JP6659482B2 - Welding device and welding method - Google Patents

Description

  The present invention relates to a welding device and a welding method.

  The assembled battery is configured by stacking a plurality of unit cells having electrode tabs. The electrode tabs of the stacked unit cells are electrically connected by a bus bar.

  For example, Patent Literature 1 below discloses a welding method of laser welding a plurality of electrode tabs and a plurality of busbars.

JP-T-2012-515418A

  Generally, when laser welding is performed, a weld is eluted to generate fumes as metal vapor. For this reason, for example, when a plurality of electrode tabs and a plurality of bus bars are sequentially welded as in Patent Document 1, fumes generated when one electrode tab and one bus bar are welded stay around the welding portion. I do. In addition, when the electrode tab and the bus bar are welded to each other, the welding flaw may be hindered by the retained fume.

  The present invention has been made to solve the above-described problem, and has as its object to provide a welding device and a welding method that can appropriately weld an electrode tab and a bus bar.

  A welding device according to the present invention that achieves the above object is a welding device that performs laser welding between an electrode tab of a battery and a bus bar. A welding device according to the present invention includes a block, a pump, a driving unit, and a laser beam irradiation unit. The block is provided with a gas flow path having an opening, and is disposed in a state where the opening faces a welding portion between the bus bar and the electrode tab. The pump supplies air to the gas flow path or exhausts the gas flow path. The driving unit relatively presses the bus bar or the electrode tab against the block to bring the bus bar into contact with the electrode tab. The laser beam irradiating unit irradiates a laser beam for joining the bus bar and the electrode tab.

  Further, a welding method according to the present invention for achieving the above object is a welding method of laser welding an electrode tab of a battery and a bus bar. A block provided with a gas flow path having an opening is disposed in a state where the opening faces a welding portion between the bus bar and the electrode tab. The bus bar or the electrode tab is relatively pressed against the block to bring the bus bar into contact with the electrode tab. Laser light is applied to the gas passage while air is supplied to or exhausted from the gas passage, and the bus bar and the electrode tab are laser-welded.

  According to the welding apparatus and the welding method according to the present invention having the above configuration, the electrode tab and the bus bar can be suitably welded.

It is a perspective view which shows the battery pack which concerns on embodiment. FIG. 2 is an exploded perspective view showing the battery pack according to the embodiment. FIG. 4 is a diagram provided for describing a connection between a pair of bus bars and a plurality of electrode tabs constituting the battery pack according to the embodiment. It is the arrow view seen from the arrow 3B direction of FIG. 3A. It is a perspective view which shows the cell which comprises the assembled battery which concerns on embodiment. It is a schematic diagram showing a welding device concerning an embodiment. FIG. 6 is a view as viewed from an arrow 6 direction in FIG. 5. It is a perspective view showing the welding jig which constitutes the welding device concerning an embodiment. It is a flowchart which shows the welding method which concerns on embodiment. It is the schematic which shows the welding jig which concerns on the modification 1 of embodiment. It is the schematic which shows the welding jig which concerns on the modification 2 of embodiment. It is the schematic which shows the welding jig which concerns on the modification 3 of embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following description does not limit the technical scope and the meaning of the terms described in the claims. In addition, the dimensional ratios in the drawings are exaggerated for convenience of description, and may be different from the actual ratios.

  First, an assembled battery 100 according to an embodiment will be described with reference to FIGS.

  FIG. 1 is a perspective view showing the battery pack 100. FIG. 2 is an exploded perspective view showing the battery pack 100. FIG. 3A is a perspective view for explaining a connection state between a pair of bus bars 121 and a plurality of electrode tabs 115 constituting the battery pack 100. FIG. 3B is a view as viewed from an arrow 3B in FIG. 3A. FIG. 4 is a perspective view showing a cell 111 constituting the battery pack 100.

  Note that, in the drawing, the direction of stacking the unit cells 111 is indicated by an arrow Z. The direction crossing the stacking direction Z and along the longitudinal direction of the cell 111 is indicated by an arrow X. Further, a direction intersecting with the stacking direction Z and along the short direction of the cell 111 is indicated by an arrow Y.

  The assembled battery 100 according to the present embodiment is configured as an assembled battery used for a power unit of an electric vehicle. However, the application target of the battery pack 100 is not particularly limited to the power unit of the automobile.

  1 and 2, the battery pack 100 includes a stacked body 110 in which a plurality of flat unit cells 111 are stacked in the thickness direction, and a bus bar unit 120 including a plurality of bus bars 121. ing. The battery pack 100 further includes a protective cover 130 that covers the bus bar unit 120, and a housing 140 that houses the stacked body 110. Hereinafter, the battery pack 100 will be described in detail.

  As illustrated in FIGS. 2 and 4, the stacked body 110 is configured by stacking a plurality of unit cells 111 and a plurality of spacers 112 that support the unit cells 111.

  Each of the cells 111 can be constituted by, for example, a lithium ion secondary battery. As shown in FIGS. 3A, 3B, and 4, each of the cells 111 includes a power generation element 113, an exterior member 114 that encloses the power generation element 113, and is electrically connected to the power generation element 113. And an electrode tab 115 led out to the outside.

  The power generation element 113 has a function of receiving power supplied from the outside, charging the power, and supplying power while discharging to an external electric device. The power generating element 113 is configured by laminating a plurality of members (not shown) in which a positive electrode and a negative electrode are sandwiched between separators.

  The exterior member 114 can be made of, for example, a laminated film in which both sides of a metal foil are covered with insulating sheets. In the present embodiment, the exterior member 114 is configured by sealing the peripheral edges of the pair of laminate films in a state where the electrode tab 115 is extended. Note that the exterior member 114 may be configured by bending a single laminated film and sandwiching the power generation element 113 therebetween.

  As shown in FIG. 4, the electrode tab 115 includes a positive electrode tab 115a connected to the positive electrode of the power generation element 113 and a negative electrode tab 115k connected to the negative electrode of the power generation element 113. In the present embodiment, the positive electrode tab 115a and the negative electrode tab 115k are derived from the same side of the outer periphery of the exterior member 114. Note that the positive electrode tab 115a and the negative electrode tab 115k may be derived from different sides of the outer periphery of the exterior member 114.

  The base end of the positive electrode tab 115a (the side connected to the power generation element 113) extends along a direction intersecting with the stacking direction Z (direction of arrow X), as shown in FIGS. 3A and 3B. . The tip of the positive electrode tab 115a is bent downward in the stacking direction Z. Similarly, the base end of the negative electrode tab 115k (the side connected to the power generation element 113) also extends along the direction intersecting the stacking direction Z (the direction of the arrow X). Similarly, the tip of the negative electrode tab 115k is also bent downward in the stacking direction Z. As described above, the positive electrode tab 115a and the negative electrode tab 115k have an L-shaped outer shape when viewed in plan from the direction of the arrow Y.

  The positive electrode tab 115a can be made of, for example, aluminum according to the characteristics of the constituent members of the positive electrode of the power generation element 113. The negative electrode tab 115k can be made of, for example, copper in accordance with the characteristics of the components of the negative electrode of the power generating element 113.

  In the present embodiment, the stacked body 110 includes two types of cells 111 in which the lead-out positions of the positive electrode tab 115a and the negative electrode tab 115k in the arrow Y direction are different. Specifically, as shown in FIG. 3A, the stacked body 110 includes a cell 111 in which the positive electrode tab 115a is disposed on the left side in FIG. 3A and a cell 111 in which the negative electrode tab 115k is disposed on the left side in FIG. 3A. ,have. The stacked body 110 is configured such that the position of the positive electrode tab 115a and the position of the negative electrode tab 115k in the arrow Y direction change every time three unit cells 111 are stacked.

  As shown in FIG. 4, the spacer 112 includes a first spacer 112a attached to a side of the unit cell 111 from which the electrode tab 115 extends, and a second spacer attached to face the first spacer 112a with the unit cell 111 interposed therebetween. 112b.

The first spacer 112a and the second spacer 112b extend along the short side of the exterior member 114.

  It is preferable that the constituent material of the first spacer 112a and the second spacer 112b is a material having an insulating property and a certain strength. As such a material, for example, a reinforced plastic can be used.

  As shown in FIG. 2, the bus bar unit 120 includes a plurality of bus bars 121 that electrically connect the electrode tabs 115 of the unit cells 111 stacked together, a terminal 122 that can be electrically connected to an external device, and a bus bar 121. And a holder 123 for holding the terminal 122.

  As shown in FIGS. 3A and 3B, the bus bar 121 has three positive electrode tabs 115a electrically connected to the three positive electrode tabs 115a arranged in the stacking direction Z and three negative electrode tabs 115k arranged in the stacking direction Z. And a negative electrode bus bar 121k that is electrically connected to the negative electrode bus bar 121k. As shown in FIG. 2, the bus bar unit 120 includes a plurality of positive bus bars 121a and a plurality of negative bus bars 121b according to the number of stacked cells 111.

  As shown in FIG. 3B, each positive electrode bus bar 121a is connected to a first joint portion 124a to which the distal end portions of the three positive electrode tabs 115a are joined, and is connected to an end of the first joint portion 124a and is adjacent to the negative electrode bus bar 121k. And a second joining portion 125a to which are joined. The first joint 124a has a substantially flat outer shape. The second joint 125a protrudes from the end of the first joint 124a toward the side opposite to the side where the positive electrode tab 115a is provided.

  Similarly, each of the negative electrode bus bars 121k is connected to the first bonding portion 124k to which the distal end portions of the three negative electrode tabs 115k are bonded, and the end of the first bonding portion 124k, and the adjacent positive electrode bus bar 121a is bonded. A second joining portion 125k. The first joint 124k has a substantially flat outer shape. The second joint 125k protrudes from the end of the first joint 124k toward the side opposite to the side where the negative electrode tab 115k is provided.

  Each bus bar 121 and each electrode tab 115 are joined by laser welding. The adjacent positive bus bar 121a and negative bus bar 121k can be joined by, for example, ultrasonic joining. As described above, in the present embodiment, by connecting the adjacent positive bus bar 121a and negative bus bar 121k, the three unit cells 111 connected in parallel and the three unit cells 111 connected in parallel are connected in series. Connected.

  The positive electrode bus bar 121a is made of aluminum in accordance with the constituent material of the positive electrode tab 115a. The negative electrode bus bar 121k is made of copper in accordance with the constituent material of the negative electrode tab 115k.

  As shown in FIG. 2, the terminal 122 is connected to a positive terminal 122a connected to the positive terminal of the cell group connected in parallel and in series, and connected to a negative terminal of the cell group connected in parallel and in series. And a negative electrode terminal 122k.

  The holder 123 integrally holds the plurality of bus bars 121 in a matrix so that each of the plurality of bus bars 121 faces the corresponding electrode tab 115.

  The constituent material of the holder 123 preferably has an insulating property. As such a material, for example, plastic can be used.

  The protective cover 130 has a function of covering the bus bar unit 120 to prevent the bus bars 121 from short-circuiting each other, or prevent the bus bar 121 from short-circuiting or leaking due to contact with an external member.

  The protective cover 130 has a shape that covers the bus bar unit 120 and fits into the bus bar unit 120. The protective cover 130 is provided with holes 130a and 130b such that the positive terminal 122a and the negative terminal 122k face the outside.

  The constituent material of the protective cover 130 preferably has an insulating property. As such a material, for example, plastic can be used.

  The housing 140 has a function of accommodating the stacked body 110 in a state where the stacked body 110 is pressed in the stacking direction Z.

  The housing 140 includes an upper pressing plate 141 and a lower pressing plate 142 arranged to sandwich the stacked body 110 in the stacking direction Z, and a pair of side plates 143 provided between the upper pressing plate 141 and the lower pressing plate 142. , Is provided. By joining the upper pressing plate 141, the lower pressing plate 142, and the pair of side plates 143, a space capable of accommodating the stacked body 110 is formed inside.

  Next, a welding device 200 according to the present embodiment will be described with reference to FIGS.

  FIG. 5 is a schematic diagram showing the welding device 200. FIG. 6 is a view as seen from the direction of arrow 6 in FIG. FIG. 7 is a perspective view showing a welding jig 210 included in the welding device 200. In FIG. 5, a chain line indicates a gas flow, and a portion surrounded by a dotted line indicates a welding portion W. 6, a part of the spacer 112 is omitted.

  The welding device 200 is configured as a welding device that laser-welds the plurality of bus bars 121 and the plurality of electrode tabs 115 included in the battery pack 100.

  When outlined with reference to FIG. 5, the welding apparatus 200 includes a welding jig 210 including a block 211 provided with a gas flow path 215, and a pump 220 that supplies air to the gas flow path 215. . The welding device 200 further irradiates the driving unit 230 that presses the bus bar 121 and the block 211 relatively to contact the bus bar 121 and the electrode tab 115, and irradiates a laser beam that joins the bus bar 121 and the electrode tab 115. And a laser light irradiating unit 240. Hereinafter, the welding device 200 will be described in detail.

  As shown in FIG. 6, the welding jig 210 includes a block 211 in contact with one bus bar 121 (the positive bus bar 121a or the negative bus bar 121k), and a first support portion 212 and a second support portion 213 supporting the block 211. And as a basic unit 210U. The welding jig 210 is configured by connecting a plurality of basic units 210U in accordance with the number of bus bars 121 arranged in the stacking direction Z. That is, the welding jig 210 is configured to be able to be pressed at a time against a group of busbars arranged in the stacking direction Z in FIG. As shown in FIG. 6, the adjacent basic units 210U are connected via a connecting portion 214.

  Each block 211 has a substantially flat outer shape. As shown in FIG. 7, each block 211 includes a contact surface 211 a that contacts one bus bar 121, and a pair of opposing surfaces 211 b that face the welding portions W located on both sides of the block 211. . The block 211 has a recess 211c formed by recessing the contact surface 211a in the thickness direction.

  The depression 211c forms a gas flow path 215 that opens on the pair of opposing surfaces 211b. Specifically, the depression 211c communicates the three first depressions 211d extending from one surface of the pair of opposing surfaces 211b toward the other surface, and the three first depressions 211d. A second depression 211e.

  The first recess 211d and the second recess 211e have a semi-cylindrical inner surface shape. However, the inner surface shapes of the first depression 211d and the second depression 211e are not particularly limited as long as the gas flow path 215 can be formed, and may be, for example, a quadrangular prism or a triangular prism.

  Each first recess 211d has an opening 211f on both surfaces of a pair of opposing surfaces 211b. As described later, the gas supplied to the gas flow path 215 using the driving unit 230 blows out from the opening 211f, and blows off fume generated at the welding portion W. In particular, in the present embodiment, the gas blows out from the recess 211c recessed from the contact surface 211a with the bus bar 121, so that the gas easily hits the welding portion W. Therefore, the fume can be blown off relatively efficiently. Further, since the recess 211c is formed, the contact area between the block 211 and the bus bar 121 can be kept small. Therefore, the amount of heat absorbed by the block 211 from the bus bar 121 during welding can be reduced. As a result, the bus bar 121 can be maintained at an appropriate temperature, and the bus bar 121 and the electrode tab 115 can be welded better.

  In the present embodiment, as shown in FIG. 5, each opening 211f is provided at a position overlapping each welding portion W when the block 211 is brought into contact with the bus bar 121 and viewed from the direction of the arrow Y. Therefore, the gas blown out from the opening 211f can be appropriately applied to the welding portion W. However, the position where the opening 211f is provided is not particularly limited as long as it is located at a position facing the welding portion W and at least a part of the gas blown out from the opening 211f is provided at a position where the fume generated in the welding portion W can be blown off. For example, each opening 211f may be provided at a position that does not partially overlap with each welding site W when viewed from the arrow Y direction.

  The second depression 211e extends along the stacking direction Z. However, in the present embodiment, the second recess 211e does not penetrate the block 211 in the stacking direction Z. Accordingly, it is possible to prevent the gas supplied from the pump 220 from being blown out from a surface not facing the welding site W. The second depression 211e may penetrate the block 211 in the stacking direction Z.

  The first support portion 212 and the second support portion 213 are provided to face each other in the stacking direction Z with the block 211 interposed therebetween.

  As shown in FIG. 6, each of the first support portion 212 and the second support portion 213 extends from the end of the block 211 toward the side opposite to the side where the bus bar 121 is arranged.

  The first support portion 212 is provided with an air supply port 215 a that communicates with the gas flow path 215 and is connected to the pump 220. The second support portion 213 is provided with an exhaust port 215b that communicates with the gas flow path 215 and that is opened outward. By providing the air supply port 215a and the exhaust port 215b with the gas flow path 215 interposed therebetween, the gas supplied from the pump 220 flows from the air supply port 215a to the exhaust port 215b. Therefore, the gas spreads to the opening 211f disposed between the air supply port 215a and the exhaust port 215b. As a result, fumes generated at the welding site W can be blown off appropriately. Note that the first support portion 212 may be provided with an exhaust port, and the second support portion 213 may be provided with an air supply port. Further, it is not necessary to provide the exhaust port in both the first support portion 212 and the second support portion 213.

  The connection part 214 connects the front end of the first support part 212 (the end opposite to the side on which the block 211 is provided) and the front end of the second support part 213. The connected first support part 212, second support part 213, and connection part 214 form a space 214a in which the second joint part 125a of the positive bus bar 121a and the second joint part 125k of the negative bus bar 121k can be accommodated inward. Has formed.

  The constituent materials of the block 211, the first support part 212, the second support part 213, and the connecting part 214 are not particularly limited, but for example, plastic, metal, or the like can be used.

  The pump 220 is connected to the air supply port 215a and has a function of supplying gas to the gas flow path 215.

  The pump 220 can be constituted by, for example, a compressor. The gas supplied by the pump 220 is not particularly limited. For example, an inert gas that can suppress oxidation of the bus bar 121 during welding can be used. By blowing out the inert gas from the opening 211f, fumes generated around the welding portion W can be blown off, and further, oxidation of the bus bar 121 can be prevented. Note that air may be used as the gas supplied by the pump 220, for example.

  The drive unit 230 relatively moves the block 211 between a position where the block 211 is relatively pressed against the bus bar 121 to contact the bus bar 121 and the electrode tab 115 and a position where the block 211 is separated from the bus bar 121. Generates possible driving forces. By welding the bus bar 121 and the electrode tab 115 during welding, good welding quality can be obtained.

  The drive unit 230 can be configured by, for example, an industrial robot. In the present embodiment, in a state in which the stacked body 110 is fixed, the driving unit 230 holds the first support unit 212 and the second support unit 213 and moves the block 211 toward and away from the bus bar 121.

  Further, the driving section 230 may have a function of moving the block 211 along the arrow Y direction. Thereby, for example, after welding a row of bus bar groups and electrode tab groups arranged on the left side in the arrow Y direction of FIG. 2, the block 211 is moved to the right side in the arrow Y direction, and the block 211 is moved to the right side in the arrow Y direction. Can be welded to the bus bar group and the electrode group arranged in a row.

  The laser beam irradiating section 240 is constituted by a YAG (yttrium aluminum garnet) laser. However, the laser light irradiating section 240 is not particularly limited as long as it can irradiate laser light capable of welding the bus bar 121 and the electrode tab 115.

  The laser beam from the laser beam irradiating unit 240 irradiates the bus bar 121 with the optical path adjusted by, for example, an optical fiber or a mirror and condensed by a condenser lens. The laser beam from the laser beam irradiating section 240 may be split by, for example, a half mirror, and may be simultaneously radiated to the welding portions W located on both sides of the block 211.

  Next, a welding method using the welding device 200 will be described with reference to FIG.

  In general, the welding method according to the present embodiment is configured such that the block 211 provided with the gas flow path 215 having the opening 211f is placed in a state where the opening 211f faces the welding portion W between the bus bar 121 and the electrode tab 115. It is arranged (S11). Next, the bus bar 121 and the block 211 are pressed relatively to contact the bus bar 121 and the electrode tab 115 (S12). Next, a laser beam is irradiated while gas is supplied to the gas flow path 215, and the bus bar 121 and the electrode tab 115 are laser-welded (S13). Hereinafter, the welding method will be described in detail.

  In the present embodiment, prior to welding the bus bar 121 and the electrode tab 115, the stacked body 110 is housed in the housing 140. The housing 140 containing the stacked body 110 is mounted on a mounting table and fixed (not shown). The bus bar 121 is held by a holder 123. The holder 123 holding the bus bar 121 is arranged on the side of the laminate 110 from which the electrode tab 115 extends.

  In step S11, first, when the block 211 abuts on the bus bar 121, the welding jig 210 is attached to the drive unit 230 with the opening 211f arranged so as to face the welding portion W. Then, the drive unit 230 is driven to move the block 211 closer to the bus bar 121 so that the block 211 contacts the bus bar 121. As a result, the block 211 is arranged in a state where the opening 211f faces the welding site W. Further, thereby, the welding jig 210 is brought into contact with the bus bar group arranged in a row in the Z direction in FIG. 2 at a time.

  In step S12, the drive unit 230 is driven to move the block 211 closer to the bus bar 121, and the block 211 is pressed against the bus bar 121. Thus, the bus bar 121 and the electrode tab 115 are brought into contact.

  In step S13, the pump 220 is driven to supply gas to the gas flow path 215. The supplied gas blows out from the opening 211f of the gas flow path 215 toward the welding portion W. In this state, laser light is sequentially irradiated from the laser light irradiation section 240 toward each welding portion W. At this time, fumes are generated from the welding site W. The generated fume is blown off by the gas blown out from the opening 211f. For this reason, when sequentially welding a plurality of welding portions W which are spaced apart at a small interval, it is possible to preferably prevent the fumes generated in the previous welding from staying and deteriorating the quality of the next welding. it can. Further, since the gas flow path 215 is provided in the block 211 pressed against the bus bar 121, gas can be blown out from a position relatively close to the welding portion W. For this reason, fumes can be removed more efficiently.

  Next, the drive unit 230 is driven to move the welding jig 210 in the direction of the arrow Y in FIG. 2, and the steps S11 to S13 are executed again, and the other bus bar group and electrode tab group arranged in the stacking direction Z Is laser welded.

  As described above, the welding device 200 according to the present embodiment is a welding device that laser-welds the electrode tab 115 of the unit cell 111 and the bus bar 121, and includes a block 211, a pump 220, a driving unit 230, and a laser beam irradiation unit. 240. The block 211 is provided with a gas flow path 215 having an opening 211f, and is arranged in a state where the opening 211f faces a welding portion W between the bus bar 121 and the electrode tab 115. The pump 220 supplies gas to the gas flow path 215. The driving unit 230 relatively presses the bus bar 121 and the block 211 to bring the bus bar 121 into contact with the electrode tab 115. The laser beam irradiating unit 240 irradiates a laser beam for joining the bus bar 121 and the electrode tab 115.

  For this reason, by supplying air to the gas flow path 215 and blowing off fumes around the welding portion W, fumes generated at the welding portion W can be removed. As a result, the electrode tab 115 and the bus bar 121 can be suitably welded.

  In addition, the block 211 includes a contact surface 211a that contacts the bus bar 121, and the gas flow path 215 is formed by a recess 211c formed by recessing the contact surface 211a. Since gas is blown out from the depression 211c that is depressed from the surface in contact with the bus bar 121, the gas easily hits the welding portion W. Therefore, fumes can be efficiently blown off. Further, since the contact area between the block 211 and the bus bar 121 can be kept small, the amount of heat absorbed by the block 211 from the bus bar 121 during welding can be reduced. For this reason, the bus bar 121 can be maintained at an appropriate temperature, and the bus bar 121 and the electrode tab 115 can be welded better.

  In addition, the welding device 200 further includes support portions 212 and 213 that support the block 211. The support portions 212 and 213 include an air supply port 215a connected to the pump 220 and supplying air to the gas flow path 215, and an exhaust port 215b communicating with the gas flow path 215 and exhausting the gas flow path 215. , Are provided. For this reason, gas flows from the air supply port 215a provided in the support parts 212 and 213 toward the exhaust port 215b, and the gas reaches the opening 211f provided between the air supply port 215a and the exhaust port 215b. As a result, fumes generated at the welding site W can be blown off appropriately.

  The first support portion 212 and the second support portion 213 are provided with the block 211 interposed therebetween. The first support portion 212 is provided with an air supply port 215a, and the second support portion 213 is provided with an exhaust port. A mouth 215b is provided. For this reason, gas can be made to flow more easily from the air supply port 215a toward the exhaust port 215b.

  Further, the welding jig 210 is provided with a gas flow path 215 having an opening 211f, and has a block 211 arranged in a state where the opening 211f faces a welding portion W between the bus bar 121 and the electrode tab 115. . Therefore, if a pump 220 capable of supplying gas is connected to the gas flow path 215 of the welding jig 210, fumes generated from the welding portion W can be blown off. As a result, the electrode tab 115 and the bus bar 121 can be suitably welded.

  Further, the welding method according to the above embodiment is a welding method in which the electrode tab 115 of the unit cell 111 and the bus bar 121 are laser-welded. The block 211 provided with the gas flow path 215 having the opening 211f is disposed in a state where the opening 211f faces the welding portion W between the bus bar 121 and the electrode tab 115. The bus bar 121 and the block 211 are relatively pressed against each other to bring the bus bar 121 into contact with the electrode tab 115. The laser beam is irradiated while the gas flow path 215 is being supplied with air, and the bus bar 121 and the electrode tab 115 are laser-welded.

  For this reason, it is possible to supply air to the gas flow path 215 and blow off fume generated from the welding portion W. As a result, the electrode tab 115 and the bus bar 121 can be suitably welded.

(Modification 1)
Next, a welding jig 310 according to a first modification of the embodiment will be described with reference to FIG. FIG. 9 is a schematic diagram showing a welding jig 310 according to a first modification of the embodiment.

  The welding jig 310 according to the first modification is different from the welding jig 210 according to the above embodiment in that a gas flow path 315 is formed by a first tubular member 316a and a second tubular member 316b. Hereinafter, the welding jig 310 will be described in detail. In addition, about the structure similar to the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The block 211 includes three first tubular members 316a included in the block 211 and extending from one surface of the pair of opposed surfaces 211b toward the other surface, and three first tubular members 316a. And a second tubular member 316b communicating therewith.

  A gas flow path 315 is formed by the first tubular member 316a and the second tubular member 316b. Each first tubular member 316a has an opening 311f on both surfaces of the pair of opposed surfaces 211b. The second tubular member 316b extends along the stacking direction Z. Since the block 211 includes the first tubular member 316a and the second tubular member 316b, the strength of the block 211 can be maintained satisfactorily while forming the gas flow path 315.

  Further, the first support portion 212 is provided with a third tubular member 316c which is included in the first support portion 212 and communicates the air supply port 215a and the gas flow path 315. Further, the second support portion 213 is provided with a fourth tubular member 316d which is included in the second support portion 213 and communicates the exhaust port 215b and the gas flow path 315. For this reason, the strength of the first support portion 212 and the second support portion 213 can be favorably maintained.

  As described above, according to the welding jig 310 according to Modification Example 1, the gas flow path 315 is formed by the first tubular member 316a and the second tubular member 316b included in the block 211. Therefore, the strength of the block 211 can be kept good while the gas flow path 315 is formed in the block 211.

(Modification 2)
Next, a welding jig 410 according to a second modification of the above embodiment will be described with reference to FIG. FIG. 10 is a schematic diagram showing a welding jig 410 according to Modification 2 of the embodiment.

  The welding jig 410 according to Modification 2 differs from the welding jig 210 according to the above embodiment in that the gas flow path 415 is formed by continuous gaps (voids) of a porous material. Hereinafter, the welding jig 410 will be described in detail. In addition, about the structure similar to the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The block 411 includes a porous portion 412 that comes into contact with the bus bar 121, and a lid portion 413 that covers a surface of the porous portion 412 opposite to a surface that comes into contact with the bus bar 121.

  The porous portion 412 is made of a porous material. The porous material is not particularly limited as long as it has a continuous gap. For example, urethane foam having an open-cell structure can be used.

  The gas passage 415 is formed by continuous gaps of the porous material. The gas supplied from the pump 220 blows out from a number of gaps provided in the porous portion 412. A number of gaps are provided at various positions and face various directions. For this reason, gas can be blown to the welding site W from various positions and from various directions. As a result, fumes generated from the welded portion W can be blown off more appropriately. Further, by making the contact area between the bus bar 121 and the block 411 relatively small, the amount of heat absorbed by the block 411 can be reduced. For this reason, the bus bar 121 can be maintained at an appropriate temperature, and the bus bar 121 and the electrode tab 115 can be welded better.

  The lid 413 is preferably made of a material that is less permeable to gas than the porous part 412. Thus, it is possible to suppress the gas supplied to the gas flow path 415 from blowing out from the surface of the block 411 on the side opposite to the side where the bus bar 121 is provided.

  As described above, according to the welding jig 410 according to Modification 2, the constituent material of the block 411 includes a porous material having a large number of continuous gaps, and the gas flow path 415 is formed by a large number of continuous gaps. ing. For this reason, the fume generated from the welded portion W can be more suitably blown off. Therefore, the bus bar 121 and the electrode tab 115 can be suitably welded. Further, since the contact area between the block 411 and the bus bar 121 can be kept small, the amount of heat absorbed by the block 411 from the bus bar 121 during welding can be reduced. For this reason, the bus bar 121 can be maintained at an appropriate temperature, and the bus bar 121 and the electrode tab 115 can be welded better.

(Modification 3)
Next, a welding jig 510 according to a third modification of the embodiment will be described with reference to FIG. FIG. 11 is a schematic diagram showing a welding jig 510 according to Modification 3 of the embodiment.

  In the above embodiment, the electrode tab 151 is joined to a surface of the bus bar 121 that faces the cell 111 among the two surfaces. On the other hand, in the modified example 3, the electrode tab 151 is bent downward in the stacking direction Z with the end portion inserted through the bus bar 121, and is opposite to the surface of the bus bar 121 opposite to the surface facing the cell 111. Surface. Hereinafter, the welding jig 510 will be described in detail. In addition, about the structure similar to the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The welding jig 510 is configured as a welding jig used for laser welding a plurality of bus bars 121 and a plurality of electrode tabs 115 whose distal ends are bent downward in the stacking direction Z with the bus bars 121 inserted. are doing.

  The welding jig 510 includes a block 511 that contacts the three electrode tabs 115. In the block 511, a gas flow path 215 having an opening 211f is formed as in the above embodiment.

  The drive unit 230 moves the block 511 between a position where the block 511 is relatively pressed against the plurality of electrode tabs 115 to contact the electrode tab 115 with the bus bar and a position where the block 211 is separated from the plurality of electrode tabs 115. Generates a driving force for relatively moving the.

  As described above, the welding device and the welding method according to the present invention have been described through the embodiments and the modified examples. However, the present invention is not limited to the respective configurations described above, and may be appropriately changed based on the description in the claims. It is possible.

  For example, in the above-described embodiment, an example has been described in which the driving unit holds the support unit and moves the block toward and away from the bus bar. However, for example, the drive unit may hold the block and move the block toward and away from the bus bar. The drive unit may move the electrode tab and the bus bar toward and away from the block with the welding jig fixed.

  In the above embodiment, the welding jig is provided with a plurality of blocks, and has been described in the form in which the welding jig is pressed at a time against a group of busbars arranged in the stacking direction. However, the welding jig may include only one block. In this case, the welding jig may be sequentially moved in the laminating direction by the driving unit.

  Further, the number of electrode tabs and bus bars to be welded using the welding device and the welding method according to the present invention is not particularly limited. For example, the welding apparatus and the welding method according to the present invention can be applied to a case where one bus bar and one electrode tab are laser-welded. Also in this case, since fumes are removed during welding, welding quality can be improved. In addition, the welding device and the welding method according to the present invention are also applicable to a case where one electrode tab is laser-welded to each of the positive bus bar and the negative bus bar joined to each other.

  Further, in the above embodiment, the form in which the electrode tab is bent in the stacking direction has been described, but the outer shape of the electrode tab is not particularly limited as long as the electrode tab has a surface that comes into contact with the bus bar. For example, a plurality of flat electrode tabs that are not bent may be stacked, a bus bar may be stacked thereon, and laser bonding may be performed.

  Further, in the above embodiment, the mode in which the bus bar is provided with the second joint portion protruding in the direction intersecting with the laminating direction Z has been described. Not limited. For example, the positive bus bar and the negative bus bar do not include a portion corresponding to the second bonding portion, have a flat outer shape, and may be bonded to each other in a state of being overlapped with each other.

  Further, the gas flow path can be formed by appropriately combining the depression, the tubular member, and the porous material described in the above embodiment and the modified examples.

  Further, the pump may be configured to exhaust the gas flow path. In this case, the pump can be constituted by, for example, a device such as a vacuum pump capable of sucking gas containing fumes in the gas flow path. As a result, fumes are taken into the gas flow path from the opening of the gas flow path facing the welding position, and the fume is removed from the welding position. Therefore, the electrode tab and the bus bar can be suitably welded.

  Further, the welding apparatus according to the present invention may be configured such that the pump is directly connected to the gas flow path of the block without the support.

  Further, in the above embodiment, the case where the air supply port is provided in the first support portion and the exhaust port is provided in the second support portion has been described. However, for example, both the air supply port and the exhaust port may be provided in the first support portion, and the gas flow path may be formed in a U shape so as to communicate with the air supply port and the exhaust port.

100 assembled batteries,
111 cells,
115 electrode tabs,
121 Busba,
200 welding equipment,
210, 310, 410, 510 welding jig,
211, 411, 511 blocks,
211f aperture,
212, 213 support,
215, 315, 415 gas flow path,
215a air inlet,
215b exhaust port,
220 pumps,
230 drive,
240 laser light irradiation part,
W Weld site.

Claims (8)

A welding device for laser welding an electrode tab and a bus bar of a battery,
A gas flow path having an opening is provided, and a block arranged in a state where the opening faces the welding portion between the bus bar and the electrode tab,
A pump that supplies air into the gas flow path or exhausts the gas flow path,
A drive unit that relatively presses the bus bar or the electrode tab and the block to contact the bus bar and the electrode tab,
A welding device comprising: a laser beam irradiation unit that emits a laser beam that joins the bus bar and the electrode tab. The block includes a contact surface that contacts the bus bar or the electrode tab,
The welding device according to claim 1, wherein the gas flow path is formed by a depression in which the contact surface is depressed.   The welding device according to claim 1, wherein the gas flow path is formed by a tubular member included in the block. The constituent material of the block includes a porous material having a large number of continuous gaps,
The welding device according to claim 1, wherein the gas flow path is formed by the large number of continuous gaps. Further comprising a support for supporting the block,
The support portion includes an air supply port connected to the pump and supplying air to the gas flow path, and an exhaust port communicating with the gas flow path and exhausting the gas flow path. The welding device according to any one of claims 1 to 4, wherein The support portion includes a first support portion and a second support portion provided with the block interposed therebetween,
The first support portion is provided with the air supply port,
The welding device according to claim 5, wherein the exhaust port is provided in the second support portion. It is a welding jig used for the welding device according to any one of claims 1 to 6,
A welding jig provided with a gas flow path having an opening, and having a block arranged at a welding portion between the bus bar and the electrode tab with the opening facing the welding portion. A welding method of laser welding an electrode tab and a bus bar of a battery,
A block provided with a gas flow path having an opening is arranged in a state where the opening faces the welding portion between the bus bar and the electrode tab,
The bus bar or the electrode tab and the block are pressed relatively to contact the bus bar and the electrode tab,
A welding method, comprising irradiating a laser beam while supplying air to the gas flow path or exhausting the gas flow path, and laser-welding the bus bar and the electrode tab.