阅读说明：本技术 锂电池的卷芯组装方法 (Method for assembling winding core of lithium battery ) 是由 高冲 程辉 吴德 于 2020-12-17 设计创作，主要内容包括：本发明公开锂电池的卷芯组装方法,包括以下步骤：步骤S1：将两个卷芯同一侧的极耳通过焊接在底板上；步骤S2：焊印处贴附绝缘胶带；步骤S3：通过绝缘膜包覆住两个卷芯的侧面,连接部穿过绝缘膜,并将两个卷芯进行合芯,使绝缘膜包裹在外部；步骤S4：将卷芯组的连接部与盖板组件焊接；步骤S5:塞入壳体,并焊接,完成了锂电池的卷芯组装。本发明的有益效果：焊接点均位于盖板组件上,实现了降低卷芯焊接短路率的目的；通过将连接片直接装配到盖板组件上的方式,可进一步提升锂电池能量密度；绝缘胶带防止焊接粉尘进入卷芯的内部,避免电芯短路。(The invention discloses a method for assembling a winding core of a lithium battery, which comprises the following steps: step S1: welding the lugs on the same side of the two winding cores on the bottom plate; step S2: attaching an insulating tape at the welding position; step S3: the side surfaces of the two winding cores are coated by the insulating film, the connecting part penetrates through the insulating film, and the two winding cores are combined to enable the insulating film to be coated outside; step S4: welding the connecting part of the winding core group with the cover plate assembly; and step S5, plugging the shell, and welding to complete the assembly of the lithium battery roll core. The invention has the beneficial effects that: the welding points are all positioned on the cover plate assembly, so that the purpose of reducing the welding short circuit rate of the winding core is realized; the energy density of the lithium battery can be further improved by directly assembling the connecting sheet on the cover plate assembly; the insulating tape prevents that the welding dust from getting into the inside of rolling up the core, avoids electric core short circuit.)

1. The method for assembling the winding core of the lithium battery is characterized by comprising the following steps of:

step S1: arranging two winding cores in a mirror image mode, welding the lugs on the same side of the two winding cores through a connecting sheet, wherein the connecting sheet comprises a bottom plate and a connecting part arranged on the bottom plate, and welding the lugs on the bottom plate;

step S2: attaching an insulating tape at the solder mark generated in step S1;

step S3: the side surfaces of the two winding cores are coated by the insulating film, the connecting part penetrates through the insulating film, and the two winding cores are combined to ensure that the insulating film is coated outside to form a winding core group; if the number of the winding core groups is multiple, connecting the connecting parts of the winding core groups together;

step S4: welding a connecting part of the winding core group with a cover plate assembly, wherein the cover plate assembly is provided with a hole for the connecting part to pass through, and the connecting part is welded in the hole;

and step S5, the core welded in the step S4 is plugged into the shell, and the shell and the cover plate assembly are welded to complete the assembly of the core of the lithium battery.

2. The method of claim 1, wherein the connecting portion is a boss vertically connected to the base plate, and in step S1, the tabs of the two winding cores have tab through holes, the tabs of the two winding cores on the same side are overlapped together, the boss passes through the tab through holes, and the tabs on the two sides are welded to the base plate.

3. The method of claim 1, wherein the connecting portion is a boss vertically connected to the base plate, the base plate has a hole slot, the boss is disposed on one side of the hole slot, and in step S1, the tabs of the two winding cores are inserted through the hole slot from one side of the base plate and welded to the other side of the base plate.

4. The method of claim 1, wherein the connecting portion is a U-shaped bent piece, the bottom of the U-shaped bent piece is connected to the bottom plate, and in step S1, the tabs of the two winding cores are respectively welded to two sides of the bottom plate on a side away from the U-shaped bent piece.

5. The method of claim 1, wherein the connecting portion is a U-shaped bending piece, a bottom horizontal edge of the U-shaped bending piece is connected to the bottom plate, a hole groove is formed in the bottom plate, the U-shaped bending piece is arranged on one side of the hole groove, and in step S1, the tabs of the two winding cores penetrate through the hole groove from one side of the bottom plate and are welded to the other side of the bottom plate.

6. The method of claim 1, wherein the connecting portion is an L-shaped bent piece, a bottom horizontal edge of the L-shaped bent piece is connected to the bottom plate, and in step S1, the tabs of the two winding cores are respectively welded to two edges of the bottom plate on a side away from the L-shaped bent piece; in step S3, if there are a plurality of winding core groups, the L-shaped bent pieces of the plurality of winding core groups are connected together.

7. The method for assembling the winding core of the lithium battery according to claim 1, wherein the cover plate assembly comprises a base plate, an insulating gasket, a pole, an explosion-proof valve and a liquid injection hole, the base plate is provided with a mounting hole, the insulating gasket is in an I-shaped structure, a first hole for a connecting part to pass through is formed in the vertical center of the I-shaped structure, the insulating gasket is wrapped at the mounting hole, the pole is mounted on the insulating gasket, the middle part of the pole is a penetrating pole hole, the pole hole and the first hole of the insulating gasket are coaxially arranged, the explosion-proof valve is mounted on the base plate, and the liquid injection hole is formed in the base plate; step S4: and (4) sequentially penetrating the connecting part of the winding core group through the first hole of the insulating gasket and the pole hole and then welding.

8. The method of claim 7, wherein the connecting portion is a U-shaped bent piece, a bottom horizontal edge of the U-shaped bent piece is connected to the bottom plate, and in step S1, the tabs of the two winding cores are respectively welded to two edges of the bottom plate on a side away from the U-shaped bent piece; the pole column hole is a sheet-shaped hole, the first hole is a sheet-shaped hole, the top end of the pole column is provided with a groove, the cover plate assembly further comprises a plug sheet, and the plug sheet is embedded into the groove; in the step S4, after the U-shaped bent piece of the winding core set sequentially passes through the first hole and the pole hole of the insulating gasket, the top end of the U-shaped bent piece is bent into the groove, and then the plug piece is welded at the groove.

9. The method of claim 7, wherein the connecting portion is a U-shaped bent piece, a bottom horizontal edge of the U-shaped bent piece is connected to the bottom plate, and in step S1, the tabs of the two winding cores are respectively welded to two edges of the bottom plate on a side away from the U-shaped bent piece; the pole column hole is a sheet-shaped hole, and the first hole is a sheet-shaped hole; in the step S4, the U-shaped bent pieces of the winding core set are bent toward the middle portion and aligned, and then sequentially pass through the first hole and the pole hole of the insulating spacer and are welded.

10. The method of assembling a lithium battery jelly roll according to claim 1, wherein the insulating tape is provided with a positioning hole for the connection part to pass through, and a plurality of vent holes.

11. The method of assembling a lithium battery jelly roll according to claim 1, wherein in step S3, the jelly rolls are combined and then bonded together by fastening tape to form a jelly roll group; if the number of the winding core groups is multiple, connecting the connecting parts of the winding core groups together; and then the outer large adhesive tape is wrapped outside the winding core group.

Technical Field

The invention relates to the technical field of lithium ion batteries, in particular to a method for assembling a winding core of a lithium battery.

Background

At present, the assembly of the roll core of the power lithium battery mostly adopts a double-roll core butterfly welding process, such as the application number: 201721484494.0, background art in a butterfly welding clamp for assembling lithium battery electric core: the tabs a1 of the two winding cores a are prewelded by an ultrasonic welding machine respectively; after the two winding cores a are paired, welding a tab a1, a gasket a2 and a soft connecting sheet a3 together by using an ultrasonic welding machine; welding the gasket a2 and the cover plate a4 together by using a laser welding machine; the two cores are combined and then taped with tape a5, a process also known as butterfly welding.

However, this process requires that the spacing between the jelly rolls be greater than the width of the cover sheet, which results in an excessively long tab for the jelly roll. After the double-winding core is combined, the tabs of the winding core are folded, so that the tabs are in contact with the pole piece inside the winding core and the external aluminum shell, and the risk of short circuit of the lithium battery is greatly increased; and the overlong pole lug also increases the using amount of foil, and the material cost of manufacture is improved.

In traditional two core butterfly welding process that roll up, after two core that roll up closed the core, the clearance between apron and the core that rolls up is great, and the inner space of unable make full use of aluminum hull to lithium cell energy density's promotion has been restricted.

Aiming at the parallel assembly of multiple winding cores, the traditional winding core assembly mode cannot be compatible with the assembly of any multiple winding core, so that the wide application of the lithium battery technology is limited.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: how to solve the problem that the existing lithium battery roll core assembling method is easy to cause short circuit.

The invention solves the technical problems through the following technical means:

the method for assembling the winding core of the lithium battery comprises the following steps:

step S1: arranging two winding cores in a mirror image mode, welding the lugs on the same side of the two winding cores through a connecting sheet, wherein the connecting sheet comprises a bottom plate and a connecting part arranged on the bottom plate, and welding the lugs on the bottom plate;

step S2: attaching an insulating tape at the solder mark generated in step S1;

step S3: the side surfaces of the two winding cores are coated by the insulating film, the connecting part penetrates through the insulating film, and the two winding cores are combined to ensure that the insulating film is coated outside to form a winding core group; if the number of the winding core groups is multiple, connecting the connecting parts of the winding core groups together;

step S4: welding a connecting part of the winding core group with a cover plate assembly, wherein the cover plate assembly is provided with a hole for the connecting part to pass through, and the connecting part is welded in the hole;

and step S5, the core welded in the step S4 is plugged into the shell, and the shell and the cover plate assembly are welded to complete the assembly of the core of the lithium battery.

According to the invention, the bottom plate of the connecting sheet is welded with the lug, after the core is wound and combined, the connecting part on the connecting sheet is welded with the cover plate assembly, and the welding points are all positioned on the cover plate assembly, so that the purpose of reducing the welding short circuit rate of the winding core is realized; through the mode of directly assembling the connection piece on the apron subassembly, can further promote lithium cell energy density.

Preferably, connecting portion are the boss, the boss is vertical to be connected on the bottom plate, in step S1, on the utmost point ear of two book cores, have utmost point ear through-hole, two book cores are in the same side utmost point ear overlap joint together, the boss passes utmost point ear through-hole, and the utmost point ear welding of both sides is on the bottom plate.

Preferably, the connecting portion is a boss, the boss is vertically connected to the bottom plate, a hole groove is formed in the bottom plate, the boss is arranged on one side of the hole groove, and in the step S1, the tabs of the two winding cores penetrate through the hole groove from one side of the bottom plate and are welded to the other side of the bottom plate.

Preferably, the connecting portion is a U-shaped bending piece, the bottom of the U-shaped bending piece is connected to the bottom plate, and in step S1, the tabs of the two winding cores are respectively welded to two sides of one side of the bottom plate, which is far away from the U-shaped bending piece.

Preferably, connecting portion are U type bending pieces, the bottom level limit of U type bending pieces is connected the bottom plate, be equipped with the hole groove on the bottom plate, U type bending pieces sets up the one side in the hole groove, in step S1, the utmost point ear of two book cores passes the hole groove and welds on the opposite side of bottom plate by one side of bottom plate.

Preferably, the connecting portion is an L-shaped bending piece, a bottom horizontal edge of the L-shaped bending piece is connected to the bottom plate, and in step S1, the tabs of the two winding cores are respectively welded to two edges of the bottom plate on the side far away from the L-shaped bending piece; in step S3, if there are a plurality of winding core groups, the L-shaped bent pieces of the plurality of winding core groups are connected together.

Preferably, the cover plate assembly comprises a base plate, an insulating gasket, a pole, an explosion-proof valve and a liquid injection hole, wherein the base plate is provided with a mounting hole, the insulating gasket is of an I-shaped structure, a first hole for a connecting part to pass through is formed in the vertical center of the I-shaped structure, the insulating gasket is wrapped at the mounting hole, the pole is mounted on the insulating gasket, the middle of the pole is a penetrating pole hole, the pole hole and the first hole of the insulating gasket are coaxially arranged, the explosion-proof valve is mounted on the base plate, and the liquid injection hole is formed in the base plate; step S4: and (4) sequentially penetrating the connecting part of the winding core group through the first hole of the insulating gasket and the pole hole and then welding.

Preferably, the connecting portion is a U-shaped bending piece, a bottom horizontal edge of the U-shaped bending piece is connected to the bottom plate, and in step S1, the tabs of the two winding cores are respectively welded to two edges of the bottom plate on the side far away from the U-shaped bending piece; the pole column hole is a sheet-shaped hole, the first hole is a sheet-shaped hole, the top end of the pole column is provided with a groove, the cover plate assembly further comprises a plug sheet, and the plug sheet is embedded into the groove; in the step S4, after the U-shaped bent piece of the winding core set sequentially passes through the first hole and the pole hole of the insulating gasket, the top end of the U-shaped bent piece is bent into the groove, and then the plug piece is welded at the groove.

Preferably, the connecting portion is a U-shaped bending piece, a bottom horizontal edge of the U-shaped bending piece is connected to the bottom plate, and in step S1, the tabs of the two winding cores are respectively welded to two edges of the bottom plate on the side far away from the U-shaped bending piece; the pole column hole is a sheet-shaped hole, and the first hole is a sheet-shaped hole; in the step S4, the U-shaped bent pieces of the winding core set are bent toward the middle portion and aligned, and then sequentially pass through the first hole and the pole hole of the insulating spacer and are welded.

Preferably, the insulating film is provided with a positioning hole for the connection portion to pass through, and a plurality of vent holes.

The purpose of the positioning holes of the insulating film is to fix the insulating film, and the vent holes are used for smoothly releasing gas in the battery.

Preferably, in step S3, after the cores are combined, the cores are bonded together by fastening adhesive tapes to form a core group; if the number of the winding core groups is multiple, connecting the connecting parts of the winding core groups together; and then the outer large adhesive tape is wrapped outside the winding core group.

The large outer adhesive tape prevents the roll core body from being scratched in the shell entering process.

The invention has the advantages that:

(1) according to the invention, the bottom plate of the connecting sheet is welded with the lug, after the core is wound and combined, the connecting part on the connecting sheet is welded with the cover plate assembly, and the welding points are all positioned on the cover plate assembly, so that the purpose of reducing the welding short circuit rate of the winding core is realized; the energy density of the lithium battery can be further improved by directly assembling the connecting sheet on the cover plate assembly; the insulating adhesive tape prevents welding dust from entering the inside of the winding core, and the short circuit of the battery core is avoided;

(2) the purpose of the positioning hole of the insulating film is to fix the insulating film, and the vent hole is to smoothly release the gas in the battery;

(3) the large outer adhesive tape prevents the roll core body from being scratched in the shell entering process.

Drawings

FIG. 1 is a schematic structural diagram of a double-winding core before welding according to a first embodiment of the present invention;

FIG. 2 is a side view of a dual-core roll prior to welding in accordance with a first embodiment of the present invention;

FIG. 3 is a partial schematic view of a middle ear through hole in accordance with one embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a connecting sheet according to a first embodiment of the present invention;

fig. 5 is a side view of a tab after assembly of the tab in accordance with one embodiment of the present invention;

fig. 6 is a partial view of the back side of a tab after assembly of a tab in accordance with one embodiment of the invention;

fig. 7 is a top view of a tab after being welded to a tab in accordance with one embodiment of the present invention;

FIG. 8 is a schematic view of the completed rubberizing based on FIG. 7;

FIG. 9 is a schematic view of an insulating film according to a first embodiment of the present invention;

FIG. 10 is a side view of an insulator film assembled with a jellyroll in accordance with one embodiment of the present invention;

FIG. 11 is a schematic view of the back side of an assembled insulator film and core in accordance with one embodiment of the invention;

FIG. 12 is a three-dimensional schematic view of a completed core assembly in accordance with one embodiment of the present invention;

FIG. 13 is a side view of a completed corer in accordance with one embodiment of the present invention;

FIG. 14 is a schematic view of the outer bulk tape attached to the tape of FIG. 13;

FIG. 15 is a schematic structural diagram of a cover plate assembly according to an embodiment of the present invention;

FIG. 16 is an enlarged view of a portion of FIG. 15 taken at A-A;

FIG. 17 is a cross-sectional view of the cover assembly and core after assembly in accordance with one embodiment of the present invention;

fig. 18 is a side view of the tab of the second embodiment of the invention after assembly;

fig. 19 is a rear partial view of the tab of a second embodiment of the invention after assembly with a tab;

FIG. 20 is a schematic view showing an insulating film assembled with a core in the second embodiment of the present invention;

FIG. 21 is a schematic view of a second embodiment of the present invention showing the cover plate assembly assembled with the core;

FIG. 22 is a partial cross-sectional view of a second embodiment of the present invention with the cover assembly and core assembled;

FIG. 23 is a schematic view of a third embodiment of the present invention before bending the bending tab;

FIG. 24 is a schematic view of a third embodiment of the present invention after bending the bending tab;

FIG. 25 is an assembled view of the pole plug of the third embodiment of the present invention;

FIG. 26 is a partial cross-sectional view of a third embodiment of the present invention with the cover assembly and core assembled;

FIG. 27 is a partial cross-sectional view of a fourth embodiment of the present invention with the cover assembly and core assembled;

FIG. 28 is a schematic structural view of a fifth embodiment of the present invention, wherein four cores are assembled;

FIG. 29 is a schematic structural view of a fifth embodiment of the present invention in which four core bending plates are gathered together;

FIG. 30 is a schematic structural view of a connecting piece in the sixth embodiment of the invention;

fig. 31 is a side view of a tab of a sixth embodiment of the invention after assembly with a tab;

fig. 32 is a partial view of the back side of a tab of a sixth embodiment of the invention after assembly with a tab;

fig. 33 is a partial view of a tab after welding with a tab in accordance with a sixth embodiment of the present invention;

fig. 34 is a partial view of a tab and tab after lamination according to a sixth embodiment of the invention;

FIG. 35 is a schematic structural view of a connecting piece in the seventh embodiment of the present invention;

fig. 36 is a partial view of the back side of a tab and tab assembly in accordance with a seventh embodiment of the invention;

reference numbers in the figures: 100. a winding core; 101. a roll core body; 102. a tab; 103. a tab through hole;

200. connecting sheets; 201. a base plate; 202. a boss; 203. welding and printing; 204. a U-shaped bending piece; 205. a hole groove; 206. an L-shaped bending piece;

300. an insulating tape;

400. an insulating film; 401. positioning holes; 402. an exhaust hole;

500. fastening the adhesive tape;

600. an outer big adhesive tape;

700. a cover plate assembly; 701. a substrate; 702. an insulating spacer; 703. a pole column; 704. a pole groove; 705. an explosion-proof valve; 706. a liquid injection hole; 707. a pole hole; 708. a pole plug sheet;

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The first embodiment is as follows:

the method for assembling the winding core of the lithium battery comprises the following steps:

step S1: as shown in fig. 1 and fig. 2, two winding cores 100 are respectively arranged in a mirror image manner, the polarities of the tabs 102 on the same side are the same, the tabs 102 are mutually overlapped, as shown in fig. 3, tab through holes 103 are punched on the tabs 102, and the tab through holes 103 of the two winding cores 100 are overlapped up and down;

as shown in fig. 4, the connecting piece 200 includes a bottom plate 201 and a connecting portion disposed on the bottom plate 201, in this embodiment, the connecting portion is a boss 202; the connecting sheet 200 is made of metal material with good conductivity;

as shown in fig. 5 and 6, after the base plate 201 is attached to the tab 102, the boss 202 passes through the tab through hole 103, and the base plate 201 is welded to the tab 102, as shown in fig. 7, the weld mark 203 obtained after welding can be completed by using an ultrasonic welding method, but the embodiment does not limit a specific welding method;

step S2: as shown in fig. 8, after the welding is completed, an insulating tape 300 is attached to the welding seal 203, so as to prevent welding dust from entering the inside of the winding core 100 and avoid short circuit of the battery core;

step S3: as shown in fig. 9, the insulating film 400 is provided with a positioning hole 401 and an exhaust hole 402, the positioning hole 401 corresponds to the boss 202 in position and is matched in shape, the positioning hole 401 and the boss 202 are both circular, the positioning hole 401 is used for fixing the insulating film 400, and the exhaust hole 402 is used for smoothly releasing gas inside the battery;

as shown in fig. 10 and 11, the bottom surfaces of the two winding cores 100 are covered with an insulating film 400, and the bosses 202 penetrate through the insulating film 400;

as shown in fig. 12 and 13, the two winding cores 100 are combined, the insulating film 400 is wrapped outside, and the two winding cores 100 are bonded together at the side and bottom by the fastening tape 500 to form a winding core group;

as shown in fig. 14, the outer big adhesive tape 600 is wrapped outside the winding core group, and the outer big adhesive tape 600 wraps five sides of the whole double winding core, so as to prevent the winding core body 101 from being scratched in the shell entering process;

step S4: as shown in fig. 15 and 16, the cover plate assembly 700 includes a substrate 701, an insulating gasket 702, a pole 703, an explosion-proof valve 705, a liquid injection hole 706, and a pole hole 707, where the substrate 701 and the pole 703 are made of a metal material with good electrical conductivity, a mounting hole is provided on the substrate 701, the insulating gasket 702 is of an i-shaped structure, a first hole for the boss 202 to pass through is provided at a vertical center of the i-shaped structure, the insulating gasket 702 is wrapped at the mounting hole, the pole 703 is installed on the insulating gasket 702, a pole hole 707 passing through is provided at a middle portion of the pole 703, the pole hole 707 and the first hole of the insulating gasket 702 are coaxially arranged, the explosion-proof valve 705 is installed on the substrate 701, and the liquid injection hole 706 is provided on the substrate 701;

as shown in fig. 17, the boss 202 sequentially penetrates through the first hole of the insulating gasket 702 and the pole hole 707 to match with the two, and finally the connection between the two is realized by laser welding;

step S5: and (5) plugging the roll core 100 welded in the step (S4) into a shell, and welding the shell and the cover plate assembly 700 to complete the roll core assembly of the lithium battery, wherein the shell can be an aluminum shell.

In the embodiment, the bottom plate 201 of the connecting sheet 200 is welded with the tab 102, after the core 100 is combined, the boss 202 on the connecting sheet 200 is welded with the cover plate assembly 700, and the welding points are all positioned on the cover plate assembly 700, so that the purpose of reducing the welding short circuit rate of the core 100 is achieved; the lithium battery energy density can be further improved by directly assembling the connection sheet 200 to the cap plate assembly 700.

Example two:

the difference between the present embodiment and the first embodiment is: the connection parts are different;

as shown in fig. 18 and 19, in the present embodiment, the connecting portion is a U-shaped bent piece 204, and the bottom of the U-shaped bent piece 204 is connected to the bottom plate 201;

in step S1, the tabs 102 of the two winding cores 100 are welded to the two sides of the same side of the base plate 201, and the U-shaped bent piece 204 is welded to the other side of the base plate 201.

Step S2: after the welding is completed, the insulating tape 300 is attached to the welding seal 203, as in the first embodiment;

step S3: as shown in fig. 20, a positioning hole 401 on the insulating film 400 is matched with the shape of the U-shaped bent piece 204, and in this embodiment, the positioning hole 401 is a rectangular hole;

combining the two winding cores 100 to wrap the insulating film 400 outside, and adhering the two winding cores 100 at the side parts and the bottom parts thereof by fastening adhesive tapes 500 to form a winding core group;

step S4: as shown in fig. 21 and 22, the U-shaped bent piece 204 is connected to the cover plate assembly 700; in this embodiment, in order to adapt to the U-shaped bending piece 204, the mounting holes formed on the substrate 701 are rectangular sheet structures, each U-shaped bending piece 204 corresponds to two rectangular sheet structures, the insulating gasket 702 is wrapped at the mounting holes, each insulating gasket 702 has two first holes for the U-shaped bending piece 204, and each pole 703 has two parallel pole holes 707 (not shown in the figure);

step S5: the same as in the first embodiment.

Example three:

the difference between this embodiment and the second embodiment is: on the basis of the second embodiment, the cover plate assembly 700 is additionally provided with a pole groove 704 and a pole plug sheet 708; step S4 is different;

as shown in fig. 23, the top end of the pole 703 in this embodiment is further provided with a pole groove 704, and the pole groove 704 is opened between two pole holes 707;

step S4: as shown in fig. 23, the U-shaped bent piece 204 is inserted into the post hole 707, as shown in fig. 24, the ends of the two bent pieces of the U-shaped bent piece 204 are bent into the post groove 704, as shown in fig. 25 and fig. 26, then the post plug piece 708 is installed into the post groove 704, and the U-shaped bent piece 204, the post 703 and the post plug piece 708 are fixedly connected together by laser welding, thereby completing the connection between the U-shaped bent piece 204 and the cover plate assembly 700.

Example four:

the present embodiment is different from the second embodiment in that: the number of post holes 707 in the cover plate assembly 700 is different; step S4 is different;

as shown in fig. 27, in this embodiment, each of the matching portions of the base plate 701 and the U-shaped bent piece 204 has only one mounting hole, the mounting hole is a rectangular sheet structure and can accommodate twice the thickness of the U-shaped bent piece 204, the insulating gasket 702 is wrapped at the mounting hole, each insulating gasket 702 has a first hole for the U-shaped bent piece 204, and each pole 703 has a pole hole 707;

step S4: the two sides of the U-shaped bent piece 204 are first closed together, and then the U-shaped bent piece passes through the pole 703, is matched with the pole hole 707, and is fixedly connected with the U-shaped bent piece 204 and the pole 703 in a laser welding manner.

Example five:

in the present embodiment, the difference from the second embodiment is: the connecting part is an L-shaped bending piece 206; the winding cores 100 are different in number;

step S3: as shown in fig. 28, positioning holes 401 in the insulating film 400 are matched with the shape of the L-shaped bending piece 206, and in this embodiment, the positioning holes 401 are rectangular holes;

as shown in fig. 29, to assemble four winding cores 100, a double-wound core after core combination is obtained, two double-wound cores are connected in parallel, and finally two L-shaped bent pieces 206 are folded together and assembled in the manner of the fourth embodiment.

Example six:

in this embodiment, the difference from the first embodiment is that: the connecting sheet 200 is different;

as shown in fig. 30, the connecting piece 200 includes a base plate 201, a boss 202, and a hole groove 205, wherein the boss 202 is disposed at one side of the hole groove 205;

as shown in fig. 31 and 32, in the step S1, the tabs 102 of the two winding cores 100 respectively pass through the hole slots 205 and are overlapped with each other, and then the tabs 102 and the bottom plate 201 are fixed together by ultrasonic welding, as shown in fig. 33, a welding mark 203 is formed, which is not limited to a specific welding manner in this embodiment;

step S2: as shown in fig. 34, the solder stamp 203 is covered with an insulating tape 300.

Example seven:

in this embodiment, the difference from the sixth embodiment is that: the connecting sheet 200 is different; replacing the boss 202 with a U-shaped bent piece 204;

as shown in fig. 35, the connecting piece 200 is composed of a bottom plate 201 and a U-shaped bending piece 204, a hole groove 205 is formed on the bottom plate 201, and the U-shaped bending piece 204 is located at one side of the hole groove 205;

as shown in step S1 in fig. 36, the tabs 102 of the two winding cores 100 respectively pass through the slots 205 and are overlapped with each other, and then the tabs 102 and the bottom plate 201 are fixed together by ultrasonic welding, which is not limited to a specific welding manner in this embodiment;

step S2: the solder stamp 203 is covered with an insulating tape 300.

It should be noted that: the above embodiments are distinguished by the type of the connection plate 200, the connection manner of the connection plate 200 and the tab 102, the type of the cap plate assembly 700, the connection manner of the connection plate 200 and the cap plate assembly 700, and the like. The preferred embodiments may be interchanged with corresponding components to derive different embodiments.

Except for the detailed assembly steps given in the first embodiment, the other embodiments are only different from each other, and the same operations or adaptive changes are not described.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.