阅读说明：本技术 锂电池极耳焊接结构及其焊接牢固程度检测方法 (Lithium battery tab welding structure and welding firmness degree detection method thereof ) 是由 *** 徐秋鹏 胡庆军 张叶鑫 于 2019-09-20 设计创作，主要内容包括：本发明公开了一种锂电池极耳焊接结构,用于将锂电池电芯的极耳(1)焊接到汇流排(2)上,在焊接过程中,在所述的极耳(1)和汇流排(2)的接合面之间,插入弹性片(4),并深入到焊接点位置。本发明还公开了该焊接结构的焊接牢固程度检测方法。采用上述技术方案,对极耳与汇流排焊接牢固程度进行可靠的测试,并能够检测出焊接是否符合要求；检测方法简单易行,能够实行全检,防止发生不合格产品的漏检。(The invention discloses a lithium battery tab welding structure, which is used for welding a tab (1) of a lithium battery cell to a bus bar (2), wherein an elastic sheet (4) is inserted between the joint surfaces of the tab (1) and the bus bar (2) and extends into the position of a welding point in the welding process. The invention also discloses a method for detecting the welding firmness degree of the welding structure. By adopting the technical scheme, the welding firmness degree of the pole lug and the bus bar is reliably tested, and whether the welding meets the requirement or not can be detected; the detection method is simple and easy to implement, can implement full detection, and prevents the occurrence of missed detection of unqualified products.)

1. The utility model provides a lithium battery tab welded structure for on welding busbar (2) with utmost point ear (1) of lithium cell electricity core, its characterized in that: in the welding process, an elastic sheet (4) is inserted between the joint surfaces of the tab (1) and the bus bar (2) and extends deeply to the welding point.

2. the lithium battery tab welding structure as claimed in claim 1, wherein: the elastic piece (4) is provided with an elastic piece pulling mechanism (5), and the pulling direction of the elastic piece pulling mechanism (5) is the direction of separating the lug (1) from the bus bar (2).

3. the lithium battery tab welding structure as claimed in claim 1, wherein: the tensile force of the elastic sheet pulling mechanism (5) is equal to the standard tensile strength of the welding point.

4. A tab welding structure for a lithium battery as claimed in claim 1, 2 or 3, wherein: the welding point is a fusion area (3).

5. the method for detecting the welding firmness of a tab welding structure of a lithium battery as claimed in any one of claims 1 to 4, wherein: the detection method comprises the following detection process steps:

step 1, inserting an elastic sheet (2) between joint surfaces of a tab (1) and a busbar (2) and penetrating into a welding point;

step 2, moving the elastic sheet (4) towards a direction perpendicular to the elastic sheet (4) and towards a direction enabling the lug (1) to be separated from the bus bar (2) through the elastic sheet pulling mechanism (5) until the elastic sheet (4) is completely separated from the lug (1) and the bus bar (2);

And 3, judging whether the welding firmness meets the requirement or not according to the existence or non-existence of damage of the welding point.

6. The lithium battery tab welding structure as claimed in claim 5, wherein: the detection standard determining process of the detection method is as follows:

Step 1, analyzing the stressed stretching limit and shearing limit of the tab (1) under various conditions through simulation under a specified working condition;

step 2, testing the ratio of the welding shear failure strength to the tensile failure strength;

step 3, converting the shear strength limit obtained by analysis in the step 1 into a tensile strength limit, comparing the tensile strength limit with the tensile strength limit obtained by analysis, and selecting a numerical value as a detection standard;

And 4, manufacturing an elastic sheet (4), and applying the detection standard tensile strength obtained in the step 3 to the welding point to the maximum extent when the welded pole lug (1) is flatly picked upwards.

Technical Field

The invention belongs to the technical field of manufacturing process equipment of electrical products. More particularly, the present invention relates to a tab welding structure for a lithium battery. In addition, the invention also relates to a method for detecting the welding firmness degree of the welding structure.

Background

in recent years, with the increasing energy and environmental crisis, the development of new energy vehicles becomes a necessary trend, and the performance and safety of power lithium batteries as energy supply devices of new energy vehicles are very important.

At the in-process of module is made to electric core, need weld the utmost point ear of electric core to the busbar on, and the bad phenomenon of utmost point ear and busbar welding often appears in the package welding process. Products with poor welding are put into use, which can cause larger internal resistance, higher temperature and even welding falling in the using process to strike fire, which can cause great influence on the performance and safety of the power battery.

disclosure of Invention

The invention provides a lithium battery tab welding structure, and aims to better detect whether the welding quality of a lithium battery tab meets requirements.

in order to achieve the purpose, the invention adopts the technical scheme that:

the invention relates to a lithium battery tab welding structure, which is used for welding tabs of a lithium battery cell to a bus bar; during welding, an elastic sheet is inserted between the joint surfaces of the tab and the busbar and extends deeply to the welding point.

And the elastic sheet is provided with an elastic sheet pulling mechanism, and the pulling direction of the elastic sheet pulling mechanism is the direction for separating the lug from the bus bar.

the pulling force of the elastic sheet pulling mechanism is equal to the standard tensile strength of the welding point.

The welding point is a fusion area.

In order to achieve the same purpose as the technical scheme, the invention also provides a method for detecting the welding firmness degree of the lithium battery tab welding structure, which comprises the following steps:

the detection method comprises the following detection process steps:

step 1, inserting an elastic sheet between joint surfaces of a tab and a busbar and penetrating into a welding point;

Step 2, moving the elastic sheet towards a direction perpendicular to the elastic sheet and enabling the lug to be separated from the busbar through the elastic sheet pulling mechanism until the elastic sheet is completely separated from the lug and the busbar;

And 3, judging whether the welding firmness meets the requirement or not according to the existence or non-existence of damage of the welding point.

The detection standard determining process of the detection method is as follows:

Step 1, analyzing the stressed stretching limit and shearing limit of the tab under various conditions through simulation under the specified working condition;

Step 2, testing the ratio of the welding shear failure strength to the tensile failure strength;

Step 3, converting the shear strength limit obtained by analysis in the step into a tensile strength limit, comparing the tensile strength limit with the tensile strength limit obtained by analysis, and selecting a numerical value as a detection standard;

And 4, manufacturing an elastic sheet, and applying the detection standard tensile strength obtained in the step to the welding point to the maximum extent when the welded pole lug is flatly picked upwards.

By adopting the technical scheme, the welding firmness degree of the pole lug and the bus bar is reliably tested, and whether the welding meets the requirement or not can be detected; the detection method is simple and easy to implement, can implement full detection, and prevents the occurrence of missed detection of unqualified products.

Drawings

The contents of the drawings and the reference numbers in the drawings are briefly described as follows:

FIG. 1 is a schematic view of a module structure according to the present invention;

FIG. 2 is a schematic structural view of the positional relationship between the tab and the busbar of the present invention;

fig. 3 is a structural diagram illustrating the detection structure of the welding firmness of the tab in the present invention.

labeled as:

1. The electrode tab pulling mechanism comprises an electrode tab 2, a bus bar 3, a fusion area 4, an elastic sheet 5 and an elastic sheet pulling mechanism.

Detailed Description

The following detailed description of the embodiments of the present invention will be given in order to provide those skilled in the art with a more complete, accurate and thorough understanding of the inventive concept and technical solutions of the present invention.

The structure of the present invention, as shown in fig. 1 to 3, is a tab welding structure of a lithium battery for welding a tab 1 of a lithium battery cell to a bus bar 2. The lithium battery tab welding structure and the method for detecting the welding firmness degree of the tab can detect whether the welding meets the requirements.

in order to overcome the defects of the prior art and achieve the purpose of better detecting whether the welding quality of the lithium battery tab meets the requirements, the invention adopts the technical scheme that:

As shown in fig. 1 to 3, in the tab welding structure of a lithium battery according to the present invention, an elastic sheet 4 is inserted between the joint surfaces of the tab 1 and the bus bar 2 and extends into the welding point during the welding process.

By adopting the technical scheme, the welding firmness degree of the pole lug and the bus bar is reliably tested, and whether the welding meets the requirement or not can be detected; the detection method is simple and easy to implement, can implement full detection, and prevents the occurrence of missed detection of unqualified products.

The specific implementation method comprises the following steps:

The elastic sheet 4 is provided with an elastic sheet pulling mechanism 5, and the pulling direction of the elastic sheet pulling mechanism 5 is the direction of separating the tab 1 from the bus bar 2.

the pulling force of the elastic sheet pulling mechanism 5 is equal to the standard tensile strength of the welding point.

the welding point is a fusion welding area 3.

in order to achieve the same purpose as the technical scheme, the invention also provides a method for detecting the welding firmness degree of the lithium battery tab welding structure, which comprises the following steps:

The process for detecting the welding firmness degree of the 3P small module lug comprises the following steps: :

step 1, inserting an elastic sheet 2 between joint surfaces of a tab 1 and a busbar 2, and penetrating into a welding point;

Step 2, moving the elastic sheet 4 towards a direction perpendicular to the elastic sheet 4 and enabling the tab 1 to be separated from the bus bar 2 through the elastic sheet pulling mechanism 5 until the elastic sheet 4 is completely separated from the tab 1 and the bus bar 2;

And 3, judging whether the welding firmness meets the requirement or not according to the existence or non-existence of damage of the welding point.

The detection standard determining process of the detection method is as follows:

step 1, analyzing the stressed stretching limit and shearing limit of the tab 1 under various conditions through simulation under a specified working condition;

Step 2, testing the ratio of the welding shear failure strength to the tensile failure strength;

Step 3, converting the shear strength limit obtained by analysis in the step 1 into a tensile strength limit, comparing the tensile strength limit with the tensile strength limit obtained by analysis, and selecting a numerical value as a detection standard;

and 4, manufacturing an elastic sheet 4, and applying the detection standard tensile strength obtained in the step 3 to the welding point to the maximum extent when the welded lug 1 is flatly picked upwards.

The detection technology is that after welding of each minimum module unit is completed, the welding firmness is detected and then the next procedure is performed.

The invention analyzes the ultimate tensile strength value which ensures the welding firmness, applies corresponding tensile strength to the welding point by using the elastic sheet, and the welding point is qualified if the welding point is not damaged and needs rework if the welding point is damaged. The invention has the beneficial effects that:

1. a reliable test is given to the welding firmness degree of the lug and the bus bar;

2. the detection is simple and easy to implement, and the full detection can be realized.

The invention has been described above with reference to the accompanying drawings, it is obvious that the invention is not limited to the specific implementation in the above-described manner, and it is within the scope of the invention to apply the inventive concept and solution to other applications without substantial modification.