A steel shell assembly with an integrated explosion-proof valve structure

Abstract

The present invention discloses a steel shell assembly with an integrated explosion-proof valve structure, comprising a shell with at least one end open and a closure member that blocks the open end of the shell, the closure member comprising a cover plate adapted to the open end of the shell, an explosion-proof notch being arranged on the surface of the cover plate or the surface of the shell, and the residual thickness of the explosion-proof notch gradually increasing or decreasing from one end of the explosion-proof notch to the other end opposite thereto. The present invention adopts the method of integrally forming the explosion-proof valve with the cover plate or the shell, eliminating the need to assemble and weld the explosion-proof valve, reducing the process steps, simplifying the production process, improving the production efficiency and the yield rate, and greatly reducing the thickness of the cover plate, making the cover plate easier to stamp.

Description

Technical Field

[0001] The present invention relates to the technical field of power batteries, and in particular to a steel shell assembly with an integrated explosion-proof valve structure. Background Art

[0002] The stainless steel shell is welded from stainless steel into a square shell with two ends open, and a stainless steel bottom cover is welded at one end to form the shell of the secondary battery. The battery inside the sealed shell may generate high-temperature and high-pressure gas during use, which may cause the shell to explode. In order to prevent the shell from exploding, it is necessary to release the pressure of the high-temperature and high-pressure gas generated inside the shell to prevent explosion. The conventional method is to stamp or CNC-process an explosion-proof countersunk hole for installing an explosion-proof valve on the bottom cover of the shell, and then weld the explosion-proof valve sheet on the explosion-proof countersunk hole. There are many processes. At the same time, in order to ensure the strength and squareness of the bottom cover, In order to weld the explosion-proof valve plate smoothly at the explosion-proof countersunk hole, the cover plate needs to be thicker, usually about 1.5mm. Since the hardness of stainless steel is as high as 150-180HV, the stamping and thinning process is difficult. The thicker the cover plate, the more difficult it is to stamp, which will greatly shorten the stamping life of the mold. Moreover, after actual stamping, arc transitions are formed at the junction of each step, and the corners cannot be cleared. It is easy to interfere with the subsequent installation of the explosion-proof valve plate, making it difficult to install the explosion-proof valve plate and the welding yield is low. The cost of CNC milling the steps of the explosion-proof countersunk hole is high, the production efficiency is slow, and it is not suitable for mass production. Summary of the invention

[0003] In view of this, an object of the present invention is to provide a steel shell assembly with an integrated explosion-proof valve structure to solve the problems of multiple processes, thick materials, difficult assembly and welding, and low welding yield in the prior art for manufacturing explosion-proof steel shells.

[0004] To achieve the above-mentioned purpose, the present invention provides a steel shell assembly with an integrated explosion-proof valve structure, comprising a shell with an opening at at least one end and a closure member that seals the open end of the shell, the closure member comprising a cover plate that is adapted to the open end of the shell, and an explosion-proof notch is provided on the surface of the cover plate or the surface of the shell, and the residual thickness of the explosion-proof notch gradually increases or decreases from one end of the explosion-proof notch to the other opposite end.

[0005] Furthermore, a pressure relief portion is provided on the cover plate, and the pressure relief portion includes a sink formed on the cover plate, and the explosion-proof notch is provided on the surface of the sink.

[0006] The residual thickness of the explosion-proof notch changes gradually, so that each time a burst pressure relief occurs at the shell or sink, the cracking starts from the position where the residual thickness of the explosion-proof notch is the smallest. When the residual thickness of the explosion-proof notch is equal, the position where the explosion-proof notch starts to crack each time a burst pressure relief occurs cannot be predicted. In comparison, the burst stability and controllability of this scheme are stronger.

[0007] Furthermore, the residual thickness of the thinner end of the explosion-proof notch is 0.07 mm to 0.09 mm, and the residual thickness of the thicker end of the explosion-proof notch is 0.12 mm to 0.14 mm.

[0008] Furthermore, the bottom wall of the sink is configured as an arc-shaped surface with a middle portion convexly disposed upward.

[0009] Furthermore, a first sinking platform is arranged on the cover plate around the outer periphery of the sinking groove, the height of the first sinking platform is higher than the height of the sinking groove, and the first sinking platform is used for assembling the protective film.

[0010] Furthermore, the closure member also includes a steel pressure plate attached to the bottom surface of the cover plate, the steel pressure plate is provided with a second sinking platform that matches the bottom surface of the first sinking platform, and the steel pressure plate is provided with a mounting hole that matches the sinking groove.

[0011] Furthermore, the cover plate is integrally stamped from a stainless steel plate with a thickness of 0.15 mm to 0.35 mm, the shell is formed by bending and welding a stainless steel plate with a thickness of 0.15 mm to 0.25 mm, and the cover plate is fixed to the shell by welding.

[0012] Furthermore, the steel pressure plate is formed by integrally stamping a stainless steel plate having a thickness of 0.5 mm to 0.7 mm.

[0013] Further, the four edges of the cover plate are formed with downward flanges, the outer wall of the flanges is matched with the inner wall of the shell, and the upper surface of the cover plate is 0.15mm~0.4mm higher than the upper end surface of the shell; or the four edges of the cover plate are formed with U-shaped flanges opening upward, the outer wall of the U-shaped flanges is matched with the inner wall of the shell, and the upper end surface of the U-shaped flanges is flush with the upper end surface of the shell or higher than the upper end surface of the shell. Preferably, the upper end surface of the U-shaped flange is 0.15mm~0.4mm higher than the upper end surface of the shell.

[0014] Furthermore, the cover plate is formed with a U-shaped flange opening upward on the four sides, the outer wall of the U-shaped flange is adapted to the inner wall of the shell, the upper end face of the U-shaped flange is provided with a lap extending in a horizontal direction, the lower surface of the lap is fitted with the upper end face of the shell, and the outer peripheral surface of the lap is flush with the outer wall of the shell.

[0015] The present invention adopts the method of integrally stamping the explosion-proof valve and the cover plate, eliminating the need to assemble and weld the explosion-proof valve, reducing process steps, simplifying the production process, and improving production efficiency and yield rate; the thickness of the cover plate is greatly reduced, making it easier to stamp the cover plate; the residual thickness of the notch used for pressure relief is a gradual structure, which is beneficial to improving the stability and controllability of the burst; the edge of the cover plate of the present invention is provided with a flange structure, so that the edge of the cover plate has a certain elasticity, which is convenient for assembling the cover plate and the shell; after the cover plate with the flange structure is assembled with the shell, a welding step is formed between the upper end face of the shell and the outer wall of the flange, which is beneficial to form a molten pool at the welding step during welding, so that the welding between the cover plate and the shell is more stable and firm, or the flange structure The structure fits the inner wall of the shell to widen the weldable area, which can effectively prevent welding defects such as offset welding, false welding, weld penetration, and melt beads; the steel pressure plate improves the strength of the cover plate and prevents the cover plate from deformation. While ensuring the overall strength of the closure, the thickness of the cover plate is greatly reduced, making the pressure relief part on the cover plate easier to stamp and form, and the protective film pasted on the first step can effectively prevent impurities or liquids from entering the sink and corroding the explosion-proof notches; the second step is convex upward to increase the area of ​​the pressure acting on the second step when high pressure is generated inside the shell, making it easier for the second step to break at the explosion-proof notch and release pressure; the upwardly protruding second step also supports the protective film to prevent the protective film from being crushed downward during the use of the steel shell product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional diagram of a steel shell component with an integrated explosion-proof valve structure according to the present invention.

[0017] Figure 2 This is an exploded view of a steel shell assembly with an integrated explosion-proof valve structure according to the present invention.

[0018] Figure 3 The figure is a top view of a steel shell assembly with an integrated explosion-proof valve structure according to the present invention.

[0019] Figure 4 This is a top view of a steel shell assembly with an integrated explosion-proof valve structure of the present invention with the protective film removed.

[0020] Figure 5 for Figure 3 Middle AA section view.

[0021] Figure 6 for Figure 5 Enlarged view of part A in the middle.

[0022] Figure 7 For Example 1 Figure 5 Enlarged view of part B in .

[0023] Figure 8 For Example 2 Figure 5Enlarged view of part A in .

[0024] Fig. 9 For Example 3 Figure 5 Enlarged view of part A in .

[0025] Fig.10 For Example 4 Figure 5 Enlarged view of part A in .

[0026] Fig.11 It is a schematic diagram of the structure of a punch head used for engraving explosion-proof notches.

[0027] The accompanying drawings in the specification are numeraled as follows:

[0028] Shell - 10;

[0029] Closing member-20; cover plate-201; pressure relief part-202; sink groove-2021; explosion-proof notch-2022; first sink platform-2023; protective film-203; steel pressure plate-204; second sink platform-2041; mounting hole-2042; overlap-206;

[0030] Punch head-30; protrusion-301. DETAILED DESCRIPTION

[0031] This embodiment discloses a steel shell assembly with an integrated explosion-proof valve structure, such as Figure 1-Figure 5 As shown, it includes a shell 10 with at least one end open and a closure member 20 that blocks the open end of the shell 10, the closure member 20 includes a cover plate 201 adapted to the open end of the shell 10, and explosion-proof notches 2022 are provided on the surface of the cover plate 201 or the shell 10, and a pressure relief portion 202 is formed on the cover plate 201, and the pressure relief portion 202 includes a recessed groove 2021 formed on the cover plate 201, and explosion-proof notches 2022 are provided on the surface of the recessed groove 2021.

[0032] The shell 10 in this embodiment is a cylindrical body with openings at both ends. The closure member 20 is arranged on one end of the shell 10 to close the opening. In this arrangement, after the battery cell is installed in the shell 10, the other opening is closed to form a power battery or battery pack. It can be understood that the shell 10 can also be closed at one end and open at the other end. The closure member 20 is arranged at the open end to close the opening. The shell 10 in this embodiment is made of stainless steel sheet with a thickness of 0.15mm to 0.25mm, which is cut, punched with positioning holes, bent, and welded. It is preferably made of stainless steel sheet with a thickness of 0.2mm, combined with Figure 5As shown, the shell 10 in this embodiment is a rectangular thin-walled cylindrical body with openings at both ends, including two oppositely arranged wide side walls and two oppositely arranged narrow side walls, and the closure 20 as a whole is a rectangular plate body adapted to the opening of the shell 10 of the rectangular cylindrical body. It can be understood that in other feasible embodiments, the shell 10 can also be set as a square or other shaped thin-walled cylindrical body. Correspondingly, the shape of the closure 20 is adapted to the shape of the open end of the shell 10. After the shell 10 is manufactured, the closure 20 is fixedly connected to the shell 10 by welding. After being fixedly connected to the shell 10, the closure 20 seals the open end of the shell 10. In this embodiment, the shell 10 is placed vertically and the closure 20 is arranged at the upper open end of the shell 10 as an example for explanation.

[0033] The cover plate 201 is a rectangular plate. The position of the sinking groove 2021 on the cover plate 201 can be determined according to the assembly conditions inside the housing 10, and can be set at any desired position on the cover plate 201. In this embodiment, the sinking groove 2021 is set in the middle of the cover plate 201 for illustration. Figure 2 Figure 5 As shown, the sink groove 2021 can be formed by stamping at the middle position of the cover plate 201 to protrude toward the inner cavity of the shell 10, and then the explosion-proof notch 2022 is stamped on the surface of the sink groove 2021. The sink groove 2021 can be set as a circular groove, a square groove or a groove of other shapes, such as Figures 1 to 4 As shown, the sink 2021 in this embodiment is configured as an elliptical groove arranged along the length direction of the cover plate 201, combined with Figure 5 , Figure 7 As shown, an explosion-proof notch 2022 having a closed curve trajectory is engraved on the edge of the surface near the sink 2021, and the residual thickness of the explosion-proof notch 2022 is 0.07 mm to 0.14 mm. Figure 7 As shown, the residual thickness of the explosion-proof notch 2022 is defined as the remaining thickness H of the cover plate 201 after being punched and recessed at the explosion-proof notch 2022. The explosion-proof notch 2022 is formed only by the upper surface of the sink groove 2021 being recessed toward the inner cavity of the shell 10. The lower surface of the sink groove 2021 remains flat, and no downward protruding feature is generated at the place corresponding to the explosion-proof notch 2022. The cross-section of the explosion-proof notch 2022 can be a U-shaped groove, a V-shaped groove, or an inverted trapezoidal groove, such as Figure 7As shown, in this embodiment, the explosion-proof notch 2022 is preferably an inverted trapezoidal groove, thereby forming an explosion-proof valve for relieving pressure in the inner cavity of the shell 10 at the sink 2021. Since the explosion-proof valve is formed by stamping in an integral manner with the cover plate 201, there is no need to assemble and weld an explosion-proof disk separately. Therefore, the cover plate 201 does not need to be relatively thick considering the feasibility of assembly and welding with the explosion-proof disk. In general designs, this method of welding an explosion-proof disk usually requires the thickness of the cover plate 201 to be more than 1.5 mm in order to weld the explosion-proof disk to the cover plate 201 well. Furthermore, since there is no need to weld an explosion-proof disk on the cover plate 201, this solution adopts the cover plate 201 formed by stamping in one piece. It can be stamped out of thinner sheets or plates, and can be formed by integrally stamping out a stainless steel sheet or sheet with a thickness of 0.15mm to 0.35mm. For example, it can be formed by integrally stamping out a stainless steel sheet or sheet with a thickness of 0.15mm, 0.2mm, 0.25mm or 0.35mm. The cover plate 201 in this solution is preferably made of 0.2mm stainless steel sheet or plate. Therefore, due to its thin thickness, the cover plate 201 forming the integrated explosion-proof valve is easier to stamp out, the process is simple, the production efficiency is high, and the yield rate is higher. In this way, since the residual thickness at the explosion-proof notch 2022 is smaller than the thickness at other positions of the cover plate 201 at the groove 2021, when the cover plate 201 is welded and fixed to the shell 10, when the pressure of the high-pressure gas generated in the shell 10 that is closed at both ends reaches a preset value, it will first crack from the notch on the surface of the groove 2021 to release the pressure, thereby preventing the gas pressure in the shell 10 from continuing to rise and causing a more severe accident of the entire shell 10 to explode, thereby achieving the purpose of pressure relief and explosion prevention.

[0034] It can be understood that in the present invention, the explosion-proof notch 2022 can also be selectively set on the surface of the shell 10, that is, the explosion-proof notch 2022 can also be set on the outer wall or the inner wall of the shell 10 to form an explosion-proof valve structure integrated with the shell. When the explosion-proof notch 2022 is set on the surface of the shell 10, the projection of the trajectory of the explosion-proof notch 2022 on the surface of the shell 10 can also be set to an elliptical, circular, square or other shaped closed or unclosed curve, and the residual thickness of the explosion-proof notch 2022 is defined as the remaining side wall thickness of the shell 10 after the side wall is punched and recessed at the explosion-proof notch 2022. When the explosion-proof notch 2022 is set on the surface of the shell, the explosion-proof notch 2022 can be first embossed on one side surface of the sheet material used to make the shell, and then the sheet material with the explosion-proof notch 2022 embossed is bent and welded to form the shell 10.

[0035] As an improvement of this embodiment, Figures 5 to 7 As shown, the residual thickness of the explosion-proof notch 2022 gradually increases or decreases from one end of the sink 2021 to the other end. Fig.11 ， Fig.112021 . The figure is a schematic diagram of a mold of a punch head 30 used for punching explosion-proof notches 2022 on the surface of a groove 2021. In the mold, the protruding height of the protruding portion 301 used for punching the explosion-proof notches 2022 gradually decreases or increases from one end of the punch head 30 to the opposite end of the punch head 30. Therefore, the residual thickness of the explosion-proof notches 2022 punched on the surface of the groove 2021 by the punch head 30 gradually increases or decreases from one end of the groove 2021 to the other opposite end. In the present embodiment, the residual thickness of the explosion-proof notches 2022 gradually increases or decreases along the length direction of the groove 2021. It can be understood that in other feasible embodiments, the residual thickness of the explosion-proof notches 2022 may also gradually increase or decrease along the width direction of the groove 2021. The residual thickness of the thinner end of the explosion-proof notch 2022 can be set to 0.07mm~0.09mm, and the residual thickness of the thicker end of the explosion-proof notch 2022 can be set to 0.12mm~0.14mm. Preferably, when the thickness of the cover plate 201 is 0.2mm, the residual thickness of the thinner end of the explosion-proof notch 2022 is set to 0.08mm, and the residual thickness of the thicker end of the explosion-proof notch 2022 is set to 0.13mm. It can be understood that when the thickness of the cover plate 201 decreases, the residual thickness of the thinner end and the residual thickness of the thicker end of the explosion-proof notch 2022 can be appropriately reduced accordingly. When the thickness of the cover plate 201 increases, the residual thickness of the thinner end and the residual thickness of the thicker end of the explosion-proof notch 2022 can be appropriately increased accordingly. Alternatively, the residual thickness of the thinner end and the residual thickness of the thicker end can be determined according to the parameters of the battery cell in the shell 10 and the usage environment. In this way, since the residual thickness of the explosion-proof notch 2022 changes gradually, when high pressure is generated inside the shell 10, each time a burst pressure relief occurs at the sink 2021, the cracking starts from the position where the residual thickness of the explosion-proof notch 2022 is the smallest, and then gradually extends to the end of the explosion-proof notch 2022 with a thicker residual thickness, and the burst pressure relief is relatively stable. When the residual thickness of the explosion-proof notch 2022 is set to be equal and unchanged, when the shell 10 produces a burst pressure relief, the place where the explosion-proof notch 2022 starts to crack is unpredictable, or the entire explosion-proof notch 2022 may burst synchronously, causing the cover plate 201 body in the sink 2021 to splash out of the shell 10. In comparison, the present scheme has a variable residual thickness setting of the explosion-proof notch 2022, which makes the bursting stability and controllability stronger.It can be understood that, when the residual thickness of the explosion-proof notch 2022 is set to gradually change, the trajectory of the explosion-proof notch 2022 can also be an unclosed curved segment. In this case, the residual thickness of the thicker end of the explosion-proof notch 2022 is equal to the thickness of the cover plate 201. In this setting, when high pressure is generated inside the shell 10, each time a burst pressure relief occurs at the sink 2021, the cracking starts from the position where the residual thickness of the explosion-proof notch 2022 is the smallest, and then gradually extends to the end of the explosion-proof notch 2022 with a thicker residual thickness. Open, and since the thickness of the thicker end of the residual thickness of the explosion-proof notch 2022 is the same as the thickness of the cover plate 201, the thickness of the thicker end of the residual thickness of the explosion-proof notch 2022 whose relative trajectory is a closed curve is thicker, so the entire explosion-proof notch 2022 will not be completely cracked when the shell 10 is bursting and decompressing, which effectively prevents the cover plate 201 at the sink 2021 from splashing out of the cover plate 201 and damaging other components when the shell 10 is bursting and decompressing.

[0036] The sealing member 20 in this embodiment further includes a protective film 203 for covering the sink 2021 to prevent debris from entering the sink 2021 and corroding the explosion-proof notch 2022. Figure 4-Figure 6 As shown, a first sinking platform 2023 is arranged on the cover plate 201 around the outer periphery of the sinking groove 2021, and the height of the first sinking platform 2023 is higher than the height of the sinking groove 2021. The protective film 203 is pasted on the first sinking platform 2023 to cover the entire sinking groove 2021. After the protective film 203 is pasted, the lower surface of the protective film 203 is flush with the upper surface of the first sinking platform 2023, and the upper surface of the protective film 203 is not higher than the upper surface of the cover plate 201. Figure 5 As shown, in this embodiment, the bottom wall of the trough 2021 is set to be an upwardly protruding arc surface, and the highest point of the surface of the trough 2021 is not higher than the plane where the first sink platform 2023 is located. Preferably, the highest point of the surface of the trough 2021 is flush with the lower surface of the protective film 203. The bottom wall of the trough 2021 is set to be an upwardly protruding arc surface. When high pressure is generated inside the shell 10, the area of ​​the pressure acting on the bottom surface of the trough 2021 can be increased, so that the cover plate 201 at the trough 2021 is more easily broken at the explosion-proof notch 2022 to release pressure. At the same time, the upwardly protruding bottom wall of the trough 2021 can support the protective film 203 from below the protective film 203 to prevent the protective film 203 from being easily broken due to accidental squeezing of the protective film 203 during transportation and use of the shell 10 after the protective film 203 is installed. In this way, the protective film 203 can effectively prevent debris such as dust, liquid, etc. from entering the trough 2021 and corroding the explosion-proof notch 2022.

[0037] The closure member 20 in this embodiment further includes a steel pressing plate 204 for reinforcing the strength of the cover plate 201 to improve the anti-deformation capability of the closure member 20. Figure 5 , Figure 6 As shown, the steel pressure plate 204 in this embodiment is pasted on the lower surface of the cover plate 201, and the length and width dimensions of the steel pressure plate 204 are correspondingly smaller than the length and width dimensions of the cover plate 201. A mounting hole 2042 matching the sink 2021 is opened in the middle of the steel pressure plate 204, and the mounting hole 2042 is a through hole, so that the pressure generated in the shell 10 can directly act on the bottom wall of the sink 2021. The upper surface of the steel pressure plate 204 is provided with a second sink 2041 matching the first sink 2023. When the steel pressure plate 204 is attached to the lower surface of the cover plate 201, the lower surface of the cover plate 201 is attached to the upper surface of the steel pressure plate 204, and the lower surface of the first sink 2023 is attached to the upper surface of the second sink 2041. The thickness of the steel pressing plate 204 is 0.5 mm to 0.7 mm. Preferably, the steel pressing plate 204 is formed by integral stamping of a stainless steel plate with a thickness of 0.6 mm. With the reinforcement of the steel pressing plate 204, the thickness of the cover plate 201 can be as thin as possible, and can be 0.15 mm, under the condition of meeting the required service strength of the closure 20. This makes it easier to stamp the cover plate 201 and the yield rate is higher. In this embodiment, after the steel pressing plate 204 is fitted with the lower surface of the cover plate 201, the lowest point of the sink 2021 is not lower than the plane where the bottom surface of the steel pressing plate 204 is located, so as to prevent the sink 2021 from being squeezed by the battery cell in the housing 10 and causing the explosion-proof notch 2022 to crack, thereby ensuring stable blasting.

[0038] Combination Figure 5 , Figure 6As shown, in this embodiment, the four edges of the cover plate 201 are formed with downward flanges 205a, the outer wall of the flange 205a is adapted to the inner wall of the shell 10, and the height of the flange 205a is less than the thickness of the steel pressure plate 204 and the cover plate 201 after being superimposed. In this way, the lower end of the flange 205a will not exceed the lower surface of the steel pressure plate 204 below the cover plate 201 downward, and will not interfere with the battery cells and other components installed in the shell 10. Due to the setting of the flange 205a, the edge of the cover plate 201 has a certain elasticity, and when the outer wall of the flange 205a is aligned with the shell 10, the outer wall of the flange 205a is aligned with the shell 10. When the inner wall of the body 10 cooperates to cover the cover 201 on the upper port of the shell 10, the cover 201 is easier to be assembled on the upper port of the shell 10. In this embodiment, when the cover 201 is assembled on the upper port of the shell 10, the depth of the flange 205a entering the shell is 0.25mm~0.45mm (the depth of the flange 205a entering the shell is defined as the distance between the lower end surface of the flange 205a and the upper end surface of the shell 10). Preferably, the depth of the flange 205a entering the shell is 0.3mm. Of course, the depth of the flange 205a entering the shell can be reasonably adjusted according to the specifications of the product. In this embodiment, when the cover plate 201 is assembled to the upper port of the shell 10 to close the upper port of the shell 10, the upper surface of the cover plate 201 is 0.15mm to 0.4mm higher than the upper end surface of the shell 10, such as 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm or 0.4mm. Preferably, the upper surface of the cover plate 201 is 0.3mm higher than the upper end surface of the shell 10 so that the upper surface of the cover plate 201 and the upper end surface of the shell 10 form a welding step that is conducive to welding the cover plate 201 and the shell 10 together. In this way, when laser welding is used to melt-weld the cover plate 201 and the shell 10 together at the welding step, a molten pool 50a is formed at the welding step to fill the welding step. During welding, under the blowing state of protective gas, the molten pool 50a is full in shape and naturally forms a rounded corner state, and the welding effect is better.

[0039] Embodiment 2

[0040] Combination Figure 5 , Figure 8As shown, in the present embodiment, the four edges of the cover plate 201 are formed with U-shaped flanges 205b opening upward, the outer wall of the U-shaped flange 205b is matched with the inner wall of the shell 10, and the lower end surface of the U-shaped flange 205b is located in the space above the plane where the lower surface of the steel pressure plate 204 is located, or the lower end surface of the U-shaped flange 205b is flush with the lower surface of the steel pressure plate 204. In this way, the lower end of the U-shaped flange 205b will not exceed downwardly the lower surface of the steel pressure plate 204 under the cover plate 201, and will not interfere with components such as the battery cells installed in the shell 10. The upper end surface of the U-shaped flange 205b is flush with the upper end surface of the cover plate 201 or is located in the space below the plane where the upper end surface of the cover plate 201 is located. Preferably, the upper end surface of the U-shaped flange 205b is located at the cover The space below the plane where the upper end surface of the plate 201 is located has a certain elasticity due to the setting of the U-shaped flange 205b. When the outer wall of the U-shaped flange 205b is matched with the inner wall of the shell 10 to cover the cover 201 on the upper port of the shell 10, the cover 201 is more easily assembled on the upper port of the shell 10. In this embodiment, when the cover 201 is assembled on the upper port of the shell 10, the depth of the U-shaped flange 205b into the shell is 0.25mm~0.45mm (the depth of the U-shaped flange 205b into the shell is defined as the distance between the lower end surface of the U-shaped flange 205b and the upper end surface of the shell 10). Preferably, the depth of the U-shaped flange 205b into the shell is 0.3mm. Of course, the depth of the U-shaped flange 205b into the shell can be reasonably adjusted according to the specifications of the product. In this embodiment, when the cover plate 201 is assembled to the upper port of the shell 10 to close the upper port of the shell 10, the upper end surface of the U-shaped flange 205b is 0.15mm~0.4mm higher than the upper end surface of the shell 10, such as 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm or 0.4mm. Preferably, the upper end surface of the U-shaped flange 205b is 0.2mm higher than the upper end surface of the shell 10 so that the upper surface of the cover plate 201 and the upper end surface of the shell 10 form a welding step that is conducive to welding the cover plate 201 and the shell 10 together. In this way, when laser welding is used to melt-weld the cover plate 201 and the shell 10 together at the welding step, a molten pool 50b is formed at the welding step to fill the welding step. During welding, under the blowing state of protective gas, the molten pool 50bd has a full shape and naturally forms a rounded corner state, and the welding effect is better.

[0041] Embodiment 3

[0042] Combination Figure 5 , Fig. 9As shown, in the present embodiment, the four edges of the cover plate 201 are formed with U-shaped flanges 205c opening upward, the outer wall of the U-shaped flange 205c is matched with the inner wall of the shell 10, and the lower end surface of the U-shaped flange 205c is located in the space above the plane where the lower surface of the steel pressure plate 204 is located, or the lower end surface of the U-shaped flange 205c is flush with the lower surface of the steel pressure plate 204. In this way, the lower end of the U-shaped flange 205c will not exceed downwardly the lower surface of the steel pressure plate 204 under the cover plate 201, and will not interfere with components such as the battery cells installed in the shell 10. The upper end surface of the U-shaped flange 205c is flush with the upper end surface of the cover plate 201 or is located in the space below the plane where the upper end surface of the cover plate 201 is located. Preferably, the upper end surface of the U-shaped flange 205c is located. The space below the plane where the upper end surface of the cover plate 201 is located, due to the setting of the U-shaped flange 205c, the edge of the cover plate 201 has a certain elasticity. When the outer wall of the U-shaped flange 205c is matched with the inner wall of the shell 10 to cover the cover plate 201 on the upper port of the shell 10, the cover plate 201 is more easily assembled on the upper port of the shell 10. In this embodiment, when the cover plate 201 is assembled on the upper port of the shell 10, the depth of the U-shaped flange 205c into the shell is 0.4mm~0.6mm (the depth of the U-shaped flange 205c into the shell is defined as the distance between the lower end surface of the U-shaped flange and the upper end surface of the shell 10). Preferably, the depth of the U-shaped flange 205c into the shell is 0.5mm. Of course, the depth of the U-shaped flange 205c into the shell can be reasonably adjusted according to the specifications of the product. In this embodiment, when the cover plate 201 is assembled to the upper port of the shell 10 to close the upper port of the shell 10, the upper end surface of the U-shaped flange 205c is flush with the upper end surface of the shell 10. When laser welding is used, welding is performed at the gap between the shell 10 and the U-shaped flange 205c, and a molten pool 50c is formed at the gap between the upper end surface of the shell 10 and the upper end surface of the U-shaped flange 205c.

[0043] Embodiment 4

[0044] Combination Figure 5 , Fig.10As shown, in this embodiment, the four edges of the cover plate 201 are formed with U-shaped flanges 205d with an opening facing upward, the outer wall of the U-shaped flange 205d is adapted to the inner wall of the shell 10, and the lower end surface of the U-shaped flange 205d is located in the space above the plane where the lower surface of the steel pressure plate 204 is located, or the lower end surface of the U-shaped flange 205d is flush with the lower surface of the steel pressure plate 204, so that the lower end of the U-shaped flange 205d will not exceed downwardly the lower surface of the steel pressure plate 204 below the cover plate 201, and will not interfere with components such as the battery core installed in the shell 10, and the U-shaped flange 205d will not interfere with the battery core installed in the shell 10. The upper end surface of the U-shaped flange 205d is flush with the upper end surface of the cover plate 201 or is located in the space below the plane where the upper end surface of the cover plate 201 is located. Preferably, the upper end surface of the U-shaped flange 205d is located in the space below the plane where the upper end surface of the cover plate 201 is located. The upper end surface of the U-shaped flange 205d is provided with a lap 206 extending in the horizontal direction. In this embodiment, when the cover plate 201 is assembled to the upper end of the shell 10 to close the upper end of the shell 10, the lower surface of the lap 206 is in contact with the upper end surface of the shell 10, and the outer peripheral surface of the lap 206 is flush with the outer wall of the shell 10. When laser welding is adopted, welding is performed at the gap between the shell 10 and the lap 206, and a molten pool 50d is formed at the gap between the upper end outer wall of the shell 10 and the outer peripheral surface of the lap 206.

[0045] The above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A steel shell assembly with an integrated explosion-proof valve structure, comprising a shell with at least one end open and a closure member for sealing the open end of the shell, characterized in that: The closure member includes a cover plate adapted to the open end of the shell, and an explosion-proof notch is provided on the surface of the cover plate or the surface of the shell, and the residual thickness of the explosion-proof notch gradually increases or decreases from one end of the explosion-proof notch to the other opposite end.

2. The steel shell assembly with an integrated explosion-proof valve structure according to claim 1, characterized in that: The cover plate is provided with a pressure relief portion, and the pressure relief portion includes a sink groove formed on the cover plate, and the explosion-proof notch is provided on the surface of the sink groove.

3. The steel shell assembly with an integrated explosion-proof valve structure according to claim 1, characterized in that: The residual thickness of the thinner end of the explosion-proof notch is 0.07 mm to 0.09 mm, and the residual thickness of the thicker end of the explosion-proof notch is 0.12 mm to 0.14 mm.

4. The steel shell assembly with an integrated explosion-proof valve structure according to claim 2, characterized in that: The bottom wall of the sink is arranged as an arc-shaped surface with a middle portion convexly arranged upward.

5. The steel shell assembly with an integrated explosion-proof valve structure according to claim 2, characterized in that: A first sinking platform is arranged on the cover plate around the outer circumference of the sinking groove. The height of the first sinking platform is higher than the height of the sinking groove. The first sinking platform is used for assembling a protective film.

6. The steel shell assembly with an integrated explosion-proof valve structure according to claim 5, characterized in that: The closure member further comprises a steel pressing plate attached to the bottom surface of the cover plate, the steel pressing plate is provided with a second sinking platform matched with the first sinking platform, and the steel pressing plate is provided with a mounting hole matched with the sinking groove.

7. The steel shell assembly with an integrated explosion-proof valve structure according to claim 1, characterized in that: The cover plate is formed by integrally stamping a stainless steel plate with a thickness of 0.15 mm to 0.35 mm; and / or The shell is made of a stainless steel plate with a thickness of 0.15 mm to 0.25 mm through bending and welding; the cover plate is welded and fixed to the shell.

8. The steel shell assembly with an integrated explosion-proof valve structure according to claim 6, characterized in that: The steel pressing plate is formed by integrally punching a stainless steel plate with a thickness of 0.5 mm to 0.7 mm.

9. The steel shell assembly with an integrated explosion-proof valve structure according to any one of claims 1 to 8, characterized in that: The four edges of the cover plate are formed with downward flanges, the outer wall of the flanges is matched with the inner wall of the shell, and the upper surface of the cover plate is 0.15mm to 0.4mm higher than the upper end surface of the shell; or The cover plate is formed with a U-shaped flange opening upward on the four edges thereof, the outer wall of the U-shaped flange is matched with the inner wall of the shell, the upper end surface of the U-shaped flange is flush with or higher than the upper end surface of the shell, and preferably, the upper end surface of the U-shaped flange is 0.15 mm to 0.4 mm higher than the upper end surface of the shell.

10. The steel shell assembly with an integrated explosion-proof valve structure according to any one of claims 1 to 8, characterized in that: The cover plate is formed with a U-shaped flange opening upward on the four edges thereof, the outer wall of the U-shaped flange is matched with the inner wall of the shell, the upper end face of the U-shaped flange is provided with a lap extending in a horizontal direction, the lower surface of the lap is fitted with the upper end face of the shell, and the outer peripheral surface of the lap is flush with the outer wall of the shell.

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