CN213752956U

CN213752956U - Battery module

Info

Publication number: CN213752956U
Application number: CN202023346477.5U
Authority: CN
Inventors: 刘志辉; 杨培
Original assignee: China Aviation Lithium Battery Co Ltd
Current assignee: China Lithium Battery Technology Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-07-20
Anticipated expiration: 2030-12-31

Abstract

The application relates to the field of batteries and discloses a battery module. The battery module comprises a battery string and a bus bar, wherein the battery string and the bus bar are fixedly connected after being positioned by a positioning component; the battery string comprises a plurality of batteries arranged side by side, each battery is provided with a pole, the busbar is provided with a positioning hole, and the positioning assembly comprises a riveting hole arranged on the pole and a positioning hole corresponding to the riveting hole; in the orthographic projection plane of the riveting hole in the hole depth direction, the riveting hole is located in the range surrounded by the positioning hole, and the distance between the contour line of the positioning hole and the peripheral contour line of the riveting hole is 1.5-2 mm.

Description

Battery module

Technical Field

The application relates to the technical field of batteries, in particular to a battery module.

Background

In the assembly process of the battery module, in order to realize series-parallel connection between different batteries, a plurality of batteries to be connected in series-parallel are generally welded to the same bus bar, so as to achieve the purpose of series-parallel connection between different batteries. When the battery is welded with the bus bar, the pole on the battery is welded with the bus bar. In the automatic production process, in order to ensure the accuracy of the welding position and prevent the problems of offset welding and the like, the relative position of the battery and the bus bar needs to be detected before welding, and the welding is carried out when the position deviation of the battery and the bus bar is within a specified range.

Generally, a riveting hole is formed in the end face, facing the bus bar, of the pole when the cover plate assembly of the battery is assembled, and in order to accurately position the bus bar and the pole, the bus bar is provided with a positioning hole which is arranged corresponding to the riveting hole of the pole. In the automatic production process of the battery module, a CCD (charge coupled device) photographing and positioning technology is used for detecting whether the relative position of the positioning hole of the post and the positioning hole of the busbar is within an allowable error range, if so, welding is carried out, otherwise, the welding process flows to a rework process, and the alignment of the busbar and the post is carried out again.

The existing riveting hole is a conical hole, the opening aperture of the riveting hole is slightly smaller than the aperture of the positioning hole of the busbar due to the limitation of various assembly sizes and assembly strength of the battery module, and the busbar is easy to shield the riveting hole due to the small size difference of the riveting hole and the positioning hole and the reason of size tolerance, manual installation and the like of each part. Therefore, in the photographing detection process, the bus bar shields part of characteristic edge lines of the riveting hole, so that the edge characteristic information of the riveting hole cannot be accurately captured, the relative position relation between the battery and the bus bar cannot be accurately judged, the offset welding is easily caused, the rework of the battery module is further caused, and even the battery module is scrapped.

SUMMERY OF THE UTILITY MODEL

The application discloses battery module for solve among the prior art riveting hole easy by the busbar shelter from and then cause welding position inaccurate to lead to battery module reworking or condemned problem.

In order to achieve the purpose, the application provides the following technical scheme:

a battery module comprises a battery string and a bus bar, wherein the battery string and the bus bar are fixedly connected after being positioned by a positioning assembly; the battery string comprises a plurality of batteries arranged side by side, each battery is provided with a pole, the busbar is provided with a positioning hole, and the positioning assembly comprises a riveting hole arranged on the pole and the positioning hole corresponding to the riveting hole; in an orthographic projection plane of the riveting hole in the hole depth direction, the riveting hole is located in the range surrounded by the positioning hole, and the distance between the contour line of the positioning hole and the peripheral contour line of the riveting hole is 1.5-2 mm.

The beneficial effects that adopt this application's technical scheme to produce are as follows:

the application provides a battery module, including battery cluster and busbar, battery cluster and busbar fixed connection, battery cluster include a plurality of batteries that set up side by side, and the battery is equipped with utmost point post, and battery cluster and busbar utilize locating component location back fixed connection when fixed. The positioning assembly comprises a riveting hole formed in the pole and a positioning hole formed in the busbar and corresponding to the riveting hole. In the orthographic projection plane of the riveting hole in the hole depth direction, the distance between the contour line of the positioning hole and the peripheral contour line of the riveting hole is set to be 1.5-2mm, so that the probability that the characteristic edge line of the riveting hole is shielded by the busbar can be effectively reduced, and a shooting camera can conveniently and accurately acquire the information of the characteristic edge line. From this, the application provides a apron subassembly, under the prerequisite that does not reduce apron subassembly riveting strength, can improve the accuracy that counterpoints and detect, improve welding process's yield, reduce defective percentage and disability rate.

Drawings

Fig. 1 is a schematic structural diagram of a battery module according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a cover plate assembly according to an embodiment of the present disclosure;

fig. 3 is a schematic structural view of a riveting hole in a pole provided in the embodiment of the present application;

fig. 4 is a schematic top view of a riveting hole in a post according to an embodiment of the present disclosure.

Reference numerals: 10-a cover plate assembly; 11-a cover plate; 12-pole column; 120-riveting holes; 121-a first sub-aperture; 122-a second sub-aperture; 123-transition surface; 13-briquetting; 20-a battery string; 21-a wiring harness board; 22-a busbar; 221-positioning holes; 23-battery.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the 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 application.

Fig. 1 is a schematic structural diagram of a battery module according to the present application. As shown in fig. 1, the battery module includes a battery string 20 and a harness plate 21 disposed above the battery string 20, and a bus bar 22 is disposed on the harness plate 21. The battery string 20 includes a plurality of batteries 23 arranged in series.

In one embodiment of the present application, the battery includes a battery body and a cover plate assembly, a tab is disposed at one side end of the battery body, and the cover plate assembly is disposed above the battery body. In an embodiment of the present application, the tab of the battery body may be led out from above the battery body, and at this time, the cover plate assembly is disposed on the tab side of the battery body, and the tab is connected to the terminal.

Fig. 2 is a schematic structural diagram of a cover plate assembly 10 according to an embodiment of the present application. As shown in fig. 2, in one embodiment of the present application, the cover plate assembly 10 includes a cover plate 11, a pole post 12, and a compact 13. The cover plate 11 is a plate-shaped structure and has a mounting hole for mounting the pole 12, and the pole 12 passes through the mounting hole of the cover plate 11 and is riveted and fixed with the pressing block 13. In the battery 23, the pole post 12 is used for connecting a tab of the battery 23, and the compact 13 is connected to the pole post 12 and then used for connecting an external circuit.

It is understood that the post 12 may be divided into a positive post and a negative post. The positive electrode terminal is connected to a positive electrode tab of the battery 23, and the negative electrode terminal is connected to a negative electrode tab of the battery 23. Correspondingly, the briquette 13 may be divided into a positive electrode post connected to the positive electrode post and a negative electrode post connected to the negative electrode post.

The connection mode of the pole 12 and the pressing block 13 can be riveting. In this connection mode, the pressing block 13 is provided with a pole post hole, and the pole post 12 is riveted with the pressing block 13 after penetrating through the pole post hole of the pressing block 13. In the riveting process, pressure needs to be applied to the end face of the pole 12 to rivet and fix the pole 12 and the pressing block 13. In the process of applying pressure to the end surface of the pole post 12 for riveting, the thimble applying the pressure forms a riveting hole 120 on the end surface of the pole post 12. In order to ensure the riveting strength of the pole 12 and the pressing block 13, a certain tensile strength is provided between the pole 12 and the pressing block 13, the aperture of the formed riveting hole 120 cannot be too small, otherwise, the volume of the metal for discharging the pole 12 is small, and the riveting strength between the pole 12 and the pressing block 13 cannot be effectively ensured.

In the process of assembling the battery module, it is necessary to weld the plurality of batteries 23 to the bus bars 22, respectively, and the series-parallel connection between the plurality of batteries 23 is realized by the circuit arrangement of the bus bars 22. Before welding, the battery string 20 and the bus bar 22 need to be fixed by welding after being positioned by a positioning assembly. In an embodiment of the present application, the positioning assembly includes a riveting hole 120 disposed in the pole 12 and the positioning hole 221 corresponding to the riveting hole 120.

For the convenience of understanding the technical solution and the corresponding technical effects of the present application, the following explanation is made on the positioning principle of the positioning assembly.

Before soldering, the battery string 20 needs to be aligned with the bus bar 22. In the existing automatic production line, the battery string 20 and the wiring harness plate 21 are automatically aligned, and after the alignment is completed, the process flows to the welding process. Before welding, it is necessary to check whether the alignment between the battery string 20 and the bus bar 22 satisfies the welding process requirements again, and if so, welding is performed, and if not, the process flows to a rework process to perform the alignment again.

During the welding process, it is required to detect whether the alignment between the battery string 20 and the bus bar 22 meets the welding process requirement, for example, a CCD camera photographing positioning technology is used to detect whether the alignment between the battery string 20 and the bus bar 22 meets the process requirement. During the alignment detection, the riveting hole 120 and the positioning hole 221 disposed in the bus bar 22 and corresponding to the riveting hole 120 need to be used for detection, and feature edge line information of the riveting hole 120 and the positioning hole 221 is obtained by photographing to determine whether the riveting hole 120 and the positioning hole 221 meet the set position requirement.

The specific detection process is as follows: the CCD is used for photographing, positioning and detecting whether the positioning hole 221 of the bus bar 22 corresponds to the riveting hole 120 of the pole 12 or not, in the process, the CCD captures the characteristic edge line information of the riveting hole 120 and compares the characteristic edge line information of the positioning hole 221 to detect whether the error between the two is within an allowable range or not, and if yes, the alignment between the battery string 20 and the bus bar 22 is determined to meet the requirements of the welding process.

In order to accurately obtain the characteristic edge line information of the riveting hole 120 in the detection process and prevent the characteristic edge line of the riveting hole 120 from being blocked by the bus bar 22 to cause inaccurate data acquisition, in the battery module provided in the embodiment of the present application, in the orthographic projection plane of the hole depth direction of the riveting hole 120, the riveting hole 120 is located in the range surrounded by the positioning hole 221, and the distance between the contour line of the positioning hole 221 and the peripheral contour line of the riveting hole 120 is 1.5-2 mm.

In the orthographic projection plane of the riveting hole 120 in the hole depth direction, the distance between the contour line of the positioning hole 221 and the peripheral contour line of the riveting hole 120 is set to be 1.5-2mm, so that the probability that the characteristic edge line of the riveting hole 120 is shielded by the bus bar 22 can be effectively reduced, and a shooting camera can conveniently and accurately acquire the information of the characteristic edge line. From this, the apron subassembly 10 that this application provided can improve the accuracy that counterpoints and detect under the prerequisite that does not reduce apron subassembly 10 riveting strength, improves welding process's yield, reduces defective percentage and disability rate.

In this embodiment, reference may be made to fig. 3 and 4 for a structure of the staking hole 120. As shown in fig. 3 and 4, in an embodiment of the present application, the riveting hole 120 includes a first sub-hole 121 and a second sub-hole 122 that are disposed in communication, in a hole depth direction of the riveting hole 120, the first sub-hole 121 is disposed close to an end surface of the pole 12, and the second sub-hole 122 is disposed far from the end surface of the pole 12; the minimum inner diameter of the first sub-hole 121 is larger than the maximum inner diameter of the second sub-hole 122, so that a transition surface 123 of an annular structure is formed between the first sub-hole 121 and the second sub-hole 122; the second sub-hole 122 is a blind hole.

In the riveting hole 120 of the embodiment of the application, the aperture of the first sub-hole 121 is large, so that high riveting strength can be provided for riveting between the pole 12 and the pressing block 13. The reduction of the aperture of the second sub-hole 122 does not affect the riveting strength between the pole 12 and the compact 13. Because the aperture of the second sub-hole 122 is small, the transition surface 123 can be formed between the first sub-hole 121 and the second sub-hole 122, and therefore, the opening edge line of the second sub-hole 122 can be used as a feature edge line when a photo is taken in a positioning manner, so as to reduce the probability of being blocked by the bus bar 22, and facilitate the positioning camera to accurately obtain feature edge line information. From this, the application provides a apron subassembly improves the accuracy that counterpoints and detects under the prerequisite that does not reduce apron subassembly riveting strength, improves welding process's yield, reduces defective percentage and disability rate.

In the process of photographing and positioning, when the camera photographs to acquire the graphic information, for example, the light and shade can be distinguished by the reflection degree of the object, when the inclination angle of the transition surface 123 is different from the inclination angles of the first sub-hole 121 and the second sub-hole 122, an area with different light and shade degrees can be formed on the acquired image of the riveting hole 120, wherein the intersection line of the second sub-hole 122 and the transition surface 123 can form a characteristic edge line. The larger the difference between the inclination angles of the second sub-aperture 122 and the transition surface 123 is, the more obvious the difference between the brightness of the second sub-aperture 122 and the brightness of the transition surface is, and the clearer the characteristic edge line is.

In one embodiment of the present application, the transition surface 123 is a step surface of a planar structure. When the transition surface 123 is of a planar structure, the reflected light of the transition surface 123 is strongest, the difference between the reflected light and the brightness of the second sub-hole 122 is more obvious, and the formed characteristic edge line is clearer, so that the accuracy of obtaining the characteristic edge line can be improved, and the yield of the battery module welding process is further improved.

It should be noted that the shape of the first sub-hole 121 and the second sub-hole 122 is not specifically limited in the cover plate assembly of the embodiment of the present application, and may be set as needed. The first sub-hole 121 may be, for example, a cylindrical hole, a truncated cone hole, a prism hole, a frustum hole, or the like, and the second sub-hole 122 may be a truncated cone hole, a conical hole, a frustum hole, or the like.

In one embodiment of the present application, the second sub-hole 122 is a tapered hole. The second sub-apertures 122 are tapered apertures, and images of the second sub-apertures 122 in images obtained by the CCD are darker patterns so as to form contrasting colors with the transition surfaces 123.

In an embodiment of the present application, the second sub-hole 122 is a conical hole, and the conical hole is adopted, so that a thimble for forming the riveting hole 120 can be conveniently prepared, the processing difficulty is reduced, and meanwhile, when the CCD photographs, the acquired brightness of the second sub-hole 122 is more uniform.

In an embodiment of the present application, an inner diameter of the first sub-hole 121 is gradually decreased from the first sub-hole 121 to the second sub-hole 122. The first sub-hole 121 may be a circular truncated cone hole, so that an ejector pin for forming the riveting hole 120 may be conveniently prepared, and the riveting hole 120 may be conveniently formed by extrusion.

The transition surface 123 formed between the first sub-hole 121 and the second sub-hole 122 may be a circular ring structure, a rectangular ring structure, or another polygonal ring structure, and may be determined according to the specific structure of the first sub-hole 121 and the second sub-hole 122.

In one embodiment of the present application, the first sub-hole 121 and the second sub-hole 122 are coaxially disposed with the pole 12. When the first sub-hole 121, the second sub-hole 122 and the pole 12 are coaxially arranged, the riveting force acting on the pole 12 in all directions can be more uniform; meanwhile, the axis of the pole 12 serves as the center of the riveting hole 120, so that the positioning calculation between the riveting hole 120 and the positioning hole 221 is facilitated.

When the first sub-hole 121 is a circular truncated cone hole, the second sub-hole 122 is a tapered hole, and the first sub-hole 121, the second sub-hole 122 and the pole 12 are coaxially arranged, the formed transition surface 123 is a circular ring transition surface 123.

In one embodiment of the present application, an intersection of the transition surface 123 and the opening of the second sub-hole 122 forms an inner ring of the transition surface 123, an intersection of the transition surface 123 and the sidewall of the first sub-hole 121 forms an outer ring of the transition surface 123, and a distance difference between the inner ring and the outer ring is 0.4-1 mm. The distance difference can ensure that the inner ring and the outer ring do not interfere with each other in the shot image, clear imaging can be realized, meanwhile, allowable dislocation and deviation between the inner ring and the edge line of the positioning hole 221 can be increased, recognition is facilitated, and the inner ring serving as a characteristic edge line is prevented from being shielded by the bus bar 22.

To verify the dimensional stability of the staking hole 120, the present application provides the following test data.

1010 riveted cover plate assemblies were extracted, and the size of the riveting hole 120 of each sample was measured using a CCD, wherein the shape of the riveting hole 120 in the test sample was, for example, the structure shown in fig. 3 and 4. The sizes of the tested riveting holes 120 include a small circle, a middle circle and a large circle, wherein the small circle corresponds to the inner ring of the annular transition surface 123, the middle circle corresponds to the outer ring of the annular transition surface 123, the large circle corresponds to the opening circle of the first sub-hole 121, and the test results are listed in table 1.

TABLE 1

As can be seen from the test data in table 1, the diameter sizes of the middle circle and the small circle are more stable than that of the large circle, and the obtained information is also more stable when the small circle is used as the characteristic edge line. The reasons for this may be: when utilizing the thimble to rivet the utmost point post, through stop gear restriction riveting needle distance of moving, however the change of material height, the slope of frock platform etc. all can lead to the distance inconsistent that the thimble pushed down on utmost point post surface, and the great circle size that consequently obtains also can have the deviation, causes the diameter size tolerance of great circle great.

From this, the riveting hole that this application provided establishes in order to form the transition face through the cover that sets up in first sub-hole and second sub-hole, through the usable small circle of transition face as the characteristic edge line in the counterpoint testing process to reduce the big influence that causes of circle dimensional tolerance, improve the detection precision, reduce welding repair rate and disability rate.

In an embodiment of the application, in an orthographic projection plane of the riveting hole in the hole depth direction, the riveting hole is located in a range surrounded by the positioning hole, and a distance between a contour line of the positioning hole and a contour line of an opening of the second sub-hole is 1.5-2 mm.

Referring to the description of the first aspect of the present application about positioning detection, in the acquired image of the riveting hole, the opening edge of the second sub-hole corresponds to the characteristic edge line of the riveting hole, the contour line of the positioning hole is the characteristic edge line of the positioning hole, and by limiting the distance between the characteristic edge line of the positioning hole and the characteristic edge line of the riveting hole, the probability that the bus bar blocks the characteristic edge line of the riveting hole can be further reduced, the detection accuracy is improved, meanwhile, the fault-tolerant distance of the relative position can be further improved, and the rework rate is reduced.

In order to verify the alignment effectiveness of the riveting hole in the production process, the following identification verification is specially performed.

The method comprises the steps of setting the locating hole and the riveting hole coaxially, obtaining characteristic edge line information of the riveting hole at the moment, recording the characteristic edge line information as standard line information, moving the relative position relation of the riveting hole and the locating hole to enable the axes of the riveting hole and the locating hole to deviate by 0.5mm, 1mm and 1.5mm respectively, obtaining the characteristic edge line information of the riveting hole after deviation respectively, comparing the characteristic edge line information with the standard line information, and judging the similarity before and after deviation. Specific similarities are listed in table 2.

TABLE 2

Offset amount	Degree of similarity
		0.5mm	100％
1mm	100％
		1.5mm	93％

Wherein, the similarity of 36 polar columns is always kept above 90% through measurement, and most polar columns can be maintained at 100%.

As can be seen from the data in table 2, when the offset is within 1mm, the similarity before and after the offset is 100%, which indicates that the characteristic edge line of the riveting hole can be accurately determined when the positioning hole and the riveting hole are under the offset. When the offset is 1.5mm, the similarity before and after the offset is still high, and the identification precision at the moment can still meet the actual production condition.

In one embodiment of the present application, there are at least two positioning assemblies in the battery module. Through setting up two locating component, can effectively avoid battery cluster and busbar to rotate the deviation at the counterpoint in-process and exceed the allowed range, from this, can guarantee that battery cluster and busbar's counterpoint is more accurate.

In one embodiment of the present application, the battery string has a rectangular structure, and the positioning assembly is disposed at least at two corners of one diagonal line of the battery string. Through set up locating component in diagonal position, can effectively reduce locating component's detection quantity in the testing process, still can effectively guarantee the accuracy of battery cluster and backward flow row counterpoint.

Through the analysis, the riveting hole of the embodiment of the application is arranged in the cover plate assembly, so that the following beneficial effects can be achieved:

the reduction of the characteristic edge line size that is used for the location of riveting hole can avoid being sheltered from by the busbar, can realize the accurate positioning of riveting hole, reduces the partial welding. Meanwhile, the aperture of the first sub-hole is not reduced, so that the original riveting strength of the pole is maintained. In addition, the distance between the characteristic edge line of the riveting hole and the bus positioning hole is increased, the allowable dislocation and deviation are increased, and the identification is convenient. In addition, the tolerance of the feature edge line dimension of the riveting hole is small, the dimension stability of a feature circle formed by the opening of the second sub-hole is good, and the reliability of the detection result is high.

Forming a riveting hole: and applying pressure to the end surface of the pole by using a thimble so as to form the riveting hole in the pole.

It can be understood that the shape of the thimble and the shape of the riveting hole are matched, and the riveting hole in the above embodiment of the present application can be formed on the surface of the pole after the thimble is used to apply pressure on the pole. It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A battery module is characterized by comprising a battery string and a bus bar, wherein the battery string and the bus bar are fixedly connected after being positioned by a positioning component;

the battery string comprises a plurality of batteries arranged side by side, each battery is provided with a pole, the busbar is provided with a positioning hole, and the positioning assembly comprises a riveting hole arranged on the pole and the positioning hole corresponding to the riveting hole; in an orthographic projection plane of the riveting hole in the hole depth direction, the riveting hole is located in the range surrounded by the positioning hole, and the distance between the contour line of the positioning hole and the peripheral contour line of the riveting hole is 1.5-2 mm.

2. The battery module according to claim 1, wherein in a hole depth direction of the riveting hole, the riveting hole comprises a first sub-hole and a second sub-hole which are communicated with each other, the first sub-hole is arranged close to the end surface of the pole, and the second sub-hole is arranged far away from the end surface of the pole; the minimum inner diameter of the first sub-hole is larger than the maximum inner diameter of the second sub-hole, so that a transition surface of an annular structure is formed between the first sub-hole and the second sub-hole; the second sub-hole is a blind hole.

3. The battery module according to claim 2, wherein the transition surface is a planar structure.

4. The battery module according to claim 3, wherein the radial dimension of the first sub-aperture gradually decreases in a direction from the first sub-aperture to the second sub-aperture.

5. The battery module according to claim 4, wherein the second sub-hole is a tapered hole.

6. The battery module according to claim 5, wherein the second sub-hole is a conical hole.

7. The battery module according to any one of claims 2-4, wherein the first sub-aperture, the second sub-aperture and the post are coaxially disposed.

8. The battery module according to any one of claims 2 to 4, wherein an intersection of the transition surface with the opening of the second sub-aperture forms an inner ring of the transition surface, an intersection of the transition surface with the sidewall of the first sub-aperture forms an outer ring of the transition surface, and a distance difference between the inner ring and the outer ring is 0.4 to 1 mm.

9. The battery module according to any one of claims 2 to 4, wherein there are at least two positioning members.

10. The battery module according to claim 9, wherein the battery string has a rectangular structure, and the positioning members are provided at least at two corners of one diagonal line of the battery string.