Traction battery top cover, traction battery, and forming process for cover plate of traction battery top cover

Abstract

Disclosed in the present invention are a traction battery top cover, a traction battery, and a forming process for a cover plate of a traction battery top cover. The traction battery top cover comprises: a cover plate, in which at least one mounting hole is formed and extends through the cover plate; a terminal, which is arranged in the mounting hole; a sealing ring, which is pressed between the cover plate and the terminal; an upper plastic member, which is configured to isolate the cover plate from the terminal; a lower plastic member, which is pressed onto a lower surface of the cover plate; an electrolyte filling hole, which is formed in and extends through the cover plate; and a positioning groove, which is formed in the cover plate and around the mounting hole, wherein the positioning groove is open towards the upper plastic member, and the upper plastic member is positioned in the positioning groove. Compared with the prior art, the present invention can meet the requirements of the terminal and the cover plate for tension and thrust, and has a good stability and high reliability.

Description

Power battery top cover, power battery and its cover plate forming process Technical Field

[0001] The present invention relates to the technical field of new energy power batteries, and in particular to a power battery top cover, a power battery and a forming process of a cover plate thereof. Background Art

[0002] Since Plante invented the lead-acid battery, power batteries have undergone over 160 years of development. The world's first motor vehicle was an electric car powered by a lead-acid battery, but due to its low energy density and short range, it was quickly replaced by internal combustion engine vehicles. Due to dwindling global oil resources and increasing environmental pressures, the development of green and environmentally friendly new energy vehicles has become a hot topic in technological change in the automotive industry. Lithium batteries, due to their high energy density and lightweight portability, have been successfully applied to consumer electronics such as mobile phones and laptops. With the development of emerging industries such as new energy vehicles, renewable energy, and smart grids, the development of highly safe, long-life, high-capacity, and low-cost power lithium batteries has become a leading research frontier.

[0003] The power battery cover is a crucial component of lithium-ion batteries. Current power batteries consist of several battery cells, a busbar assembly that connects the cells in parallel, and poles that electrically connect to the busbar assembly and transmit power to the consumer. To maintain the internal seal of the power battery, the battery also includes an outer shell and a top cover that encloses the outer shell. The poles are fixed to the top cover and electrically isolated from the top cover plate by upper and lower plastic parts.

[0004] As shown in FIG1 , in order to fix and prevent the upper plastic part, the existing cover plate is usually provided with a circle of anti-rotation structure protruding from the cover plate surface around the mounting hole of the cover plate. The anti-rotation structure has a tooth-shaped anti-rotation groove. When the pole is assembled in place, the upper plastic part is injection-molded around the pole and in the tooth-shaped anti-rotation groove. After the upper plastic part is cured, it cooperates with the inner wall of the anti-rotation groove to fix and prevent the upper plastic part from rotating.

[0005] However, since the groove wall of the anti-rotation groove is generally perpendicular to the plane of the cover plate, the upper plastic part cannot be fixed in the axial direction. Long-term use may easily cause the upper plastic part to separate from the groove wall of the anti-rotation groove and cause axial displacement, which cannot meet the requirements of the pole for axial thrust and tension. At the same time, due to the complex tooth-shaped structure, the groove wall of the anti-rotation groove is not a smooth plane, and is usually achieved by a punching process, which will generate a large amount of waste slag during the punching process, which is difficult to clean, thereby reducing the molding efficiency of the entire power battery.

[0006] Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a power battery top cover, a power battery and a cover plate molding process, so as to solve the problems in the prior art that the thrust and pull requirements between the pole and the cover plate cannot be guaranteed, resulting in poor reliability of the top cover and time-consuming and labor-intensive processing of molding waste.

[0008] To achieve the above-mentioned objectives, a first aspect of the present invention provides a power battery top cover, comprising a cover plate with at least one mounting hole formed therethrough, a pole placed in the mounting hole, a sealing ring crimped between the cover plate and the pole, an upper plastic part for isolating the cover plate and the pole, a lower plastic part press-fitted on the lower surface of the cover plate, a liquid injection hole formed through the cover plate, and a positioning groove arranged on the cover plate around the mounting hole, the positioning groove opening toward the upper plastic part and the upper plastic part being positioned in the positioning groove.

[0009] To achieve the above-mentioned objectives, the second aspect of the present invention provides a power battery top cover, comprising a cover plate provided with a through mounting hole and an explosion-proof assembly hole, a pole penetrating the mounting hole and having a first circumferential limiting portion formed on the outer periphery, and an upper plastic part arranged in the mounting hole and arranged around the outer periphery of the pole, wherein the upper plastic part is provided with a first circumferential matching portion at a position corresponding to the first circumferential limiting portion, and the first circumferential matching portion is limitedly matched with the first circumferential limiting portion to achieve circumferential limiting of the pole.

[0010] To achieve the above-mentioned object, the third invention of the present invention provides a power battery top cover, including the power battery top cover as described above.

[0011] To achieve the above-mentioned object, a fourth aspect of the present invention provides a cover plate forming process for a power battery top cover, comprising the following steps:

[0012] Providing a plate preform having a first surface and a second surface disposed opposite to each other, and pre-punching at least one pre-punched hole in the plate preform from the first surface to the second surface;

[0013] Forging a back step at a position corresponding to the pre-pressed hole on the second surface of the plate preform;

[0014] A ring groove with an open top is forged on the first surface of the plate preform at a position corresponding to the pre-pressed hole, and a first forging surface and a second forging surface are located on the surface of the plate preform and correspond to two opposite sides of the ring groove, wherein the radial width of the ring groove is uniform at all locations along the axial direction;

[0015] The first forging surface and the second forging surface are forged downward to extrude one side wall of the annular groove outward to form an inner annular convex portion and / or to extrude the other side wall of the annular groove inward to form an outer annular convex portion, and a closed step is formed on the upper surface of the inner annular convex portion and / or the outer annular convex portion. The inner annular convex portion and / or the outer annular convex portion protrude to form a positioning groove with a variable cross-section that is larger at the bottom and smaller at the top; the back step is forged to form a mounting annular groove;

[0016] The pre-pressed hole is finely punched to form a mounting hole.

[0017] The present invention provides a positioning groove on the cover plate. During the injection molding process of the upper plastic part, the plastic raw material can flow and fill the positioning groove, so as to form a positioning portion that is in full contact with the positioning groove after solidification. Since the inner ring convex portion and / or the outer ring convex portion are provided in the positioning groove, when the positioning portion is positioned in the positioning groove, the lower surface of the inner ring convex portion and / or the outer ring convex portion can restrict the anti-slip section at the bottom of the positioning portion in the bottom groove, so as to prevent the upper plastic part from axial displacement, thereby achieving the purpose of fixing the upper plastic part; and, by providing an inner ring body and providing a notch on the inner ring body, the plastic raw material can flow into the notch during injection molding and be fixed to form an integrated upper plastic part, thereby preventing the upper plastic part from rotating in the axial direction and further improving the assembly stability of the upper plastic part; at the same time, when the inner ring convex portion and / or the outer ring convex portion are provided, their upper surface is lower than the upper surface of the cover plate, so that a height difference is formed between the inner ring convex portion and / or the outer ring convex portion and the surface of the cover plate, so as to avoid the formation of a gap between the upper plastic part and the cover plate during the molding process, thereby affecting the reliability of the product.

[0018] In addition, the present invention adopts a forging process to form a positioning groove on the cover plate as a whole. During the forging process, the excess of the plate forming various grooves or notches will flow into the pre-stressing hole in the middle and be cut off as a whole during the final fine stamping. This can effectively reduce the generation of waste slag during the forming process, is easy to clean, and forms fewer burrs in the grooves and notches, which can simplify the polishing process and thus improve the forming efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG1 is a schematic structural diagram of a cover plate in the prior art.

[0020] FIG2 is a schematic structural diagram of a power battery top cover according to an embodiment of the present invention.

[0021] FIG3 is an exploded view of FIG2 .

[0022] FIG4 is a view taken along the line AA in FIG2 .

[0023] FIG5 is a schematic structural diagram of the cover plate in FIG3 .

[0024] FIG6 is a schematic structural diagram of the pole in FIG3 .

[0025] FIG. 7 is another schematic structural diagram of the pole in FIG. 6 .

[0026] FIG8 is a three-dimensional view of the pole in FIG6 from the bottom perspective.

[0027] FIG9 is a longitudinal cross-sectional view of FIG1 at a pole, wherein the upper plastic component structure is omitted.

[0028] FIG10 is an enlarged view of point B in FIG5 .

[0029] FIG11 is a CC-arrow view in FIG5 .

[0030] FIG12 is an enlarged view of point F in FIG5 .

[0031] FIG13 is a schematic structural diagram of the upper plastic part in FIG3 .

[0032] FIG. 14 is another structural schematic diagram of the upper plastic part in FIG. 3 .

[0033] FIG15 is a DD-direction view of FIG13 .

[0034] FIG16 is an enlarged view of point H in FIG15 .

[0035] FIG17 is a schematic structural diagram of the lower plastic part in FIG3 .

[0036] FIG18 is a schematic diagram of the structure of the lower plastic part of another embodiment, in which the lower plastic part cooperates with the circular pole and the other pole structure is hidden.

[0037] Figure 19 is a schematic diagram of the assembly of the pole and the limiting groove.

[0038] FIG20 is a longitudinal cross-sectional view of one of the poles in FIG1 .

[0039] FIG21 is a schematic structural diagram of a power battery top cover according to another embodiment of the present invention.

[0040] FIG22 is an exploded view of FIG21 .

[0041] FIG23 is a schematic structural diagram of the cover plate in FIG21 .

[0042] FIG24 is a flow chart of a cover plate forming process for a power battery top cover according to an embodiment of the present invention.

[0043] FIG25 is another flow chart of FIG24. DETAILED DESCRIPTION

[0044] The following is further described in detail through specific implementation methods:

[0045] Example 1

[0046] 2 , 3 , and 4 , a power battery top cover according to an embodiment of the present invention includes a cover plate 100 having at least one mounting hole 110 formed therethrough, a terminal post 200 disposed within the mounting hole 110 , a sealing ring 300 crimped between the cover plate 100 and the terminal post 200 , a positioning groove 400 coaxially formed in the cover plate with the mounting hole 110 , an upper plastic member 500 for isolating the cover plate 100 from the terminal post 200 , and a lower plastic member 600 press-fitted onto the bottom of the cover plate 100 . The positioning groove 400 surrounds the mounting hole 110 and opens axially upward. The bottom of the upper plastic member 500 is positioned within the positioning groove 400 . A mounting annular groove 120 is formed on the lower surface of the cover plate 100 corresponding to the periphery of the mounting hole 110 , and the lower plastic member 600 is press-fitted into the mounting annular groove 120 . In this embodiment, taking the direction shown in Figure 2 as an example, the X-axis direction is defined as the length direction of the cover plate 100, the Y-axis direction is defined as the width direction of the cover plate 100, and the Z-axis direction is defined as the thickness direction or width direction of the cover plate 100 (which is also the axial direction of the mounting hole 110 and the pole 200).

[0047] The pole 200 is axially inserted into the mounting hole 110 from bottom to top, and the top of the pole 200 passes through the mounting hole 110 upward and extends out of the upper surface of the cover plate 100 to form an outlet end. The upper plastic part 500 covers the outer periphery of the outlet end of the pole 200 and the bottom of the upper plastic part 500 is positioned in the positioning groove 400 to isolate the pole 200 from the cover plate 100. The top surface of the pole 200 is exposed to the upper plastic part 500, so that the pole 200 can be connected to an external electronic component. At the same time, the bottom of the pole 200 extends out of the lower surface of the cover plate 100 and is isolated from the cover plate 100 by the lower plastic part 600. The bottom surface of the pole 200 is exposed to the corresponding position of the lower plastic part 600, so that the pole 200 can be connected to the tab of the battery cell in the power battery to achieve electrical connection between the power battery and the external electronic component. The sealing ring 300 is sleeved on the outer circumference of the pole 200 and pressed between the corresponding positions of the cover plate 100 and the pole 200. When the pole 200 is installed in place, the upper surface of the sealing ring 300 abuts against the corresponding position of the cover plate 100 and the lower surface abuts against the corresponding position of the pole 200. It can not only isolate the pole 200 from the cover plate 100, but also block the mounting hole 110 to seal the internal space of the power battery and prevent leakage of electrolyte in the power battery.

[0048] Please refer to Figure 5. The cover plate 100 is preferably provided with two mounting holes 110. The two mounting holes 110 are distributed on the cover plate 100 along the length direction of the cover plate 100 and penetrate the cover plate 100 in the thickness direction of the cover plate 100. The positioning grooves 400 are formed at the positions corresponding to the two mounting holes 110 on the cover plate 100, and a group of poles 200, sealing rings 300 and upper plastic parts 500 are assembled in the mounting holes 110. In specific implementation, one of the poles 200 serves as the positive electrode of the power battery and the other pole 200 serves as the negative electrode of the power battery to be connected to external electronic components. It is understandable that in some other embodiments, the cover plate 100 may be provided with only one mounting hole 110 and a set of poles 200, a sealing ring 300 and an upper plastic part 500 may be assembled in the mounting hole 110, with the pole 200 serving as the positive electrode of the power battery, and a connecting structure is provided on the end of the power battery opposite to the cover plate 100 as the negative electrode of the power battery to be connected to external electronic components.

[0049] The pole 200 is coaxially inserted into the mounting hole 110, and an assembly gap is defined between the pole 200 and the mounting hole 110 to form a spacer 130 between the outer circumferential surface of the pole 200 and the inner circumferential surface of the mounting hole 110. The sealing ring 300 is sleeved over the pole 200, and a portion of the upper surface of the sealing ring 300 is exposed to the spacer 130 after being assembled in place. During the injection molding process of the upper plastic part 500, the plastic material can flow into the spacer 130 and fully contact the outer circumferential surface of the pole 200, the inner circumferential surface of the mounting hole 110, and the upper surface of the corresponding position of the sealing ring 300. Subsequently, the corresponding position of the bottom of the upper plastic part 500 formed after solidification can cooperate with the sealing ring 300 to stably seal the assembly gap between the pole 200 and the cover plate 100, thereby ensuring a stable seal inside the power battery.

[0050] Of course, an explosion-proof assembly hole 140 and a liquid injection hole 150 are also provided on the cover plate 100. The hole wall of the liquid injection hole 150 protrudes downward from the lower side of the cover plate 100. The liquid injection hole 150 is used to inject electrolyte into the power battery. The explosion-proof assembly hole 140 is used to install an explosion-proof plate to relieve pressure when the internal pressure of the power battery is too high to prevent explosion due to excessive pressure.

[0051] Referring to Figure 6 , the terminal 200 includes an insertion portion 210 that extends through the mounting hole 110, a stopper 220 formed at the bottom of the insertion portion 210 and abutting against the lower surface of the sealing ring 300, and a contact portion 230 formed at the top of the insertion portion 210 and extending through the mounting hole 110. The outer circumference of the insertion portion 210 is spaced from the inner circumference of the mounting hole 110 to form the spacer 130, which allows the upper plastic component 500 to extend into and seal the assembly gap between the insertion portion 210 and the mounting hole 110. The contact portion 230 extends upward to the outside of the cover plate 100 to form the outlet end of the pole 200 and is exposed outside the upper plastic part 500 for connection with external electronic components. The outer peripheral surface of the contact portion 230 is covered by the upper plastic part 500 to achieve isolation between the pole 200 and the cover plate 100; preferably, a circle of mating annular grooves 231 are circumferentially provided on the outer peripheral surface of the contact portion 230. The inner peripheral surface of the upper plastic part 500 cooperates with the mating annular grooves 231 to position the pole 200 and prevent the pole 200 from shifting up and down in the axial direction. The diameter of the contact portion 230 is larger than the diameters of the insertion portion 210 and the contact portion 230. The contact portion 230 can adopt a conventional circular structure or a square structure. An isolation gap is formed between the upper surface of the contact portion 230 and the lower surface of the cover plate 100. The sealing ring 300 is sleeved on the outer peripheral surface of the insertion portion 210 and is located in the assembly gap, and the lower surface of the sealing ring 300 can abut against the upper surface of the contact portion 230, so that the upper surface of the contact portion 230 and the lower surface of the cover plate 100 cooperate to squeeze the sealing ring 300 to further enhance the sealing effect.

[0052] In this embodiment, the insertion portion 210, the stopper 220, and the contact portion 230 are integrally formed to form the terminal 200. No welding is required between the various components of the terminal 200 to prevent separation of the components after long-term use, which could affect the performance of the power battery. It is understood that in some other embodiments, the insertion portion 210, the stopper 220, and the contact portion 230 may also be separate structures, with each component being molded separately before being welded and assembled. This reduces the difficulty of mold opening and facilitates the assembly of the terminal 200 with the cover plate 100, the lower plastic part 600, and other structures.

[0053] 9 and 11 , the open end of the positioning groove 400 is in communication with the upper surface of the cover plate 100 , so that the bottom of the upper plastic part 500 can be positioned in the positioning groove 400 after injection molding. In this embodiment, the cross-section of the positioning groove 400 along the thickness direction of the cover plate 100 presents a variable cross-section structure with a larger bottom and a smaller top. When the bottom of the upper plastic part 500 is positioned in the positioning groove 400 , the inner wall of the positioning groove 400 at the smaller cross-section position can abut against the upper plastic part 500 to prevent the upper plastic part 500 from shifting upward in the axial direction, thereby ensuring reliable contact between the upper plastic part 500 and the cover plate 100 , thereby stably fixing the pole 200 in the mounting hole 110 and meeting the thrust and pull requirements between the pole 200 and the cover plate 100 .

[0054] Specifically, the positioning groove 400 includes a bottom groove 410 with a wider radial width and a connecting groove 420 with a narrower radial width and an opening connecting the bottom groove 410 and the positioning groove 400. The corresponding position of the bottom of the upper plastic part 500 is adapted to the shape of the connecting groove 420 and the bottom groove 410, so that the upper plastic part 500 can be fixed in the connecting groove 420 and the bottom groove 410 after injection molding to prevent the upper plastic part 500 from shifting in the axial direction. Preferably, the cross-section of the upper end of the bottom groove 410 (i.e., the end close to the connecting groove 420) is trapezoidal, and has a first inner wall and a second inner wall that are arranged opposite to each other and whose tops are close to the middle, so that the entire positioning groove 400 has a dovetail groove structure. When the pole 200 is subjected to a thrust or a pull and transmits the force to the upper plastic part 500, the bottom of the upper plastic part 500 generates an oblique outward and upward force on the first inner wall and the second inner wall. At this time, the first inner wall and the second inner wall will generate a reverse reaction force (i.e., oblique inward and downward) on the upper plastic part 500 to prevent the upper plastic part 500 from separating from the positioning groove 400, thereby achieving stable assembly of the upper plastic part 500 and the pole 200.

[0055] It is understandable that in some other embodiments, the cross-section of the bottom groove 410 may also be rectangular as a whole, so that the entire positioning groove 400 has a two-step groove structure; in this case, the bottom groove 410 has a first top wall and a second top wall arranged parallel to the bottom of the bottom groove 410, and the first top wall and the second top wall are located at the same horizontal position as the bottom of the connecting groove 420. When the pole 200 is subjected to a push or pull force, the bottom of the upper plastic part 500 will generate a vertical upward force on the first top wall and the second top wall, and correspondingly, the first top wall and the second top wall will generate a vertical downward reaction force on the upper plastic part 500 to limit the displacement of the upper plastic part 500.

[0056] In this embodiment, the positioning groove 400 is an annular groove structure disposed around the periphery of the mounting hole 110 to increase the contact area between the groove wall of the positioning groove 400 and the upper plastic part 500, thereby increasing the connection reliability between the upper plastic part 500 and the cover plate 100. It is understood that in other embodiments, the positioning groove 400 may also be a plurality of arcuate grooves disposed circumferentially on the cover plate 100 and arranged around the periphery of the mounting hole 110. The upper plastic part 500 is secured to the cover plate 100 through contact between the upper plastic part 500 and the arcuate grooves. Furthermore, the structure of the arcuate grooves is similar to that of the annular grooves, both comprising a bottom groove 410 and a connecting groove 420.

[0057] The positioning groove 400 has two opposing first and second sidewalls. The first sidewall is spaced apart from the second sidewall. An outer annular protrusion 430 is formed inwardly on the first sidewall and / or an inner annular protrusion 440 is formed inwardly on the second sidewall. The outer annular protrusion 430 and / or the inner annular protrusion 440 extend into the positioning groove 400 to separate the positioning groove 400 into the bottom groove 410 and the connecting groove 420. The outer annular protrusion 430 and / or the inner annular protrusion 440 can serve as a barrier to prevent the upper plastic part 500 from falling off and withstand the force applied by the upper plastic part 500. In a specific implementation, the outer annular protrusion 430 and / or the inner annular protrusion 440 respectively protrude into the positioning groove 400 from the middle of the first and second sidewalls of the positioning groove 400. The first and second inner walls of the bottom groove 410 are formed at the bottoms of the outer annular protrusion 430 and the inner annular protrusion 440, respectively.

[0058] In this embodiment, an outer annular protrusion 430 is provided on the first sidewall and an inner annular protrusion 440 is provided on the second sidewall, so that the cross-section of the bottom groove 410 has a symmetrical isosceles trapezoidal structure. When the upper plastic component 500 transmits the thrust and pull forces acting on the pole 200 to the cover plate 100, the outer annular protrusion 430 and the inner annular protrusion 440 can evenly share the force, further enhancing the installation stability of the upper plastic component 500. It is understood that in other embodiments, considering the difficulty and processing technology, the outer annular protrusion 430 may be provided only on the first sidewall or the inner annular protrusion 440 may be provided only on the second sidewall to independently withstand the force transmitted by the upper plastic component 500.

[0059] The upper surface of the outer ring protrusion 430 and / or the inner ring protrusion 440 is lower than the upper surface of the cover plate 100 to form a closed step 450. This configuration allows a height difference to be formed between the upper surface of the outer ring protrusion 430 and / or the inner ring protrusion 440 and the upper surface of the cover plate 100. When the upper plastic part 500 is injection-molded, the plastic material can flow to the closed step 450 and fully fill the space defined by the height difference. This allows the bottom of the solidified upper plastic part 500 to be stably supported on the closed step 450, thereby avoiding the formation of gaps between the upper plastic part 500 and the cover plate 100 due to product deformation, thereby improving product reliability.

[0060] As a preferred embodiment of this embodiment, an inner ring body 700 is further included, which is coaxially formed on the cover plate with the mounting hole and corresponds to the positioning groove 400 and the mounting hole. The inner ring body 700 is used to position the upper plastic part in the direction of axial rotation to prevent the upper plastic part from rotating. Specifically, at least one notch 710 is provided on the inner ring body 700 at intervals along the circumference. The notch 710 radially penetrates the inner and outer circumferences of the inner ring body 700. The bottom of the upper plastic part 500 can be confined within the notch 710 to prevent the upper plastic part 500 from rotating relative to the positioning groove 400 (or the cover plate 100) in the axial direction, thereby further improving the reliability of the product.

[0061] 13 , 14 and 15 , the upper plastic member 500 includes a main body 510 that is disposed around the protruding end of the pole 200 and supported on the cover 100 , a positioning portion 520 formed at the bottom of the main body 510 and positioned within the positioning groove 400 , and a sealing portion 530 formed at the bottom of the main body 510 and cooperating with the pole 200 to close the mounting hole 110 ; the main body 510 , the positioning portion 520 and the sealing portion 530 are integrally formed using an injection molding process.

[0062] The main body 510 is sleeved over the outer circumference of the contact portion 230 of the pole 200 to protect and isolate the contact portion 230. The bottom of the main body 510 is supported on the cover plate 100 and on the cover plate 100 and / or the closed step 450 on both sides of the positioning groove 400. An inwardly projecting positioning protrusion 511 is formed on the inner circumference of the main body 510. The positioning protrusion 511 is adapted in position and shape to the mating annular groove 231. After the main body 510 is formed, the positioning protrusion 511 can enter the mating annular groove 231 to prevent relative axial displacement between the main body 510 and the pole 200.

[0063] The overall structure of the positioning portion 520 is adapted to the structure of the positioning groove 400 so as to withstand the reaction force generated by the groove wall of the positioning groove 400 when the pole 200 is subjected to an external force, thereby preventing the upper plastic part 500 from falling off from the positioning groove 400 as a whole. The positioning portion 520 includes a connecting section 521 formed at the bottom of the main body 510 and positioned in the connecting groove 420, and an anti-slip section 522 formed at the bottom of the connecting section 521 and positioned in the bottom groove 410. The connecting section 521 and the anti-slip section 522 are adapted to the shapes of the connecting groove 420 and the bottom groove 410. Specifically, the anti-slip section 522 is formed with a first load-bearing wall and a second load-bearing wall at the positions corresponding to the first inner wall and the second inner wall, respectively, which can abut against the first inner wall and the second inner wall to withstand the reaction force from the first inner wall and the second inner wall to achieve anti-slip.

[0064] The blocking portion 530 can extend into the spacer 130 after molding, and the side surfaces of the blocking portion 530 correspondingly contact the outer peripheral surface of the main body 510, the inner peripheral surface of the mounting hole 110 and the upper surface of the sealing ring 300 to block the spacer 130.

[0065] Preferably, the upper plastic part 500 further includes an anti-rotation portion 540 formed at the bottom of the main body 510 and correspondingly extending into the notch 710. When the upper plastic part 500 is subjected to an axial rotation force, the side wall of the anti-rotation portion 540 abuts against the side wall of the notch 710 to achieve overall anti-rotation of the upper plastic part 500.

[0066] In this embodiment, the shape of the upper plastic part 500 matches the shape of the positioning groove 400 and is a circular structure as a whole. It is understandable that in other embodiments, the upper plastic part 500 can also be other shapes, such as triangle, square or other polygonal structures.

[0067] The lower plastic part 600 is pressed onto the lower side of the cover plate 100 and can be configured as a one-piece component with a shape that matches the cover plate 100, or as a split component that matches the number of poles 200. Specifically, when the power battery top cover is assembled with two poles 200, the number of lower plastic parts 600 can be configured to correspond one to each pole 200. The two lower plastic parts 600 are respectively used to insulate and seal the bottom of the pole 200 from the lower side of the cover plate 100, preventing electrolyte from entering the mounting hole 110 through the gap between the lower plastic part 600, the bottom of the pole 200, and the cover plate 100.

[0068] Referring to Figures 3, 4, and 17, the lower plastic member 600 shown in this embodiment is a one-piece component. A press-fit ring 640 is provided at a position corresponding to the mounting ring groove 120 on the lower plastic member 600, which is pressed into the mounting ring groove 120 to secure the lower plastic member 600. A clearance hole 610 is coaxially provided at a position corresponding to the mounting hole 110 on the lower plastic member 600. The clearance hole 610 is larger than the insertion portion 210 and smaller than the stop portion 220. This allows the stop portion 220 to limit the length of the pole 200 that can be extended when the pole 200 is inserted into the cover plate 100. The inner circumference of the clearance hole 610 protrudes inward to form an isolation ring 650 that rests between the lower surface of the cover plate 100 and the pole 200. When the pole 200 penetrates the cover plate 100, the isolation ring 650 can rest between the upper surface of the limiting portion 220 of the pole 200 and the lower surface of the cover plate 100, thereby achieving further insulation between the pole 200 and the cover plate 100.

[0069] A downwardly concave vortex structure 660 is formed in the middle of the lower plastic part 600. The sidewalls of this vortex structure 660 have a curved cross-section. Compared to conventional cylindrical or rectangular grooves, the sidewalls of this vortex structure 660 have a larger area, making it easier to demold and preventing deformation. A retaining groove 620 is provided on the lower surface of the lower plastic part 600, extending around the outer edge of the clearance hole 610. The retaining portion 220 of the pole 200 is positioned within this retaining groove 620, and the insertion portion 210 extends through the clearance hole 610 and the mounting hole 110. The shape of this retaining groove 620 is determined by the shape of the retaining portion 220 at the bottom of the pole 200. When the retaining portion 220 of the pole 200 is square, the retaining groove 620 is defined as a square retaining groove 620 that matches the outer dimensions of the square retaining portion 220. When the limiting portion 220 of the pole 200 is circular, the limiting groove 620 is defined as a circular limiting groove 620 that is adapted to the outer dimensions of the circular limiting portion 220 .

[0070] Because the lower plastic part 600, upper plastic part 500, and sealing ring 300 are typically made of plastic, plastic will expand and contract (deform) with the battery's operating temperature. It will also deform over time, due to the battery's operating environment, and due to other factors such as aging. Deformed plastic parts and sealing ring 300 can easily cause displacement and gaps between them and the terminal 200 and / or cover plate 100, affecting the sealing effect of the power battery top cover. To address this problem, embedded grooves and embedded blocks are provided between the upper plastic part 500 and the terminal 200, between the upper plastic part 500 and the cover plate 100, and between the sealing ring 300, the cover plate 100, and the terminal 200. To address the deformation and displacement issues between the lower plastic part 600, the terminal post 200, and the cover plate 100, this embodiment modifies the shape of the retaining groove 620 and combines this modified shape with the original liquid injection hole 150 on the cover plate 100 to achieve positional restraint between the lower plastic part 600, the terminal post 200, and the cover plate 100, thereby resolving the displacement issue caused by deformation of the lower plastic part 600. Specifically, the retaining groove 620 has a first diameter along the width direction of the cover plate 100 and a second diameter along the length direction of the cover plate 100 of unequal lengths. Among the first diameter and the second diameter, one of the diameters is adapted to the outer diameter of the circular limiting portion 220, so that the limiting groove 620 limits the limiting portion 220 along the direction of the one diameter; for example, the first diameter along the width direction is adapted to the outer diameter of the circular limiting portion 220, so that the groove walls on both sides of the limiting groove 620 along the width direction limit the circular limiting portion 220, thereby realizing the displacement of the lower plastic part 600 and the pole 200 in the width direction. The other diameter is larger than the outer diameter of the circular stopper 220, so that a gap is formed between the groove walls of the stopper groove 620 and the corresponding sides of the circular stopper 220 along the other diameter direction. This gap is defined as a contraction gap. It provides space for the lower plastic part 600 to contract and deform inward when the lower plastic part 600 contracts and deforms, preventing the lower plastic part 600 from generating a pushing or pulling force when contracting inward. When the pushing or pulling force accumulates to a certain number of times, it will cause the terminal 200 to loosen or shift, resulting in a gap between the terminal 200, the lower plastic part 600, and the cover plate 100. In this embodiment, limiting along the other direction (for example, limiting along the length direction) can be achieved by a groove 630 provided on the lower plastic part 600. Specifically, the groove 630 cooperates with the injection hole 150 to limit the position of the stopper 220 along the other diameter direction.

[0071] The power battery top cover of this embodiment forms a positioning groove 400 with a dovetail groove structure by correspondingly providing an inner ring protrusion 440 and an outer ring protrusion 430 on the first and second side walls of the positioning groove 400. The anti-slip section 522 and the connecting section at the bottom of the upper plastic part 500 cooperate with the bottom groove 410 and the connecting groove 420 of the positioning groove 400 to prevent the upper plastic part 500 from falling off, thereby meeting the requirements of withstanding tension and thrust between the pole 200 and the cover plate 100. At the same time, a notch 710 is provided on the inner ring body 700, and an anti-rotation portion 540 corresponding to the notch 710 is provided at the bottom of the upper plastic part 500 to prevent the upper plastic part 500 from rotating in the axial direction, thereby improving the assembly stability of the upper plastic part 500.

[0072] Example 2

[0073] Please refer to Figures 21, 22 and 23. The power battery top cover of this embodiment includes a cover plate 100, a pole 200, a sealing ring 300 and a lower plastic part 600 with the same or similar structure as in Example 1. The difference between this embodiment and Example 1 is that the positioning groove 400 and the upper plastic part 500 in this embodiment have a square structure.

[0074] In this embodiment, since the overall structure of the positioning groove 400 is a square, after the upper plastic part 500 is injection molded, the upper plastic part 500 can be prevented from rotating by the two opposite corners of the square structure without the need to set the notch 710 structure, thereby simplifying the overall structure and process of the cover 100; similarly, when the overall shape of the positioning groove 400 is set to other polygonal structures, the upper plastic part 500 can also be prevented from rotating by the corners of the polygonal structure.

[0075] The power battery top cover of this embodiment is provided with a square positioning groove 400 that cooperates with the upper plastic part 500 to achieve anti-rotation. The provision of the notch 710 on the inner ring body 700 can be eliminated, thereby simplifying the structure of the entire cover plate 100 and the molding process of the notch 710 to improve molding efficiency.

[0076] Example 3

[0077] Please refer to Figures 2 and 21. The power battery top cover of this embodiment includes a cover plate 100, a pole 200 arranged on the cover plate 100, an upper plastic part 500 that is insulated and sealed between the cover plate 100 and the pole 200, a sealing ring 300, and a lower plastic part 600. The cover plate 100 is provided with a mounting hole 110, an explosion-proof assembly hole 140, and a liquid injection hole 150. The hole wall of the liquid injection hole 150 protrudes downward from the lower side of the cover plate 100. In common application examples, the power battery top cover is usually equipped with a first pole and a second pole. The first pole can be defined as a positive pole or a negative pole. When the first pole is defined as a positive pole, the second pole is defined as a negative pole. Conversely, when the first pole is defined as a negative pole, the second pole is defined as a positive pole. Corresponding to the first and second poles, the cover plate is provided with a first mounting hole 110 for mounting the first pole and a second mounting hole 110 for mounting the second pole. A first upper insulating member, a first sealing ring 300, and a first lower plastic member are disposed between the first pole and the cover plate. A second upper insulating member, a second sealing ring 300, and a second lower plastic member are disposed between the second pole and the cover plate. Because the first and second poles have identical or similar structures, and because some embodiments may have only one pole on top of the power battery, for a clearer and more concise description of this solution, pole 200 is replaced by the first and second poles, mounting hole 110 is replaced by the first and second mounting holes 110, upper plastic member 500 is replaced by the first and second upper insulating members, and lower plastic member 600 is replaced by the first and second lower plastic members.

[0078] Referring to Figures 3 and 22, the upper side of the cover plate 100 is formed with a second axial stopper for axially limiting the upper plastic part 500 (the axial direction of the pole, in the Z direction in the figure). The second axial stopper can be defined as a positioning groove 400 distributed around the outer circumference of the pole 200, and the positioning groove 400 is coaxially arranged with the mounting hole 110. The shape of the positioning groove 400 is determined according to the shape of the upper plastic part 500. When the upper plastic part 500 is in the shape of a square ring, the positioning groove 400 is adaptively configured as a square frame. When the upper plastic part 500 is in the shape of a circular ring, the positioning groove 400 is adaptively configured as a ring. In addition, when the upper plastic part 500 is in the shape of a circular ring, the upper side of the cover plate 100 is further formed with a third circumferential stopper 160 for circumferentially limiting the upper plastic part 500, preventing relative rotation between the upper plastic part 500 and the cover plate 100.

[0079] 5 , 11 , and 12 , the cross-section of the positioning groove 400 along the axial direction of the cover plate 100 presents a variable cross-section structure with a larger bottom and a smaller top. This allows the upper plastic part 500 to be positioned in the positioning groove 400. The inner wall of the positioning groove 400 at the smaller cross-section position can abut against the upper plastic part 500 to prevent the upper plastic part 500 from shifting upward in the axial direction, thereby ensuring reliable contact between the upper plastic part 500 and the cover plate 100. This allows the pole 200 to be stably fixed in the mounting hole 110, thereby satisfying the thrust and pull requirements between the pole 200 and the cover plate 100.

[0080] In the illustrated embodiment, the positioning groove 400 includes a wide groove 460 with a relatively wide radial width and a narrow groove 470 with a relatively narrow radial width and connected to the wide groove 460 . The narrow groove 470 is located above the wide groove 460 and connected thereto. The upper end of the wide groove 460 (i.e., the end closest to the narrow groove 470) has a trapezoidal cross-section, having a first inner wall 460a and a second inner wall 460b that are oppositely disposed and whose tops converge toward the center, so that the entire wide groove 460 has a dovetail groove structure. When the pole 200 is subjected to a thrust or tension force and transmits the force to the upper plastic component 500, the bottom of the upper plastic component 500 generates an oblique outward and upward force on the first inner wall 460a and the second inner wall 460b. At this time, the first inner wall 460a and the second inner wall 460b will generate a reaction force in the opposite direction (i.e., oblique inward and downward) on the upper plastic component 500 to prevent the upper plastic component 500 from disengaging from the positioning groove 400, thereby achieving stable assembly of the upper plastic component 500 and the pole 200. It is understandable that in some other embodiments, the cross-section of the wide groove 460 may also be rectangular as a whole, so that the entire positioning groove 400 has a two-step groove structure; in this case, the wide groove 460 has a first top wall and a second top wall arranged parallel to the groove bottom of the wide groove 460, and the first top wall and the second top wall are located at the same horizontal position as the bottom of the narrow groove 470. When the pole 200 is subjected to a push or pull force, the bottom of the upper plastic part 500 will generate a vertical upward force on the first top wall and the second top wall, and correspondingly, the first top wall and the second top wall will generate a vertical downward reaction force on the upper plastic part 500 to limit the displacement of the upper plastic part 500.

[0081] The positioning groove 400 is an annular groove structure disposed around the periphery of the mounting hole 110 to increase the contact area between the groove wall of the positioning groove 400 and the upper plastic part 500, thereby improving the connection reliability between the upper plastic part 500 and the cover plate 100. It is understood that in other embodiments, the positioning groove 400 may also be a plurality of arcuate grooves disposed circumferentially on the cover plate 100 and arranged around the periphery of the mounting hole 110. The upper plastic part 500 is secured to the cover plate 100 through contact between the arcuate grooves. Furthermore, the structure of the arcuate grooves is similar to that of the annular grooves, both including a wide groove 460 and a narrow groove 470.

[0082] Please refer to Figure 10. The third circumferential limiting portion 160 can be provided between the inner periphery of the positioning groove 400 and the outer periphery of the mounting hole 110, or provided on the inner ring body 700 on the outer periphery of the positioning groove 400 and the notch 710 provided on the inner ring body 700 in the radial direction. The inner ring body 700, the positioning groove 400 and the mounting hole 110 are coaxially arranged. In the embodiment shown, the inner ring body 700 is provided around the outer periphery of the pole 200, and the outer peripheral wall of the inner ring body 700 forms the first inner wall 460a of the positioning groove 400. The notch 710 can be configured as one or more. When configured as multiple, the multiple notches 710 are distributed circumferentially around the inner ring body 700 on the inner ring body 700, and each notch 710 penetrates the inner ring body 700 radially outward to connect to the positioning groove 400.

[0083] Referring to Figures 8 and 9 , the pole 200 includes a stopper 220 disposed on the underside of the cover 100 and an insert 210 erected on the stopper 220. The insert 210 extends upward through the mounting hole 110 to be exposed on the upper side of the cover 100. The stopper 220 can be a conventional circular stopper 220 or a square stopper 220. The area of ​​the stopper 220 in horizontal projection is larger than the area of ​​the mounting hole 110, such that the stopper 220 completely covers the bottom surface of the mounting hole 110, and its outer edge overlaps the cover 100. It should be understood that the stopper 220 is not a necessary technical component of the pole. In some embodiments, the pole 200 can be directly designed as a column structure.

[0084] The outer periphery of the insert portion 210 is formed with a first axial stopper that axially engages with the upper plastic component 500. This first axial stopper is defined as an inner concave annular groove 231 disposed around the outer periphery of the insert portion 210. The inner concave annular groove 231 axially separates the insert portion 210 into a top column 21a and a bottom column 21b with larger diameters, and a center column with a smaller diameter. The lower side surfaces of the top column 21a and the upper side surfaces of the bottom column 21b are defined as the side walls of the inner concave annular groove 231, while the outer circumference of the center column is defined as the bottom surface of the inner concave annular groove 231. It should be understood that the first axial stopper is not limited to the inner concave annular groove 231 described above. For example, in some embodiments, the first axial stopper may also be defined as an outer convex annular portion (not shown) disposed around the outer periphery of the insert portion 210.

[0085] The outer periphery of the insert portion 210 is formed with a first circumferential limit portion that cooperates with the upper plastic part 500 to limit the position. The first circumferential limit portion is defined as an inner recess 232 that is recessed inward from the outer periphery of the insert portion 210. The inner recess 232 can be an inner groove or inner recess of various shapes that is recessed radially inward along the insert portion 210. In the illustrated embodiment, the outer periphery of the center column can be composed of a first flat surface 233 and an arcuate surface, so that the pole 200 has a D-shape when projected horizontally. During specific processing, the first flat surface 233 can be processed using a cutting mechanism, a milling mechanism, etc., and the space missing from the insert portion 210 after processing forms the inner recess 232, and the first flat surface 233 forms the inner concave surface of the inner recess. It should be understood that the structure of the insert portion 210 is not limited to the structure described above. For example, in some embodiments, the insert portion 210 of the pole 200 can be designed as a uniform diameter insert portion 210. When the insert portion 210 is a uniform diameter insert portion 210, the inner recess 232 is directly formed on the outer circumferential surface of the insert portion 210. Furthermore, in some embodiments, the first circumferential stopper can also be defined as an outer convex portion extending outward from the outer circumferential surface of the insert portion 210. The outer convex portion can be a convex block of various shapes extending radially outward from the insert portion 210, and can be designed with reference to the inner recess 232 described above. The outer convex surface of the outer convex portion (the surface radially away from the center of the pole 200) can be designed as a first flat surface. When the first axial stopper is defined as an outer convex ring portion, the first circumferential stopper is defined as an outer convex portion extending outward from the outer side of the outer convex ring portion.

[0086] Please refer to Figure 9. When the pole 200 is assembled in the mounting hole 110, in one embodiment (such as this embodiment), the upper side of the base column 21b is highly adapted to the upper side of the cover plate 100, and the outer diameter of the base column 21b is smaller than the aperture of the mounting hole 110, so that a filling gap 240 (annular gap) filled with injection molding glue is formed between the base column 21b and the mounting hole 110. The middle column and the top column 21a are both higher than the upper side of the cover plate 100 so that at least part of the notch of the inner concave annular groove 231 is higher than the upper side of the cover plate 100. When injection molding the upper plastic part 500, the injection molding glue is injected into the inner concave annular groove 231 to form the first axial fitting portion described below. The injection molding glue continues to be radially injected into the inner concave portion 232 (the first circumferential limiting portion) to form the first circumferential fitting portion described below. The injection molding glue is injected downward into the filling gap 240 to form the filling portion described below. The injection molding glue is injected into the space between the upper side of the cover plate 100 and the top of the mold cavity to form the main body portion 510 described below.

[0087] 13, 14, 15, and 16, the upper plastic component 500 is disposed around the periphery of the pole 200 and includes an annular main body 510, a second axially engaging portion formed at the bottom of the main body 510 and engaging with the second axially engaging portion, a third circumferentially engaging portion formed at the bottom of the main body 510 and engaging with the third circumferentially engaging portion 160, a first axially engaging portion formed at the inner periphery of the main body 510 and engaging with the first axially engaging portion, a first circumferentially engaging portion formed at the inner periphery of the main body 510 and engaging with the first circumferentially engaging portion, and a blocking portion 530 formed at the inner periphery of the main body 510 to fill the filling gap 240. The main body 510, the second axially engaging portion, the third circumferentially engaging portion, the first axially engaging portion, the first circumferentially engaging portion, and the blocking portion 530 are integrally formed using an injection molding process.

[0088] The second axially engaging portion is defined as a positioning portion 520 that is limitedly engaged with the positioning groove 400. The overall structure of the positioning portion 520 is adapted to the structure of the positioning groove 400 to withstand the reaction force generated by the groove wall of the positioning groove 400 when the pole 200 is subjected to external force, thereby preventing the upper plastic part 500 from falling out of the positioning groove 400. The positioning portion 520 includes a connecting section 521 formed at the bottom of the main body 510 and positioned within the narrow groove 470, and a retaining section 522 formed at the bottom of the connecting section 521 and positioned within the wide groove 460. The connecting section 521 and the retaining section 522 are adapted to the shapes of the narrow groove 470 and the wide groove 460. Specifically, the anti-slip section 522 is provided with a first force-bearing wall 522a and a second force-bearing wall 522b at positions corresponding to the first inner wall 460a and the second inner wall 460b, respectively, which can abut against the first inner wall 460a and the second inner wall 460b to withstand the reaction force from the first inner wall 460a and the second inner wall 460b, thereby achieving axial anti-slip of the upper plastic part 500.

[0089] The third circumferential engagement portion is disposed on the bottom surface of the main body 510 at a position corresponding to the third circumferential stopper 160. The third circumferential engagement portion is complementary in shape to the third circumferential stopper 160 and includes a concave ring 560 that engages concavely with the inner ring body 700 and an anti-rotation portion 540 that engages concavely with the notch 710. This ensures circumferential engagement between the upper plastic component 500 and the cover plate 100, preventing relative rotation between the upper plastic component 500 and the cover plate 100. During injection molding of the upper plastic component 500, the plastic is injected into the inner ring body 700 to form the concave ring 560 and into the notch 710 to form the anti-rotation portion 540.

[0090] The first axially engaging portion cooperates with the inner concave annular groove 231 to achieve axial positioning of the pole 200. In the illustrated embodiment, the first axially engaging portion is defined as a positioning protruding ring 511 disposed around the inner circumference of the main body 510 and embedded in the inner concave annular groove 231. It should be understood that in some embodiments, when the first axially engaging portion is the outer convex annular portion, the first axially engaging portion can be adaptively configured as an outer concave annular groove disposed around the inner circumference of the main body 510.

[0091] The first circumferentially engaging portion cooperates with the first circumferentially limiting portion to achieve circumferential limiting of the pole 200 and prevent rotation of the pole 200. In the illustrated embodiment, the first circumferentially engaging portion is defined as an inner convex portion 550 that cooperates with the inner recess 232. The inner convex portion 550 extends inward from the inner side surface of the positioning protruding ring 511. The inner convex surface of the inner convex portion 550 is defined as a second flat surface 551 that mates with the first flat surface 233 of the inner recess 232, achieving a limited fit with the inner recess 232 at the bottom of the inner recessed annular groove 231. In some embodiments, when the first circumferentially limiting portion is defined as an outer convex portion, the first circumferentially engaging portion is adaptively defined as an outer concave portion formed on the inner circumferential surface of the upper plastic component 500 and cooperating with the outer convex portion. Furthermore, the outer concave portion is formed by being recessed outward from the bottom surface of the outer recessed annular groove.

[0092] Continuing to refer to FIG3 and FIG22 , the lower plastic part 600 is pressed onto the lower side of the cover plate 100 and can be configured as an integral part whose shape matches the cover plate 100 , or as a split part whose number matches the number of poles 200 . Specifically, when the battery top cover is assembled with two poles 200 , the number of the lower plastic parts 600 can be configured to correspond one to one with the two poles 200 . The two lower plastic parts 600 are respectively used to insulate and seal the limiting portion 220 of the pole 200 from the lower side of the cover plate 100 , thereby preventing the electrolyte from entering the mounting hole 110 through the gap between the lower plastic part 600 and the limiting portion 220 of the pole 200 and the cover plate 100 .

[0093] In the illustrated embodiment, the lower plastic component 600 is defined as a one-piece component. An axially extending clearance hole 510 is provided on the lower plastic component 600 at a location corresponding to the mounting hole 110. To facilitate assembly of the sealing ring 300, the diameter of the clearance hole 510 is slightly larger than that of the mounting hole 110. When the sealing ring 300 is encircled over the insertion portion 210, the lower side of the sealing ring 300 contacts the retaining portion 220 of the terminal 200. The outer circumference of the sealing ring 300 can contact the inner edge of the clearance hole 510. The upper side of the sealing ring 300 contacts the lower side of the sealing portion 530 of the upper plastic component 500 located within the filling gap 240. The upper side of the sealing ring 300 also contacts the lower side of the outer edge of the cover plate 100 surrounding the mounting hole 110, thereby achieving an insulating seal along the lower side of the cover plate 100.

[0094] Referring to Figure 18 , a downwardly concave vortex structure 660 is formed in the middle of the lower plastic part 600. The sidewalls of the vortex structure 660 have a curved cross-section. Compared to conventional cylindrical or rectangular grooves, the sidewalls of the vortex structure 660 have a larger area, making it easier to demold and preventing deformation. A retaining groove 620 is provided on the lower side of the lower plastic part 600, extending around the outer edge of the clearance hole 510. The retaining portion 220 of the pole 200 is positioned within the retaining groove 620, and the insertion portion 210 extends through the clearance hole 510 and the mounting hole 110. The shape of the retaining groove 620 is determined by the shape of the retaining portion 220 of the pole 200. If the retaining portion 220 of the pole 200 is a square retaining portion 220, the retaining groove 620 is defined as a square retaining groove 620 that matches the outer dimensions of the square retaining portion 220. When the limiting portion 220 of the pole 200 is a circular limiting portion 220 , the limiting groove 620 is defined as a circular limiting portion 220 that matches the outer dimensions of the circular limiting portion 220 .

[0095] Referring to Figure 19 , since the lower plastic part 600, upper plastic part 500, and sealing ring 300 are typically made of plastic, they will expand and contract (deform) with the battery's operating temperature. They will also deform over time, due to the battery's operating environment, and due to other factors such as aging. Deformed plastic parts can easily cause displacement and gaps between them and the terminal 200 and / or cover plate 100, affecting the sealing effect of the power battery top cover. To address this issue, grooves and blocks are provided between the upper plastic part 500 and the terminal 200, between the upper plastic part 500 and the cover plate 100, and between the sealing ring 300, the cover plate 100, and the terminal 200. To address the deformation and displacement issues between the lower plastic part 600, the terminal 200, and the cover plate 100, this embodiment modifies the shape of the limiting groove 620 and combines the modified limiting groove 620 shape with the original liquid injection hole 150 on the cover plate 100 to achieve positioning between the lower plastic part 600, the terminal 200, and the cover plate 100, thereby resolving issues such as displacement and loosening caused by deformation of the lower plastic part 600. Specifically, the limiting groove 620 has a first diameter along the width direction of the cover plate 100 (the Y direction in the figure) and a second diameter along the length direction of the cover plate 100 (the X direction in the figure) of unequal length. Among the first diameter and the second diameter, one of the diameters is adapted to the outer diameter of the circular limiting portion 220, so that the limiting groove 620 limits the limiting portion 220 along the direction of the one diameter; for example, the first diameter along the width direction is adapted to the outer diameter of the circular limiting portion 220, so that the groove walls on both sides of the limiting groove 620 along the width direction limit the circular limiting portion 220, thereby preventing the lower plastic part 600 and the pole 200 from shifting in the width direction. The other diameter is larger than the outer diameter of the circular stopper 220, so that a gap is formed between the groove walls of the stopper groove 620 and the corresponding sides of the circular stopper 220 along the other diameter direction. This gap, defined as a contraction gap 670, provides space for the lower plastic part 600 to contract and deform inward when the lower plastic part 600 contracts and deforms, preventing the lower plastic part 600 from generating a pushing or pulling force when contracting inward. When the pushing or pulling force accumulates to a certain number of times, it will cause the terminal 200 to loosen or shift, resulting in a gap between the terminal 200, the lower plastic part 600, and the cover plate 100. In the illustrated embodiment, the position limitation along the other direction (e.g., the lengthwise direction) can be achieved by providing a groove 630 on the lower plastic part 600, so that the groove 630 cooperates with the injection hole 150 to limit the position of the stopper 220 along the other diameter direction.

[0096] The upper plastic part 500, cover plate 100, pole 200, and lower plastic part 600 are injection molded by an injection mold (not shown). The injection mold includes a lower mold and an upper mold. The mating surface of the lower mold has a contoured groove that matches the shape of the cover plate 100. The mating surface of the upper mold and the cover plate 100 enclose a mold cavity that matches the upper plastic part 500. The contoured groove is used to limit the horizontal position of the cover plate 100 during the injection molding process. The bottom of the contoured groove is provided with a second circumferential limit portion (not shown) for limiting the rotation of the pole 200. The second circumferential limit portion can be defined as a limiting protrusion or a limiting recess. Correspondingly, the bottom surface of the limiting portion 220 of the pole 200 is provided with a second circumferential mating portion that cooperates with the second circumferential limit portion. The second circumferential mating portion can be adaptively defined as a limiting recess 221 or a limiting protrusion. The outer facade of the limiting protrusion has at least one third flat surface for limiting the rotation of the pole 200 , and the inner facade of the limiting recess 221 has a fourth flat surface that fits with the third flat surface.

[0097] Continuing to refer to Figures 8, 18, and 19, the upper mold is provided with a gate, through which the plastic is injected into the mold cavity to form the upper plastic part 500. Typically, the gate is provided on the upper mold near the inner side of the pole 200, and when the mold is closed, the pressure at the gate is greater than the pressure at the rest of the mold. To prevent the top column 21a or bottom column 21b of the pole 200 facing the inner recess 232 from collapsing, when the pole 200 is placed in the injection mold, it is necessary to avoid the inner recess 232 and the gate being in the same orientation (for example, the inner recess 232 can be directed toward the outside of the cover plate 100). To avoid manual misjudgment or omission of orientation, in the illustrated embodiment, an orientation pointing portion 221a pointing to the orientation of the inner recess 232 can be provided on the second circumferential mating portion and / or the second circumferential limiting portion, so that the orientation of the inner recess 232 is misaligned with the gate of the injection mold. In the illustrated embodiment, the limiting recess 221 at the bottom of the limiting portion 220 is configured as an arrowhead-shaped, pointed-shaped (e.g., conical, triangular, etc.), or arrow-shaped limiting groove. For example, the limiting groove is an isosceles triangle, with its tip (orientation-pointing portion 221a) facing outward from the profiling groove, in the same direction as the inner groove. The limiting protrusion at the profiling groove is configured as an isosceles triangle-shaped limiting protrusion with its tip facing the same direction. By simply adapting the limiting recess 221 and the limiting protrusion to have a direction, with the direction pointing toward the inner recess 232, and the direction being inconsistent with the gate direction (e.g., opposite to each other), a foolproof structure can be implemented, preventing the inner recess 232 from being in the same orientation as the gate, solving problems such as the collapse of the pole 200 caused by manual misjudgment or misjudgment of orientation, and improving processing efficiency and yield.

[0098] The process principle of the power battery top cover of this embodiment is as follows: (1) providing a cover plate 100, a pole 200, a sealing ring 300 and a lower plastic part 600, wherein the cover plate 100 is equipped with an explosion-proof plate; (2) placing the pole 200 into a mold, so that the limiting groove at the limiting portion 220 of the pole 200 is limitedly matched with the limiting protrusion in the contour groove, orienting the inner groove on the pole 200 and preventing the pole 200 from rotating; (3) fitting the sealing ring 300 onto the outer periphery of the insertion portion 210; (4) placing the lower plastic part 600 into the contour groove; The limiting groove 620 is positioned in the groove and above the limiting portion 220 of the pole 200, so that the limiting groove 620 cooperates with the limiting portion 220 of the pole 200 to limit the position; (5) the cover plate 100 is placed in the contoured groove, so that the insertion portion 210 of the pole 200 passes upward through the mounting hole 110; (6) the mold is closed, and the shape of the mold cavity after the mold is closed is adapted to the upper plastic part 500, and the injection molding enters the mold cavity through the gate to form the upper plastic part 500, and at the same time, the pole 200, the cover plate 100, the sealing ring 300, the upper plastic part 500 and the lower plastic part 600 are formed into one piece.

[0099] Example 4

[0100] Please refer to Figures 23 and 24, which are flow charts of the process for forming the cover plate 100 of the power battery top cover of this embodiment. The process for forming the cover plate 100 of the power battery top cover of this embodiment is used to achieve the formation of the cover plate 100 in Example 1, Example 2, and / or Example 3. Specifically, this embodiment includes the following steps:

[0101] S301: providing a plate preform 810 and pre-punching it to form a pre-punched hole 820 .

[0102] A sheet metal preform 810 for forming a cover plate 100 is provided. The sheet metal preform 810 has an overall rectangular structure and a first surface and a second surface. The sheet metal preform 810 is pre-punched from the first surface to the second surface (i.e., along the thickness direction of the sheet metal preform), forming a pre-pressing hole 820. The pre-pressing hole 820 is used to form the mounting hole 110. During the pre-punching process, the inner diameter of the pre-pressing hole 820 is smaller than the inner diameter of the mounting hole 110 to reserve a forging margin for the subsequent forging process, thereby improving the forming accuracy.

[0103] S302: Forging the back step 830 for the first time.

[0104] A forging machine is used to forge a back step 830 at a position corresponding to the pre-stressing hole 820 on the second surface of the plate preform 810. Since the forging process will not cause waste slag to be generated in the plate preform 810, the forging margin generated by forging the back step 830 will flow into the pre-stressing hole 820 in the middle to form a back step 830 with a height difference with the second surface on the second surface. The back step 830 is used to form a mounting ring groove 120 on the cover plate in a subsequent process to press-fit with the molded lower plastic part 600.

[0105] S303: Forging the front step to form an annular groove 840.

[0106] A top-opening annular groove 840 is forged on the first surface of the plate preform 810 at a position corresponding to the pre-stressing hole 820, so as to form a first forging surface and a second forging surface of a forged closed step 450 on the upper surface of the plate preform 810 corresponding to the two sides of the annular groove. The annular groove has two oppositely arranged first and second side walls, and the radial width of the annular groove 840 is the same at all locations along the axial direction; the forging margin generated by the forging of the annular groove 840 flows into the back step 830 and the pre-stressing hole 820 respectively.

[0107] In this embodiment, for the positioning groove 400 of the annular structure, the notch 710 is forged simultaneously when the front step is forged. In this way, the two-step forming process can be combined to improve the forming efficiency.

[0108] S304 : Forging the inner ring protrusion 440 and the outer ring protrusion 430 to form the positioning groove 400 .

[0109] The first forging surface and the second forging surface are forged downward so that the first side wall is extruded inward to form an outer ring protrusion 430 and / or the second side wall is extruded outward to form an inner ring protrusion 440. The inner ring protrusion 440 and / or the outer ring protrusion 430 protrude so that the annular groove 840 becomes a positioning groove 400 with a variable cross-section that is larger at the bottom and smaller at the top.

[0110] In this embodiment, the forging head is in a "T"-shaped structure, the width of the vertical section of the forging head is smaller than the width of the annular groove and the width of the horizontal section is larger than the width of the annular groove. During forging, the vertical section of the forging head extends into the annular groove and the horizontal section is pressed on the first forging surface and the second forging surface. As the forging head is pressed downward, the first forging surface and the second forging surface are squeezed downward to form a height difference between the first forging surface and the second forging surface and the upper surface of the cover plate 100, thereby forming a closed step 450; at the same time, since the width of the vertical section is smaller than the width of the annular groove 840, the excess formed by the sinking of the first forging surface and the second forging surface will flow into the first side wall and the second side wall of the annular groove 840 to form corresponding inner ring protrusions 440 and outer ring protrusions 430 on the first side wall and the second side wall, thereby forming a positioning groove 400 with a variable cross-section.

[0111] S305 : Forging the back step 830 for the second time to form the mounting ring groove 120 .

[0112] The back step 830 is forged a second time to form the mounting ring groove 120 , and the excess of the front step that has flowed to the back step 830 during the forging in steps S303 and S304 is squeezed and adjusted into the pre-pressing hole 820 .

[0113] S306 : forming the mounting hole 110 by fine stamping.

[0114] The pre-pressed hole 820 is fine-punched according to the designed size of the mounting hole 110 to form the mounting hole 110 , thereby completing the forging process of the cover plate 100 .

[0115] The molding process of the cover plate 100 having the square structure positioning groove 400 is the same as the above molding process, and will not be described in detail here.

[0116] The forming process of the cover plate 100 of the power battery top cover of this embodiment is obtained by a forging process. During the forging process, the forging margin of the plate structure such as the forging trough body, the notch 450, and the step will flow into the pre-stressing hole in the middle and will be completely cut off during the final fine stamping. This can effectively reduce the generation of waste slag during the forming process, is easy to clean, and forms fewer burrs in the trough body and the notch 450, which can simplify the grinding process and thus improve the forming efficiency.

[0117] The present invention also discloses a power battery, comprising the power battery top cover in the above embodiment.

[0118] The power battery top cover and the power battery of the present invention have at least the following effects: (1) The circumferential position of the pole is limited by the first circumferential limiting portion provided on the outer periphery of the column and the first circumferential matching portion provided on the inner periphery of the upper insulating member, thereby preventing the pole from rotating. The first circumferential matching portion is integrally injection-molded when the upper insulating member is injected. There is no need to provide a separate ceramic positioning block, nor is there a need to provide grooves for assembling the positioning blocks on the cover plate and the pole, which greatly reduces the complexity of the process, and the injection-molded first circumferential matching portion and the first circumferential limiting portion cooperate more closely, further ensuring the insulating sealing effect. (2) The axial position of the pole is also limited by the first axial limiting portion provided on the outer periphery of the column and the first axial matching portion provided on the upper insulating member, thereby preventing the pole from axial movement. Specifically, the first axial limiting portion is designed as an inner concave annular groove around the outer circumference of the column. The inner concave annular groove is formed by forging, which effectively reduces waste residue. The first axial matching portion is integrally injection-molded when the upper insulating part is injected. The first axial matching portion is an inner convex annular portion. The design of the inner convex annular portion can increase the radial size of the upper insulating part, increase the sealing contact surface between the upper insulating part and the column, extend the permeation path for the electrolyte to penetrate outward, and increase the sealing performance and connection stability. (3) The first circumferential limiting portion is arranged on the inner circumference of the first axial limiting portion, which realizes the anti-rotation function of the pole and further increases the sealing contact surface between the upper insulating part and the column. The larger sealing contact surface can better prevent the pole and / or the upper insulating part from moving in the circumferential, radial and axial directions. (4) The pole limiting is achieved by providing a second circumferential limiting portion in the contoured groove of the injection mold and a second circumferential matching portion at the bottom of the pole limiting portion, and by providing an azimuth pointing portion, the orientation of the azimuth pointing portion is consistent with the inner concave portion. When the pole is placed in the injection mold, the orientation of the azimuth pointing portion is inconsistent with the gate of the injection mold, thereby solving the problem that the portion of the column body axially facing the inner concave portion is prone to collapse due to the high pressure of the injection mold, thereby improving the yield rate. (5) When the pole limiting portion is a circular limiting portion, by providing limiting grooves of different diameters (for example, elliptical limiting grooves) on the lower plastic part, the diameter in one direction is adapted to the circular limiting portion to limit the pole in that direction, and the existing liquid injection hole on the cover plate and the groove provided on the lower plastic part are used to achieve limiting in the other vertical direction, thereby preventing relative rotation between the pole and the lower plastic part; in addition, by making the diameter in the other vertical direction larger than the outer diameter of the circular limiting portion, a shrinkage gap is formed to prevent the pole from being squeezed or pulled when the lower insulation is deformed, further preventing loosening between the pole and the lower plastic part. (6) Axial limiting between the upper insulator and the side surface of the cover plate is achieved by providing a second axial limiting portion provided on the cover plate and a second axial matching portion provided on the bottom of the upper insulator, thereby preventing the upper insulator from axially moving and forming a gap with the upper side surface of the cover plate. Specifically, during the injection molding process of the upper insulating member, the injection molding glue can flow and fill the positioning groove on the side of the cover plate, so as to form a positioning portion that is in full contact with the positioning groove after solidification, thereby achieving the purpose of fixing the insulating member.(7) Circumferential positioning between the upper insulator and the upper side of the cover plate is achieved by a third circumferential limiting portion provided on the cover plate and a third circumferential mating portion provided at the bottom of the upper insulator, thereby preventing circumferential movement of the upper insulator and the formation of a gap between the upper side of the cover plate. The third circumferential limiting portion is configured to form a convex ring integrally on the cover plate using a forging process. During the forging process, the generation of waste residue during the forming process is effectively reduced, cleaning is facilitated, burrs are reduced, the polishing process is simplified, and forming efficiency is improved.

Claims

1. A power battery top cover, comprising a cover plate having at least one mounting hole formed therethrough, a pole placed in the mounting hole, a sealing ring crimped between the cover plate and the pole, an upper plastic part for isolating the cover plate and the pole, a lower plastic part press-fitted on the lower surface of the cover plate, and a liquid injection hole formed through the cover plate, characterized in that: It also includes a positioning groove arranged on the cover plate around the mounting hole, the positioning groove opens toward the upper plastic part and the upper plastic part is positioned in the positioning groove.

2. The power battery top cover according to claim 1, characterized in that: The positioning groove includes a bottom groove with a wider radial width and a connecting groove with a narrower radial width and connecting the bottom groove and the opening. The corresponding position of the bottom of the upper plastic part conforms to the connecting groove and the bottom groove and is positioned in the bottom groove and the connecting groove.

3. The power battery top cover according to claim 2, characterized in that: The positioning groove has two oppositely arranged first side walls and a second side wall, the first side wall protrudes inward to form an outer ring protrusion and / or the second side wall protrudes outward to form an inner ring protrusion, the outer ring protrusion and / or the inner ring protrusion protrudes into the positioning groove to separate the positioning groove into the bottom groove and the connecting groove.

4. The power battery top cover according to claim 2, characterized in that: It also includes an inner ring body coaxially formed on the cover plate with the mounting hole and corresponding to the positioning groove and the mounting hole, wherein at least one notch is arranged on the inner ring body at intervals along the circumferential direction, and the notch radially penetrates the inner circumferential surface and the outer circumferential surface of the inner ring body; the upper plastic part includes an anti-rotation portion that can extend into the notch and cooperate with the notch to prevent rotation.

5. The power battery top cover according to claim 4, characterized in that: The level of the upper surface of the outer ring convex portion and / or the inner ring convex portion is lower than the level of the upper surface of the cover plate to form a closed step, and the lower surface of the upper plastic part is supported on the closed step.

6. The power battery top cover according to claim 4, characterized in that: A spacing portion is formed between the outer circumferential surface of the pole and the inner circumferential surface of the mounting hole; the pole is arranged in intervals from bottom to top in the mounting hole and passes through the mounting hole upward, and the upper plastic part also includes a main body portion which is arranged around the passing end of the pole and supported on the cover plate, a positioning portion which is formed at the bottom of the main body portion and positioned in the positioning groove, and a blocking portion which is formed at the bottom of the main body portion and cooperates with the pole to close the mounting hole, the blocking portion extends into the spacing portion, abuts against the sealing ring and blocks the spacing portion, and the anti-rotation portion is formed on the inner circumference of the main body portion and protrudes toward the pole.

7. The power battery top cover according to claim 6, characterized in that: The positioning portion includes a connecting section formed at the bottom of the main body and positioned in the connecting groove, and an anti-slip section formed at the bottom of the connecting section and positioned in the bottom groove. The connecting section and the anti-slip section are adapted to the shapes of the connecting groove and the bottom groove.

8. The power battery top cover according to claim 6, characterized in that: The inner circumferential surface of the main body is formed with a positioning protruding ring protruding inwardly; The pole includes an insertion portion passing through the mounting hole, a limiting portion formed at the bottom of the insertion portion and resting against the lower surface of the sealing ring, and a contact portion formed at the top of the insertion portion and passing through the mounting hole. The outer circumferential surface of the insertion portion and the inner circumferential surface of the mounting hole are spaced apart to form the spacing portion, and the outer circumferential surface of the contact portion is concavely formed at a position corresponding to the positioning convex ring to form a matching ring groove that matches the positioning convex ring.

9. The power battery top cover according to claim 1, characterized in that: A mounting ring groove is formed on the lower surface of the cover plate corresponding to the periphery of the mounting hole, and a press-fitting ring pressed into the mounting ring groove is provided at a position corresponding to the mounting ring groove on the lower plastic part; a clearance hole is coaxially provided at a position corresponding to the mounting hole on the lower plastic part, and an inner circumferential surface of the clearance hole protrudes inward to form an isolation ring that abuts between the lower surface of the cover plate and the pole.

10. A power battery top cover, characterized in that: The invention comprises a cover plate provided with a through mounting hole and an explosion-proof assembly hole, a pole penetrating the mounting hole and having a first circumferential limiting portion formed on the outer circumference thereof, and an upper plastic part provided in the mounting hole and around the outer circumference of the pole, wherein a first circumferential matching portion is provided at a position of the upper plastic part corresponding to the first circumferential limiting portion, and the first circumferential matching portion is limitedly matched with the first circumferential limiting portion to realize the circumferential limiting of the pole.

11. The power battery top cover according to claim 10, characterized in that: The first circumferential limiting portion is defined as an inner concave portion sunken inward from the outer circumferential surface of the pole, and the first circumferential matching portion is defined as an inner convex portion formed on the inner circumferential surface of the upper plastic part and matching with the inner concave portion; or The first circumferential limiting portion is defined as an outer convex portion extending outward from the outer circumferential surface of the pole, and the first circumferential matching portion is defined as an outer concave portion formed on the inner circumferential surface of the upper plastic part and matching with the outer convex portion.

12. The power battery top cover according to claim 11, characterized in that: The inner concave surface of the inner concave portion or the outer convex surface of the outer convex portion is defined as a first flat surface, and the inner convex surface of the inner convex portion or the outer concave surface of the outer concave portion is defined as a second flat surface that fits with the first flat surface.

13. The power battery top cover according to claim 10, characterized in that: A first axial limiting portion that is axially limited and matched with the upper plastic part is formed on the outer periphery of the pole, and a first axial matching portion is provided at a position on the inner periphery of the upper plastic part corresponding to the first axial limiting portion, and the first axial matching portion is limited and matched with the first axial limiting portion to achieve axial limiting of the pole.

14. The power battery top cover according to claim 13, characterized in that: The first axial limiting portion is defined as a matching annular groove arranged around the outer circumference of the pole, and the matching annular groove divides the pole into a top column and a bottom column with larger diameters and a middle column with smaller diameters along the axial direction. The lower side surface of the top column and the upper side surface of the bottom column are defined as the groove walls on both sides of the matching annular groove, and the outer circumferential surface of the middle column is defined as the groove bottom surface of the matching annular groove; the first circumferential limiting portion is defined as an inner concave portion recessed inward from the groove bottom of the matching annular groove; the first axial matching portion is defined as a groove around the inner circumference of the upper plastic part. A positioning convex ring is arranged around the periphery of the pole, and the first circumferential matching portion is defined as an inner convex portion protruding inwardly from the inner side surface of the positioning convex ring; or the first axial limiting portion is defined as an outer convex ring portion arranged around the periphery of the pole, and the first circumferential limiting portion is defined as an outer convex portion protruding outwardly from the outer side surface of the outer convex ring portion; the first axial matching portion is defined as an outer concave annular groove arranged around the inner periphery of the upper plastic part, and the first circumferential matching portion is defined as an outer concave portion recessed outwardly from the groove bottom surface of the outer concave annular groove.

15. The power battery top cover according to claim 10, characterized in that: The first circumferential limiting portion is defined as an inner concave portion sunken inward from the outer circumference of the pole; the upper plastic part, the cover plate and the pole are injection molded by an injection mold, the injection mold is provided with a contoured groove that is contoured with the cover plate, the contoured groove is provided with a second circumferential limiting portion for limiting the rotation of the pole, the bottom surface of the limiting portion is provided with a second circumferential matching portion that is limitedly matched with the second circumferential limiting portion, the second circumferential matching portion and / or the second circumferential limiting portion have an azimuth pointing portion pointing to the orientation of the inner concave portion, and on the horizontal projection plane, the orientation of the inner concave portion is misaligned with the gate orientation of the injection mold.

16. The power battery top cover according to claim 15, characterized in that: The second circumferential limiting portion is defined as a limiting convex portion, and the second circumferential matching portion is defined as a limiting concave portion that matches with the limiting convex portion; or the second circumferential limiting portion is defined as a limiting concave portion, and the second circumferential matching portion is defined as a limiting convex portion that matches with the limiting concave portion; The outer facade of the limiting protrusion has at least one third straight surface for limiting the rotation of the pole; the inner facade of the limiting concave portion has a fourth straight surface that fits with the third straight surface.

17. The power battery top cover according to any one of claims 10 to 16, characterized in that: It also includes a lower plastic part arranged on the lower side of the cover plate, the lower plastic part is provided with a clearance hole extending axially therethrough, and a limiting groove arranged around the outer edge of the clearance hole is formed on the lower side surface of the lower plastic part; the pole includes an insertion portion and a limiting portion arranged at the lower end of the insertion portion, the limiting portion of the pole is arranged in the limiting groove, and the insertion portion passes through the clearance hole and the mounting hole.

18. The power battery top cover according to claim 17, characterized in that: The limiting portion of the pole is defined as a circular limiting portion, and the limiting groove has a first diameter along the width direction of the cover plate and a second diameter along the length direction of the cover plate of unequal lengths; among the first diameter and the second diameter, one of the diameters is adapted to the outer diameter of the circular limiting portion, so that the limiting groove limits the limiting portion along the direction of the one of the diameters; the other diameter is larger than the outer diameter of the circular limiting portion, so that a gap is formed between the groove walls on both sides of the limiting groove along the other diameter direction and the corresponding sides of the circular limiting portion; a liquid injection hole is also provided on the cover plate, and the hole wall of the liquid injection hole protrudes downward from the lower side surface of the cover plate; a groove is also provided on the lower plastic part, and the groove cooperates with the liquid injection hole to limit the limiting portion along the other diameter direction.

19. A power battery, characterized in that: It comprises a power battery top cover as described in any one of claims 1 to 9 or a power battery top cover as described in any one of claims 10 to 18.

20. A cover plate forming process for a power battery top cover, characterized in that: The following steps are involved: Providing a plate preform having a first surface and a second surface disposed opposite to each other, and pre-punching at least one pre-punched hole on the plate preform from the direction from the first surface to the second surface; Forging a back step at a position corresponding to the pre-pressing hole on the second surface of the plate preform; A ring groove with a top opening and a first forging surface and a second forging surface located on the surface of the plate preform and corresponding to two opposite sides of the ring groove are forged at a position corresponding to the pre-pressing hole on the first surface of the plate preform, wherein the radial width of the ring groove is the same at all locations along the axial direction; The first forging surface and the second forging surface are forged downward to extrude one side wall of the annular groove outward to form an inner annular convex portion and / or to extrude the other side wall of the annular groove inward to form an outer annular convex portion, and a closed step is formed on the upper surface of the inner annular convex portion and / or the outer annular convex portion, and the inner annular convex portion and / or the outer annular convex portion protrude to make the annular groove a positioning groove with a variable cross-section that is larger at the bottom and smaller at the top; Forging the back step to form a mounting ring groove; The pre-pressed hole is finely punched to form a mounting hole.

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