JP6469768B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module configured by connecting a plurality of chargeable / dischargeable rectangular lithium ion secondary batteries.

  Lithium ion secondary batteries (hereinafter referred to as lithium ion batteries) that use the insertion and extraction of lithium ions for charge / discharge reactions provide higher energy density than conventional lead batteries and nickel cadmium batteries, and contribute to charge / discharge reactions Because of the fact that almost no lithium is deposited on the electrode as metallic lithium, the capacity is reproducible when charging and discharging are repeated, and stable charging and discharging characteristics can be obtained. The battery is highly expected as a battery that can be applied to various applications such as a power source for portable electronic devices, a power source for assisting disasters, and a power source for moving bodies such as automobiles and motorcycles.

  In particular, automobiles are equipped with a motor that is driven by the power from the secondary battery, and is driven by the driving force from the motor, a zero emission electric vehicle, a hybrid electric vehicle that is equipped with both an engine and a motor that uses fossil fuel, and There is a plug-in hybrid electric vehicle in which a secondary battery is directly charged from a system power source.

  When this lithium-ion battery is installed in a hybrid vehicle or zero-emission electric vehicle, the load voltage and load capacity required for the lithium-ion battery increase, so multiple battery cells can be connected in series or in parallel, or a combination of these. In many cases, an assembled battery (battery module) is constructed and stored in a housing.

  In the battery cell of a lithium ion battery, the electrode expands during charge and discharge, and the interval between the positive electrode terminal and the negative electrode terminal widens, so that the internal resistance increases and the output decreases. Further, since the battery cell is composed of a metal outer can, and a short current flows when the outer can having a potential difference is electrically connected, the battery cells need to be insulated from each other.

  Therefore, a battery block in which a plurality of rectangular battery cells having a positive electrode terminal and a negative electrode terminal on the same surface are arranged and stacked has a spacer that directly holds the battery cell and maintains an insulation state between adjacent battery cells. A structure has been proposed in which a pair of rigid end plates are arranged at both ends of the battery block in the stacking direction of the battery cells, and the interval between the end plates is fixed while being pressed from both ends by a connecting fixture. (See Patent Document 1).

JP 2008-282582 A

  In the method of tying in a state in which the distance between the end plates is kept constant, the effective load applied to the battery block greatly changes due to the tolerance of the battery cell thickness. For example, if only battery cells having a small thickness are collected within the tolerance range, the effective load applied to the battery block that falls within a certain interval is reduced. On the other hand, if only battery cells having a large thickness within the tolerance range are collected, the effective load applied to the battery block that falls within a certain interval increases. As a result, even if the dimensions of the battery modules are the same, the load applied to the battery block varies greatly among the battery modules. If the variation in the load is large, the deterioration of the characteristics of the battery module that cannot be secured with an appropriate load cannot be sufficiently suppressed. Therefore, an end plate interval suitable for each battery block, that is, a structure that can be secured with an appropriate load is required. In particular, since battery modules used in automobiles are required to have vibration resistance, a module structure with high assembly accuracy and resistance to vibration is desired.

  The present invention has been made in view of the above points, and an object of the present invention is to propose a structure of a battery module in which a spacer can slide with a guide member constituting the battery module and the spacer can be positioned. To do.

  The battery module of the present invention that solves the above-described problem is a battery module having a battery block in which a plurality of rectangular battery cells are arranged and stacked, and a spacer interposed between the plurality of battery cells, and the spacer as the battery. A guide member that is slidably supported along the cell stacking direction, and a pair of end plates that are respectively disposed on one side and the other side of the guide member in the slide movement direction and sandwich the battery block from both sides of the slide movement direction. It is characterized by having.

  According to this invention, a spacer can be arrange | positioned in the arbitrary positions of the lamination direction of a battery cell. Therefore, the interval between the end plates can be adjusted to an interval suitable for the size of the battery block, and can be secured with an appropriate load. Therefore, even if each battery cell has a tolerance, it is possible to manufacture a battery module in which the deterioration of characteristics is suppressed. Further, since the guide member has a fitting structure for positioning the spacer, the assembly accuracy can be improved and the vibration resistance is also improved.

The external appearance perspective view of the battery module which concerns on 1st Embodiment. The disassembled perspective view of the battery module which concerns on 1st Embodiment. The external appearance perspective view which shows the battery cell which concerns on 1st Embodiment. The external appearance perspective view which shows the spacer which concerns on 1st Embodiment. The external appearance perspective view explaining the method of assembling the battery module which concerns on 1st Embodiment. The side view which shows the fitting structure of the side plate and spacer which concern on 1st Embodiment. The external appearance perspective view explaining the method of assembling the battery module which concerns on 2nd Embodiment. The side view which shows the fitting structure of the side plate and spacer which concern on 2nd Embodiment. The side view which shows another example of the fitting structure of the side plate and spacer which concern on 2nd Embodiment. The side view which shows another example of the fitting structure of the side plate and spacer which concern on 2nd Embodiment. The side view which shows another example of the fitting structure of the side plate and spacer which concern on 2nd Embodiment. The external appearance perspective view which shows the other Example of the battery module which concerns on 1st Embodiment.

  Hereinafter, the best mode for carrying out the present invention will be described by way of specific examples, but the present invention is not limited thereto. Further, the drawings in the embodiments are schematic diagrams and do not guarantee the accuracy of the positional relationship, dimensions, etc. in the drawings. Various changes and modifications can be made by those skilled in the art within the scope of the technical idea disclosed in this specification. In all the drawings for explaining the present invention, components having the same function are denoted by the same reference numerals, and repeated description thereof may be omitted.

[First Embodiment]
FIG. 1 is an external perspective view of a battery module according to the present embodiment, and FIG. 2 is an exploded perspective view thereof.
The battery module 9 includes a battery block 8 in which a plurality of rectangular battery cells 1 are arranged and stacked. A spacer 2 is interposed between the plurality of battery cells 1. Since the spacer 2 has a structure in which the battery cell 1 is accommodated by combining the two, it is hereinafter referred to as a cell holder. The battery module 9 has a guide member that supports the cell holder 2 so as to be slidable along the stacking direction of the battery cells 1 (see FIG. 5). A pair of end plates 3 that sandwich the battery block 8 from both sides in the slide movement direction are respectively arranged on one side and the other side of the guide member in the slide movement direction.

  The guide member includes a pair of side plates 4 facing the side surfaces of the battery block 8 and a base plate 5 facing the bottom of the battery block 8. The side plate 4 can be made from various materials such as metal or resin. The pair of side plates 4 includes a pair of side surface facing portions 41 facing the side surfaces on both sides of the battery cell 1 in the cell width direction, and an upper surface facing portion 42 facing the upper surface of the battery cell 1 in the cell height direction. The upper surface facing portion 42 is provided with a fitting recess 43 that is recessed in a direction perpendicular to the sliding movement direction and extends along the sliding movement direction and fits with a fitting projection 26 of the cell holder 2 described later. It has been. The fitting recess 43 has a semicircular arc shape that is recessed upward.

  In addition, the upper surface facing portion 42 of the side plate 4 is provided with slits 44 at predetermined intervals in the slide movement direction, and each cell holder 2 is attached in a direction perpendicular to the slide movement direction by caulking downward. The bottom surface PB of the battery cell 1 can be pressed against the bottom surface facing portion 51 of the base plate 5 by force.

  The base plate 5 has a bottom surface facing portion 51 that faces the bottom surface PB on the lower side in the cell height direction of the battery cell 1. The base plate 5 is provided with a cooling pipe 6 for circulating a refrigerant therein. As a material of the base plate 5, aluminum or an aluminum alloy can be suitably used in consideration of thermal conductivity and moldability.

FIG. 3 is an external perspective view of the battery cell.
The battery cell 1 is a square lithium ion secondary battery, and an electrode group having a positive electrode and a negative electrode is housed in a battery container made of an aluminum alloy together with a non-aqueous electrolyte. The battery container of the battery cell 1 includes a flat box-shaped battery can 11 and a battery lid 12 that seals the opening of the battery can 11. The battery can 11 is a flat rectangular container formed by deep drawing, and includes a rectangular bottom surface PB, a pair of wide side surfaces PW rising from the long side of the bottom surface PB, and a pair of narrow widths rising from the short side of the bottom surface PB. It has a side surface PN.

  The battery lid 12 is formed of a rectangular flat plate member and has an upper surface PU. The battery lid 12 is provided with a positive external terminal 13 and a negative external terminal 14 for inputting and outputting voltage. The positive electrode external terminal 13 and the negative electrode external terminal 14 are arranged at positions separated from each other in the long side direction of the battery lid 12.

  The positive external terminal 13 and the negative external terminal 14 are each provided with a nut fastening bolt for fastening the bus bar. The battery lid 12 accommodates the electrode group in the battery can 11 and then laser welded to the battery can 11 to seal the opening of the battery can 11.

  At an intermediate position in the long side direction of the battery lid 12, an inlet 15 for injecting the non-aqueous electrolyte into the battery can 11 and a gas discharge valve 16 that is cleaved by an increase in internal pressure and discharges the gas in the battery container. Is provided. A plurality of battery cells 1 are arranged and stacked in the thickness direction to constitute a battery block 8 of the battery module 9.

FIG. 4 is an external perspective view of the cell holder.
The cell holder 2 is made of an insulating material, and can be manufactured by molding engineering plastics such as PBT (Polybutylene phthalate) or PC (Polycarbonate), rubber, or the like.

  The cell holder 2 has a configuration for holding the battery cell 1 by combining the two. The cell holder 2 is interposed between the two battery cells 1. The cell holder 2 has a pair of narrow wall portions 21 facing the wide side surface PW of the battery cell 1 and a narrow side surface PN on both sides in the cell width direction of the battery cell 1 facing each other in the cell width direction both ends of the narrow wall portion 21. A pair of side wall portions 22 interposed between the side facing portions 41, an upper wall portion 25 interposed between the upper surface PU and the upper surface facing portion 42 on the upper side in the cell height direction of the battery cell 1, and the battery cell 1 has a bottom wall portion 23 interposed between a bottom surface PB on the lower side in the cell height direction and a bottom surface facing portion 51. The upper wall portion 25 is provided with a fitting convex portion 26 that fits with the fitting concave portion 43. The fitting convex portion 26 has a semicircular cross section that protrudes upward at both ends of the upper wall portion 25 in the cell width direction.

  The sandwiching wall portion 21 has a size that faces the entire wide side surface PW of the battery cell 1, and a notch portion 24 that is notched and opened at a certain height across the cell width direction. A plurality are provided. The notch portion 24 communicates with the opening 22 a of the pair of side wall portions 22.

  The pair of side wall portions 22 project from the both end portions in the cell width direction of the sandwiching wall portion 21 toward one side and the other side in the stacking direction and extend in the cell height direction with a constant width. The battery cell 1 has a size facing the narrow side surface PN of each battery cell 1 disposed on one side and the other side in the stacking direction.

  The bottom wall portion 23 protrudes from the lower end portion in the cell height direction of the sandwiching wall portion 21 toward the one side and the other side in the stacking direction and extends over the cell width direction with a constant width. The battery cell 1 has a size opposed to the bottom surface PB of each battery cell 1 disposed on one side and the other side in the arrangement direction. The bottom wall portion 23 is provided with a notch 23 a for exposing the bottom surface PB of the battery cell 1 to face the bottom surface facing portion 51 of the base plate 5. The bottom surface PB of the battery cell 1 is in contact with the bottom surface facing portion 51 of the base plate 5 through the notch 23a.

  When the two cell holders 2 are arranged in combination, the pair of side wall portions 22 and the bottom wall portion 23 has one end in the arrangement direction facing the other end in the arrangement direction of the adjacent cell holders 2. The cell holders 2 are continuous with each other in the arrangement direction. The ends on the one side in the arrangement direction of the pair of side wall portions 22 and the bottom wall portion 23 are opposed to the ends on the other side in the arrangement direction of the cell holders 2 adjacent to each other in a direction orthogonal to the arrangement direction. Yes.

  The pair of side wall portions 22 are provided with a plurality of opening portions 22a communicating with the respective cutout portions 24 of the sandwiching wall portion 21, and for example, cooling gas is supplied to the opening portions 22a of the side wall portion 22 on one side in the cell width direction. From the opening 22a of the side wall 22 on the other side in the cell width direction. Yes. In the present embodiment, there is no structure for flowing cooling gas through the opening 22a and the notch 24.

FIG. 5 is an external perspective view illustrating a method for assembling the battery module according to the present embodiment.
The pair of side plates 4 are fixed to the base plate 5 by rivets 7, respectively. One end plate 3 is caulked and fixed to the side plate 4 in advance (the back side in FIG. 5). The cell holder 2 and the battery cell 1 are stacked by sliding in the direction of the arrow in FIG. 5 using the side plate 4 and the base plate 5 as guide members. Each battery cell 1 is inserted in the order in which the positive external terminal 13 and the negative external terminal 14 are alternately arranged in the sliding movement direction.

  After all the cell holders 2 and the battery cells 1 are inserted, the other end plate 3 is welded and fixed to the side plate 4 (front side in FIG. 5).

  Here, the fixing method of the end plate 3 that is first fixed to the side plate 4 is not limited to caulking, and can be fixed using screws, rivets, bolts, and the like. The fixing method of the other end plate 3 is not limited to welding, but can also be fixed using screws, rivets, bolts, etc. after caulking, pressure welding, or additional holes. The side plate 4 is fixed to the base plate 5 by rivets 7. However, the side plate 4 can be fixed using screws, rivets, bolts, or the like. The upper part of the side plate 4 is pressed in a light caulking manner, and a vertical load is applied to each cell holder 2 to fix it.

FIG. 6 is a side view showing a fitting structure between the side plate and the cell holder according to the present embodiment.
The battery cell 1 has a wide side surface PW facing the sandwiching wall portion 21 of the cell holder 2, a narrow side surface PN facing the side wall portion 22 of the cell holder 2, and a bottom surface PB facing the bottom wall portion 23 of the cell holder 2. The PU faces the upper wall portion 25 of the cell holder 2. Therefore, the cell holder 2 is held by the cell holder 2 in a state where movement in the stacking direction and the direction orthogonal to the stacking direction is restricted.

  In the cell holder 2, the side wall portion 22 faces the side surface facing portion 41 of the side plate 4, the bottom wall portion 23 faces the bottom surface facing portion 51 of the base plate 5, and the upper wall portion 25 faces the top surface facing portion 42 of the side plate 4. opposite. And the fitting convex part 26 provided in the upper wall part 25 of the cell holder 2 is fitted in the fitting concave part 43 provided in the upper surface opposing part 42 of the side plate 4. Therefore, the side plate 4 and the base plate 5 are supported so as to be movable along the stacking direction in a state where movement in the direction orthogonal to the stacking direction is restricted.

  In the present embodiment, the fitting portion between the cell holder 2 and the side plate 4 has an R-R fitting structure in which a fitting convex portion and a fitting concave portion having a semicircular cross section are combined. With this fitting structure, since the cell holder 2 can be positioned in the vertical and horizontal directions on the surface perpendicular to the stacking direction of the battery cells 1, the battery module 9 can be manufactured with good assemblability and high assembling accuracy. Therefore, the battery module 9 manufactured with this structure has a high vibration resistance. Further, since the cell holder 2 can be arranged at an arbitrary position in the stacking direction of the battery cells 1, even if the battery cells 1 have variations in tolerance, the cell holder 2 is fixed at the lashing position corresponding to the dimensions of each battery block 8, that is, lashing load. It can be bound.

  Furthermore, by pressing the upper part of the side plate 4 divided by the slits 44 in a light caulking manner, by applying a vertical load to each cell holder 2 and fixing it, the tolerance of the vertical dimension of each cell holder 2 is absorbed, and It can be secured with a load applied. A countless pattern can be applied to the fitting structure other than the RR fitting structure. Further, the fitting structure is not limited to two on the left and right, and a plurality of fitting structures may be provided.

  Although the side plate 4 is fixed to the base plate 5 with the rivets 7, the fixing method is not limited to this, and fixing by various methods such as screws and bolts is possible. Although one cooling pipe 6 is passed through the base plate 5, one that has been processed into a U shape or a B shape may be used, or a plurality may be used. It is not a thing. Although the side plate 4 is used in this embodiment, a guide member such as a metal band having a fitting structure may be used.

  As described above, according to the present embodiment, the cell holder 2 and the side plate 4 serving as the guide member have the R-R fitting structure, so that the cell holder 2 is slid with respect to the side plate 4 to be arbitrarily moved. Since it can be arranged at a position, it can be secured according to the dimensions of the battery block 8.

  Further, according to the present embodiment, since the side plate 4 serving as a guide member can be used for positioning the cell holder 2, it is possible to improve the assembling property and the assembling accuracy of the battery module 9 simultaneously with the securing according to the above-described dimensions. Thus, the battery module 9 having high vibration resistance can be manufactured.

  In the present embodiment, the battery module 9 has been described as having a cooling structure that includes only the cooling pipe 6 provided on the base plate 5, but the present invention is not limited to this. For example, as shown in FIG. 12, an opening hole 45 communicating with the opening 22a of the cell holder 2 is provided, cooling air is introduced into the cell holder 2 from the opening hole 45, and the cooling air passes between the battery cells 1. You may combine with the structure cooled and letting it cool.

  As described above, the present invention has been described according to the embodiments. However, the battery module of the present invention can be used as a vehicle-mounted battery module mounted on a hybrid vehicle using a motor as a drive source, a zero emission electric vehicle, or the like. Moreover, this invention does not limit the use of a battery module to the said use. The power supply device of the present invention can be used as a power storage system that charges and stores a battery with electric power generated by solar power generation or wind power generation, regardless of whether it is for home use, business use, or industrial use, or It can also be used as a power storage system that charges and stores a battery using late-night power at night, or as a power storage system that can be used outside the ground, such as a space station, spacecraft, or space base. Furthermore, the present invention can be applied as a power source for medical devices, construction machines, power storage systems, elevators, unmanned mobile vehicles, and the like as a power source for mobile bodies such as golf carts and turret cars as industrial applications.

[Second Embodiment]
Next, a second embodiment of the present invention will be described below with reference to FIGS.
FIG. 7 is an external perspective view for explaining a method of assembling the battery module according to the present embodiment, and FIG. 8 is a side view showing a fitting structure between the side plate and the spacer. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  What is characteristic in the present embodiment is that the fitting concave portion and the fitting convex portion are provided on the side surface facing portion 41 of the side plate 4 and the side wall portion 22 of the cell holder 2, and the slit 44 in the first embodiment is omitted. It is a structure.

  The fitting recess 41 </ b> A is provided in the side facing portions 41 of the pair of side plates 4. And the fitting convex part 22A is provided in the side wall part 22 of the cell holder 2, and it fits into the fitting concave part 41A. The fitting convex portion 22A has a tenon shape with a rectangular cross section extending across the sliding movement direction of the side wall portion 22, and the fitting concave portion 41A extends across the sliding movement direction of the side facing portion 41. Thus, it has a tenon groove shape with a rectangular cross section that fits into the fitting convex portion 22A.

  The fitting structure may be other than the tenon-groove fitting structure, such as an ant tenon-dent groove structure shown in FIG. 9 or a sickle tenon-sickle groove structure shown in FIG. Further, the relationship of the cell holder-side plate fitting structure shown in FIGS. 8, 9, and 10 may be reversed as shown in FIG. For example, a structure such as a groove-tenon structure shown in FIG. 11 is also possible.

  In the embodiment shown in FIG. 9, the fitting convex portion 22 </ b> B has a dovetail shape extending in the sliding movement direction of the side wall portion 22, and the fitting concave portion 41 </ b> B is slidably moved by the side facing portion 41. It has a dovetail shape with a rectangular cross section that extends over the direction and fits into the fitting convex portion 22B.

  In the embodiment shown in FIG. 10, the fitting convex portion 22 </ b> C has a sickle tenon shape extending over the sliding movement direction of the side wall portion 22, and the fitting concave portion 41 </ b> C is slidably moved by the side facing portion 41. It has a sickle groove shape with a rectangular cross section that extends in the direction and fits into the fitting convex portion 22C.

  In the embodiment shown in FIG. 11, the fitting recess 22 </ b> D has a tenon groove shape having a rectangular cross section extending over the sliding movement direction of the side wall portion 22, and the fitting protrusion 41 </ b> D is formed on the side facing portion 41. It has a tenon shape with a rectangular cross section extending in the sliding movement direction and fitted into the fitting recess 22D.

  By actively providing such a fitting structure, the cell holder 2 can be positioned in the vertical and horizontal directions of the surface perpendicular to the stacking direction of the battery cells with high accuracy, so that the assembly is good and the assembly accuracy is high. High battery module can be manufactured. Therefore, the battery module manufactured by these structures has a very high vibration resistance. Further, since the cell holder 2 can be arranged at an arbitrary position in the stacking direction of the battery cells 1, even if the battery cells 1 have variations in tolerance, the cell holder 2 is fixed at the lashing position corresponding to the dimensions of each battery block 8, that is, lashing load. It can be bound. Innumerable patterns other than those described above can be applied to the fitting structure. There may be a plurality of fitting structures.

  Although one cooling pipe 6 is passed through the base plate 5, one that has been processed into a U shape or a B shape may be used, or a plurality may be used. It is not a thing. Although the side plate 4 is used in this embodiment, a guide member such as a metal band having a fitting structure may be used.

  As described above, according to the present embodiment, the cell holder 2 and the side plate 4 serving as the guide member are positively engaged with the tenon-groove fitting portion, the ant tenon-ant groove fitting portion, the sickle tenon-sickle groove fitting. Since the cell holder 2 can be slid with respect to the side plate 4 and arranged at an arbitrary position by providing the portion, the groove-tenon fitting portion, and the like, the battery block 8 can be secured according to the dimensions. Moreover, according to this embodiment, since the side plate 4 used as a guide member can be used for positioning of the cell holder 2, it becomes possible to improve the assembling property and assembling accuracy of the battery module 9 at the same time as securing according to the above-described dimensions. The battery module 9 having very high vibration resistance can be produced.

  Although the present invention has been described with reference to the embodiments, the battery module of the present invention can be used as an in-vehicle battery module mounted on a hybrid vehicle using a motor as a drive source, a zero emission electric vehicle, or the like. Moreover, this invention does not limit the use of a battery module to the said use. The power supply device of the present invention can be used as a power storage system that charges and stores a battery with electric power generated by solar power generation or wind power generation, regardless of whether it is for home use, business use, or industrial use, or It can also be used as a power storage system that charges and stores a battery using late-night power at night, or as a power storage system that can be used outside the ground, such as a space station, spacecraft, or space base. Furthermore, the present invention can be applied as a power source for medical devices, construction machines, power storage systems, elevators, unmanned mobile vehicles, and the like as a power source for mobile bodies such as golf carts and turret cars as industrial applications.

1 Battery cell 2 Spacer (cell holder)
3 End plate 4 Side plate 5 Base plate 6 Cooling tube 7 Rivet 8 Battery block 9 Battery module 11 Battery can 12 Battery cover 13 Positive electrode external terminal 14 Negative electrode external terminal 15 Inlet 21 Nipping wall portion 22 Side wall portion 22a Opening portions 22A, 22B, 22C fitting convex part 22D fitting concave part 23 bottom wall part 24 notch part 25 upper wall part 26 fitting convex part 41 side facing part 41A, 41B, 41C fitting concave part 41D fitting convex part 42 upper surface opposing part 43 fitting Recess 44 Slit

Claims (2)

One surface of the external terminal is disposed, and a battery block that has a plurality stacked battery cells of prismatic and a side surface connected to said one surface of said external terminals are arranged,
A spacer disposed between the battery cells;
A battery module that includes a side plate that is engaged with the spacer and disposed on a side surface of the battery cell,
The engagement portion between the spacer and the side plate is provided along the stacking direction of the battery cells, faces the one surface where the external terminals of the battery cells are disposed, and is lateral to the external terminals. Has been placed,
The side plate has a facing portion that faces the one surface of the external terminals of the battery cells are arranged,
An engaging portion between the spacer and the side plate is provided on the spacer and protrudes in a direction away from the one surface. The engaging portion is provided on the facing portion of the side plate and faces the protruding portion. A recess that fits in a direction away from the one surface, extends in the stacking direction of the battery cells, and fits the projection.
Between the convex portion and the external terminal, a protruding portion protruding from the spacer toward the direction away from the one surface is disposed,
In the projecting direction of the projecting portion, an end portion of the opposing portion that is farthest from the one surface includes an end portion of the farthest the protruding portion from the one surface, and wherein arranged are possible between the one surface Battery module. The battery module according to claim 1 ,
The convex portion has a semicircular cross section, and the concave portion has a semicircular cross section.

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