Pre-welding pressing structure and square battery cover welding device

Abstract

According to the pre-welding pressing structure and the square battery cover welding device, on one hand, the connecting rod and the pressing block are connected in a detachable mode, after the connecting block or the pressing block is damaged, the damaged part is detached, and the production cost can be saved; on the other hand, the middle of the end, away from the connecting rod, of the pressing block is hollowed out, the situation of the weld joint can be accurately detected, visual misjudgment is reduced, the welding track can be avoided, and the pressing block cannot be damaged when the track deviates.

Description

Technical Field

[0001] The utility model relates to the field of square shell battery core packaging of energy storage batteries, in particular to a pre-welding pressing structure and a square battery cover welding device. Background Art

[0002] With the proposal of the goals of carbon peak and carbon neutrality, the strategic position of renewable energy represented by photovoltaic and wind power has become prominent, and energy storage, as a key technology to support the development of renewable energy, is also developing rapidly.

[0003] At present, when packaging the square shell battery core of energy storage batteries, in order to ensure the packaging effect, pre-spot welding (top welding method) is carried out after the top cover and the aluminum shell are press-fitted. For butt welding, it is necessary to ensure that the gap between the top cover and the aluminum shell is less than 10% of the wall thickness of the aluminum shell, which is beneficial to the welding effect and can also effectively prevent laser leakage during welding from damaging the battery core. Therefore, it is necessary to ensure the gap at the welding point before pre-spot welding. However, the current pre-welding pressing structure is not very good at grasping the distance reserved for the weld seam, and when over-pressing the aluminum shell, indentations will be generated on the surface of the aluminum shell, affecting the product performance; in addition, generally, the connecting rod and the pressing block on the market are an integral structure of the same material, and the material is either polyether ether ketone or stainless steel; however, for the integral structure of polyether ether ketone, although it causes less damage to the aluminum shell and its superior hardness can ensure the pressing gap and the indentation is acceptable, during use, because it is necessary to ensure pressing, the distance between the pressing block and the welding point is very close. If light reflection occurs, it is easy to damage the peek and contaminate the battery core, and the laser trajectory debugging requirements are high, the error tolerance rate is low and the maintenance cost is increased. For the integral structure of stainless steel, using stainless steel metal material can ensure a better pressing gap, but the pressing block needs to be buffered by a spring. The contact area between the pressing block and the aluminum shell is small. Without buffering, serious point pressing damage will occur to the aluminum shell, and when the spring fails, the pressing force will also be insufficient and the gap will exceed the standard, which increases the risk points. Moreover, in the case of one component of the integral structure being damaged, the other component also has to be discarded, increasing the production cost.

[0004] Therefore, it is urgent to invent a pre-welding pressing structure for the square battery top cover to effectively solve at least one of the above technical problems. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a pre-welding pressing structure and a square battery cover welding device to effectively solve at least one of the technical problems of ensuring the gap at the welding point before pre-spot welding, saving costs, and generating indentations on the surface of the aluminum shell when over-pressing the aluminum shell during the packaging of the square shell battery core of the energy storage battery.

[0006] To achieve the above object, the present utility model provides a pre-welding pressing structure, including: a connecting rod and a pressing block. One end of the connecting rod is used to connect with a cylinder, and the other end is detachably connected to the pressing block; the middle of the end of the pressing block away from the connecting rod is hollowed out.

[0007] Further, the material of the connecting rod is stainless steel.

[0008] Further, the material of the pressing block is polyetheretherketone.

[0009] Further, the material of the pressing block can also be copper.

[0010] Further, the connecting rod and the pressing block are connected by threads.

[0011] Further, the connecting rod and the pressing block can also be connected by structural adhesive.

[0012] Further, the length range of the connecting rod is 80 mm to 90 mm.

[0013] Further, the pressing block is a cylinder with upper and lower hollows, and the outer diameter range of the cylinder is 8 mm to 12 mm.

[0014] Further, the inner diameter range of the cylinder is 5 mm to 7 mm.

[0015] Further, the end of the pressing block away from the connecting rod is a rounded corner.

[0016] The present utility model also proposes a square battery top cover welding device, including the pre-welding pressing structure described above, and the cylinder, and one end of the connecting rod is connected to the cylinder.

[0017] Compared with the prior art, the beneficial effects of the present utility model are mainly reflected in: in the provided pre-welding pressing structure and the square battery cover welding device, on the one hand, the connecting rod and the pressing block are connected in a detachable manner. After the connecting block or the pressing block is damaged, the damaged part can be removed, which can save production costs; on the other hand, the middle of the end of the pressing block away from the connecting rod is hollowed out, which can not only accurately detect the situation at the weld, reduce visual misjudgment, but also avoid the welding trajectory, and will not damage the pressing block when the trajectory deviates.

[0018] In addition, the end of the pressing block away from the connecting rod (the end in contact with the aluminum shell) is set as a rounded corner, which can reduce the indentation on the surface of the aluminum shell during the process of pressing the aluminum shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the pre-welding pressing structure in an embodiment of the present utility model;

[0020] Figure 2Explosion diagram of the pre-welding pressing structure according to an embodiment of the present utility model;

[0021] Figure 3 Schematic working diagram when the pressing block contacts the aluminum shell according to an embodiment of the present utility model.

[0022] In the figure, 1 is a connecting rod; 101 is a connecting hole; 2 is a pressing block; 201 is a pressing block connecting hole; 3 is the weld position; 4 is the aluminum shell and the top cover. Detailed implementation manners

[0023] The following will describe in more detail a pre-welding pressing structure and a square battery cover welding device of the present utility model with reference to the accompanying drawings, in which the preferred embodiments of the present utility model are shown. It should be understood that those skilled in the art can modify the present utility model described herein while still achieving the advantageous effects of the present utility model. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation to the present utility model.

[0024] In the following paragraphs, the present utility model will be described more specifically by way of example with reference to the accompanying drawings. According to the following description, the advantages and features of the present utility model will be clearer. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise scales, only for the purpose of conveniently and clearly assisting in explaining the purpose of the embodiments of the present utility model.

[0025] Embodiment 1

[0026] As Figure 1 and Figure 2 shown, this embodiment proposes a pre-welding pressing structure, including: a connecting rod 1 and a pressing block 2. One end of the connecting rod 1 is used to connect with a cylinder (not shown), and the other end is detachably connected to the pressing block 2; the middle of the end of the pressing block 2 away from the connecting rod 1 is hollowed out.

[0027] In this embodiment, the material of the connecting rod 1 is stainless steel.

[0028] In this example, the material of the pressing block 2 is polyetheretherketone.

[0029] Furthermore, the material of the pressing block 2 can also be copper.

[0030] The connecting rod 1 and the pressing block 2 are independently provided and are made of two materials respectively. On the one hand, it can solve the problem of surface pressing damage of the aluminum shell caused by overpressure of the integral stainless steel material. On the other hand, it can also solve the problem of light reflection during the welding process of the integral polyetheretherketone material, which damages the pre-welding pressing structure and pollutes the battery core, improving the error tolerance and reducing the maintenance cost.

[0031] In a specific example, the connecting rod 1 and the pressing block 2 are connected by threads: internal threads are provided on the inner sides of the connecting parts of the connecting rod 1 and the pressing block 2 (not shown in the figure), and a screw is screwed from the pressing block connection hole 201 into the connection hole 101.

[0032] Furthermore, the connecting rod 1 and the pressing block 2 can also be connected by structural adhesive: the structural adhesive is evenly applied to the connection surface of the connecting rod 1 and the pressing block 2 to ensure that the two are firmly adhered together.

[0033] Specifically, the length range of the connecting rod 1 is 80 mm to 90 mm, and the preferred length is 81.4 mm. The surface of the connecting rod 1 in contact with the pressing block 2 is a hollow structure, and the diameter of the hollow part is preferably 5 mm.

[0034] In this example, the pressing block 2 is a cylinder with upper and lower hollows, and the outer diameter range of the cylinder is 8 mm to 12 mm, and the preferred diameter is 10 mm.

[0035] Furthermore, the diameter range of the inner circle of the cylinder (i.e., the connection hole 101) is 5.5 mm to 7 mm. Preferably, the diameter of the inner circle is 6 mm. The width of the hollow part of the contact surface between the cylinder and the aluminum shell is 6.5 mm.

[0036] Specifically, a pressing block connection hole 201 is also provided at the bottom of the hollow surface of the cylinder.

[0037] Furthermore, one end of the pressing block 2 away from the connecting rod 1, that is, the end in contact with the aluminum shell, is a rounded corner. Here, the "rounded corner" means that the edge of this end is not sharp but is processed into a smooth curve shape to reduce the possible damage or stress concentration to the aluminum shell caused by stress concentration at the sharp edge. This design also improves the durability or safety of the pressing block.

[0038] As Figure 3 shown, this is the state of the application of the present utility model in actual work. The pressing block 2 is pressed tightly on the aluminum shell and the top cover 4, specifically at the weld position 3. The two sides of the pressing block can be used as feature points for scanning pictures by a 3D profiler to accurately locate the weld position 3 for detecting the gap.

[0039] The cooperation mechanism process is as follows: after the cell and the aluminum shell are press-fitted, they are transferred to the welding and pressing station. A single-point single-cylinder controls the connecting rod 1 to drive the pressing block 2 to press down to the aluminum shell surface. The cylinder pressure can be controlled and monitored separately to ensure the pressing force and the gap. After pressing, the two sides of the pressing block 2 are used as equal-height features, and the weld position 3 is scanned by a 3D profiler to accurately detect whether the gap meets the standard.

[0040] The whole process is an automated and precisely controlled process, aiming to ensure the welding quality between the battery cell and the aluminum shell, and to guarantee the performance and safety of the final product through precise gap control.

[0041] Embodiment 2

[0042] This embodiment provides a welding device for the top cover of a square battery, which adopts the pre-welding pressing structure described in Embodiment 1 and the cylinder, and one end of the connecting rod is connected to the cylinder.

[0043] When the cylinder drives the pre-welding pressing structure to press the battery top cover, since the material of the connecting rod 1 is stainless steel and the material of the pressing block 2 is polyetheretherketone or copper, after contacting the aluminum shell, the force exerted can be lighter than that of the pre-welding pressing structure made of stainless steel as a whole, and the indentation left is shallower, without affecting the overall effect.

[0044] In summary, the present utility model provides a pre-welding pressing structure for the top cover of a square battery, achieving the following service performances:

[0045] 1. Precise control of the weld gap to ensure welding quality

[0046] This structure adopts a two-component design of a connecting rod and a detachable pressing block, which can effectively solve the problem that the existing integral structure cannot accurately control the weld gap. Specifically, the connecting rod is connected to the cylinder, and can precisely control the force of the pressing block pressing down to the surface of the aluminum shell. The material of the pressing block can be selected from polyetheretherketone or copper. Through the cooperation with the hollow part of the connecting rod, it can ensure that the optimal weld gap is maintained during the welding process, that is, less than 10% of the wall thickness of the aluminum shell, which is beneficial to the welding effect.

[0047] This ability to precisely control the weld gap can not only ensure the welding quality, but also effectively prevent laser leakage damage to the battery cell during the welding process, further improving the product performance and safety.

[0048] 2. Solve the material conflict problem of the integral structure

[0049] In the existing integral structure, the pressing block and the connecting rod are usually made of the same material, and there is a trade-off in material selection. For example, the polyetheretherketone material can better protect the aluminum shell from being pressed, but it is easy to cause light reflection pollution to the battery cell; while the stainless steel material can better control the weld gap, but it needs to be matched with a spring buffer and is prone to indentation.

[0050] This new pre-welding pressing structure adopts a separated design of the connecting rod and the pressing block, allowing for the selection of the best materials for each. The connecting rod is made of stainless steel, which can ensure the control effect of the weld gap; the pressing block can be made of relatively softer materials such as polyether ether ketone or copper, effectively solving the problems of surface indentation on the aluminum shell and light reflection polluting the battery core. This "division of labor and cooperation" design greatly improves the adaptability and fault tolerance of the structure.

[0051] 3. Improve maintenance convenience and cost-effectiveness

[0052] Compared with the existing integrated structure, the connecting rod and the pressing block of this new pre-welding pressing structure are detachable, greatly improving maintenance convenience. Once a certain component fails, only this component needs to be replaced, without the need to discard the whole, thus reducing maintenance costs.

[0053] At the same time, the connecting rod and the pressing block can be connected by threads or structural adhesives, which are easy to disassemble and assemble, and the maintenance is more efficient. The interference fit design between the pressing block and the hollow part of the connecting rod also enhances the stability and durability of the structure.

[0054] In addition, the optimized design of parameters such as the length of the connecting rod and the size of the pressing block further improves the applicability and versatility of this structure, and it can be widely used in the packaging process of square battery top covers with different specifications.

[0055] 4. Improve the automation level and production efficiency

[0056] This new pre-welding pressing structure incorporates automated control technology. The entire work process includes: pressing and assembling the battery core and the aluminum shell - welding and pressing - weld gap detection, all of which are automated and precisely controlled processes.

[0057] Among them, when the pressing block presses on the weld position, the two side edges can be used as feature points for 3D profiler scanning to accurately locate the weld position for gap detection. This highly automated process flow not only improves production efficiency but also ensures the consistency and reliability of product quality.

[0058] Generally speaking, through the separated design of the connecting rod and the pressing block and the incorporation of automated control technology, this new pre-welding pressing structure has achieved certain advantages in precisely controlling the weld gap, solving the material conflict of the integrated structure, improving maintenance convenience and production efficiency, etc.

[0059] It should be understood that the above specific embodiments of the present utility model are only used for exemplary illustration or explanation of the principle of the present utility model, and do not constitute a limitation to the present utility model. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present utility model shall be included within the protection scope of the present utility model. In addition, the appended claims of the present utility model are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A pre-welding pressing structure, characterized in that, It includes: a connecting rod and a pressing block. One end of the connecting rod is used to connect with a cylinder, and the other end is detachably connected to the pressing block; the middle of the end of the pressing block away from the connecting rod is hollowed out.

2. The pre-welding pressing structure according to claim 1, wherein The material of the connecting rod is stainless steel.

3. The pre-welding pressing structure according to claim 1, characterized in that The material of the pressing block is polyetheretherketone.

4. The pre-welding pressing structure according to claim 1, characterized in that The material of the pressing block is copper.

5. The pre-welding pressing structure according to claim 1, wherein The connecting rod and the pressing block are connected by threads.

6. The pre-welding pressing structure according to claim 1, wherein, The connecting rod and the pressing block are connected by structural adhesive.

7. The pre-welding pressing structure according to claim 1, wherein The length range of the connecting rod is 80mm to 90mm.

8. The pre-welding pressing structure according to claim 1, characterized in that, The pressing block is a cylinder with upper and lower hollows, and the outer diameter range of the cylinder is 8mm to 12mm.

9. The pre-welding pressing structure according to claim 8, wherein, The inner diameter range of the cylinder is 5.5mm to 7mm.

10. The pre-welding pressing structure according to claim 1, wherein The end of the pressing block away from the connecting rod is rounded.

11. A square battery top cover welding device, characterized in that, It includes the pre-welding pressing structure according to any one of claims 1-10, and the cylinder, and one end of the connecting rod is connected to the cylinder.

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