole defects;

Step 23, accessories installation: sequentially install the insulating rings (16), titanium screws (17), bearings (4) and conductive rings (3) at both ends of the cathode roller;

At this point, the cathode roller is manufactured.
The method for manufacturing the cathode roller for producing electrolytic copper foil as claimed in claim 6, characterized in that:

When polishing the outer circumference of the titanium cylinder:

When using 40# PVA grinding wheel, the grinding wheel speed is 400-450r/min, the grinding wheel longitudinal feed is 30-40mm/min, the pressure is 0.25-0.3MPa, the cathode roller speed is 4.0-4.5r/min, and the grinding wheel consumption is 2;

When using 80# PVA grinding wheel, the grinding wheel speed is 450-500r/min, the grinding wheel longitudinal feed is 25-30mm/min, the pressure is 0.2-0.25MPa, the cathode roller speed is 4.5-5r/min, and the grinding wheel consumption is 1.5;

When using 120# PVA grinding wheel, the grinding wheel speed is 450-500r/min, the grinding wheel longitudinal feed is 25-30mm/min, the pressure is 0.2-0.25MPa, the cathode roller speed is 4.5-5r/min, and the grinding wheel consumption is 1.5;

When using 220# PVA grinding wheel, the grinding wheel speed is 500-550r/min, the grinding wheel longitudinal feed is 20-25mm/min, the pressure is 0.15-0.2MPa, the cathode roller speed is 5.5-6r/min, and the grinding wheel consumption is 1;

When using 320# PVA grinding wheel, the grinding wheel speed is 500-550r/min, the grinding wheel longitudinal feed is 20-25mm/min, the pressure is 0.15-0.2MPa, the cathode roller speed is 5.5-6r/min, and the grinding wheel consumption is 0.5;

When using 600# PVA grinding wheel, the grinding wheel speed is 550-600r/min, the grinding wheel longitudinal feed is 15-20mm/min, the pressure is 0.1-0.15MPa, the cathode roller speed is 6-6.5r/min, and the grinding wheel consumption is 0.5.