A tab tension adjusting swing roller for a lithium battery roller press

Abstract

The utility model provides a kind of tab tension adjusting swing roller for lithium battery roller press, including swing roller body and adjusting assembly, the swing roller body is equipped with multiple notches along the axial direction, the adjusting assembly includes rubber ring unit and response component, the rubber ring unit is arranged in notch, and rubber ring unit includes hydraulic cylinder, rubber ring base and elastic rubber ring, the piston rod of hydraulic cylinder is connected with rubber ring base, and elastic rubber ring is sleeved on rubber ring base, swing roller body is worn with infusion pipeline, and infusion pipeline is communicated with hydraulic cylinder. The swing roller can adjust the protruding outer diameter of elastic rubber ring in real time according to the thickness difference of pole piece coating area and tab area during rolling process, so as to effectively control the elongation of tab, reduce tab wrinkle and improve production efficiency.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery production technology, and in particular to a tension regulating swing roller for a lithium battery rolling mill. Background Technology

[0002] Lithium-ion batteries require a rolling process during production to compact and control the thickness of the electrodes, thereby optimizing electrode porosity and improving ion / electron conductivity. Electrodes typically consist of a coated area containing active material and an uncoated tab area (also called an empty foil area). Due to the significant thickness difference between the coated area (typically 100–300 μm thick) and the tab area (only 6–15 μm thick), the uneven stretching and deformation during rolling can easily lead to stress concentration at the interface, causing wrinkles in the tab area. Wrinkled tabs are prone to folding or damage during subsequent slicing, winding, and welding processes, resulting in defective products and scrap. Furthermore, wrinkled tabs increase the proportion of incomplete welds during ultrasonic welding, leading to poor welding, increased internal resistance, severe battery overheating, and shortened cycle life.

[0003] Existing solutions mostly rely on manually attaching gaskets or Teflon tape to the tab area to create a local height difference, allowing the tab area to stretch during rolling. While this method can improve the flatness of the tab to some extent, it has significant limitations: Firstly, the manual attachment process is complex, relying on the operator's visual positioning, which has low accuracy and is prone to misalignment of the upper and lower layers of tape, resulting in large positioning deviations; secondly, Teflon tape is prone to wear during production or needs to be replaced due to model changes, requiring machine downtime for each adjustment, typically taking about 40 minutes and resulting in a large number of scrapped electrode sheets, significantly impacting production efficiency. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a tension adjusting swing roller for electrode tabs in a lithium battery rolling mill, which reduces electrode tab wrinkles and improves the accuracy and efficiency of adjustment.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a swing roller for adjusting the tab tension of a lithium battery roller press, including a swing roller body and an adjusting component. The swing roller body has multiple notches along the axial direction. The adjusting component includes a rubber ring unit and a sensing component. The rubber ring unit is disposed in the notch. The rubber ring unit includes a hydraulic cylinder, a rubber ring base and an elastic rubber ring. The piston rod of the hydraulic cylinder is connected to the rubber ring base, and the elastic rubber ring is sleeved on the rubber ring base. A liquid delivery pipe is inserted through the swing roller body and is connected to the hydraulic cylinder.

[0006] Furthermore, the sensing component includes a displacement sensor and a proportional servo valve. The displacement sensor is fixed to the outside of the cylinder body of the hydraulic cylinder, and the axis of the displacement sensor body is arranged parallel to the axis of the piston rod. The proportional servo valve is arranged on the liquid delivery pipe outside the swing roller body.

[0007] Furthermore, multiple rubber ring bases are provided within the notch, and these multiple rubber ring bases are arranged at intervals along the circumferential direction. Multiple hydraulic cylinders are provided, and these multiple hydraulic cylinders are arranged at intervals along the circumferential direction corresponding to the rubber ring bases.

[0008] Furthermore, the two ends of the swing roller body are provided with rotary joints, which are located on the infusion pipes outside the swing roller body.

[0009] Furthermore, the piston rod includes an extension section and a pushing section. The extension section is connected to the output end of the hydraulic cylinder, and the pushing section abuts against the inner wall of the rubber ring base.

[0010] Furthermore, the rubber ring base is fixed to the pushing section.

[0011] Furthermore, the swing roller also includes a controller.

[0012] The beneficial effects of this utility model are:

[0013] (1) This utility model sets up an infusion pipe in the body of the swing roller and connects it with multiple hydraulic cylinders, so that the rubber ring unit can be automatically adjusted during the rolling process, thereby avoiding manual pasting of gaskets or tapes, and realizing that the tab area remains flat during the rolling process, thus improving production efficiency.

[0014] (2) The present invention provides a rubber ring base and an elastic rubber ring sleeved on the outside of the notch of the swing roller body. The piston rod of the hydraulic cylinder is connected to the rubber ring base, so that the adjustment process is completed with the swing roller. The operation is simple and only requires rolling to achieve the adaptation of the tab area.

[0015] (3) By setting multiple notches in the axial position of the swing roller body and installing corresponding rubber ring units in the notches, the swing roller can be adjusted according to the position of the tab area of ​​different electrodes, making the positioning more accurate and the application range wider. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the operation of the swing roller of this utility model;

[0017] Figure 2 This is a cross-sectional view of the elastic rubber ring unit of this utility model;

[0018] In the figure, 1-swing roller body; 2-rubber ring unit; 21-hydraulic cylinder; 211-extension section; 212-pushing section; 22-rubber ring base; 23-elastic rubber ring; 3-displacement sensor; 4-proportional servo valve; 5-infusion pipeline; 6-rotary joint; 7-coating area; 8-tab area. Detailed Implementation

[0019] The present invention will now be further described with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0020] like Figure 1 The diagram shows the working principle of the swing roller of this utility model. When the electrode passes along the surface of the swing roller, the area coated with active material is the coating area 7, and the uncoated area used to form the tab is the tab area 8.

[0021] like Figure 1 and Figure 2 As shown, a tension adjustment swing roller for a lithium battery rolling mill includes a swing roller body 1 and an adjustment assembly. The outer circular surface of the swing roller body 1 has multiple notches along the axial direction; in the accompanying drawings of this embodiment, there are three notches, each arranged sequentially along the axial direction of the swing roller and corresponding to the tab region 8 on the electrode sheet on the swing roller surface, so as to adjust and adapt the corresponding position of the tab region 8.

[0022] The adjustment assembly includes a rubber ring unit 2 and a sensing assembly. The rubber ring unit 2 is disposed within the aforementioned notch and includes a hydraulic cylinder 21, a rubber ring base 22, and an elastic rubber ring 23. The piston rod of the hydraulic cylinder 21 is connected to the rubber ring base 22, and the elastic rubber ring 23 is fitted around the outer periphery of the rubber ring base 22. Specifically, the piston rod of the hydraulic cylinder 21 consists of an extension section 211 and a pushing section 212. The extension section 211 is connected to the output end of the hydraulic cylinder 21, and the pushing section 212 is fixed to the rubber ring base 22. Specifically, the inner end of the extension section 211 passes through the end cap of the hydraulic cylinder 21 and is fixed to the piston inside the hydraulic cylinder. Furthermore, the end of the extension section 211 can be fixedly connected to the piston center hole by means of threads, pins, or interference fits, so that the reciprocating motion of the piston under hydraulic pressure can directly drive the extension section 211 to move synchronously, realizing the extension and retraction of the piston rod. The outer end of the extension section 211 is integrally or fixedly connected to the pushing section 212, thereby driving the rubber ring base 22 to achieve radial movement. Moreover, the hydraulic cylinder 21 is a miniature hydraulic cylinder, with a piston inside the cylinder body. The piston is separated by a seal to form a working chamber. When hydraulic oil supplied through the fluid delivery pipe 5 enters the corresponding working chamber, it drives the piston to move axially, thereby causing the extension section 211 of the piston rod to extend and retract relative to the cylinder body.

[0023] Furthermore, in this embodiment, three rubber ring bases 22 are provided in each notch of the swing roller body 1. The three rubber ring bases 22 are arranged at intervals along the circumference of the swing roller body 1, with gaps between adjacent rubber ring bases 22 to ensure that the piston rod can push the rubber ring base 22 radially outward from the circumference of the swing roller, thereby causing a change in the outer diameter of the elastic rubber ring 23. If the rubber ring base 22 is a continuous integral annular structure, it will restrict the radial extension and retraction of the piston rod, making it difficult to achieve independent pushing and adjustment of the elastic rubber ring 23. Corresponding to the three rubber ring bases 22, three hydraulic cylinders 21 are also provided, each connected to a corresponding rubber ring base 22. The three hydraulic cylinders 21 are arranged at intervals along the circumference with the center of the swing roller body 1 as the center, so that the piston rod pushing section 212 of each hydraulic cylinder 21 can act on the corresponding rubber ring base 22 respectively. The infusion pipeline 5 is introduced from the outside of the swing roller through the rotary joint 6, passes through and extends along the center of the swing roller body 1, and is connected to the oil inlet branch of each hydraulic cylinder 21 at the center, thereby ensuring that hydraulic oil can be delivered to the three hydraulic cylinders 21 at the same time.

[0024] It should be noted that in this embodiment, the swing roller body 1 is an integral structure, with a through-flow fluid delivery pipe 5 channel arranged along the axial direction inside for the introduction and distribution of hydraulic oil. A receiving cavity is formed at the notch on the outer circumference of the swing roller body 1. This receiving cavity is used to install the rubber ring unit 2, including a hydraulic cylinder 21, a rubber ring base 22, and an elastic rubber ring 23. The receiving cavity is formed as a partially opened cavity structure, ensuring that the hydraulic cylinder 21, the rubber ring base 22, and the elastic rubber ring 23 can be placed and moved within it. Furthermore, within the receiving cavity, to ensure the normal extension and retraction of the piston rod driven by the hydraulic cylinder 21, the path from the hydraulic cylinder 21 to the piston rod pushing section 212 is designed as a cavity; to ensure that the rubber ring base 22 and the elastic rubber ring 23 can protrude radially outward, the areas corresponding to the rubber ring base 22 and the elastic rubber ring 23 are also opened cavities; a channel for the fluid delivery pipe 5 is provided at the center position between multiple hydraulic cylinders 21 for delivering hydraulic oil to each hydraulic cylinder 21. Apart from the aforementioned receiving cavity and channel area, the rest of the swing roller body 1 is a solid structure to maintain the overall strength and integrity of the swing roller. Thus, although the outer surface of the swing roller has three notches, the swing roller body 1 is a single-piece molded structure, rather than being divided into multiple independent segments.

[0025] The fluid delivery pipe 5 is introduced from the hydraulic lines outside the swing roller, enters the swing roller body 1 through the rotary joint 6, extends axially, and connects to the oil inlet of each hydraulic cylinder 21 through branches. The rotary joint 6 is used to achieve sealed transmission of hydraulic oil between the stationary oil pipe and the rotating swing roller body 1. In this embodiment, the rotary joint 6 is specifically set at the position where the fluid delivery pipe 5 enters the swing roller body 1, that is, the connection end of the fluid delivery pipe 5 that turns from the horizontal direction into the rotating part, thus becoming vertical, ensuring that the swing roller body 1 can rotate continuously during the rolling process without causing the oil pipe to become entangled.

[0026] The sensing components include a proportional servo valve 4 and a displacement sensor 3. The proportional servo valve 4 is mounted on the fluid delivery pipe 5 outside the swing roller body 1, and is used to regulate the input state of the hydraulic oil in the fluid delivery pipe 5 to achieve precise control of the hydraulic oil supply to the hydraulic cylinder 21. The displacement sensor 3 is fixed to the outside of the cylinder body of the hydraulic cylinder 21. The axis of the displacement sensor 3 is parallel to the axis of the piston rod, and the sensing end of the displacement sensor 3 faces the end of the piston rod. When the piston rod extends or retracts axially under hydraulic pressure, the relative distance between its surface and the sensing end of the displacement sensor 3 changes. The displacement sensor 3 can convert this displacement into a displacement signal to reflect the change in the piston rod's stroke. The displacement sensor 3 can adopt a laser or ultrasonic structure to achieve non-contact detection of the piston rod displacement.

[0027] In a further embodiment, the swing roller also includes a controller. The controller may be a programmable logic controller (PLC) for electrical connection with the proportional servo valve 4 and the displacement sensor 3. Through this connection, the controller can uniformly manage and coordinate the opening degree of the proportional servo valve 4 and the detection signal of the displacement sensor 3 to achieve overall control of the extension and retraction adjustment process of the hydraulic cylinder 21.

[0028] Workflow:

[0029] When the swing roller starts working, the target height H0 is first set in the controller. The target height H0 is set based on the following: the electrode elongation is ε, the roller diameter is r, the coating area thickness is h, and the angular velocity of the swing roller is ω. After being stretched by the swing roller, the elongation of the foil area is required to be consistent with the overall elongation of the electrode, that is, the linear velocity enhancement coefficient must meet the following requirements:

[0030] From this we can obtain Solving

[0031] During operation, the displacement sensor 3, mounted on the hydraulic cylinder 21, continuously monitors the relative displacement of the piston rod. Specifically, the displacement sensor 3 is fixed to the outside of the hydraulic cylinder 21, with its sensing end positioned opposite to the end of the piston rod. When the piston rod moves axially under hydraulic pressure, the outer surface of the piston rod displaces relative to the sensing end of the displacement sensor 3. The sensor 3 converts this displacement into a signal representing the actual height H1 and feeds it back to the controller. The controller compares H0 with H1 to obtain the deviation value ΔH = H0 - H1.

[0032] When ΔH > 0 (actual height is lower than target height): the controller issues a command to increase the oil supply of the proportional servo valve 4, and the hydraulic oil enters the working chamber of the hydraulic cylinder 21 through the fluid supply pipe 5, pushing the piston outward. As the piston moves, the piston rod gradually extends, driving the push section 212 to push the rubber ring base 22 outward, so that the outer diameter of the elastic rubber ring 23 sleeved on its outer periphery protrudes further.

[0033] Since the circumferential linear velocity of the oscillating roller is proportional to its radius (v = ω·r, where ω is the angular velocity and r is the radius), when the outer diameter of the elastic rubber ring 23 increases, the local circumferential linear velocity at the location of the tab region 8 also increases. Thus, the tab region 8 experiences additional elongation relative to the coating area 7 as it passes through the oscillating roller, resulting in a greater stretch ratio. This compensatory stretching allows the originally thin and wrinkle-prone tab region to remain taut during the rolling process, preventing wrinkles caused by uneven elongation.

[0034] When ΔH < 0 (actual height is higher than target height): The controller issues a command to adjust the proportional servo valve 4 to the return oil state. Part of the hydraulic oil in the hydraulic cylinder 21 is discharged through the return oil port, the pressure in the working chamber decreases, and the piston moves back under the action of the internal and external pressure difference, and the piston rod gradually retracts. The pushing section 212 then drives the rubber ring base 22 to retract, and the outer diameter protrusion of the elastic rubber ring 23 decreases.

[0035] Since the circumferential linear velocity v = ω·r, a decrease in radius leads to a decrease in local linear velocity, and consequently, a decrease in the tensile strength of the tab region 8. Under certain conditions (e.g., when the electrode material is brittle, the thickness difference between the coating area and the tab region is small, or production requires reducing local tension to avoid breakage), appropriately reducing the tensile strength of the tab region can prevent the tab from being overstretched, ensuring the overall strength of the electrode and the stability of subsequent processing.

[0036] Through the aforementioned real-time detection, calculation, and adjustment cycle, the controller can quickly adjust the opening of the proportional servo valve 4, driving the extension and retraction of the hydraulic cylinder 21, so that the outer diameter of the elastic rubber ring 23 is maintained near the set height H0. This allows for precise control of the linear velocity of the tab region 8 during the rolling process, thereby effectively controlling the tab's elongation rate.

[0037] Example

[0038] like Figure 1 and Figure 2As shown, a tension-adjusting swing roller for lithium battery rolling mill includes a swing roller body 1, a rubber ring unit 2, and a sensing component. It is suitable for the rolling process of 314Ah energy storage cells. The positive electrode coating area of ​​the 314Ah energy storage cell has a thickness of 191μm and a width of 373mm; the coating area thickness is 191μm, the edge tab width is 31mm, and the middle tab width is 62mm. The speed of the tension-adjusting swing roller for this lithium battery rolling mill is 80m / min, the roller surface width is 1.2m, the roller diameter is 60mm, and the elastic rubber ring 23 is made of polyurethane (PU85A). The measured elongation of the electrode sheet is 1.2%, and the elongation of the foil area after stretching by the swing roller also needs to reach 1.2%, that is, the linear velocity increases by 1.2% after stretching.

[0039] And V = wR, then but Where r is the roller diameter of 60mm, h is the coating thickness of 191μm, and ω is the angular velocity of the oscillating roller, the final calculated value is H0 = 0.72mm. When the oscillating roller starts working, the target height H0 is first set to 0.72mm in the controller, and it can rise to the set height within 3 seconds. The height fluctuation during operation is <0.003mm. The produced electrode tabs have a smooth surface without wrinkles, no scrap occurred during the debugging process, and the equipment maintained continuous operation.

[0040] Comparative Example

[0041] The tab stretching ratio was adjusted manually by applying Teflon tape. Five layers of 150μm thick Teflon tape were applied to the tab area, with a target height of 0.75mm and an actual measured height of 1.14mm, resulting in a height error of 0.39mm. This process, due to the time-consuming application and alignment, resulted in a 48-minute downtime and approximately 41.7kg of scrapped positive electrode sheets. The produced tabs exhibited obvious stretching lines and had poor surface smoothness.

[0042] The results of the comparative examples and comparative embodiments show that the present invention is significantly superior to the traditional method in terms of thickness control accuracy, production efficiency, and tab appearance quality. The traditional tape method has a thickness control accuracy of approximately 0.1mm, and the thickness specification of Teflon tape is 0.1mm. The overall thickness is controlled by the number of iron layers when applying Teflon tape. In contrast, the present invention achieves a thickness control accuracy of 0.001mm through hydraulic drive and closed-loop control. The thickness adjustment time is reduced from 40 minutes in the traditional method to within 3 seconds. The production process avoids tape breakage and scrap caused by manual tape application, ensuring a smooth and wrinkle-free tab area and significantly improving production line efficiency.

[0043] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it. They should not be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the protection scope of this utility model.

Claims

1. A tension-adjusting swing roller for a lithium battery roller press, comprising a swing roller body (1) and an adjustment assembly, characterized in that: The swing roller body (1) has multiple notches along the axial direction. The adjustment component includes a rubber ring unit (2) and a sensing component. The rubber ring unit (2) is set in the notch. The rubber ring unit (2) includes a hydraulic cylinder (21), a rubber ring base (22) and an elastic rubber ring (23). The piston rod of the hydraulic cylinder (21) is connected to the rubber ring base (22). The elastic rubber ring (23) is sleeved on the rubber ring base (22). An infusion pipe (5) is provided inside the swing roller body (1). The infusion pipe (5) is connected to the hydraulic cylinder (21).

2. The electrode tension adjusting swing roller for a lithium battery roller press according to claim 1, characterized in that: The sensing component includes a displacement sensor (3) and a proportional servo valve (4). The displacement sensor (3) is fixed to the outside of the cylinder body of the hydraulic cylinder (21). The axis of the displacement sensor (3) is parallel to the axis of the piston rod. The proportional servo valve (4) is installed on the liquid delivery pipe (5) outside the swing roller body (1).

3. The electrode tension adjusting swing roller for a lithium battery roller press according to claim 1, characterized in that: Multiple rubber ring bases (22) are provided within the notch, and the multiple rubber ring bases (22) are arranged at intervals along the circumferential direction. Multiple hydraulic cylinders (21) are provided, and the multiple hydraulic cylinders (21) are arranged at intervals along the circumferential direction corresponding to the rubber ring bases (22).

4. The electrode tension adjusting swing roller for a lithium battery roller press according to claim 1, characterized in that: The two ends of the swing roller body (1) are provided with rotary joints (6), which are located on the infusion pipe (5) outside the swing roller body (1).

5. The electrode tension adjusting swing roller for a lithium battery roller press according to claim 1, characterized in that: The piston rod includes an extension section (211) and a pushing section (212). The extension section (211) is connected to the output end of the hydraulic cylinder (21), and the pushing section (212) abuts against the inner wall of the rubber ring base (22).

6. The electrode tension adjusting swing roller for a lithium battery roller press according to claim 5, characterized in that: The rubber ring base (22) is fixed to the pushing section (212).

7. The electrode tension adjusting swing roller for any one of the lithium battery roller presses according to claims 1 to 5, characterized in that: The swing roller also includes a controller.

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