Battery pack

Abstract

The disclosed invention relates to a pack case which, in one example, includes a base plate, a side plate connected along the edge of the base plate to form a storage space therein, a lower cross beam connected to the base plate so as to horizontally partition the storage space inside the base plate, and an upper cross beam connected to the lower cross beam.

Description

[Technical Field]

[0001] The present invention relates to a battery pack, and more particularly to a battery pack having a structure in which a cell stack or a battery module can be closely installed to a partition wall without interference from a weld bead. In particular, the present invention provides a battery pack suitable for a cell-to-pack (CTP) structure in which a cell stack is directly installed in the battery pack.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0097556, filed August 4, 2022, and Korean Patent Application No. 10-2023-0035431, filed March 17, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference. [Background technology]

[0003] Conventionally, a battery pack has been manufactured by accommodating a plurality of battery modules, each of which has a plurality of cell stacks accommodated in a module housing, in a pack case.

[0004] However, in such conventional battery packs, thermal resin is applied twice, once between the cell stack and the module housing and once between the module housing and the pack case, which increases manufacturing costs and reduces cooling performance. Furthermore, additional parts are required for the module components that constitute the battery module and the pack case, increasing parts costs. Furthermore, when welding the partition walls that separate the battery modules to the pack case, weld beads formed on the partition walls make it difficult to install the module housing in close contact with the partition walls, resulting in reduced space utilization in the pack case and reduced energy density of the battery pack.

[0005] Even in a simplified structure in which the module housing is removed and the cell stack is directly attached to the pack case to realize a battery pack with a cell-to-pack structure, the problem of interference with the cell stack due to the weld beads of the partition walls still remains.

[0006] Furthermore, when installing cell stacks between partition walls without a module housing, it is extremely advantageous from the standpoint of productivity to use a loading jig that can grasp and insert multiple cell stacks into the partition walls at once. However, in order to stably transport a group of heavy cell stacks, interference occurs between the loading jig, which grips the cell stacks deeply, and the partition walls, making it difficult to install a large number of cell stacks into a pack case at once.

[0007] Therefore, there is a need for the development of a technology that can simplify the structure of a battery pack, eliminate interference from weld beads to improve space utilization and energy density, and facilitate the installation of a pack case for a cell stack. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent Publication No. 10-2022-0102484 (Published July 20, 2022) Summary of the Invention [Problem to be solved by the invention]

[0009] One object of the present invention is to provide a pack case that allows easy welding work to join the cross beam to the base plate, that can apply uniform surface pressure to multiple cell stacks, and that allows a loading jig that handles multiple cell stacks as a single unit to work stably without interference from the cross beam.

[0010] Another object of the present invention is to provide a pack case that can solve the problem of interference between the cell stack and the weld beads that inevitably occur when welding the cross beams to the base plate.

[0011] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below. [Means for solving the problem]

[0012] The present invention relates to a pack case, which in one example includes a base plate, side plates that are connected along the edges of the base plate to form an internal storage space, a lower cross beam that is connected to the base plate so as to horizontally partition the internal storage space of the base plate, and an upper cross beam that is connected to the lower cross beam.

[0013] The upper cross beam is connected upward to the lower cross beam to form one cross beam.

[0014] In one embodiment, a center beam is connected to the base plate so as to vertically divide the storage space inside the base plate, and the lower cross beam and upper cross beam can horizontally divide each storage space divided by the center beam.

[0015] The lower cross beam may have a first uneven structure in which recesses and protrusions are alternately formed in the joining direction of the upper cross beam, and the upper cross beam may have a second uneven structure complementary to the first uneven structure.

[0016] The lower cross beam may be welded to the base plate, and the upper cross beam may be bolted to the lower cross beam.

[0017] In one embodiment, the lower cross beam and the upper cross beam may be made of different materials, and the upper cross beam may be made of a lighter material than the lower cross beam.

[0018] Meanwhile, the lower cross beam may have at least one recessed weld groove on its interface with the base plate.

[0019] For example, the weld grooves may be provided on both sides of the lower cross beam.

[0020] The weld grooves provided on both sides of the lower cross beam may be distributed along the direction in which they face each other so that they do not overlap at least partially.

[0021] The lower cross beam is welded to the base plate through the weld groove, and the weld bead formed in the weld groove may not protrude outside the lower cross beam.

[0022] Meanwhile, the present invention may provide a battery pack including a pack case having the above-described configuration and a plurality of cell stacks mounted in divided accommodation spaces of the pack case.

[0023] An insulating sheet or a compression pad may be interposed between the contact surfaces of the lower and upper cross beams and the cell stack.

[0024] Such a battery pack can be manufactured by a method including: a first step of preparing a pack case having a base plate, side plates coupled along the edge of the base plate to form an accommodation space therein, and a lower cross beam coupled to the base plate to define the accommodation space inside the base plate; a second step of mounting a plurality of cell stacks in the accommodation space defined by the lower cross beam; a third step of coupling an upper cross beam to the lower cross beam on which the plurality of cell stacks are mounted; and a fourth step of repeating the second and third steps to mount a plurality of cell stacks in all of the accommodation spaces.

[0025] Here, in a manufacturing method for a battery pack according to one embodiment of the present invention, the first step is a step of preparing a pack case having a first uneven structure in which the lower cross beam has repeated recesses and protrusions in a joining direction of the upper cross beam, and the second step is a step of loading a plurality of cell stacks into an accommodating space partitioned by the lower cross beam using a loading jig having a gripper that grips the plurality of cell stacks as a whole, and the gripper may enter the recesses of the first uneven structure to load the gripped plurality of cell stacks onto the base plate.

[0026] The second step may be a step in which the gripper of the loading jig grips the plurality of cell stacks together and places them on the base plate, and then releases the gripper and releases the stack directly above the lower cross beam. [Effects of the Invention]

[0027] As described above, the pack case of the present invention has a two-layer structure with one cross beam connected to the base plate, a lower cross beam, and an upper cross beam connected above the lower cross beam. The two-layer cross beam structure improves the accessibility of the welding tool tip, facilitating the welding of the lower cross beam to the base plate. Furthermore, by placing multiple cell stacks inside the pack case before assembling the upper cross beam, the operability of the loading jig is improved.

[0028] Furthermore, by constructing the cross beam as a two-layer structure, the upper cross beam, which does not require welding to the base plate, can be made of a lightweight, dissimilar material, such as engineering plastic, which can contribute to reducing the weight of the battery pack.

[0029] In addition, according to one embodiment of the present invention, the lower cross beam is provided with a first uneven structure, which allows the gripper of the loading jig to firmly grasp and enter the cell stack without interfering with the lower cross beam, and also allows the cell stack to be stably placed on the base plate without any impact.

[0030] However, the technical effects that can be obtained by the present invention are not limited to the effects described above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below. [Brief explanation of the drawings]

[0031] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention, and therefore the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Figure 1] 1 is a perspective view of a pack case according to an embodiment of the present invention. [Figure 2] 2 is a perspective view illustrating the pack case of FIG. 1 with an upper cross beam separated. FIG. [Figure 3] 1 is a view illustrating a coupling structure of a lower cross beam and an upper cross beam; [Figure 4] FIG. 4 is a cross-sectional view taken along line "AA" in FIG. 3. [Figure 5] FIG. 10 is a perspective view illustrating a welding structure of a lower cross beam to a base plate. [Figure 6] FIG. 10 is a plan view illustrating the welding points of the lower cross beam to the base plate. [Figure 7] 1 is a perspective view of a battery pack according to an embodiment of the present invention; [Figure 8] FIG. 8 is a cross-sectional view taken along line "BB" in FIG. 7. [Figure 9] FIG. 10 is a perspective view illustrating an embodiment in which the grippers of a loading jig holding multiple cell stacks enter the lower cross beam. [Figure 10] 10 is a cross-sectional view illustrating a state in which the loading jig of FIG. 9 has entered the lower cross beam. [Figure 11] 10A and 10B are cross-sectional views illustrating a process of removing the loading jig after seating a plurality of cell stacks; [Figure 12] FIG. 10 is a cross-sectional view illustrating a state in which the upper cross beam is fastened after the loading jig is released. DETAILED DESCRIPTION OF THE INVENTION

[0032] Because the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0033] However, this is not intended to limit the invention to any particular embodiment, but is understood to include all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0034] In the present invention, the terms "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, and are understood as not precluding the presence or possible addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0035] Furthermore, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion therebetween. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion therebetween. Furthermore, in this application, being "located on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0036] The present invention relates to a pack case, which in one example includes a base plate, side plates that are connected along the edges of the base plate to form an internal storage space, a lower cross beam that is connected to the base plate so as to horizontally partition the internal storage space of the base plate, and an upper cross beam that is connected to the lower cross beam.

[0037] The upper cross beam is joined upward to the lower cross beam to form one cross beam.

[0038] As described above, the pack case of the present invention has a two-layer structure with a lower cross beam that connects to the base plate and an upper cross beam that connects above the lower cross beam. The two-layer cross beam structure improves the accessibility of the welding tool tip, facilitating the welding of the lower cross beam to the base plate. Furthermore, by placing multiple cell stacks inside the pack case before assembling the upper cross beam, the operability of the loading jig is improved.

[0039] Furthermore, by constructing the cross beam as a two-layer structure, the upper cross beam, which does not require welding to the base plate, can be made of a lightweight, dissimilar material, such as engineering plastic, which can contribute to reducing the weight of the battery pack.

[0040] Hereinafter, specific embodiments of a pack case 100 and a battery pack 200 including the same according to the present invention will be described in detail with reference to the accompanying drawings. For reference, the directions of front, back, up, down, left, and right specifying relative positions used in the following description are intended to facilitate understanding of the invention, and unless otherwise specified, are based on the directions shown in the drawings.

[0041] (First embodiment) Fig. 1 is a perspective view of a pack case 100 according to one embodiment of the present invention, and Fig. 2 is a perspective view illustrating a state in which an upper cross beam 136 is separated from the pack case 100 of Fig. 1. The overall configuration of the pack case 100 according to one embodiment of the present invention will be described with reference to Figs. 1 and 2.

[0042] The present invention relates to a pack case 100 that houses a number of equally divided cell stacks 210. The cell stack 210 is a single completed battery cell that can be charged and discharged as a secondary battery, and in this specification, the term is used in a comprehensive sense regardless of its external shape, such as a pouch-type battery or a prismatic battery. Furthermore, although it is not excluded that a battery module in which multiple cell stacks 210 are housed in a single housing is mounted in the pack case 100, in consideration of the fact that the pack case 100 of the present invention is particularly suited to a cell-to-pack structure that does not use various modular components such as a module housing, the multiple cell stacks 210 are illustrated in the drawings as a simple collection of pouch-type batteries.

[0043] The illustrated pack case 100 includes a base plate 110 and side plates 120 that are coupled along the edges of the base plate 110 to form an internal storage space. The pack case 100 also includes a cross beam 130 that is coupled to the base plate 110 in the horizontal direction as viewed in the drawing and serves as a partition member that divides the internal storage space of the base plate 110. The pack case 100 of the present invention may include a center beam 140 that is coupled to the base plate 110 to vertically divide the internal storage space of the base plate 110. In this case, the cross beam 130 horizontally divides each storage space divided by the center beam 140.

[0044] 2, the cross beam 130 is made up of a lower cross beam 132 that is directly connected to the base plate 110 so as to horizontally divide the storage space inside the base plate 110, and an upper cross beam 136 that is connected to the lower cross beam 132. The upper cross beam 136 is connected above the lower cross beam 132, in other words, the upper cross beam 136 is connected to the lower cross beam 132 in an aligned state so that it overlaps with the top of the lower cross beam 132, thereby forming a single cross beam 130, which has a two-layer structure.

[0045] As described above, the pack case 100 of the present invention has a two-layer structure in which one cross beam 130 is divided into the lower cross beam 132 and the upper cross beam 136, which provides many advantages. For example, because only the lower cross beam 132 needs to be joined to the base plate 110, the lower the height of the cross beam 130, the better the accessibility of the welding tool tip, making welding to the lower cross beam 132 easier. Furthermore, multiple cell stacks 210 can be loaded into the pack case 100 before assembling the upper cross beam 136, which solves the problem of interference with the cross beam 130 and improves the operability of the loading jig 300, which handles multiple cell stacks 210 at once.

[0046] Furthermore, by constructing the cross beam 130 in a two-layer structure, the upper cross beam 136, which does not require welding to the base plate 110, can be made of a lightweight dissimilar material; for example, the lower cross beam 132 can be made of a metal material such as stainless steel that can be welded, while the upper cross beam 136 can be made of an even lighter engineering plastic, which can contribute to reducing the weight of the battery pack 200.

[0047] Fig. 3 is a drawing illustrating one embodiment of the connection structure of the lower cross beam 132 and the upper cross beam 136, and Fig. 4 is a cross-sectional view taken along line "AA" in Fig. 3. According to the illustrated embodiment, the lower cross beam 132 has a first concave-convex structure 133 in which recesses 133-1 and protrusions 133-2 are repeated in the upward connection direction of the upper cross beam 136, and correspondingly, the upper cross beam 136 has a second concave-convex structure 137 having a shape complementary to the first concave-convex structure 133.

[0048] Here, the phrase "the first concave-convex structure 133 and the second concave-convex structure 137 have complementary shapes" means that the recess 133-1 of the first concave-convex structure 133 and the protrusion 137-2 of the second concave-convex structure 137, and the protrusion 133-2 of the first concave-convex structure 133 and the recess 137-1 of the second concave-convex structure 137, face each other, forming a kind of interlocking structure. The complementary concave-convex structures 133 and 137 determine a single joining position of the upper cross beam 136 relative to the lower cross beam 132, thereby accurately aligning the lower cross beam 132 and the upper cross beam 136. This facilitates the work of fastening the lower cross beam 132 and the upper cross beam 136 with bolts 138 in a pre-assembled state. Furthermore, as described below, the first concave-convex structure 133 of the lower cross beam 132 is also advantageously used to avoid interference with the loading jig 300.

[0049] As described above, the lower cross beam 132 may be connected to the base plate 110 by welding, and the upper cross beam 136 may be connected to the lower cross beam 132 with bolts 138. This separate, two-layer connection structure allows the upper cross beam 136 to be made of lightweight, dissimilar materials. Referring to FIG. 3, when considering the effective thread fastening depth of the bolts 138, it is advantageous to have a short access path from the upper cross beam 136 to the lower cross beam 132. Therefore, the bolts 138 are fastened in the region where the recesses 137-1 of the second concave-convex structure 137 are joined to the protrusions of the first concave-convex structure 133.

[0050] 4, the lower cross beam 132 and the upper cross beam 136 are essentially hollow, with ribs connecting both side walls for added rigidity. The hollow structure of the lower cross beam 132 and the upper cross beam 136 makes it possible to reduce weight, and also advantageously slows down heat propagation due to thermal runaway by preventing heat generated in one of the cell stacks 210 in the pack case 100 from transferring via conduction to another cell stack 210 between the cross beams 130.

[0051] (Second embodiment) FIG. 5 is a perspective view illustrating the welding structure of the lower cross beam 132 to the base plate 110, and FIG. 6 is a plan view illustrating the welding points of the lower cross beam 132 to the base plate 110.

[0052] The cross beam 130 is an important member that reinforces the lateral rigidity of the pack case 100, and is connected to the base plate 110 by welding, bolting, etc. Welding is often used in consideration of fastening strength, productivity, and weight reduction, but in this case, weld beads 135 formed on the welded surfaces of the cross beam 130 and the base plate 110 can cause problems with the safety and capacity of the battery pack 200.

[0053] That is, multiple cell stacks 210 are mounted inside the cross beam 130, and particularly in a cell-to-pack structure without a module housing or a simplified one, the cell stacks 210 are likely to be interfered with by the weld beads 135, and in an environment where vibrations and impacts are present for a long period of time, the cell stacks 210 interfered with by the weld beads 135 are likely to be damaged or broken, which may cause serious safety issues such as fire. Furthermore, a design that avoids interference with the weld beads 135 creates dead space, thereby reducing the energy density of the battery pack 200.

[0054] 5 and 6 can solve the problem of such weld beads 135. Referring to the drawings, the lower cross beam 132 has at least one or more recessed weld grooves 134 on the boundary with the base plate 110. The lower cross beam 132 is welded to the base plate 110 through the weld grooves 134, so that the weld beads 135 are formed in the recessed spaces within the weld grooves 134, and the weld beads 135 formed within the weld grooves 134 do not protrude outside the lower cross beam 132. This can prevent interference with the cell stack 210 due to the weld beads 135 and / or the occurrence of dead spaces due to the avoidance design.

[0055] The size of the weld groove 134 can be designed taking into consideration the size of the welding tool tip and the size of the weld bead 135 depending on the welding method. For example, since wire laser welding uses a small tip size and the size of the weld bead 135 is about 2 to 3 mm, the size of the weld groove 134 can be made correspondingly to a height and depth of about several millimeters.

[0056] In one embodiment of the present invention, the welding grooves 134 may be provided on both sides of the lower cross beam 132. In this case, as shown in Fig. 6, the welding grooves 134 provided on both sides of the lower cross beam 132 may be distributed so that they do not overlap at least partially in the direction in which they face each other, in other words, so that they are alternately arranged. By distributing the welding grooves 134 evenly on both sides of the lower cross beam 132, it is possible to ensure stable weld strength while reducing the risk of deformation due to welding heat.

[0057] (Third embodiment) 7 is a perspective view of a battery pack 200 according to one embodiment of the present invention. The battery pack 200 is completed by mounting a plurality of cell stacks 210 in each of a plurality of storage spaces divided by the cross beam 130, or the cross beam 130 and the center beam 140 (the embodiment shown in the drawings), in the pack case 100 of the present invention described in the first and second embodiments. For reference, the illustrated embodiment is a battery pack 200 with a cell-to-pack structure in which a plurality of cell stacks 210 are gathered between a bus bar frame assembly (BFA) for electrical connection without a separate module housing, and leads closing the top surface have been omitted to illustrate the internal structure.

[0058] 8 is a cross-sectional view taken along line "BB" in FIG. 7, showing an insulating sheet or compression pad 220 interposed between the contact surfaces of the lower cross beam 132 and the upper cross beam 136 and the cell stack 210. For convenience, the terms "insulating sheet" and "compression pad" refer to a thin member and a relatively resilient thick member, respectively. Both are protective members that reinforce electrical insulation and the impact resistance and abrasion resistance of the cell stack 210, and serve to protect the cell stack 210 from the cross beam 130.

[0059] 9 to 12 show a series of steps for manufacturing a battery pack 200 using the pack case 100 of the present invention described above. The method for manufacturing a battery pack 200 starts with a first step of preparing the pack case 100 of the present invention, that is, the pack case 100 including a base plate 110, side plates 120 coupled along the edges of the base plate 110 to form an accommodating space therein, and a lower cross beam 132 coupled to the base plate 110 to define the accommodating space inside the base plate 110.

[0060] In particular, in the first step, only the lower cross beam 132 of the entire cross beam 130 is prepared in the pack case 100, and in this state, the cell stack 210 is loaded. That is, in the second step, a plurality of cell stacks 210 are seated in the receiving space partitioned by the lower cross beam 132, and a loading jig 300 capable of handling a large number of cell stacks 210 at once may be used for productivity reasons.

[0061] 9 is a perspective view illustrating one embodiment in which the gripper 310 of the loading jig 300 gripping a plurality of cell stacks 210 enters the lower cross beam 132, and FIG. 10 is a cross-sectional view illustrating the state in which the loading jig 300 of FIG. 9 has entered the lower cross beam 132. To ensure smooth operation of the loading jig 300, it is preferable that the pack case 100 prepared in the first step has a first concave-convex structure 133 in which the lower cross beam 132 has an alternating recess 133-1 and protrusion 133-2 in the joining direction of the upper cross beam 136.

[0062] 9 and 10, the loading jig 300 includes grippers 310 that grip a plurality of cell stacks 210 as a unit. The grippers 310 of the loading jig 300 are provided as a pair that grip both sides of the cell stack 210 parallel to the lower cross beam 132, and an additional gripper 310 that grips the other side of the cell stack 210 may be provided. In particular, the grippers 310 that grip both sides of the cell stack 210 facing the lower cross beam 132 may include a plurality of legs that correspond to the positions (or the positions and number) of the recesses 133-1 of the first concave-convex structure 133 formed on the lower cross beam 132. As a result, the grippers 310 of the loading jig 300 enter the recesses 133-1 of the first concave-convex structure 133 to seat the gripped cell stacks 210 on the base plate 110.

[0063] Generally, the depth of the recess 133-1 of the first uneven structure 133 is deeper than half the total height of the cell stack 210. Therefore, the gripper 310 of the loading jig 300 can secure a gripping area that is at least half the total height of the cell stack 210. In other words, because the lower cross beam 132 is provided with the first uneven structure 133, the gripper 310 of the loading jig 300 can firmly grip and advance on the cell stack 210 without interfering with the lower cross beam 132, and the cell stack 210 can be stably placed on the base plate 110 without impact.

[0064] For reference, a thermal resin 230 (not described) serves to improve the heat dissipation performance of the battery pack 200 by promoting conductive heat transfer between the base plate 110 and the cell stack 210. Of course, before the cell stack 210 is mounted in the pack case 100, the thermal resin 230 is evenly applied to a suitable thickness on the base plate 110.

[0065] 11 is a cross-sectional view illustrating the process of removing the loading jig 300 after seating a plurality of cell stacks 210. Because the gripper 310 is thinner than the lower cross beam 132, when the gripper 310 of the loading jig 300 seats a plurality of cell stacks 210 on the base plate 110 while gripping them together, the gripper 310 retreats to release the grip, and then the cell stacks can be removed directly above the lower cross beam 132.

[0066] After the plurality of cell stacks 210 are integrally mounted in a single receiving space through these steps, a third step is performed in which the upper cross beam 136 is coupled to the lower cross beam 132 on which the plurality of cell stacks 210 are seated, as shown in FIG. 12 . By coupling the upper cross beam 136 to the lower cross beam 132, sufficient surface pressure can be applied to the entire height of the cell stack 210. The surface pressure applied to the cell stack 210 can effectively suppress swelling that occurs as the cell stack 210 is repeatedly charged and discharged. In addition, the above-mentioned insulating sheet or compression pad 220 can be attached to the gripping surfaces of the plurality of cell stacks 210 held by the loading jig 300, and such insulating sheet or compression pad 220 also helps suppress swelling.

[0067] Then, the above-mentioned second and third steps, i.e., the second step of seating the plurality of cell stacks 210 in the storage space partitioned by the lower cross beam 132 and the third step of connecting the upper cross beam 136 to the lower cross beam 132 on which the plurality of cell stacks 210 are seated, are repeated, and a fourth step of installing the plurality of cell stacks 210 in all storage spaces is performed, thereby completing the battery pack 200 in which the cell stacks 210 are mounted without exception in the pack case 100 of the present invention.

[0068] The present invention has been described in more detail above with reference to the drawings and embodiments, etc. However, the configurations shown in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, at the time of filing this application, there may be various equivalents and modifications that can replace them. [Explanation of symbols]

[0069] 100: Pack case 110: Base plate 120: Side plate 130: Cross beam 132: Lower cross beam 133: First uneven structure 133-1: Recess 133-2:Protrusion 134: Welding groove 135: Weld bead 136: Upper cross beam 137:Second uneven structure 137-1: Recess 137-2:Protrusion 138: Bolt 140: Center beam 200: Battery pack 210: Cell stack 220: Insulation sheet or compression pad 230: Thermal resin 300: Loading jig 310: Gripper

Claims

1. A base plate and a side plate coupled to the base plate along an edge thereof to form an accommodation space therein; a lower cross beam coupled to the base plate so as to laterally define an inner storage space of the base plate; an upper cross beam coupled to the lower cross beam; Including, the lower cross beam has a first uneven structure in which recesses and protrusions are alternately formed in a coupling direction of the upper cross beam, The upper cross beam has a second concave-convex structure that is complementary to the first concave-convex structure.

2. The pack case according to claim 1 , wherein the upper cross beam is joined upwardly to the lower cross beam to form a single cross beam.

3. a center beam coupled to the base plate so as to vertically divide an inner storage space of the base plate; The pack case according to claim 1 , wherein the lower cross beam and the upper cross beam laterally partition each storage space divided by the center beam.

4. the lower cross beam is welded to the base plate; The pack case of claim 1 , wherein the upper cross beam is connected to the lower cross beam with bolts.

5. The lower cross beam and the upper cross beam are made of different materials, 5. The pack case according to claim 4, wherein the upper cross beam is made of a material that is lighter than the lower cross beam.

6. The lower cross beam is The pack case according to claim 1 , further comprising at least one recessed welding groove on an interface with the base plate.

7. The welding groove is The pack case according to claim 6, provided on both sides of the lower cross beam.

8. Each welding groove provided on both sides of the lower cross beam is The pack case according to claim 7 , wherein the plurality of sheets are arranged in a dispersed manner so as not to overlap at least partially along the direction in which they face each other.

9. the lower cross beam is welded to the base plate through the weld groove; The pack case according to claim 6 , wherein the weld bead formed in the weld groove does not protrude outside the lower cross beam.

10. The pack case according to any one of claims 1 to 9, a plurality of cell stacks mounted in the divided storage spaces of the pack case; Including the battery pack.

11. The battery pack according to claim 10 , wherein an insulating sheet or a compression pad is interposed between the lower cross beam and the contact surface of the upper cross beam and the cell stack.

12. a first step of preparing a pack case including a base plate, side plates coupled along edges of the base plate to form an internal storage space, and a lower cross beam coupled to the base plate to define the internal storage space of the base plate; a second step of seating a plurality of cell stacks in a receiving space partitioned by the lower cross beam; a third step of connecting an upper cross beam to the lower cross beam on which the plurality of cell stacks are seated; a fourth step of repeating the second and third steps to mount a plurality of cell stacks in all of the storage spaces; Including, the lower cross beam has a first uneven structure in which recesses and protrusions are alternately formed in a coupling direction of the upper cross beam, the upper cross beam has a second concave-convex structure that is complementary to the first concave-convex structure.

13. The second step comprises:

13. The method of manufacturing a battery pack according to claim 12, wherein the step of placing the plurality of cell stacks in the accommodation space partitioned by the lower cross beam using a loading jig having a gripper that grips the plurality of cell stacks as a whole, the gripper entering into the recesses of the first uneven structure to place the gripped plurality of cell stacks on the base plate.

14. The second stage comprises:

14. The method of manufacturing a battery pack according to claim 13, wherein a gripper of the loading jig grips the plurality of cell stacks together and seats them on the base plate, and releases the gripper from the stack, and then the stack is released directly above the lower cross beam.

Images