KR20210074577A - Pressing Jig For Enhancing Adhesion of Welding Object - Google Patents

Abstract

The present invention relates to a pressurizing jig capable of enhancing the adhesion of welding objects. More specifically, the present invention relates to a pressurizing jig (200) for pressurizing an electrode lead (132) for welding the electrode lead (132) of a battery cell (130) on a bus bar (140). The pressing jig (200) comprises: a fixed body (210) with a first penetrating spear (211) for a welding laser to penetrate; a first pressurizing unit (220) placed under the fixed body (210) and including a horizontal unit (221) having a second penetrating spear (221'); a guide unit (230) connecting the fixed body (210) to the first pressurizing unit (220); and a second pressurizing unit (240) placed under the first pressurizing unit (220). The pressurizing jig is able to enhance the adhesion of the welding objects.

Description

A pressing jig capable of improving the adhesion of welding objects {Pressing Jig For Enhancing Adhesion of Welding Object}

The present invention relates to a pressing jig capable of improving the adhesion of welding objects, and more particularly, by providing a plurality of pressing parts capable of vertical movement independently of each other, thereby improving the adhesion of welding objects and improving welding quality. It's about the jig.

As technology development and demand for mobile devices such as cell phones, laptops, camcorders, and digital cameras increase, technologies related to rechargeable batteries that can be charged and discharged are becoming active. In addition, secondary batteries are an alternative energy source for fossil fuels that cause air pollutants, and are being applied to electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and the like. The need for development is increasing day by day.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel-based secondary batteries, so charging and discharging are free and easy. , the self-discharge rate is very low and the energy density is high.

Meanwhile, when the secondary battery as described above is used in a device requiring a large capacity and high voltage, such as an electric vehicle, it is used in the form of a battery module or battery pack having a structure in which a plurality of battery cells are arranged.

For example, in a battery module, a plurality of battery cells are connected in series and parallel to each other to improve capacity and output, and a bus bar is used for electrical connection between these battery cells, and a bus bar and a battery are used. Since the leads of the cell are metal that conducts electricity, they are usually connected by welding.

Korean Patent Application Laid-Open No. 2015-0125387 discloses a laser welding apparatus in which electrode terminals 12 of battery cells corresponding to each other are welded to bus bars 11 of a module case, respectively. That is, as shown in FIG. 1, which is a cross-sectional view of a laser welding apparatus equipped with a jig according to the prior art, it is movable toward the electrode terminals corresponding to each other disposed on both ends of the bus bar of the module case and provided with a laser beam irradiation unit ( a laser welding head 14 equipped with 15); and a fixing jig 13 provided in the laser welding head 14 and respectively pressing the corresponding electrode terminals when the laser welding head is moved to be in close contact with both ends of the bus bar 11, respectively. it is a device

According to the laser welding apparatus of the prior document, it is possible to press the corresponding electrode terminals, respectively, so that they can be brought into close contact with the bus bar of the module case, and thus, the effect of preventing poor welding of the electrode terminals is expected.

However, as shown in FIG. 2, which is a plan view for explaining the close contact position between the jig and the electrode lead according to the prior art, when the electrode lead 12 is seated slightly out of the center of the bus bar 11, the center of the welding point is used. If the three sides are not pressurized and the electrode leads or bus bars are not flat, a lifting phenomenon occurs in some positions, so there is a problem that it may still cause poor welding.

Korea Patent Publication No. 2015-0125387

In order to solve the above problems, an object of the present invention is to provide a pressure jig capable of minimizing welding defects even when an electrode lead and a bus bar are not accurately positioned.

Another object of the present invention is to provide a pressure jig capable of minimizing welding defects even when a lifting phenomenon occurs in an overlapping portion of an electrode lead and a bus bar.

In order to solve the above problems, the pressure jig capable of improving the adhesion of welding objects according to the present invention is an electrode lead ( As a pressing jig 200 for pressing 132, the pressing jig 200 includes a fixed body 210 provided with a first through window 211 so that a welding laser can penetrate; a first pressing part 220 positioned under the fixed body 210 and including a horizontal part 221 provided with a second through-window 221 ′; a guide part 230 connecting the fixed body 210 and the first pressing part 220; and a second pressing unit 240 positioned below the first pressing unit 220 .

In addition, in the pressing jig according to the present invention, the first pressing portion 220 is a horizontal portion 221 in which the second through window 221 ′ is formed, as long as the horizontal portion 221 is bent at both ends at a predetermined angle. A pair of vertical portions 222, and a pair of wing portions 223 bent at a predetermined angle from the pair of vertical portions 222, through-holes 223' are formed.

In addition, in the pressure jig according to the present invention, the guide part 230 has one side connected to the fixed body 210 and the other side of the guide rod 231 passing through the through hole 223 ′ of the wing unit 223 . , and a first elastic means 232 positioned in a shape surrounding the guide rod 231 .

In addition, in the pressing jig according to the present invention, only one side of the guide rod 231 is the fixed body 210 or the wing portion so that the separation distance between the fixed body 210 and the first pressing unit 220 can be varied. It is characterized in that it is fixed to (223).

In addition, in the pressing jig according to the present invention, it is characterized in that the second elastic means 250 for connecting the first pressing part 220 and the second pressing part 240 is further provided.

In addition, in the pressing jig according to the present invention, the second pressing part 240 is characterized in that a third through window 241 ′ is formed in the center of two pairs of sidewalls 241 facing each other.

In addition, in the pressing jig according to the present invention, the first pressing part 220 is characterized in that a plurality of second pressing parts 240 are provided.

In addition, in the pressing jig according to the present invention, the plurality of second pressing parts 240 is characterized in that it can move independently.

In addition, in the pressing jig according to the present invention, the second elastic means 250 is characterized in that two or more.

In addition, in the pressing jig according to the present invention, the second elastic means 250 is characterized in that four.

In addition, the pressing jig according to the present invention is a pressing jig 200 for pressing the electrode lead 132 in order to weld the electrode lead 132 of the battery cell 130 to the bus bar 140, the pressing jig ( 200), a fixed body 210 provided with a first through window 211 so that the welding laser can penetrate; and a first pressing unit 220 positioned under the fixed body 210 and including a first pressing body 221 having a second through window 221 ′, wherein the second through window 221 . ') is characterized in that one or more partition walls 224 are further provided.

In addition, the method of welding the electrode lead 132 of the battery cell 130 to the bus bar 140 using a pressure jig according to the present invention includes the steps of: positioning the electrode lead 132 on the bus bar 140 ; Placing a pressure jig on the upper surface of the electrode lead 132 and pressing the pressure to a predetermined pressure; and welding the bus bar 140 and the electrode lead 132 by irradiating a laser beam.

According to the pressing jig capable of improving the adhesion of the welding objects according to the present invention, the first pressing portion including a plurality of second pressing bodies capable of independently contracting and expanding is additionally provided, so that the bus bar and the electrode lead overlap Even if there is some lifting phenomenon in the part or they do not exactly match each other, it is possible to press them reliably, and thus there is an advantage that welding defects can be minimized.

1 is a cross-sectional view of a laser welding apparatus equipped with a jig according to the prior art.
2 is a plan view for explaining the close contact position between the jig and the electrode lead according to the prior art.
3 is a perspective view showing a state in which the pressure jig according to the first preferred embodiment of the present invention is seated on the battery module.
4 is a perspective view showing a state in which the pressing part of the pressing jig according to the first preferred embodiment of the present invention is in close contact with the upper portion of the electrode lead.
5 is a perspective view for explaining a path through which a laser beam passes in the pressing jig according to the first preferred embodiment of the present invention.
6 is a front view of the pressing jig according to the first preferred embodiment of the present invention.
7 is an enlarged perspective view of part A of FIG. 6 .
8 is a bottom view of a portion A of FIG. 6 as viewed from below.
9 is an enlarged perspective view of a portion B of FIG. 7 .
10 is a perspective view of a first pressing part according to a second preferred embodiment of the present invention.

In the present application, terms such as “comprises”, “have” or “have” are intended to designate the existence of features, numbers, steps, components, parts, or combinations thereof described in the specification, and one or more other It is to be understood that this does not preclude the possibility of the presence or addition of features or numbers, steps, operations, components, parts, or combinations thereof.

In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions. Throughout the specification, when a part is said to be connected to another part, it includes not only a case in which it is directly connected, but also a case in which it is indirectly connected with another element interposed therebetween. In addition, the inclusion of a certain component does not exclude other components unless otherwise stated, but means that other components may be further included.

Hereinafter, a pressure jig capable of improving adhesion of welding objects according to the present invention will be described.

3 is a perspective view showing a state in which the pressing jig according to the first preferred embodiment of the present invention is seated on the battery module, and FIG. 4 is a pressing part of the pressing jig according to the first preferred embodiment of the present invention on the upper part of the electrode lead. It is a perspective view showing the adhered state.

3 and 4, the pressurizing jig 200 according to the present invention is located above the unit module 100 in which a plurality of battery cells are gathered to form an aggregate, and the electrode lead is welded to the bus bar. This is to pressurize the electrode lead.

Specifically, in the battery module 100 , a plurality of battery cells 130 are disposed adjacent to each other in a vertical direction between a pair of end plates 110 , and an upper cover 130 is mounted on the battery cells 130 . has been

In the battery cell 130 , an electrode assembly (not shown) is accommodated in the cell case 131 , and a pair of electrode leads 132 made of a positive electrode and a negative electrode are led out to the outside of the case 131 .

And the electrode lead 132 of each battery cell 130 is seated on the upper surface of the bus bar 140 so as to increase the output of the battery module 100, and in order to press the electrode lead 132 with a predetermined force, the electrode lead ( 132) A pressure jig is located on the upper surface.

On the other hand, the electrode assembly constituting the battery cell 130 is a jelly-roll-type assembly having a structure in which a separator is interposed between a long sheet-shaped positive electrode and a negative electrode and then wound, or a state in which a rectangular positive electrode and a negative electrode are interposed between the separator A stack-type assembly consisting of unit cells stacked with a structure, a stack-folding assembly in which the unit cells are wound by a long separation film, or a lamination in which unit cells are stacked with a separator interposed therebetween and attached to each other - It may consist of a stack-type assembly, but is not limited thereto.

The cell case 131 typically has a laminate sheet structure of an inner layer/metal layer/outer layer. Since the inner layer is in direct contact with the electrode assembly, it must have insulation and electrolyte resistance, and for sealing with the outside, the sealing property, that is, the sealing portion where the inner layers are thermally bonded to each other, must have excellent thermal bonding strength. The material of the inner layer may be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, polybutylene, etc., polyurethane resins and polyimide resins having excellent chemical resistance and good sealing properties, but is not limited thereto, Polypropylene excellent in mechanical properties such as tensile strength, rigidity, surface hardness, and impact resistance and chemical resistance is the most preferable.

The metal layer in contact with the inner layer corresponds to a barrier layer that prevents moisture or various gases from penetrating into the battery from the outside, and as a preferable material for the metal layer, an aluminum film that is lightweight and has excellent formability may be used.

And an outer layer is provided on the other side of the metal layer, and this outer layer can use a heat-resistant polymer excellent in tensile strength, moisture permeability and air permeability to secure heat resistance and chemical resistance while protecting the electrode assembly, As an example, nylon or polyethylene terephthalate may be used, but is not limited thereto.

On the other hand, the pair of electrode leads 132 may have a structure in which the positive tab and the negative tab of the electrode assembly are electrically connected to each other and then exposed to the outside of the cell case 131 , and the electrode lead 132 without the positive tab and the negative tab ) may be directly connected to the electrode assembly.

Subsequently, the pressing jig 200 is configured to include a fixed body 210 , a first pressing part 220 , a guide part 230 , a second pressing part 240 , and a second elastic means 250 . .

The fixed body 210 has a predetermined thickness and has a substantially rectangular cross-section, and has a first center in the center so that the welding laser beam can pass to the first pressing part 220 and the second pressing part 240 located below. A through window 211 is perforated.

Although not shown in the drawings, a separate moving means (not shown) for pressing down or lifting the fixed body 210 is connected to a predetermined portion of the side or upper surface of the fixed body 210 .

The first pressing unit 220 is spaced apart from the fixed body 210 by a predetermined distance, is located under the fixed body 210, and has a second through window 221 ′. And between the fixed body 210 and the first pressing part 220, a guide part 230 for physically connecting them to each other is positioned.

In addition, the second pressing portion 240 is located under the first pressing portion 220, the third through window 241' is formed, these are physically connected by the second elastic means (250).

Specific configurations of the first pressing unit 220 , the guide unit 230 , the second pressing unit 240 , and the second elastic means 250 will be described later.

5 is a perspective view for explaining a path through which a laser beam passes in the pressing jig according to the first preferred embodiment of the present invention. As shown in FIG. 5 , the laser beam irradiated downward through the first through window 211 of the fixed body 210 is applied to the second through window 221 ′ of the first pressing unit 220 and the second pressing unit. The bus bar 140 and the electrode lead 132 are welded by sequentially passing through the third through window 241 ′ of the part 240 and reaching the upper surface of the electrode lead 132 .

6 is a front view of a pressing jig according to a first preferred embodiment of the present invention, FIG. 7 is an enlarged perspective view of part A of FIG. 6, FIG. 8 is a bottom view of part A of FIG. 6 from below, and FIG. 9 is It is an enlarged perspective view of part B of FIG. 7 .

6 to 9 , the first pressing unit 220 , the guide unit 230 , the second pressing unit 240 , and the second elastic means 250 will be described in detail.

First, the first pressing part 220 has a predetermined width and length and is substantially perpendicular to the horizontal part 221 in which the second through-window 221 ′ is formed along the longitudinal direction, and at both ends of the horizontal part 221 . A pair of vertical portions 222 extending upwardly while being bent, and a pair of wing portions 223 positioned parallel to the horizontal portion 221 by being bent at approximately right angles from one end of the vertical portion 222 do. And the wing part 223 is provided with a through hole 223' for accommodating the guide rod 231, which will be described later.

The guide part 230 positioned between the fixed body 210 and the first pressing part 220 and connecting them to each other has one side connected to the fixed body 210 and the other side is a through hole 223 of the wing part 224 . ') and a guide rod 231 passing through, and a first elastic means 232 such as a coil spring mounted in a shape surrounding the outer periphery of the guide rod 231.

Here, only one side of the guide rod 231 should be fixed. For example, if the lower end of the guide rod 231 is fixed to the through hole 223', the upper end should simply be fastened to the fixed body 210, and conversely, the upper end of the guide rod 231 is fixed to the fixed body ( If it is fixed to the 210, the lower end means a state that is simply fastened to the through-hole 223'.

This means that even when the fixed body 210 is pressed with a predetermined force, the fixed body 210 and the first pressing unit 220 are maximally spaced apart by the first elastic means 232 when the electrode lead 132 is not in contact. This is because the first elastic means 232 is contracted when in close contact with the electrode lead 132 and, conversely, the separation distance between the fixed body 210 and the first pressing part 220 can be narrowed. to be.

The second pressing unit 240 is connected to the first pressing unit 220 through the second elastic means 250 , and a third through window 241 ′ is formed in the center thereof, and the third through window 241 is formed in the center. ') in the center and has a rectangular prism shape composed of two pairs of sidewalls 241 facing each other.

In particular, as shown in FIG. 9 , a curved portion 242 is formed on the upper outer side of the sidewall 241 facing the first pressing portion 220, and it is preferable that the cross-sectional area is relatively larger than the lower portion in close contact with the electrode lead, which is The contact area with the first pressing part 220 is increased to ensure stable adhesion, and even if the width of the electrode lead 132 is narrow or the electrode lead 132 is seated at a position slightly deviated from the center of the bus bar 140, the electrode lead ( 132) can be reliably pressurized.

For example, the width of the second through window 221' is D1, the width of the first horizontal part 221 is D2, the width of the third through window 241' of the second pressing part 240 is D3, and When the width of the upper end of the second pressing part 240 is defined as D4, D2 may be less than D4, and D3 may be less than D1.

On the other hand, the second elastic means 250 made of a coil spring, etc. is located on the upper surface of the side wall 241 constituting the second pressing part 240, and the second pressing part 240 is inclined at a predetermined angle in a desired direction. It is preferable that there are two or more, and more preferably four or more.

Although the accompanying drawings show that there are six second pressing units 240 , this is merely an example and can be changed as much as possible, and in this case, each of the second pressing units 240 moves independently of each other.

10 is a perspective view of the first pressing part in the second preferred embodiment of the present invention. In the second embodiment of the present invention, the second pressing part and the second elastic means are not provided, while the first pressing part 220 is not provided. One or more fixed partition walls 224 are provided on the horizontal portion 221 of the That is, when the partition wall 224 dividing the second through window 221 ′ into a plurality is provided, the pressing force is transmitted to the electrode lead 132 by the partition wall 224 , so that the electrode lead 132 and the bus bar 140 are provided. ) can improve adhesion.

Here, it is preferable to coincide with the lower end of the horizontal portion 221 so that the lower end of the partition wall 224 does not protrude.

Subsequently, a method of welding an electrode lead and a bus bar using the pressure jig of the present invention will be described.

A welding method according to the present invention comprises the steps of placing an electrode lead 132 on a bus bar 140; Placing a pressure jig on the upper surface of the electrode lead 132 and pressing the pressure to a predetermined pressure; and welding the bus bar 140 and the electrode lead 132 by irradiating a laser beam.

As shown in FIG. 10 , a large force from the fixed body 210 is transmitted to the first pressing unit 220 and presses the whole, and some lifts at the overlapping portion of the bus bar 140 and the electrode lead 132 . Even if there is a phenomenon, a plurality of first pressing units 220 capable of independently contracting and expanding are additionally provided, so that the overlapping surfaces of the bus bar 140 and the electrode leads 132 can be in uniform contact.

As the specific part of the present invention has been described in detail above, for those of ordinary skill in the art, these specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereby, It is obvious to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention, and it is natural that such variations and modifications fall within the scope of the appended claims.

100: battery module
110: end plate
120: upper cover
130: battery cell
131: cell case 132: electrode lead
140: bus bar
200: pressure jig
210: fixed body
211: first through window
220: first pressing unit
221: horizontal portion 221′: second through window
222: vertical part 223: wing part
223′: through hole 224: bulkhead
230: guide unit
231: guide rod 232: first elastic means
240: second pressing unit
241: side wall 241′: third through window
242: curved part
250: second elastic means

Claims (12)

As a pressing jig 200 for pressing the electrode lead 132 in order to weld the electrode lead 132 of the battery cell 130 to the bus bar 140,
The pressing jig 200 includes a fixed body 210 having a first through window 211 through which a welding laser can penetrate;
a first pressing part 220 positioned under the fixed body 210 and including a horizontal part 221 provided with a second through-window 221 ′;
a guide part 230 connecting the fixed body 210 and the first pressing part 220; and
A pressing jig comprising a second pressing part (240) positioned below the first pressing part (220).
According to claim 1,
The first pressing part 220 includes a horizontal part 221 in which a second through window 221' is formed, a pair of vertical parts 222 bent at both ends of the horizontal part 221 at a predetermined angle, and A pressure jig comprising a pair of wing portions 223 bent at a predetermined angle in the pair of vertical portions 222 and having a through-hole 223 ′.
3. The method of claim 2,
The guide part 230 has one side connected to the fixed body 210 and the other side of the guide rod 231 passing through the through hole 223' of the wing part 223, and the guide rod 231. A pressing jig comprising a first elastic means (232) positioned in a shape surrounding the.
4. The method of claim 3,
It characterized in that only one side of the guide rod 231 is fixed to the fixed body 210 or the wing portion 223 so that the separation distance between the fixed body 210 and the first pressing unit 220 can be varied. pressurizing jig.
According to claim 1,
A pressing jig, characterized in that the second elastic means (250) for connecting the first pressing part (220) and the second pressing part (240) is further provided.
6. The method of claim 5,
The second pressing part 240 is a pressing jig, characterized in that the third through-window 241' is formed in the center of two pairs of sidewalls 241 facing each other.
7. The method of claim 6,
A pressing jig, characterized in that the first pressing unit 220 is provided with a plurality of second pressing units (240).
8. The method of claim 7,
The plurality of second pressing part 240 is a pressing jig, characterized in that it can move independently.
9. The method of claim 8,
The second elastic means 250 is a pressure jig, characterized in that two or more.
10. The method of claim 9,
The second elastic means (250) is a pressing jig, characterized in that four.
As a pressing jig 200 for pressing the electrode lead 132 in order to weld the electrode lead 132 of the battery cell 130 to the bus bar 140,
The pressing jig 200 includes a fixed body 210 having a first through window 211 through which a welding laser can penetrate; and
It is located under the fixed body 210 and includes a first pressing part 220 including a horizontal part 221 provided with a second through window 221 ′,
The second through-window (221') is a pressure jig, characterized in that one or more partition walls (224) are further provided.
A method of welding an electrode lead 132 of a battery cell 130 to a bus bar 140 using the pressure jig according to any one of claims 1 to 10, comprising:
The welding method includes: positioning an electrode lead 132 on a bus bar 140;
Placing a pressure jig on the upper surface of the electrode lead 132 and pressing the pressure to a predetermined pressure; and
A method of welding an electrode lead and a bus bar comprising welding the bus bar 140 and the electrode lead 132 by irradiating a laser beam.

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