Battery pack

Abstract

A housing of a battery pack according to Embodiment 1 includes a box-shaped exterior case in which a battery pack including a plurality of battery cells is to be housed, and corner blocks (5) fixed to at least seven corner parts of the exterior case. The corner block (5) has a rectangular parallelepiped outer shape and is provided with three or more pin connection surfaces (51) including three planes disposed perpendicular to each other, and one or more fixing surfaces (52) each disposed parallel to and facing the respective pin connection surface (51). A pin insertion hole (53) for inserting a lift pin is opened in the pin connection surface (51), and a screw insertion hole (54) through which the fixing screw (6) is to be inserted is provided on the fixing surface (52). The corner block (5) is disposed such that the three pin connection surfaces (51) are flush with or parallel to three surfaces forming each corner portion of the exterior case, and the pin insertion holes (53) are provided on the three surfaces of the corner portion of the housing.

Description

Battery pack

[0001] The present disclosure relates to a battery pack containing multiple battery cells.

[0002] Battery packs containing a large number of chargeable and dischargeable battery cells have been developed. Such battery packs are used as power sources for electric vehicles, electric heavy machinery, forklifts, and the like. In particular, in recent years, there has been a demand for higher capacity battery packs, and battery packs containing a larger number of battery cells have been adopted. Such battery packs containing a large number of battery cells are quite heavy, weighing between 10 kg and several tens of kg. Therefore, when transporting or installing them, they can be lifted efficiently using a lifting device such as a crane or lift.

[0003] As described above, a method for lifting a heavy battery pack is to connect detachable lift pins to the battery pack housing and pull these lift pins with a lifting machine such as a crane or lift, allowing for convenient lifting. To lift the battery pack with a lifting machine via the lift pins, the lift pins are connected to multiple locations on the battery pack housing, for example, to the four corners of the top surface of a rectangular parallelepiped housing. In this way, even a heavy battery pack can be lifted stably and with good balance.

[0004] Such lift pins are generally cylindrical and have a retractable locking portion at the tip, such as a ball lock pin. The battery pack can be lifted by inserting the pin body of each lift pin into the pin insertion holes provided at the four corners of the top surface of the housing, locking the locking portions inside the pin insertion holes, and then simultaneously pulling up the lift pins in this state.

[0005] However, the installation orientation of a battery pack varies depending on its usage state and conditions. For example, in a battery pack whose housing has a rectangular box-like outer shape, it is not possible to determine which of the three adjacent faces that are vertically positioned faces upward when the battery pack is installed. For this reason, in a rectangular battery pack, the face that will be the upper face when the battery pack is in use must be the lifting face, and pin insertion holes for connecting lift pins must be provided at the four corners of the face. As a result, if the lifting face differs depending on the product, it is necessary to design each product separately, which increases manufacturing costs.

[0006] Furthermore, the battery pack's orientation when installed in the main device is not necessarily optimal for transportation. Depending on the product, the battery pack may be efficiently loaded and transported in an upright, vertical position during transportation, but when installed in the main device, the battery pack may be placed sideways due to the position of the output terminals. In this way, when the lifting surface is different during transportation and installation, the positions and number of pin insertion holes for connecting the lift pins become complicated, further increasing manufacturing costs.

[0007] JP 2017-162703 A JP 2016-24856 A

[0008] The present disclosure provides a battery pack that can be lifted in the normal directions of three mutually perpendicular faces of a box-shaped housing while connecting the lift pins to the four corners of the top surface of the housing.

[0009] A battery pack according to one aspect of the present disclosure includes a battery pack including a plurality of battery cells and a housing that houses the battery pack. The housing includes a box-shaped outer case that houses the battery pack and a plurality of corner blocks that are fixed to at least seven corners of the outer case and to which lift pins for lifting the battery pack are connected. The corner blocks have a rectangular parallelepiped outer shape and include three or more pin connection surfaces, including three surfaces that are perpendicular to each other, and one or more fixing surfaces that are parallel to and opposite the pin connection surfaces. Each pin connection surface has a pin insertion hole for inserting a lift pin, and the fixing surface has a screw insertion hole for inserting a fixing screw for fixing the corner block to the outer case. In the battery pack, the corner blocks are fixed to each corner of the outer case with fixing screws, and the three pin connection surfaces are arranged flush with or parallel to the three surfaces that form the corners of the outer case, and pin insertion holes are provided on the three surfaces of the corners of the housing.

[0010] The battery pack of the present disclosure has the advantage that when lifting the battery pack using lift pins, the battery pack can be lifted in the normal direction of three mutually perpendicular faces of the box-shaped housing while the lift pins are connected to the four corners of the top surface of the housing.

[0011] FIG. 1 is a schematic perspective view of a battery pack according to an embodiment of the present disclosure. FIG. 2 is a perspective view of a battery pack according to the first embodiment of the present disclosure. FIG. 3 is an exploded perspective view of the battery pack shown in FIG. 2. FIG. 4 is an exploded perspective view of the battery pack shown in FIG. 3, as viewed from the rear side. FIG. 5 is a cross-sectional view of the battery pack shown in FIG. 2, taken along line V-V. FIG. 6 is an exploded perspective view of the battery block shown in FIG. 3. FIG. 7 is a bottom perspective view of a cylindrical case. FIG. 8 is an exploded perspective view showing a state in which a corner block is being connected to the cylindrical case shown in FIG. 7. FIG. 9 is a perspective view showing an example of a corner block. FIG. 10 is a rear perspective view of the corner block shown in FIG. 9, as viewed from below. FIG. 11 is a perspective view showing a state in which the battery pack shown in FIG. 2 is lifted using lift pins. FIG. 12 is a perspective view showing a state in which the battery pack shown in FIG. 2 is lifted in a different position. FIG. 13 is a perspective view showing a state in which the battery pack shown in FIG. 2 is lifted in a different position. FIG. 14 is a cross-sectional view of the battery pack shown in FIG. 13, taken along line XIV-XIV. FIG. 15 is a perspective view showing another example of a corner block. FIG. 16 is a rear perspective view of the corner block shown in FIG. 15 , as viewed from below. FIG. 17 is a cross-sectional view showing a structure for fixing the corner block shown in FIG. 15 to a cylindrical case. FIG. 18 is a perspective view showing another example of a corner block. FIG. 19 is a rear perspective view of the corner block shown in FIG. 18 , as viewed from below. FIG. 20 is a cross-sectional view of the corner block shown in FIG. 18 , taken along line XX-XX. FIG. 21 is a perspective view showing another example of a corner block. FIG. 22 is a perspective view of a battery pack according to the second embodiment of the present disclosure. FIG. 23 is a rear perspective view of the battery pack shown in FIG. 22. FIG. 24 is an exploded perspective view of the battery pack shown in FIG. 22. FIG. 25 is an exploded perspective view of the battery block shown in FIG. 24. FIG. 26 is an exploded perspective view showing the connection structure between the outer case and corner block of the battery pack shown in FIG. 22. FIG. 27 is a horizontal cross-sectional view showing the connection structure between the outer case and corner block of the battery pack shown in FIG. 22. FIG. 28 is a vertical cross-sectional view showing the connection structure between the outer case and corner block of the battery pack shown in FIG. 22. FIG. 29 is a perspective view of a battery pack of a comparative example.

[0012] First, one focus of the present disclosure will be described. When a battery pack, which houses a battery pack including a large number of battery cells in a box-shaped housing, is to be lifted using a lifting machine such as a crane or lift by connecting lift pins to the four corners of the top surface, it is necessary to provide pin insertion holes for inserting the lift pins at the four corners of the top surface that will serve as the lifting surface. In particular, in order to lift the battery pack while it is in different positions, it is necessary to provide pin insertion holes at the four corners of the surface that will serve as the lifting surface. This not only requires time and effort in manufacturing and increases manufacturing costs, but also poses the problem of being unable to lift the battery pack in a specific direction depending on the structure of the housing.

[0013] For example, as shown in FIG. 29 , in a comparative example battery pack 90 in which a housing 93 for accommodating a battery pack is composed of a cylindrical metal case 93A and a lid 93B that closes both end openings of the metal case 93A, pin insertion holes 95 can be drilled directly into the metal case 93A. The metal case 93A of the housing 93 shown in the figure is a rectangular tubular shape formed by connecting both side edges of a pair of main surfaces 93a with a pair of side surfaces 93b, and both end openings are closed by lids 93B. The metal case 93A has a box-shaped outer shape, and pin insertion holes 95 are drilled at each corner of the metal case 93A. The metal case 93A in FIG. 29 has pin insertion holes 95 drilled at each of the four corners of the main surface 93a and the four corners of the side surfaces 93b. When the battery pack 90 is in a position where the main surface 93a is the upper surface, as shown in FIG. 29 , it can be lifted using lift pins inserted into pin insertion holes 95 provided at the four corners of the main surface 93a. Also, when the side surface 93b is the upper surface, it can be lifted using lift pins inserted into pin insertion holes 95 provided at the four corners of the side surface 93b. However, because pin insertion holes cannot be provided at the four corners of the end surface 93c of the cylindrical metal case 93A, the battery pack 90 cannot be lifted using lift pins when the end surface 93c is the upper surface, i.e., when the lid 93B is arranged vertically. Thus, in a structure in which the housing 93 is formed by a cylindrical metal case 93A, both axial end surfaces are openings, so pin insertion holes cannot be provided at the four corners of the end surface, and therefore, there is a problem in that it cannot be lifted when the end surface 93c is the upper surface.

[0014] Furthermore, in a structure in which the housing is constructed using a plastic exterior case, it is difficult to directly provide pin insertion holes, as in the case of the metal case 93A, due to structural and strength issues. Here, when providing pin insertion holes at the four corners of the surface that will serve as the lifting surface of a box-shaped housing, in order to use multiple surfaces as lifting surfaces, it is necessary to provide multiple pin insertion holes in intersecting directions at one corner, which may reduce the strength of the corner. If the strength of the corners of a plastic exterior case is reduced, there is a problem of reduced safety when lifting via lift pins. The present disclosure was developed to solve the above problems.

[0015] A battery pack according to one embodiment of the present disclosure includes a battery pack including a plurality of battery cells and a housing that houses the battery pack. The housing includes a box-shaped outer case that houses the battery pack and a plurality of corner blocks that are fixed to at least seven corners of the outer case and to which lift pins for lifting the battery pack are connected. Each corner block has a rectangular parallelepiped outer shape and includes three or more pin connection surfaces, including three surfaces that are perpendicular to each other, and one or more fixing surfaces that are parallel to and opposite the pin connection surfaces. Each pin connection surface has a pin insertion hole for inserting a lift pin, and the fixing surface has a screw insertion hole through which a fixing screw is inserted to fix the corner block to the outer case. The corner blocks are fixed to each corner of the outer case with fixing screws, and the three pin connection surfaces are arranged flush with or parallel to the three surfaces that form the corners of the outer case, and the pin insertion holes are provided on the three surfaces of the corners of the housing.

[0016] The above configuration has the advantage that the battery pack can be lifted in the normal directions of three mutually orthogonal faces of the box-shaped housing while connecting lift pins to the four corners of the top surface of the housing. This is because the above battery pack has corner blocks at at least seven corners of the housing, and each corner block has pin insertion holes opening in a pin connection surface that is flush with or parallel to the three faces forming the corner. In this battery pack, the corner blocks arranged at each corner of the housing have pin insertion holes opening in three directions. Therefore, regardless of which side of the battery pack with the corner blocks arranged at the four corners is the upper surface, the battery pack can be lifted by connecting lift pins to the pin insertion holes arranged at the four corners of the top surface, thereby achieving the advantage of being able to lift the box-shaped housing in the normal directions of the three mutually orthogonal faces. For example, by providing corner blocks at the seven corners of the box-shaped outer case, the above battery pack can be placed at the four corners of the three mutually orthogonal faces of the box-shaped housing. Therefore, regardless of which of the three surfaces with corner blocks at the four corners is the upper surface, the battery pack can be lifted by connecting lift pins to the pin insertion holes located at the four corners of the upper surface.In other words, by providing corner blocks at the seven corners of the box-shaped exterior case, the battery pack can be lifted in three directions, with any of the three surfaces with corner blocks at the four corners being the upper surface.

[0017] In this specification, the term "rectangular prism" does not mean that the corner block has a rectangular prism shape, but rather a hexahedron with adjacent flat surfaces all perpendicular to each other. A rectangular prism-shaped corner block may have adjacent surfaces that are slightly tilted from the perpendicular rather than perfectly perpendicular, and each surface may not be flat but may have some curvature or unevenness. Furthermore, the number of surfaces is not limited to six; a polyhedron with more than six surfaces may be formed by decorative deformations or chamfering. In other words, in this specification, the term "rectangular prism" refers to a shape in which the main surfaces, such as the pin connection surfaces with pin insertion holes and the fixing surfaces with screw insertion holes, are arranged to form the sides of a rectangular prism. This term is used in a broad sense to include shapes that deviate slightly from a rectangular prism shape for other purposes.

[0018] In a battery pack according to another embodiment of the present disclosure, the housing can fix corner blocks to eight corner portions of the exterior case.

[0019] According to the above configuration, corner blocks are fixed to the eight corners of the housing, so that the battery pack can be lifted by connecting lift pins to the corner blocks located at the four corners of the top surface, regardless of whether the battery pack is positioned with any of the housing faces upward. In the above battery pack, corner blocks are provided at all eight corners of the box-shaped outer case, so corner blocks are located at the four corners of all six sides of the box-shaped housing. Therefore, regardless of whether any of the six sides is the upper surface, the battery pack can be lifted by connecting lift pins to the pin insertion holes located at the four corners of the top surface. In other words, by providing corner blocks at the eight corners of the box-shaped outer case, the above battery pack can be lifted in six directions, with any of the six sides of the housing facing upward.

[0020] In another embodiment of the battery pack of the present disclosure, the pin insertion hole provided on the pin connection surface and the screw insertion hole provided on the fixing surface are arranged coaxially on the pin connection surface and the fixing surface of the corner block, which are arranged opposite each other, and the inner diameter of the screw insertion hole is made smaller than the inner diameter of the pin insertion hole, and the outer diameter of the screw head of the fixing screw inserted into the screw insertion hole can be made smaller than the inner diameter of the pin insertion hole.

[0021] According to the above configuration, when fixing the corner block to the outer case, the fixing screws are inserted through the pin insertion holes and then through the screw insertion holes, so that the corner block can be fixed to the outer case simply and easily.

[0022] In another embodiment of the battery pack of the present disclosure, the corner block has a structure in which multiple plate portions are connected to form a hollow portion inside, and the surface of each plate portion can be used as a pin connection surface and a fixing surface.

[0023] With the above-mentioned configuration, the corner block is constructed of multiple connected plate sections, with the surfaces of the plate sections serving as pin connection and fixing surfaces. Therefore, the locking portions of the lift pins inserted into the pin insertion holes on the pin connection surfaces are locked onto the inner opening edges of the pin insertion holes, allowing for reliable lifting. In particular, the load-bearing strength can be adjusted by the thickness of the plate sections, allowing for stable lifting. Furthermore, the corner block is hollow, which reduces the amount of material used, making it lightweight and inexpensive.

[0024] In a battery pack according to another embodiment of the present disclosure, an opening can be provided on one surface of the corner block, and a hollow portion can be formed along the inner periphery of the opening.

[0025] The above-mentioned structure has the advantage that the hollow portion can be efficiently formed inside the corner block during molding. In addition, by making one side open, it is possible to reduce the amount of material used, resulting in a lightweight and inexpensive corner block.

[0026] In a battery pack according to another embodiment of the present disclosure, the corner block can be fixed to the exterior case via a single fixing screw.

[0027] With this configuration, the corner block is fastened to the exterior case via a single fastening screw inserted through the screw insertion hole in the fastening surface, making it simple and easy to fasten the corner block to the exterior case. In particular, since one corner block is fastened with a single fastening screw, the number of screw fastening processes can be minimized, reducing manufacturing costs and enabling inexpensive production.

[0028] In another embodiment of the battery pack of the present disclosure, the corner block has two adjacent faces arranged perpendicular to each other as fixing surfaces, and the corner block can be fixed to the outer case via two fixing screws inserted in directions that intersect with each other.

[0029] With this configuration, two adjacent, perpendicularly arranged surfaces are used as fixing surfaces, allowing the corner block to be securely fixed to the exterior case via fixing screws inserted through the screw holes on these fixing surfaces. In particular, because the fixing surfaces intersect perpendicularly, the fixing screws inserted through the fixing surfaces of the corner block can be threaded in directions that intersect with each other to secure the corner block to the exterior case, firmly securing the corner block to the exterior case. This allows the battery pack to be lifted stably and safely using the lift pin inserted into the corner block.

[0030] In a battery pack according to another embodiment of the present disclosure, the corner blocks have a cubic outer shape, and the outer case has a connecting recess at the corner where the corner block is located, which is shaped to fit into the corner block.

[0031] According to the above configuration, the corner block is cubic in shape with six faces of the same size as a square, which allows for flexibility in the direction of fixation when fixing to the outer case, and has the advantage that the connecting direction of the corner block can be adjusted so that the fixing surface faces in the optimal direction.

[0032] In another embodiment of the battery pack of the present disclosure, the outer case includes a cylindrical case and a cover that closes both end openings of the cylindrical case, the cylindrical case includes an inner wall that is connected to the outer wall and extends in the axial direction inside the outer wall, and a connecting recess for fixing the corner block can be formed in the corner where the corner block is to be disposed. The connecting recess has openings on three sides of the corner of the cylindrical case, where the three pin connection surfaces of the corner block are disposed, and the inner walls are exposed inward to serve as fixing portions that fix the fixing surfaces of the corner block while positioning them, and the corner block disposed in the connecting recess can be fixed to the fixing portion via a fixing screw.

[0033] According to the above configuration, the outer case is composed of a cylindrical case and a lid body, and connecting recesses are formed at the corner portions where the corner blocks are placed to secure the corner blocks.By connecting lift pins to the corner blocks placed at the four corners of the opening surface of the cylindrical case and lifting them, the battery pack can also be lifted in the axial direction of the cylindrical case.

[0034] In another embodiment of the battery pack of the present disclosure, the exterior case has a box-like shape molded from plastic, and the exterior case can have a connecting recess for fixing the corner block to the corner portion where the corner block is to be placed. The connecting recess has openings on three sides of the corner portion of the exterior case where the three pin connection surfaces of the corner block are to be placed, and a fixing portion is provided on the inside for positioning and fixing the fixing surface of the corner block, so that the corner block placed in the connecting recess can be fixed to the fixing portion via a fixing screw.

[0035] According to the above configuration, while the outer case is made of plastic, connecting recesses for fixing the corner blocks are formed in the corner portions where the corner blocks are placed, and lift pins can be connected to the pin insertion holes provided in the four corners with the surfaces with the corner blocks provided at the four corners facing up, allowing for safe and reliable lifting without reducing the strength of the corner portions of the plastic outer case.

[0036] The present disclosure will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "upper," "lower," and other terms including these terms) will be used as necessary. However, the use of these terms is intended to facilitate understanding of the present disclosure with reference to the drawings, and the meanings of these terms do not limit the technical scope of the present disclosure. Furthermore, parts that appear with the same reference numerals in multiple drawings indicate the same or equivalent parts or members.

[0037] Furthermore, the embodiments described below are specific examples of the technical ideas of the present disclosure and are not intended to limit the present disclosure to the following. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended to be illustrative and not to limit the scope of the present disclosure. Furthermore, the content described in one embodiment or example can also be applied to other embodiments or examples. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity.

[0038] The schematic configuration of a battery pack according to the present disclosure will be described with reference to a schematic perspective view of a battery pack 100 shown in FIG. 1 . When the battery pack 100 is lifted using lift pins 7 (not shown in FIG. 1 ), the housing 3 housing a battery pack 2 (not shown in FIG. 1 ) is connected to the four corners of the top surface of the housing 3. The battery pack 100 can be lifted in the normal directions of the three mutually orthogonal faces of the box-shaped housing 3, i.e., in three mutually orthogonal directions, thereby improving work efficiency during transportation and installation. As shown in FIG. 1 , the housing 3, which is formed in a rectangular box shape, includes a box-shaped outer case 4 and a plurality of corner blocks 5 fixed to the corners of the outer case 4. The outer case 4 has six outer surfaces, namely, a main surface 41, a side surface 42, and an end surface 43, which are arranged opposite each other. Specifically, the box-shaped outer case 4 includes a pair of main surfaces 41, each consisting of a first main surface 41A and a second main surface 41B, which are arranged parallel to each other. The exterior case 4 also has a pair of side surfaces 42 consisting of a first side surface 42A and a second side surface 42B that are arranged parallel to each other and connect the side edges of the first main surface 41A and the second main surface 41B. The exterior case 4 also has a pair of end surfaces 43 consisting of a first end surface 43A and a second end surface 43B that are arranged parallel to each other and connect the end edges of the pair of main surfaces 41 and the pair of side surfaces 42. In order to enable the battery pack of the present disclosure to be lifted in an orientation in which any of the main surface 41, the side surface 42, and the end surface 43 of the box-shaped housing 3 is the upper surface, corner blocks 5 are fixed to the four corners of the main surface 41, the side surface 42, and the end surface 43 that form the lifting surface 30, and the corner blocks 5 have pin insertion holes 53 that open in three directions for connecting lift pins 7. The housing 3 is lifted by connecting the lift pins 7 to the pin insertion holes 53 of the corner blocks 5 located at the four corners of the lifting surface 30, with the surface located on the upper surface being the lifting surface 30, and simultaneously lifting the four lift pins 7 with a lifting machine (not shown) such as a crane or lift. Therefore, the battery pack of the present disclosure can be lifted in an orientation in which any of the main surface 41, side surface 42, and end surface 43 of the housing 3 is the upper surface, and the housing 3 can be lifted in three mutually perpendicular directions.

[0039] In this structure in which lift pins 7 are connected to corner blocks 5 arranged at the four corners of the upper surface (lifting surface 30), corner blocks 5 are fixed to all eight corners of the box-shaped housing 3, allowing the housing 3 to be lifted by arranging the corner blocks 5 at the four corners of the upper surface (lifting surface 30) regardless of which of the six surfaces is the upper surface. However, by arranging corner blocks 5 at seven of the eight corners, the housing 3 can be lifted in three mutually perpendicular directions. For example, in the housing 3 shown in the schematic perspective view of FIG. 1 , corner blocks 5 are fixed to the four corners of the first main surface 41A, the first side surface 42A, and the first end surface 43A, which are three surfaces adjacent to each other in a mutually perpendicular orientation, thereby arranging corner blocks 5 at seven corners of the housing 3. As a result, regardless of whether the first main surface 41A, the first side surface 42A, or the first end surface 43A is the upper surface, the housing 3 can be lifted by connecting the lift pins 7 to the corner blocks 5 provided at the four corners, with the upper surface serving as the lifting surface 30. In this case, no corner blocks 5 are provided at the remaining corner portions of the housing 3, i.e., corner portions formed by the second main surface 41B, the second side surface 42B, and the second end surface 43B. However, the housing 3 can be lifted regardless of whether the first main surface 41A, the first side surface 42A, or the first end surface 43A is the upper surface. Therefore, by fixing the corner blocks 5 to at least seven of the eight corner portions of the box-shaped housing 3, the battery pack of the present disclosure can be lifted in the normal directions of the three mutually perpendicular faces of the box-shaped housing 3.

[0040] 2 to 8 , a battery pack 100 according to a first embodiment includes a battery pack 2 including a plurality of battery cells 1, and a housing 3 that houses the battery pack 2. The housing 3 includes a box-shaped outer case 4 that houses the battery pack 2, and corner blocks 5 that are fixed to at least seven corners of the outer case 4 and to which lift pins 7 for lifting the battery pack 100 are connected. The corner blocks 5 have a rectangular parallelepiped outer shape and include three or more pin connection surfaces 51, including three surfaces that are perpendicular to each other, and one or more fixing surfaces 52 that are parallel to and opposite the pin connection surfaces 51. The pin connection surfaces 51 each have a pin insertion hole 53 through which the lift pin 7 is inserted, and the fixing surfaces 52 each have a screw insertion hole 54 through which a fixing screw 6 for fixing the corner block 5 to the outer case 4 is inserted. The corner blocks 5 are fixed to each corner of the outer case 4 via the fixing screws 6 inserted through the screw insertion holes 54. In addition, the three pin connection surfaces 51 of the corner blocks 5 fixed to each corner portion are arranged so as to be flush with or parallel to the three surfaces forming each corner portion of the outer case 4, and pin insertion holes 53 are provided on the three surfaces of the corner portions of the housing 3.

[0041] (Housing 3) The housing 3 has a structure having a storage section 31 capable of storing the battery pack 2 therein. The housing 3 includes an outer case 4 having a rectangular box-like outer shape and corner blocks 5 fixed to at least seven of the eight corners of the box-shaped outer case 4. For example, the housing 3 of the battery pack 100 according to embodiment 1 shown in FIG. 2 has corner blocks 5 fixed to all eight corners of the outer case 4, for a total of eight corner blocks 5. The battery pack 100 having this structure can be lifted using the upper surface as the lifting surface 30 regardless of the orientation of any surface of the housing 3. However, as described above, the corner blocks 5 can also be fixed to seven of the eight corners of the outer case. The housing 3 having this structure can be lifted using the upper surface as the lifting surface while being oriented with the surface with the corner blocks 5 at the four corners facing upward.

[0042] (External Case 4X) The external case 4X shown in Figures 2 to 5 includes a cylindrical case 4A and a lid 4B that closes both end openings of the cylindrical case 4A. The cylindrical case 4A shown in the figures has a shape in which both side edges of a pair of opposing main surfaces 41 are connected by a pair of side surfaces 42, and the cross section of the outer peripheral wall 44 is rectangular. Furthermore, the cylindrical case 4A shown in the figures includes an inner wall 45 that is connected perpendicularly to the outer peripheral wall 44 and extends in the axial direction inside the outer peripheral wall 44. The cylindrical case 4A shown in the figures has first inner walls 45A that connect the opposing first outer peripheral walls 44A to each other inside both widthwise ends of the first outer peripheral walls 44A that constitute the pair of main surfaces 41. The cylindrical case 4A also has second inner walls 45B connecting the opposing second outer peripheral walls 44B and first inner walls 45A inside both widthwise ends of the second outer peripheral walls 44B that constitute the pair of side surfaces 42. In the cylindrical case 4A with this structure, the space surrounded by the pair of first outer peripheral walls 44A and the pair of first inner walls 45A serves as a storage section 31 for the battery pack 2. Furthermore, the cylindrical case 4A also has a vent section 32 that serves as a space surrounded by the opposing second outer peripheral walls 44B, first inner walls 45A, and first outer peripheral walls 44A, allowing outside air to flow in the axial direction of the cylindrical case 4A, thereby improving the heat dissipation of the cylindrical case 4A. The cylindrical case 4A shown in the figure has an intermediate wall 46 between the opposing second inner walls 45B that connects the first inner wall 45A and the second outer peripheral wall 44B, thereby reinforcing the cylindrical case 4A and dividing the ventilation section 32 into multiple sections.

[0043] Furthermore, the cylindrical case 4A shown in the figures has multiple rows of ridges 47 extending in the axial direction on the surface of the outer peripheral wall 44, and these ridges 47 function as heat dissipation fins to improve the heat dissipation characteristics of the cylindrical case 4A. In the first embodiment, the cylindrical case 4A having the above-described shape is made of metal, for example, and can be formed into a predetermined cylindrical shape by extruding aluminum.

[0044] (Cover 4B) The cover 4B is fixed to both end surfaces 43 of the cylindrical case 4A to close both end openings of the cylindrical case 4A. The cover 4B shown in Figures 2 to 4 has an outer shape that closes the opening of the storage section 31 provided in the cylindrical case 4A. The outer case 4X shown in the figures has positive and negative output terminals 19 provided on one cover 4B (on the left side in the figures).

[0045] The lid 4B is a plate-like member molded from metal or resin, and is fixed to an end surface 43 of the cylindrical case 4A via a set screw 16 that penetrates the outer peripheral edge. The cylindrical case 4A shown in Figures 3 to 5 has protrusions 48 that extend in the axial direction on the inside of the center of the first outer peripheral wall 44A and on the inside of the boundary between the first outer peripheral wall 44A and the first inner wall 45A, and the protrusions 48 serve as bosses into which the set screws 16 are threaded.

[0046] (Coupling Recesses 40) As shown in FIGS. 7 and 8 , the exterior case 4 has a rectangular box-like overall shape, and the corners where the corner blocks 5 are located are provided with coupling recesses 40 for positioning and securing the corner blocks 5. The illustrated housing 3 secures the corner blocks 5 to eight corners, so coupling recesses 40 are formed in the eight corners of the exterior case 4X. The coupling recesses 40 have openings on three sides of the cylindrical case 4A where the three pin connection surfaces 51 of the corner blocks 5 are located. The coupling recesses 40 shown in FIGS. 7 and 8 are formed by partially removing the outer peripheral wall 44 at the corners of the cylindrical case 4A to provide space for accommodating the rectangular corner blocks 5. The coupling recesses 40 have openings on the main surface 41, side surfaces 42, and end surfaces 43 of the cylindrical case 4A, respectively, that expose the pin connection surfaces 51 of the corner blocks 5. The corner block 5 placed in the connecting recess 40 is fixed so that its three pin connection surfaces 51 are exposed and positioned flush with or parallel to the main surface 41, side surface 42, and end surface 43 of the exterior case 4X. Furthermore, the connecting recess 40 has an inner wall 45 exposed inward by partially removing the outer peripheral wall 44, and the inner wall 45 serves as a fixing portion 33 that positions and fixes the fixing surface 52 of the corner block 5. The corner block 5 is placed in a fixed position in the connecting recess 40 with the fixing surface 52 in surface contact with the inner wall 45, and is fixed to the inner wall 45, which serves as the fixing portion 33, via fixing screws 6 inserted through the screw insertion holes 54.

[0047] The illustrated exterior case 4 has a connecting recess 40 shaped to fit into the corner block 5. The corner block 5 shown in the figure has a hexahedral, cubic exterior shape, so the connecting recess 40 is shaped like a cubic recess. In particular, the connecting recess 40 is preferably formed so that, when the corner block 5 is positioned, the main surface 41 and side surface 42, which form the outer wall 44 of the cylindrical case 4A, and the end surface 43 of the cylindrical case 4A are flush with the pin connecting surface 51 of the corner block 5. This structure prevents the corner block 5, which is fixed to the corner portion, from protruding from or being recessed into the surface of the cylindrical case 4A, improving the appearance and improving safety during use by eliminating surface snags. However, the corner block 5 is not necessarily limited to a structure in which all of the pin connecting surfaces 51 are flush with the surface of the cylindrical case 4A. The corner block 5 can also be arranged so that any or all of the pin connection surfaces 51 are protruding or recessed in a parallel position relative to the surface of the cylindrical case 4A.

[0048] (Corner Block 5) As shown in Figures 9 and 10 , the corner block 5 is formed so that adjacent surfaces are vertical, giving it an overall rectangular parallelepiped shape. The corner block 5 has at least three pin connection surfaces 51, including three surfaces that are perpendicular to each other. Each pin connection surface 51 has a pin insertion hole 53 for inserting a lift pin 7. The corner block 5 also has at least one fixing surface 52 that is parallel to and faces the pin connection surface 51. The fixing surface 52 has a screw insertion hole 54 through which a fixing screw 6 for fixing the corner block 5 to the outer case 4X is inserted. The corner block 5 is positioned in a predetermined orientation at a corner of the box-shaped housing 3, and the pin insertion holes 53 are located on three surfaces of the corner of the housing 3. The corner block 5 is positioned so that the three pin connection surfaces 51 are flush with or parallel to the three surfaces that form the corners of the outer case 4, and the pin insertion holes 53 are located on three surfaces of the corner of the housing 3.

[0049] 14, the pin insertion hole 53 is a circular through-hole into which the pin body 7A of the lift pin 7 can be inserted. The pin insertion hole 53 allows the pin body 7A to be inserted from the outside, but has an inner diameter such that when the inserted pin body 7A has its locking portion 7B protruding inside the corner block 5, the locking portion 7B locks onto the inner opening edge of the pin insertion hole 53, preventing the pin body 7A from being pulled out. In other words, the inner diameter of the pin insertion hole 53 is slightly larger than the outer diameter of the pin body 7A of the lift pin 7, but smaller than the outer diameter of the lift pin 7 with its locking portion 7B protruding.

[0050] Furthermore, the corner block 5 has a pin insertion hole 53 in the pin connection surface 51 and a screw insertion hole 54 in the fixing surface 52 that face each other, and the inner diameter of the screw insertion hole 54 is smaller than the inner diameter of the pin insertion hole 53. Furthermore, the outer diameter of the screw head 6A of the fixing screw 6 inserted into the screw insertion hole 54 is equal to or smaller than the inner diameter of the pin insertion hole 53. When fixing the corner block 5 with this structure to the outer case 4X, the fixing screw 6 can be inserted through the pin insertion hole 53 and into the screw insertion hole 54 while the corner block 5 is positioned in a fixed position in the connecting recess 40 of the outer case 4X, and fixed to the outer case 4X.

[0051] The corner block 5 shown in Figures 9 and 10 is a box-shaped structure consisting of multiple connected plate members 57 of a predetermined thickness, with a hollow portion 56 formed inside. The surfaces of each plate member 57 of the corner block 5 serve as a pin connection surface 51 and a fixing surface 52. In this hollow box-shaped corner block 5, an opening 55 can be formed on one surface, and the hollow portion 56 can be formed along the inner periphery of the opening 55.

[0052] Furthermore, the corner block 5 shown in Figures 9 and 10 has a hexahedral cubic exterior shape. The cubic corner block 5 has six equally sized square faces, allowing for flexibility in the orientation of the corner block when attached to the exterior case 4X. The cubic corner block 5 can have a side length of, for example, 20 to 40 mm, depending on the size of the exterior case 4. However, the corner block of the present disclosure can also have a regular rectangular prism shape with two opposing faces being square, or a rectangular prism shape with all faces being rectangular. In this case, the long side of the rectangle can be 30 to 80 mm.

[0053] The corner blocks of the present disclosure are preferably made of metal. Metal corner blocks can be made of iron or iron alloys, or aluminum or aluminum alloys. For example, stainless steel, which is iron containing chromium, can be used as such corner blocks. Metal corner blocks can be formed, for example, by powder metallurgy. These corner blocks can be formed by placing metal powders mixed in a predetermined ratio into a mold, compressing them in a press to form a predetermined shape, and sintering the compacted product to achieve a predetermined strength. Furthermore, metal corner blocks can be cast, or a metal block can be formed into a predetermined shape by cutting or drilling. For example, in the case of a corner block of the present disclosure having a hollow portion on one side, after forming the block into a hollow block shape, pin insertion holes and screw insertion holes can be drilled. Furthermore, the corner blocks of the present disclosure can be made of hard plastic or formed by solidifying metal powder with a binder.

[0054] The corner block 5 shown in Figures 9 and 10 has six cubic faces, four of which, including three faces that are adjacent to each other and perpendicular to each other, serve as pin connection faces 51 and have pin insertion holes 53 opened in them.Of the remaining faces, one face serves as a fixing face 52 and has a screw insertion hole 54 opened in it, and the other face serves as an opening 55 and has a hollow portion 56 opened in it.

[0055] The corner block 5 is disposed and fixed in a connecting recess 40 provided in a corner portion of the outer case 4X. As shown in FIG. 8 , the corner block 5 is fixed in the connecting recess 40 with one fixing surface 52 facing the second inner wall 45B, which is the fixing portion 33 of the outer case 4X, and three of the four pin connecting surfaces 51 exposed to the outside. At this time, the three exposed pin connecting surfaces 51 are positioned flush with or parallel to the three surfaces (main surface 41, side surface 42, and end surface 43) that form the corner portion of the outer case 4X. The fixing surface 52 is positioned in surface contact with the fixing portion 33 provided in the connecting recess 40 and is fixed to the fixing portion 33 via a fixing screw 6 inserted through a screw insertion hole 54. The fixing screw 6 can be a tapping screw threaded into the fixing portion 33, or can be threaded into a female screw hole provided in the fixing portion 33. In this case, the corner block 5 fixed to the connecting recess 40 can be positioned so that the opening 55 is in communication with the ventilation section 32 of the cylindrical case 4A. When the temperature of the cylindrical case 4A rises due to heat generation from the stored battery cells 1, this structure effectively suppresses the temperature rise of the cylindrical case 4A by allowing air flowing through the ventilation section 32 due to natural convection to pass through the pin insertion holes 53 in the corner block 5 and be exhausted to the outside (see FIG. 14 ).

[0056] The corner block 5 shown in FIG. 8 is fixed to the second inner wall 45B, which is the fixing portion 33 of the outer case 4X, via a single fixing screw 6. The fixing portion 33 shown in the figure has an internal structure in the second inner wall 45B that includes an intermediate wall 46 connecting the first inner wall 45A and the second outer peripheral wall 44B, improving mechanical rigidity and firmly fixing the corner block 5. Furthermore, the interior of the corner block 5 into which the fixing screw 6 is screwed is a hollow space 56, eliminating the risk of adverse effects even if the sharp tip of the fixing screw 6 protrudes. Therefore, it is possible to use a thicker and longer fixing screw 6 to secure the corner block 5 more firmly. Thus, by using a structure in which the corner block 5 is fixed via a single fixing screw 6, it can be simply and easily fixed while still being firmly fixed to the fixing portion 33. However, the corner block of the present disclosure can also be fixed to the fixing portion via multiple fixing screws.

[0057] As shown in Figures 11 to 14, the battery pack 100 described above is oriented such that the surfaces to which the corner blocks 5 are fixed at the four corners face up, and lift pins 7 are inserted into the pin insertion holes 53 provided in the corner blocks 5 at the four corners to lock them in place (see Figure 14). In this state, the battery pack 100 can be lifted by simultaneously pulling up the lift pins 7 at the four corners with a lifting machine (not shown). Figure 11 shows the state in which the main surface 41 of the outer case 4X faces up, and the lift pins 7 are inserted into the pin insertion holes 53 of the corner blocks 5 provided at the four corners, with the main surface 41 serving as the lifting surface 30. Figure 12 shows the state in which the side surface 42 of the outer case 4X faces up, and the lift pins 7 are inserted into the pin insertion holes 53 of the corner blocks 5 provided at the four corners, with the side surface 42 serving as the lifting surface 30. 13 and 14 show a state in which the end surface 43 of the exterior case 4X is set as the upper surface, and the end surface 43 is set as the lifting surface 30, and lifting is performed by inserting lift pins 7 into pin insertion holes 53 in corner blocks 5 provided at the four corners. Regardless of which surface of the battery pack 100 shown in these figures is set as the upper surface, corner blocks 5 can be placed at the four corners of the upper surface, and the battery pack 100 can be lifted by inserting lift pins 7 into pin insertion holes 53 provided in the corner blocks 5 at the four corners.

[0058] (Another Example of Corner Block 5) Furthermore, the corner block 5 shown in FIGS. 15 to 17 has two adjacent faces arranged perpendicular to each other as fixing faces 52. The corner block 5 shown in FIGS. 15 to 16 has an overall cubic outer shape. Of the six faces of the corner block 5, three adjacent faces arranged perpendicular to each other serve as pin connection faces 51 and have pin insertion holes 53. Of the remaining three faces, two serve as fixing faces 52 and have screw insertion holes 54. One face serves as an opening 55 and has a hollow portion 56. In the corner block 5, the pin insertion hole 53 in the pin connection face 51 and the screw insertion hole 54 in the fixing face 52 are arranged coaxially on the opposing pin connection face 51 and fixing face 52. The inner diameter of the screw insertion hole 54 is smaller than the inner diameter of the pin insertion hole 53. The outer diameter of the screw head 6A of the fixing screw 6 inserted into the screw insertion hole 54 is equal to or smaller than the inner diameter of the pin insertion hole 53.

[0059] When the corner block 5 is placed in the connecting recess 40 provided in the corner portion of the outer case 4X, the two fixing surfaces 52 are fixed in a position facing the two fixing portions 33 of the outer case 4X, while the three pin connecting surfaces 51 are fixed to the connecting recess 40 in a position exposed on the three surfaces forming the corner portion of the outer case 4X. The outer case 4X shown in Figure 17 has a first inner wall 45A and a second inner wall 45B forming the connecting recess 40 as fixing portions 33, and the corner block 5 is fixed by being positioned so that the two fixing surfaces 52 of the corner block 5 are in surface contact with the first inner wall 45A and the second inner wall 45B, which are perpendicular to each other. The corner block 5 shown in Figure 17 is fixed to the first inner wall 45A and the second inner wall 45B, which are fixing portions 33 of the outer case 4X, via two fixing screws 6. The fixing screws 6 inserted through the screw insertion holes 54 provided in the two fixing surfaces 52 are threaded into the first inner wall 45A and the second inner wall 45B, which are the fixing portions 33, respectively, to fix the corner block 5 to the connecting recess 40 of the exterior case 4X. The second inner wall 45B, which is one of the fixing portions 33, has an internal structure that provides an intermediate wall 46 connecting the first inner wall 45A and the second outer peripheral wall 44B, improving mechanical rigidity and firmly fixing the corner block 5. The first inner wall 45A, which is the other fixing portion 33, is reinforced with a protrusion 48 formed inside the boundary between the first outer peripheral wall 44A and the first inner wall 45A, thereby enabling the fixing screws 6 to be more firmly fixed. Adjusting the thickness of the protrusion 48 also prevents the sharp tip of the fixing screw 6 from being exposed in the storage portion 31.

[0060] This structure, in which two adjacent surfaces serve as fixing surfaces 52 and the corner block 5 is fixed to the outer case 4X via the fixing screws 6, has the advantage of more firmly securing the corner block 5 to the outer case 4X. In particular, since the two adjacent surfaces serve as fixing surfaces 52, the two fixing screws 6 can be screwed in and fixed in mutually intersecting directions. When lifting the corner block 5 via the lift pins 7, one of the fixing screws 6 is oriented intersecting the lifting direction, so the load applied when lifting the corner block 5 via the lift pins 7 acts as a shear force on the fixing screws 6 fixed in the intersecting direction. This effectively prevents the corner block 5 from coming off the outer case 4X, allowing the corner block 5 to be reliably lifted via the lift pins 7 connected to the corner block 5. However, the corner block 5 shown in FIGS. 15 and 16 may also be fixed to the outer case 4X via a single fixing screw 6.

[0061] Furthermore, the corner block of the present disclosure may have six faces each consisting of a pin connection surface 51 and a fixing surface 52, while forming a hollow portion 56 without providing an opening 55 as shown in FIGS. 10 and 16 . Such a corner block can be molded, for example, using a 3D printer. Although not shown, at least three of the six faces of this corner block, including three faces that are vertically adjacent to each other, can be pin connection surfaces 51 with pin insertion holes 53, and at least one of the remaining faces can be a fixing surface 52 with a screw insertion hole 54. For example, four of the six faces of this corner block, including three faces that are vertically adjacent to each other, can be pin connection surfaces 51, and two faces can be fixing surfaces 52. Furthermore, this corner block may have faces that do not have pin insertion holes 53 or screw insertion holes 54.

[0062] Furthermore, the corner block 5 shown in Figures 18 to 20 does not have a hollow portion 56 inside, but has pin insertion holes 53 and screw insertion holes 54 formed by drilling multiple holes in a solid, cubic block material. The corner block 5 in these figures has a cube shape with six faces, with adjacent faces arranged perpendicular to each other. The cube-shaped corner block 5 has four faces, including three adjacent faces, that serve as pin connection faces 51, and the remaining two faces that serve as fixing faces 52. Each pin connection face 51 has a pin insertion hole 53 drilled in its center, and each fixing face 52 has a screw insertion hole 54 drilled in its center. The pin insertion holes 53 drilled in the centers of the opposing pin connection faces 51 are drilled so as to completely pass through the corner block 5. The pin insertion hole 53 drilled in the center of the pin connection surface 51 facing the fixing surface 52 is drilled to a predetermined depth without penetrating the corner block 5, leaving a plate portion 57 of a predetermined thickness between the bottom surface of the pin insertion hole 53 and the outer surface of the fixing surface 52. The screw insertion hole 54 drilled in the center of the fixing surface 52 is provided so as to penetrate the plate portion 57. The screw insertion hole 54 is drilled coaxially with the pin insertion hole 53, and the inner diameter of the screw insertion hole 54 is smaller than the inner diameter of the pin insertion hole 53. The pin insertion holes 53 drilled in the center of the pin connection surface 51, which is made up of three adjacent surfaces orthogonal to each other, are provided so as to intersect with each other at the center of the corner block 5. The spaces formed by the pin insertion holes 53 drilled from three directions and intersecting at the center of the corner block 5 realize a structure in which the locking portion 7B of the lift pin 7 inserted through the pin insertion hole 53 can be locked.

[0063] However, in the case of a cubic corner block 5 having six faces, three adjacent faces can be used as pin connection surfaces 51 to drill pin insertion holes 53, and three faces parallel to the pin connection surfaces 51 can be used as fixing surfaces 52 to drill screw insertion holes 54. In addition, in the case of a cubic corner block 5 having six faces, five faces can be used as pin connection surfaces 51 to drill pin insertion holes 53, and the remaining face can be used as the fixing surface 52 to drill screw insertion holes 54.

[0064] (Chamfered Portions 58) Furthermore, the corner block 5 is arranged so that adjacent pin connection surfaces 51 and fixing surfaces 52 are vertical, but the boundaries and corners between adjacent surfaces can be chamfered to form inclined or curved surfaces. For example, the corner block 5 shown in Figure 21 has three adjacent pin connection surfaces 51 arranged perpendicular to each other, with the boundaries chamfered and the corners chamfered into a triangular shape to form chamfered portions 58. In this way, a structure in which chamfered portions 58 are provided at the boundaries between pin connection surfaces 51 arranged on the outside of the housing 3 has the advantage of improving safety during work by rounding the corners of the housing 3.

[0065] 21, when the corners of the corner block 5 are largely chamfered to form chamfered portions 58, the rectangular parallelepiped corner block 5 may become a polyhedron with more faces than a hexahedron. Therefore, in this specification, the expression "a rectangular parallelepiped outer shape" is used in a broad sense to include a polyhedron with more faces than a hexahedron due to the provision of such chamfered portions.

[0066] 3 to 6 , the battery pack 100 contains a plurality of battery cells 1 housed in a housing 3 as a battery assembly 2. The battery cells 1 are grouped in a predetermined arrangement to form a battery block 10, and the battery blocks 10 are connected together to form the battery assembly 2. The battery pack 100 shown in the figures has two battery blocks 10 connected side-by-side to form the battery assembly 2.

[0067] (Battery Cell 1) The battery cell 1 is a non-aqueous electrolyte secondary battery cell, such as a lithium-ion battery. However, this disclosure does not limit the battery cell 1 to a lithium-ion battery; all currently used and future-developed secondary batteries, including other non-aqueous electrolyte secondary batteries and nickel-metal hydride batteries, can be used. The battery cell 1 in FIG. 6 is a cylindrical battery with electrode end faces at both ends. However, the battery pack of this disclosure does not limit the battery cell to a cylindrical battery. This is because rechargeable prismatic batteries and other types of batteries can also be used for the battery cell 1. The cylindrical battery shown in the figure contains electrodes and electrolyte in a cylindrical metal case. The metal case has a sealed structure in which a sealing plate is airtightly fixed to the opening of an outer can that closes the bottom. The outer can is manufactured by pressing a metal plate. The sealing plate is airtightly fixed to the periphery of the opening of the outer can by crimping via an insulating packing. Note that the prismatic battery has insulated positive and negative electrode terminals on the sealing plate that closes the opening of the metal case.

[0068] (Battery Block 10) In the battery block 10, multiple battery cells 1 are arranged parallel to one another, with the electrode end surfaces of each battery cell 1 positioned on the same plane. In the battery block 10, multiple battery cells 1 are positioned in fixed positions using a plastic battery holder 12. The battery block 10 shown in Figure 6 houses 112 cylindrical batteries in the battery holders 12, with 14 battery cells 1 arranged in eight rows. In the battery block 10, each battery cell 1 is positioned parallel to the other, with the electrode end surfaces of the battery cells 1 positioned on the same plane, and lead plates 11 connected to the electrode end surfaces on the same plane.

[0069] (Lead Plates 11) The battery block 10 connects multiple battery cells 1 in series and parallel using multiple lead plates 11. The lead plate 11 shown in FIG. 6 has a laminated structure consisting of connection lead plates 11A with connection portions that connect to the electrode end surfaces of multiple battery cells 1, and current-carrying lead plates 11B that reduce electrical resistance between battery cells 1 connected in parallel or series. The connection lead plates 11A are connected to the electrode end surfaces using methods such as laser welding, spot welding, or ultrasonic welding. The battery block 10 shown in FIG. 6 has 112 battery cells 1 connected in 16 parallel and 7 series configurations. However, the number and connection state of the multiple battery cells are not limited to the above. The battery block of the present disclosure allows for various changes in the number and connection state of the connected battery cells.

[0070] (Battery Holder 12) The battery holder 12 in Figure 6 is designed to hold multiple battery cells 1 in fixed positions. The battery holder 12 in Figure 6 is molded from insulating plastic and has a cylindrical insertion section 13 for multiple battery cells 1 molded integrally therewith. The insertion section 13 holds the battery cells 1 set therein in fixed positions. The battery holder 12 in the figure uses cylindrical batteries, and the insertion section 13 is shaped to insert cylindrical batteries and hold them in fixed positions. The battery holder 12 in the figure arranges 112 battery cells 1 in eight rows of 14 battery cells in the front-to-back direction, with the battery cells 1 arranged in the valleys between adjacent battery cells 1 on the left and right, similar to a rice bale stack.

[0071] As shown in Figure 6, the battery holder 12 is formed as a pair of separate cell holders 12A, 12B. Each of the cell holders 12A, 12B that make up the battery holder 12 has an insertion tube portion 13 into which a battery cell 1 is inserted in a parallel position. The insertion tube portion 13 is open at both ends, exposing the electrode end surfaces of the inserted cylindrical battery so that lead plates 11 can be connected to the electrode end surfaces. The insertion tube portions 13 of the cell holders 12A, 12B are long enough to insert approximately half of a battery cell 1. Each battery cell 1 is positioned in a fixed position in the battery holder 12 by inserting half into one cell holder 12A and the other half into the other cell holder 12B. The battery holder 12 constructed as described above has the advantage of being able to securely hold multiple battery cells 1 in fixed positions by inserting the battery cells 1 into the insertion tube portions 13 of the two separate cell holders 12A, 12B.

[0072] Furthermore, the battery holder 12 has multiple connecting bosses 14 protruding from both side surfaces to secure the battery block 10 to the outer case 4X. As shown in FIG. 5 , when the battery block 10 is housed in the outer case 4X, the connecting bosses 14 are positioned on the upper surfaces of protrusions 48 formed on the inside of the bottom-side first outer peripheral wall 44A, and fixing bolts 15 that pass through the protrusions 48 are threaded into the connecting bosses 14 to secure the battery block 10 to the outer case 4X. The cylindrical case 4A shown in the figures has protrusions 48 extending in the axial direction on the inner surfaces of the central portions of the pair of opposing first outer peripheral walls 44A, and the protrusions 48 are positioned between and outside the battery blocks 10 that are arranged side by side. As shown in FIGS. 5 and 7 , the protrusions 48 formed on the bottom-side first outer peripheral wall 44A have recesses 49 on the outer surfaces of their intermediate portions, and the battery block 10 is secured to the cylindrical case 4A via fixing bolts 15 that pass through the protrusions 48 in the recesses 49.

[0073] (Circuit Board 18) The battery pack 100 shown in Figure 3 also includes a circuit board 18. The circuit board 18 is positioned in a fixed position in the exterior case 4X via a board holder 17. As shown in Figures 3 and 4, the board holder 17 is located between the battery block 10 and the lid 4B of the exterior case 4X, and protects the circuit board 18 by positioning it inside. The circuit board 18 is mounted with electronic components (not shown) that are connected to the battery cells 1 and implement a protection circuit for the battery cells 1. The protection circuit is a circuit that prevents overcharging or overdischarging of the battery cells 1, a circuit that prevents overcurrent, or a circuit that cuts off current when the temperature rises abnormally.

[0074] 22 to 27, a battery pack 200 includes a housing 3 that houses an assembled battery 2 having a plurality of battery cells 1. The housing 3 includes a box-shaped outer case 4Y molded from plastic, and corner blocks 5 fixed to each corner of the outer case 4Y. The housing 3 shown in the figures has corner blocks 5 fixed to all corners of the outer case 4Y, so that the upper surface can be used as a lifting surface 30 to lift the housing 3, regardless of which surface of the housing 3 is facing up.

[0075] (External Case 4Y) The box-shaped external case 4Y has a pair of opposing main surfaces 41 connected at both side edges by a pair of side surfaces 42, and both end edges of the main surfaces 41 and the side surfaces 42 connected by a pair of end surfaces 43. Furthermore, the external case 4Y shown in the figure is divided into two parts, a main case 4C and a lid case 4D, at the midpoint between the main surfaces 41 and the side surfaces 42. The main case 4C and the lid case 4D are container-shaped with a peripheral wall 62 provided around a bottom plate 61, forming a storage compartment 31 inside which the battery pack 2 can be stored. The main case 4C and the lid case 4D have different overall lengths of the peripheral wall 62 connected to the bottom plate 61, which makes the main case 4C deeper than the lid case 4D. The main body case 4C and the lid case 4D are formed into a cylindrical shape by connecting the first peripheral wall 62A arranged on the main surface 41 side and the second peripheral wall 62B arranged on the side surface 42 side at both side edges, and are formed into a deep container shape by connecting a bottom plate 61 to one end face and forming the other end face as an opening.

[0076] The illustrated exterior case 4Y has multiple rows of grooves 27 formed on the surface of the peripheral wall 62. The multiple grooves 27 are parallel to one another, reducing the overall weight of the exterior case 4Y and increasing the surface area, thereby improving the heat dissipation characteristics of the exterior case 4Y. The main case 4C and the lid case 4D have multiple rows of grooves 27 extending from the bottom plate 61 toward the opening, but no grooves 27 are provided on the edge of the opening; instead, flanges 28, 29 are provided along the edge of the opening. The main case 4C and the lid case 4D are connected to each other by connecting the opposing flanges 28, 29 via set screws 26. As shown in FIG. 26 , the lid case 4D has a through-hole 29A in the flange 29 for inserting the set screw 26, and the main case 4C has the flange 28 serving as a boss into which the set screw 26 is threaded. The main body case 4C and the lid case 4D are connected to each other by a set screw 26 that passes through a flange portion 29 and is screwed into a flange portion 28. A groove 27 provided in the lid case 4D also serves as a tool gap that guides a screwdriver when screwing in the set screw 26.

[0077] Furthermore, as shown in Figures 26 to 28, the box-shaped outer case 4Y has connecting recesses 40 formed in each corner for positioning and securing the corner blocks 5. The illustrated housing 3 secures corner blocks 5 to all corners, so connecting recesses 40 are formed in eight corners of the outer case 4Y. The connecting recesses 40 have openings on three sides of the corners, where the three pin connection surfaces 51 of the corner blocks 5 are located. The connecting recesses 40 shown in Figures 26 to 28 have the peripheral wall 62 partially removed at the corners of the outer case 4Y to provide space for accommodating rectangular parallelepiped corner blocks 5. The connecting recesses 40 have openings on the main surface 41, side surface 42, and end surface 43 of the outer case 4Y, respectively, that expose the pin connection surfaces 51 of the corner blocks 5. The corner blocks 5 placed in the connecting recesses 40 are secured so that the three pin connection surfaces 51 are flush with or parallel to the main surface 41, side surface 42, and end surface 43 of the outer case 4Y. Furthermore, the connecting recess 40 has an open section formed by partially removing the peripheral wall 62 and the bottom plate 61, and an inner wall 63 is provided and exposed inside the connecting recess 40. The connecting recess 40 has the inner wall 63 as the fixing portion 33 that fixes the fixing surface 52 of the corner block 5 while positioning it. The corner block 5 is placed in a fixed position in the connecting recess 40 with the fixing surface 52 in surface contact with the inner wall 63, and is fixed to the fixing portion 33, that is, the inner wall 63, via the fixing screws 6 inserted into the screw insertion holes 54.

[0078] The connecting recess 40 shown in FIG. 26 is sized and shaped to fit the corner block 5 and includes inner walls 63 that face three surfaces of the corner block 5. The corner block 5 shown in FIG. 26 has the same structure as the corner block 5 shown in FIGS. 9 and 10 . The inner walls 63 shown in FIGS. 26 to 28 include a first inner wall 63A that is parallel to the end surface 43 of the exterior case 4Y, a second inner wall 63B that is parallel to the main surface 41, and a third inner wall 63C that is parallel to the side surface 42. The first inner wall 63A, the second inner wall 63B, and the third inner wall 63C are arranged perpendicular to each other, allowing the three surfaces of the corner block 5 placed in the connecting recess 40 to be in surface contact and positioned. The corner block 5 shown in the figure has one of its inner surfaces as a fixing surface 52, which is fixed in a position facing the first inner wall 63A. 27 and 28, the first inner wall 63A facing the fixing surface 52 of the corner block 5 has a protrusion 64 that protrudes inward, allowing the fixing screws 6 to be screwed in securely. Furthermore, the first inner wall 63A shown in the figures has a reinforcing collar 65 embedded therein to allow the fixing screws 6 to be screwed in more firmly. However, the reinforcing collar 65 can be omitted.

[0079] 26 to 28 has one fixing surface 52 and is fixed by screwing one fixing screw 6 into the first inner wall 63A. However, as mentioned above, the corner block 5 can also be provided with two or three fixing surfaces 52. In this case, the second inner wall 63B or the third inner wall 63C can serve as the fixing portion 33 into which the fixing screw 6 is screwed, and the corner block 5 can be fixed to the outer case 4Y via multiple fixing screws 6.

[0080] (Battery assembly 2) In the battery pack 200 shown in Fig. 24 , multiple battery cells 1 are assembled in a predetermined arrangement to form a battery block 20, and multiple battery blocks 20 are connected to form the battery assembly 2. In the battery pack 200 shown in the figure, two battery blocks 20 are stacked one above the other and connected to form the battery assembly 2. In the battery assembly 2 in Fig. 25 , two battery blocks 20 stacked one above the other with an insulating plate 39 interposed therebetween are connected via connecting plates 25A and 25B.

[0081] (Battery Block 20) ​​In the battery block 20, multiple battery cells 1 are arranged parallel to one another, with the electrode end surfaces of each battery cell 1 positioned on the same plane. In the battery block 20, multiple battery cells 1 are positioned in fixed positions using a plastic battery holder 22. As shown in Figure 25 , the battery holder 22 is divided into a pair of cell holders 22A, 22B, and each cell holder 22A, 22B has an insertion tube portion 23 into which the battery cells 1 are inserted in a parallel position. The battery block 10 in Figure 25 houses 154 cylindrical batteries in the battery holders 22, arranged in 14 rows of 11 battery cells 1 per row.

[0082] In the battery block 20, the battery cells 1 are positioned parallel to one another, with the electrode end surfaces of the battery cells 1 arranged flush with one another, and lead plates 21 are connected to the flush electrode end surfaces. The battery block 20 connects the battery cells 1 in parallel with multiple lead plates 21. The lead plate 21 shown in FIG. 25 has a laminated structure consisting of connection lead plates 21A with connecting portions that connect to the electrode end surfaces of the multiple battery cells 1 and current-carrying lead plates 21B that reduce electrical resistance between the parallel-connected battery cells 1. Furthermore, the battery block 20 connects the parallel-connected battery cells 1 in series via bus bars 24 arranged on the side of the battery holder 22. The battery block 10 shown in FIG. 25 has 154 battery cells 1 connected in 22 parallel and 7 series configurations. However, the number and connection state of the battery cells are not limited to the above. The battery block of the present disclosure allows for various changes in the number and connection state of the connected battery cells.

[0083] The battery packs 100, 200 described above are oriented with the surfaces to which the corner blocks 5 are fixed at the four corners facing up, and the lift pins 7 are inserted into the pin insertion holes 53 provided in the corner blocks 5 at the four corners to lock them in place. In this state, the battery packs 100, 200 can be lifted by simultaneously pulling up the lift pins 7 at the four corners with a lifting machine (not shown).

[0084] The present disclosure can be used, for example, in battery packs used as power sources for electric vehicles, or for electric heavy machinery, forklifts, etc. In particular, the present disclosure can be effectively used in battery packs that house a large number of battery cells in a housing.

[0085] REFERENCE SIGNS LIST 1 Battery cell 2 Battery pack 3 Housing 4 Outer case 4A Cylindrical case 4B Lid 4C Main case 4D Lid case 4X Outer case 4Y Outer case 5 Corner block 6 Fixing screw 6A Screw head 7 Lift pin 7A Pin body 7B Locking portion 10 Battery block 11 Lead plate 11A Connection lead plate 11B Current-carrying lead plate 12 Battery holder 12A Cell holder 12B Cell holder 13 Insertion tube portion 14 Connecting boss portion 15 Fixing bolt 16 Set screw 17 Board holder 18 Circuit board 19 Output terminal 20 Battery block 21 Lead plate 21A Connection lead plate 21B Current-carrying lead plate 22 Battery holder 22A Cell holder 22B Cell holder 23 Insertion tube portion 24 Bus bar 25A Connecting plate 25B Connecting plate 26 Set screw 27 Groove portion 28 Flange portion 29 Flange portion 29A Through hole 30 Suspension surface 31 Storage portion 32 Ventilation portion 33 Fixing portion 39 Insulating plate 40 Connecting recess 41 Main surface 41A First main surface 41B Second main surface 42 Side surface 42A First side surface 42B Second side surface 43 End surface 43A First end surface 43B Second end surface 44 Outer peripheral wall 44A First outer peripheral wall 44B Second outer peripheral wall 45 Inner wall 45A First inner wall 45B Second inner wall 46 Intermediate wall 47 Convex rib 48 Convex portion 49 Recess 51 Pin connecting surface 52 Fixing surface 53 Pin insertion hole 54 Screw insertion hole 55 Opening 56 Hollow portion 57 Plate portion 58 Chamfered portion 61 Bottom plate 62 Peripheral wall 62A First peripheral wall 62B Second peripheral wall 63 Inner wall 63A First inner wall 63B Second inner wall 63C Third inner wall 64 Convex portion 65 Reinforcing collar 90 Battery pack 93 Housing 93A Metal case 93B Lid 93a Main surface 93b Side surface 93c End surface 95 Pin insertion hole 100 Battery pack 200 Battery pack

Claims

1. A battery pack comprising: an assembled battery having a plurality of battery cells; and a housing for housing the assembled battery, wherein the housing comprises: a box-shaped outer case in which the assembled battery is housed; and a plurality of corner blocks fixed to at least seven corners of the outer case and to which lift pins for lifting the battery pack are connected, wherein the corner blocks have a rectangular external shape and comprise three or more pin connection surfaces including three faces arranged perpendicular to one another, and one or more fixing faces arranged parallel to and facing the pin connection surfaces, wherein each of the pin connection surfaces has a pin insertion hole formed therein for inserting the lift pin, and each of the fixing faces has a screw insertion hole through which a fixing screw for fixing the corner block to the outer case is inserted, and wherein the corner blocks are fixed to each corner of the outer case via the fixing screws, and the three pin connection surfaces are arranged flush with or parallel to the three faces forming the respective corners of the outer case, and the pin insertion holes are provided on the three faces of the corners of the housing.

2. A battery pack as described in claim 1, wherein the housing has the corner blocks fixed to eight corners of the exterior case.

3. A battery pack as described in claim 1 or 2, wherein the corner block has a pin connecting surface and a fixing surface that are arranged opposite each other, the pin insertion hole on the pin connecting surface and the screw insertion hole on the fixing surface are arranged coaxially, the inner diameter of the screw insertion hole is smaller than the inner diameter of the pin insertion hole, and the outer diameter of the screw head of the fixing screw inserted into the screw insertion hole is equal to or smaller than the inner diameter of the pin insertion hole.

4. A battery pack as described in claim 3, wherein the corner block has a structure in which a plurality of plate sections are connected together, a hollow section is formed inside, and the surfaces of the plate sections serve as the pin connection surface and the fixing surface.

5. A battery pack as described in claim 4, wherein the corner block has an opening on one surface, and the hollow portion is formed along the inner periphery of the opening.

6. A battery pack as described in claim 3, wherein the corner block is fixed to the exterior case via one of the fixing screws.

7. A battery pack as described in claim 3, wherein the corner block has two adjacent faces arranged perpendicular to each other as the fixing faces, and the corner block is fixed to the exterior case by two fixing screws that are inserted in directions that intersect with each other.

8. A battery pack as claimed in claim 1 or 2, wherein the corner block has a cubic external shape, and the exterior case has a connecting recess at the corner where the corner block is arranged, the connecting recess being shaped to fit into the corner block.

9. A battery pack as defined in claim 1 or 2, wherein the outer case comprises a cylindrical case and a lid for closing both end openings of the cylindrical case, the cylindrical case has an inner wall inside its outer peripheral wall, connected to the outer peripheral wall and extending in the axial direction, and a connecting recess is formed in the corner portion at which the corner block is disposed, for fixing the corner block, the connecting recess has an opening on three sides of the corner portion of the cylindrical case where the three pin connecting surfaces of the corner block are disposed, and the inner wall is exposed inward to serve as a fixing portion for fixing the fixing surface of the corner block while positioning it, and the corner block disposed in the connecting recess is fixed to the fixing portion via the fixing screw.

10. A battery pack as described in claim 1 or 2, wherein the outer case is a box-shaped plastic body, the outer case has a connecting recess formed in the corner portion where the corner block is arranged, for fixing the corner block, the connecting recess has openings on three sides of the corner portion of the outer case where the three pin connecting surfaces of the corner block are arranged, and a fixing portion is provided on the inside for fixing while positioning the fixing surface of the corner block, and the corner block arranged in the connecting recess is fixed to the fixing portion via the fixing screw.

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