JP7653294B2 - Battery pack - Google Patents

Description

The present invention relates to a battery pack.

Battery packs that are installed in vehicles such as forklifts and golf carts are known. For example, Patent Document 1 discloses a battery pack in which multiple lead-acid batteries are housed in an iron casing (storage case) and connected in series.

JP 2011-146222 A

Many vehicles equipped with assembled batteries are used outdoors, and there is a demand for the ability to drain water that seeps into the casing to the outside.

Therefore, the object of the present invention is to provide a battery pack that can discharge water that has entered the housing to the outside of the housing.

The battery pack according to one aspect of the present invention comprises a conductive housing having a first bottom and a first side standing from an edge of the first bottom, with an opening formed in the first bottom, a lead-acid battery having a second bottom and a second side standing from an edge of the second bottom, housed in the housing so that the second bottom faces the first bottom, and an insulating side spacer arranged between the outer periphery of a battery group consisting of a plurality of lead-acid batteries and the first side so as to contact the first side and the second side, a plurality of side spacers being provided along the first side, and a communication passage extending in a vertical direction perpendicular to the first bottom is formed by the gap between adjacent side spacers.

In a battery pack of this configuration, a communication passage extending vertically is formed by the gap between the side spacers arranged around the battery group. As a result, water that has entered the inside of the housing is guided to the bottom of the housing through the communication passage and is discharged to the outside of the housing through an opening formed in the bottom of the housing. As a result, water that has entered the inside of the housing can be discharged to the outside of the housing.

In a battery pack according to one aspect of the present invention, the side spacer may be formed with a gap extending in one direction, and the side spacer may be arranged so that the extension direction of the gap is along the vertical direction. In this configuration, in addition to the communication passage described above, a gap extending in the vertical direction is formed, so that water that penetrates inside the housing can be efficiently guided to the bottom of the housing.

In a battery pack according to one aspect of the present invention, the communication passage may be formed by a gap between a side spacer arranged in contact with one first side portion and a side spacer arranged in contact with the other first side portion at a corner of the housing where the first sides intersect. This configuration can prevent insufficient pressure being applied to the storage battery by the side spacers and improve ease of assembly.

The battery pack according to one aspect of the present invention includes a conductive housing having a first bottom and a first side standing from an edge of the first bottom, with an opening formed in the first bottom, a lead-acid battery having a second bottom and a second side standing from an edge of the second bottom, housed in the housing so that the second bottom faces the first bottom, and an insulating side spacer disposed between the outer periphery of a battery group consisting of a plurality of lead-acid batteries and the first side, and disposed so as to contact the first side and the second side, the side spacer having a gap formed therein that extends in one direction, and the side spacer disposed so that the extension direction of the gap is along the vertical direction.

In a battery pack of this configuration, a vertically extending gap is formed in the side spacer. This allows water that has entered the housing to be guided through the gap to the bottom of the housing and then discharged to the outside of the housing through an opening formed in the bottom of the housing. As a result, water that has entered the housing can be discharged to the outside of the housing.

In a battery pack according to one aspect of the present invention, the lead-acid battery has an upper surface on the opposite side of the second bottom in the vertical direction, and the upper end of the side spacer may be located vertically below the upper surface of the lead-acid battery. With this configuration, water that has entered the housing from outside can be prevented from accumulating on the upper surface of the lead-acid battery.

In the battery pack according to one aspect of the present invention, a water refill tap for refilling water into the lead-acid battery may be provided on the top surface of the lead-acid battery. In this configuration, water that spills during the refilling operation of refilling the lead-acid battery from the water refill tap can be efficiently drained to the outside of the housing without remaining on the top surface.

In the battery pack according to one aspect of the present invention, a gap may be provided between the lower end of the side spacer and the first bottom of the housing. In this configuration, water can be effectively guided from the communication passage or gap to the bottom of the housing.

In a battery pack according to one aspect of the present invention, the lead-acid batteries may have a chamfered portion between the second bottom and the second side, and a flow path may be formed by the space surrounded by the chamfered portion and the first bottom of each of the adjacent lead-acid batteries. In this configuration, water guided to the bottom of the housing can be guided in a desired direction.

In a battery pack according to one aspect of the present invention, the opening may be formed on the flow path. In this configuration, water guided to the bottom of the housing can be guided to the opening via the flow path. This allows water to be effectively discharged from the housing.

In a battery pack according to one aspect of the present invention, the openings may be formed to overlap the boundaries between adjacent lead-acid batteries in a plan view seen from the vertical direction. In this configuration, water that flows from above the lead-acid batteries to the bottom of the housing through the gaps between the lead-acid batteries can be discharged to the outside of the housing.

In a battery pack according to one aspect of the present invention, the battery group may have lead-acid batteries arranged in a first direction and a second direction that are mutually perpendicular in a plan view seen from the vertical direction, and the opening may be formed to overlap an intersection between a boundary between adjacent lead-acid batteries in the first direction and a boundary between adjacent lead-acid batteries in the second direction. In this configuration, the opening is formed in a location in the gap between the lead-acid batteries where water is likely to flow from above the lead-acid batteries to the bottom of the housing. This allows water to be more effectively discharged to the outside of the housing.

The battery pack according to one aspect of the present invention may have a fastening portion that fastens the side spacer to the housing. In this configuration, the fastening portion fixes the side spacer to the housing, so that the side spacer can be prevented from protruding from between the housing and the battery group. Therefore, it is possible to effectively prevent a short circuit between the inner surface of the housing and the storage battery included in the battery group.

In the battery pack according to one aspect of the present invention, the side spacer may have a plurality of insulating members stacked along a direction perpendicular to the first side of the housing with which the side spacer contacts. In this configuration, the side spacer can be formed, for example, by inserting a number of insulating members according to the size of the gap between the inner surface and the battery group. This makes it possible to manufacture many different types of battery packs even when the type of housing is limited.

In the battery pack according to one aspect of the present invention, the side spacer may have a fixing portion that fixes the multiple insulating members together. In this configuration, the insulating members do not protrude from between the housing and the battery group, so that the function as a side spacer can be well maintained.

According to the present invention, water that has entered the housing can be discharged to the outside of the housing.

FIG. 1 is a schematic plan view showing a battery pack according to an embodiment. FIG. 1 is a perspective view showing a battery pack according to an embodiment. FIG. 3 is a perspective view showing a part of the storage battery according to the embodiment in a cutaway state. 4(a) is a diagram showing the positive electrode as viewed from a first direction, and FIG. 4(b) is an enlarged cross-sectional view taken along line IVb-IVb in FIG. 4(a). FIG. 5 is a plan view showing the negative electrode according to the embodiment. FIG. 6 is a diagram showing the positional relationship between the side surface of the housing, the side spacer, and the storage battery when viewed from a first direction. 7(a) is a cross-sectional view of the flow channel taken along line VIIA-VIIA in FIG. 1, and FIG. 7(b) is a cross-sectional view of the flow channel taken along line VIIB-VIIB in FIG. FIG. 8A is a plan view of the housing showing the position of the opening, and FIG. 8B is a diagram showing the relationship between the opening and the position of the storage battery. 9(a), 9(b), 9(c), 9(d), 9(e) and 9(f) are diagrams showing cross-sectional configurations of side spacers according to modified examples. 10A, 10B, 10C, and 10D are diagrams showing cross-sectional configurations of side spacers according to modified examples. Fig. 11(a) is a diagram showing the relationship between the opening and the arrangement position of the storage battery according to a modified example, and Fig. 11(b) is a schematic plan view showing the battery pack according to a modified example. FIG. 12 is a schematic cross-sectional view of a side spacer according to a modified example.

A preferred embodiment of one aspect of the present disclosure will be described in detail below with reference to the attached drawings. In the following description, the same elements or elements having the same functions will be denoted by the same reference numerals, and duplicate descriptions will be omitted.

The battery pack 100 shown in Figures 1 and 2 is a battery pack having multiple cells of the same type, and is used, for example, as an automobile battery, the main power source for an electric vehicle (or electric vehicle) such as an electric forklift, and a backup power source to be used during a power outage. The battery pack 100 has a battery group 2 having multiple storage batteries 1, a housing 20, multiple side spacers 30, and a communication passage 40.

The housing 20 houses the battery group 2 and the side spacer 30. The housing 20 is formed of a conductive material. The housing 20 has a bottom (first bottom) 21, a side (first side) 22 standing along the edge of the bottom 21, and a reinforcing portion 25. The bottom 21 and the side 22 are each formed of, for example, a metal plate or an alloy plate, and are integrated with each other. The bottom 21 and the side 22 may be formed by processing a single metal plate or alloy plate, or may be integrated with each other by welding or the like. The side 22 has a first portion 22a, a second portion 22b, a third portion 22c, and a fourth portion 22d. In a plan view, the first portion 22a constitutes one end of the side portion 22 in the second direction Y, the second portion 22b constitutes the other end of the side portion 22 in the second direction Y, the third portion 22c constitutes one end of the side portion 22 in the first direction X, and the fourth portion 22d constitutes the other end of the side portion 22 in the first direction X.

In this embodiment, the bottom 21 has a rectangular shape in a plan view, and the side 22 has a square frame shape in a plan view, but is not limited to this. The bottom 21 may have a polygonal shape, a circular shape, or an elliptical shape in a plan view. Similarly, the side 22 may have a polygonal frame shape, a circular frame shape, or an elliptical frame shape in a plan view. In the following, the direction in which the short side of the bottom 21 extends is the first direction X, the direction in which the long side of the bottom 21 extends is the second direction Y, and the direction perpendicular to the first direction X and the second direction Y is the third direction Z. In this embodiment, the third direction Z corresponds to the up-down direction (vertical direction), and viewing from the third direction Z corresponds to viewing from the plan view.

The reinforcing portion 25 extends along the first direction X in a plan view. The reinforcing portion 25 extends from the third portion 22c to the fourth portion 22d of the side portion 22, and is integrated with the side portion 22. One end of the reinforcing portion 25 in the first direction X contacts the third portion 22c, and the other end of the reinforcing portion 25 in the first direction X contacts the fourth portion 22d. The reinforcing portion 113 is welded to each of the third portion 22c and the fourth portion 22d of the side portion 22, for example. Note that the reinforcing portion 25 does not have to be provided as a part of the housing 20.

The battery group 2 is composed of a plurality of storage batteries 1 housed in the housing 20. In this embodiment, the battery group 2 is composed of a total of 24 storage batteries 1. In addition to the plurality of storage batteries 1, the battery group 2 has a plurality of internal connection members 101 and external connection members 102, 103 for connecting to an external device. Each of the plurality of internal connection members 101 is a member for electrically connecting adjacent storage batteries 1 to each other. The internal connection member 101 has, for example, a conductive part connected to both adjacent storage batteries 1 and a protective part for protecting the conductive part. In this embodiment, by using the plurality of internal connection members 101, the plurality of storage batteries 1 included in the battery group 2 are connected in series to each other, but this is not limited to this. The plurality of storage batteries 1 may be connected in parallel to each other. In addition, the battery group 2 may be connected in series and in parallel. The external connection member 102 is located on one side of the first direction X, and the external connection member 103 is located on the other side of the first direction X. In addition, the external connection members 102, 103 are located on one side of the second direction Y.

The structure of the storage battery 1 will now be described in detail with reference to Figures 3 to 5. As shown in Figure 3, the storage battery 1 is, for example, a lead-acid battery. In this embodiment, the storage battery 1 is, for example, a clad-type lead-acid battery equipped with clad-type electrodes. The storage battery 1 includes an electrode group 3, a positive electrode terminal 5A, a negative electrode terminal 5B, a water supply tap 6, and a case 7. The case 7 includes a body 8 and a lid 9.

The main body 8 is a battery container formed into a cylindrical shape with a bottom. The main body 8 is formed of a material such as polypropylene. The main body 8 contains the electrode group 3 and the electrolyte. The main body 8 has a bottom (second bottom) 8a and four side parts (second side parts) 8b standing upright from the edge of the bottom 8a. The storage battery 1 is contained in the housing 20 so that the bottom 8a of the main body 8 and the bottom 21 of the housing 20 are in contact (facing each other).

The lid 9 covers the opening of the body 8 and constitutes the top surface of the storage battery 1. The lid 9 is provided with a positive electrode terminal 5A, a negative electrode terminal 5B, and a water refill tap 6. In the battery group 2, the positive electrode terminal 5A and the negative electrode terminal 5B are each covered with either an internal connection member 101, an external connection member 102, or an external connection member 103 (see Figures 1 and 2). The water refill tap 6 is provided between the positive electrode terminal 5A and the negative electrode terminal 5B.

The electrode group 3 is an assembly of multiple electrode plates, and has multiple positive electrodes 10, multiple negative electrodes 12, and multiple separators 13. In the electrode group 3, the positive electrodes 10 and the negative electrodes 12 are arranged alternately. The separator 13 is located between adjacent positive electrodes 10 and negative electrodes 12. Therefore, the positive electrodes 10, the separator 13, and the negative electrodes 12 are stacked in order in a predetermined direction. In this embodiment, the negative electrodes 12 are arranged at the ends of the arrangement direction of the positive electrodes 10, the negative electrodes 12, and the separators 13 in the electrode group 3 (hereinafter, sometimes simply referred to as the "arrangement direction" or the "stacking direction"). In addition, the assembly of the positive electrodes 10, the negative electrodes 12, and the separators 13 is also referred to as a battery electrode group (electrode plate group). When the electrode group 3 and the electrolyte are accommodated in the main body 8, the electrolyte is present in the gap between the positive electrodes 10 and the separators 13, in the separators 13, etc. The arrangement direction (stacking direction) corresponds to the first direction X.

As shown in Fig. 3, Fig. 4(a) and Fig. 4(b), the positive electrode 10 is, for example, a clad type positive electrode plate. In the storage battery 1, each positive electrode 10 is electrically connected to a positive electrode terminal 5A. Each positive electrode 10 and the positive electrode terminal 5A are electrically connected by a positive electrode strap 17. The positive electrode 10 has a current collector 14, a plurality of cylindrical bodies 15 (tubes) that house a part of the current collector 14, a positive electrode material 16 housed in the cylindrical bodies 15, and an upper link 19A and a lower link 19B that are attached to the current collector 14.

The current collector 14 has a number of cores 14a, a connecting portion that connects the multiple cores 14a, and ears 14c that protrude from the connecting portion. The current collector 14 is formed, for example, by casting. The constituent material of the current collector 14 may be any conductive material, such as a lead alloy such as a lead-calcium-tin alloy or a lead-antimony-arsenic alloy. The lead alloy may contain selenium, silver, bismuth, etc.

The multiple core metals 14a are rod-shaped portions extending along the third direction Z and are arranged in a row along the second direction Y. One end of each core metal 14a in the third direction Z is connected to a connecting portion (not shown) covered by the upper linking seat 19A. The other end of each core metal 14a in the third direction Z is fixed to the lower linking seat 19B. The length of each core metal 14a is, for example, 170 to 650 mm. The length of each core metal 14a may be 600 mm or less, or 450 mm or less. The connecting portion is a portion that supports the core metal 14a and the ear portion 14c, and extends along the second direction Y. When the positive electrode 10 is housed in the case 7, the connecting portion is arranged on the positive electrode terminal 5A side in the third direction Z. The ear portion 14c is a terminal portion that protrudes from the connecting portion in the third direction Z and is connected to the positive electrode strap 17. In the third direction Z, the protruding direction of the ear 14c is opposite to the protruding direction of the core metal 14a. When the positive electrode 10 is housed in the case 7, the ear 14c is located on the lid 9 side in the third direction Z.

The multiple cylindrical bodies 15 are insulating members that constitute a group of tubes (clad tubes) for holding active material. The group of tubes for holding active material is a collection of cylindrical porous tubes also known as "gauntlets." For this reason, multiple holes are provided in each cylindrical body 15. In this embodiment, the thickness of the cylindrical bodies 15 is uniform, but this is not limited to this. Each cylindrical body 15 extends along the third direction Z and houses a corresponding core metal 14a. Each cylindrical body 15 is, for example, a resin molded product.

The positive electrode material 16 is filled inside the cylindrical body 15 together with the metal core 14a. Therefore, the metal core 14a and the positive electrode material 16 are housed in the cylindrical body 15. As shown in FIG. 4B, the positive electrode material 16 surrounds the metal core 14a inside the cylindrical body 15. The positive electrode material 16 includes an active material. The active material includes both the active material after chemical formation and the raw material of the active material before chemical formation. The positive electrode material 16 includes the active material after chemical formation. The positive electrode material 16 after chemical formation includes, for example, the raw material of the positive electrode active material. In this embodiment, the positive electrode material 16 may include a positive electrode active material and an additive. The positive electrode active material is, for example, lead powder, red lead, or the like. Examples of the additive include a carbon material or short reinforcing fibers. The positive electrode active material after chemical formation is, for example, lead dioxide, or the like.

The upper linking seat 19A is an insulating structure attached to the connecting portion of the current collector 14, and covers the connecting portion when viewed from the third direction Z. The upper linking seat 19A seals one end of each cylindrical body 15 in the third direction Z. For example, the upper linking seat 19A is welded to each cylindrical body 15, but this is not limited to this. The upper linking seat 19A and each cylindrical body 15 may be fixed to each other, for example, via an adhesive or the like. The upper linking seat 19A is provided, for example, by welding an insulating resin member to the current collector 14. The lower linking seat 19B is an insulating structure attached to the multiple core metals 14a of the current collector 14. The lower linking seat 19B is attached to the current collector 14, for example, by inserting and fitting the core metal 14a of the current collector 14 into an insulating resin member. The lower linking seat 19B seals the other end of each cylindrical body 15 in the third direction Z. As a result, the position of each cylindrical body 15 in the positive electrode 10 is fixed by the upper linking seat 19A and the lower linking seat 19B. For example, the lower linking seat 19B is welded to each cylindrical body 15, but this is not limited to this. The lower linking seat 19B and each cylindrical body 15 may be fixed to each other by, for example, an adhesive or the like.

As shown in FIG. 4, the negative electrode 12 is a negative electrode plate in the storage battery 1 and is electrically connected to the negative electrode terminal 5B. Each negative electrode 12 and the negative electrode terminal 5B are electrically connected by a negative electrode strap 18. The negative electrode 12 has a current collector 12a and a negative electrode material 12b. The current collector 12a is formed, for example, by casting, and has a negative electrode grid 12c and an ear portion 12d. The negative electrode grid 12c is a main body portion of the negative electrode 12 and holds the negative electrode material 12b. In this embodiment, the thickness of the portion of the negative electrode 12 where the negative electrode material 12b is held is greater than the thickness of the negative electrode grid 12c, but is not limited to this. The negative electrode material 12b may contain a negative electrode active material and an additive. The negative electrode active material is, for example, sponge-like lead. Examples of additives include barium sulfate, carbon material, lignin, or short reinforcing fibers.

The ear 12d is a terminal portion that protrudes from the negative electrode grid 12c along the third direction Z and is connected to the negative electrode strap 18. The ear 12d and the negative electrode grid 12c do not overlap each other in the first direction X. In this embodiment, the negative electrode grid 12c is covered by the separator 13. The negative electrode grid 12c is provided with protrusions 12e and 12f. The protrusions 12e and 12f are arranged at a predetermined interval and are legs that protrude outward from the negative electrode grid 12c. The protrusions 12e and 12f protrude in a direction opposite to the protrusion direction of the ear 12d. In this embodiment, the protrusion direction of the ear 12d and the protrusion direction of the protrusions 12e and 12f are each perpendicular to the arrangement direction. In addition, the ear 12d and the negative electrode grid 12c do not overlap each other in the arrangement direction.

Returning to FIG. 3, the separator 13 is a battery component (battery separator) for preventing a short circuit between the positive electrode 10 and the negative electrode 12. The separator 13 is not particularly limited as long as it electrically insulates the positive electrode 10 and the negative electrode 12 while allowing ions to pass therethrough and is resistant to oxidation on the positive electrode 10 side and reduction on the negative electrode 12 side. Examples of materials for the separator 13 include glass fiber, resin, and inorganic substances. In this embodiment, the separator 13 covers the negative electrode grid 12c and the protruding portions 12e and 12f of the negative electrode 12, and the ear portion 12d of the negative electrode 12 is exposed from the separator 13.

When viewed from the first direction X, the aspect ratio of the dimension of the separator 13 along the second direction Y to the dimension of the separator 13 along the third direction Z is, for example, 1.4 or more and 4.0 or less. The aspect ratio may be 1.5 or more and 3.8 or less, 1.8 or more and 3.5 or less, or 2.0 or more and 3.0 or less. At least one of the front surface and the inner surface of the separator 13 may be provided with a rib. When viewed from the thickness direction of the separator 13, the rib may extend in a straight line, a wavy line, or a zigzag shape. When viewed from the thickness direction, the rib may be dot-shaped, circular, elliptical, or polygonal.

Returning to Figures 1 and 2, the side spacer 30 is an insulating member that is arranged between the side 22 of the housing 20 and the outer periphery of the battery group 2 in a plan view, and is arranged so as to contact the side 22 of the housing 20 and the side 8b of the storage battery 1. The side spacer 30 is a plate-like member having a substantially rectangular parallelepiped shape. The side spacer 30 is, for example, a resin molded body such as polypropylene or polyvinyl chloride. The side spacer 30 may be deformable in its thickness direction. In this case, the side spacer 30 can be compressed by the housing 20 and the battery group 2.

A plurality of side spacers 30 are provided along the side portion 22 that forms the inner peripheral surface of the housing 20. In this embodiment, four side spacers 30 (first side spacer 31, second side spacer 32, third side spacer 33, and fourth side spacer 34) are arranged to correspond to the first portion 22a, second portion 22b, third portion 22c, and fourth portion 22d that respectively constitute the side portion 22.

In this embodiment, the side spacer 30 is fixed to the side 22 of the housing 20 via a fixing portion (not shown). The fixing portion is made of a material (adhesive material) that can adhere to both the side spacer 30 and the housing 20, such as an organic adhesive.

The first side spacer 31 extends along the first direction X in plan view and contacts the first portion 22a of the side portion 22. At least a portion of the first side spacer 31 is fixed to the first portion 22a via the fixing portion. One end of the first side spacer 31 in the first direction X has a gap between it and the third side spacer 33, and the other end of the first side spacer 31 in the first direction X contacts the fourth side spacer 34. The second side spacer 32 extends along the first direction X in plan view and contacts the second portion 22b of the side portion 22. At least a portion of the second side spacer 32 is fixed to the second portion 22b via the fixing portion. One end of the second side spacer 32 in the first direction X contacts the third side spacer 33, and the other end of the second side spacer 32 in the first direction X has a gap between it and the fourth side spacer 34.

The third side spacer 33 extends along the second direction Y in plan view and contacts the third portion 22c of the side portion 22. At least a portion of the third side spacer 33 is fixed to the third portion 22c via the fixing portion. One end of the third side spacer 33 in the second direction Y has a gap between it and the first side spacer 31, and the other end of the third side spacer 33 in the second direction Y contacts the second side spacer 32. The fourth side spacer 34 extends along the second direction Y in plan view and contacts the fourth portion 22d of the side portion 22. At least a portion of the fourth side spacer 34 is fixed to the fourth portion 22d via the fixing portion. One end of the fourth side spacer 34 in the second direction Y contacts the first side spacer 31, and the other end of the fourth side spacer 34 in the second direction Y has a gap between it and the second side spacer 32.

As shown in FIG. 6, a gap is provided between the lower end of the side spacer 30 and the bottom 21. That is, the lower end of the side spacer 30 and the bottom 21 of the housing 20 are not in contact. The gap between the lower end of the side spacer 30 and the bottom 21 forms a flow path 42 for water that has entered the housing 20. The upper end of the side spacer 30 is located below the upper surface 9a of the lid 9 of the storage battery 1. The recess formed by the upper end of the side spacer 30, the side 22 of the housing 20, and the side 8b of the storage battery 1 forms a flow path 41 for water that has entered the housing 20.

The thickness of the first side spacer 31 and the second side spacer 32 corresponds to the dimension of the first side spacer 31 and the second side spacer 32 along the second direction Y. The thickness of the third side spacer 33 and the fourth side spacer 34 corresponds to the dimension of the third side spacer 33 and the fourth side spacer 34 along the first direction X. The thicknesses of the first side spacer 31 to the fourth side spacer 34 may be the same or different. Among the first side spacer 31 to the fourth side spacer 34, the thickness of some of the side spacers 30 may be the same. The height of the first side spacer 31 to the fourth side spacer 34 corresponds to the dimension of the first side spacer 31 to the fourth side spacer 34 along the third direction Z. The heights of the first side spacer 31 to the fourth side spacer 34 may also be the same or different. Among the first side spacer 31 to the fourth side spacer 34, the height of some of the side spacers 30 may be the same. That is, the thickness and height of the side spacers 30 may be uniform or non-uniform.

As shown in FIG. 1, the communication passage 40 is formed by the gap between the adjacent side spacers 30, 30, and extends along the vertical direction. In this embodiment, two communication passages 40, 40 are formed. One communication passage 40 is formed by the gap between the first side spacer 31 and the third side spacer 33. More specifically, it is formed by a space surrounded by one end of the first side spacer 31 in the first direction X, the other end of the third side spacer 33 in the second direction Y, the first part 22a of the side portion 22, and the third part 22c of the side portion 22. The other communication passage 40 is formed by the gap between the second side spacer 32 and the fourth side spacer 34. More specifically, it is formed by a space surrounded by the other end of the second side spacer 32 in the first direction X, one end of the fourth side spacer 34 in the second direction Y, the second part 22b of the side portion 22, and the fourth part 22d of the side portion 22. The two communication passages 40 are formed in diagonally opposite corners of the housing 20.

As shown in FIG. 7(a) and FIG. 7(b), a chamfered portion 8c is formed between the bottom portion 8a and the side portion 8b of the main body 8 of the storage battery 1. The chamfered portion 8c in this embodiment is formed by R-chamfering. An example of the processing radius of the chamfered portion 8c is 3 mm to 10 mm. As shown in FIG. 7(a), a flow path Cy extending in the second direction Y is formed by a space S surrounded by the chamfered portions 8c, 8c of the storage batteries 1, 1 adjacent to each other in the first direction X and the bottom portion 21 of the housing 20. Also, as shown in FIG. 7(b), a flow path Cx extending in the first direction X is formed by a space S surrounded by the chamfered portions 8c, 8c of the storage batteries 1, 1 adjacent to each other in the second direction Y and the bottom portion 21 of the housing 20.

Between the multiple storage batteries 1 constituting the battery group 2 and the bottom 21 of the housing 20, an intersection Cz is formed where a flow path Cx extending in the first direction X and a flow path Cy extending in the second direction Y intersect. As shown in FIG. 8(a), two openings 21a, 21b are formed in the bottom 21 of the housing 20. As shown in FIG. 8(b), the two openings 21a, 21b are formed at positions that coincide with the intersection Cz of the flow path Cx and the flow path Cy formed between the storage battery 1 and the bottom 21 when the storage battery 1 is accommodated in the housing 20.

The effects of the battery pack 100 of the above embodiment will be described. In the battery pack 100 of the above embodiment, a communication passage 40 extending along the third direction Z is formed by the gap between the side spacers 30, 30 arranged around the battery group 2. As a result, water that has entered the inside of the housing 20 is guided through the communication passage 40 to the bottom 21 of the housing 20 and is discharged to the outside of the housing 20 through the openings 21a, 21b formed in the bottom 21 of the housing 20. As a result, water that has entered the inside of the housing 20 can be discharged to the outside of the housing 20.

In the battery pack 100 of the above embodiment, the communication passage 40 is provided at the corner of the housing 20 where the side portions 22 of the housing 20 intersect. This configuration can prevent insufficient pressure from being applied to the storage battery 1 by the side spacers 30 and can improve assembly.

In the battery pack 100 of the above embodiment, as shown in FIG. 6, the upper end of the side spacer 30 is located vertically below the upper surface 9a of the lid 9 of the storage battery 1. This makes it possible to prevent water that has entered from outside the housing 20 from accumulating on the upper surface 9a of the lid 9 of the storage battery 1. A water refilling tap 6 for refilling water into the storage battery 1 is provided on the upper surface 9a of the lid 9 of the storage battery 1 of the above embodiment, and the water refilling work is performed by an operator from the water refilling tap 6. With this configuration, water that spills during the refilling work can be efficiently discharged to the outside of the housing 20 without remaining on the upper surface 9a of the lid 9.

In the battery pack 100 of the above embodiment, as shown in FIG. 6, a gap is provided between the lower end of the side spacer 30 and the bottom 21 of the housing 20, so that water can be effectively guided from the above-mentioned communication passage 40 to the bottom 21 of the housing 20. In addition, the flow path 42 formed by the gap between the lower end of the side spacer 30 and the bottom 21 can guide water that has entered the housing 20 to a desired location.

In the battery pack 100 of the above embodiment, as shown in Figures 7(a) and 7(b), flow paths Cx, Cy are formed by the space S surrounded by the chamfered portions 8c, 8c of the adjacent storage batteries 1, 1 and the bottom 21, so that water guided to the bottom 21 of the housing 20 can be guided in the desired direction.

In the battery pack 100 of the above embodiment, as shown in Figs. 8(a) and 8(b), the openings 21a and 21b are formed on the flow paths Cx and Cy. As a result, water guided to the bottom 21 of the housing 20 is guided to the openings 21a and 21b via the flow paths Cx and Cy, so that the water can be effectively discharged to the outside of the housing 20.

In the battery pack 100 of the above embodiment, as shown in FIG. 8(b), the openings 21a and 21b are formed so as to overlap the boundary B between the adjacent storage batteries 1, 1 in a plan view. This allows water flowing from above the storage batteries 1 to the bottom 21 of the housing 20 through the gap between the storage batteries 1, 1 to be discharged to the outside of the housing 20. In addition, in the battery pack 100 of the above embodiment, the storage batteries 1 are arranged in the first direction X and the second direction Y that are perpendicular to each other in a plan view in the battery group 2, and the openings 21a and 21b are formed so as to overlap the intersection Cz between the boundary B between the storage batteries 1, 1 adjacent to each other in the first direction X and the boundary B between the storage batteries 1, 1 adjacent to each other in the second direction Y. As a result, the openings 21a and 21b are formed at the locations where water is likely to flow from above the storage batteries 1 to the bottom 21 of the housing 20, even among the gaps between the storage batteries 1, 1. As a result, water can be more effectively discharged outside the housing 20.

In the battery pack 100 of the above embodiment, the side spacer 30 is fixed to the housing 20 by the fastening portion, so that the side spacer 30 can be prevented from protruding from between the housing 20 and the battery group 2. Therefore, it is possible to effectively prevent a short circuit between the inner surface of the housing 20 and the storage battery 1 included in the battery group 2.

Although one embodiment has been described above, the present invention is not limited to the above embodiment. Various modifications are possible without departing from the spirit of the invention.

In the battery pack 100 of the above embodiment, an example was given in which the gaps between the side spacers 30, 30 arranged around the battery group 2 form a communication passage 40 extending along the third direction Z. However, instead of or in addition to this communication passage 40, side spacers 30A to 30J in which gaps G extending along one direction are formed as shown in Figures 9(a), 9(b), 9(c), 9(d), 9(e), 9(f), 10(a), 10(b), 10(c), and 10(d) may be arranged so that the extension direction of the gap G is along the vertical direction.

The side spacer 30A shown in FIG. 9(a) will be described. The side spacer 30A has a pair of first and second surfaces 35 and 36 facing each other, and a plurality of ribs 37 arranged between the first and second surfaces 35 and 36. Each of the first and second surfaces 35 and 36 is plate-shaped. The first and second surfaces 35 and 36 are formed, for example, in a rectangular shape (rectangular shape). It is preferable that the first and second surfaces 35 and 36 are formed according to the shape of the side portion 22 of the housing 20. The first and second surfaces 35 and 36 are spaced apart at a predetermined interval. In the side spacer 30A, a gap G is formed by the pair of first and second surfaces 35 and 36. Each of the ribs 37 is arranged at a predetermined interval. Each of the ribs 37 is inclined at a predetermined angle θ with respect to the first and second surfaces 35 and 36.

Examples of side spacers having a gap G extending in one direction are not limited to side spacer 30A, but may be, for example, side spacers 30B to 30F shown below. As shown in FIG. 9(b), side spacer 30B has ribs 37 perpendicular to first surface 35 and second surface 36. As shown in FIG. 9(c), side spacer 30C has first surface 35 and second surface 36, and side portions 38, 38 connecting both ends of first surface 35 and second surface 36. That is, side spacer 30C may be cylindrical. As shown in FIG. 9(d), side spacer 30D has a gap G formed by first surface 35, second surface 36, and rib 37 in a triangular shape. As shown in FIG. 9(e), side spacer 30E has a gap G formed by rib 37 in a circular shape. As shown in FIG. 9(f), side spacer 30F has a gap G formed only in a part of the cross section.

Further examples of side spacers having a gap G extending in one direction may include, for example, side spacers 30G to 30J shown below. As shown in FIG. 10(a), side spacer 30G is a plate-shaped member having a corrugated (bellows-like) cross section. As shown in FIG. 10(b), side spacer 30H is a member having cross-shaped sections arranged in a row. As shown in FIG. 10(c), side spacer 30I is a member having a corrugated (rectangular wave) cross section. As shown in FIG. 10(d), side spacer 30J is a member having circular cross sections arranged in a row.

In the above embodiment and modified example, the communication passage 40 and the gap G are described as extending along the third direction Z, which is a substantially vertical direction, but as long as the communication passage 40 or the gap G communicates from above to below, it may extend in an oblique direction intersecting the vertical direction. Even in this case, water that has entered the housing 20 can be guided from above to below the housing 20.

In the battery pack 100 of the above embodiment, as shown in FIG. 1, an example was given in which the communication passage 40 is formed in the corner of the housing 20, but instead of or in addition to this configuration, as shown in FIG. 11(a), the communication passage 40 may be provided in the center of the side portion 22 in the first direction X and the second direction Y. In this case, the communication passage 40 is formed by a gap formed between the side spacers 30, 30, two of which are provided in each of the first portion 22a to the fourth portion 22d of the side portion 22.

As shown in FIG. 6, the upper end of the side spacer 30 in the above embodiment and modified example is described as being located below the upper surface 9a of the lid 9 of the storage battery 1, but it may be configured to be at the same height as the upper surface 9a of the lid 9 of the storage battery 1, i.e., flush with the upper surface 9a of the lid 9. The upper end of the side spacer 30 may also be located above the upper surface 9a of the lid 9 of the storage battery 1. Even in this case, water that has entered the upper part of the housing 20 can be guided to the bottom 21 of the housing 20.

In the above embodiment and modified example, as shown in Fig. 7(a) and Fig. 7(b), an example was given in which a chamfered portion 8c with R-chamfering is formed between the bottom portion 8a and the side portion 8b of the main body 8 of the storage battery 1, but C-chamfering may be performed instead of R-chamfering.

In the above embodiment and modified example, as shown in FIG. 8(b), the two openings 21a, 21b are formed at a position that coincides with the intersection Cz of the flow path Cx and the flow path Cy when the storage battery 1 is housed in the housing 20. However, as shown in FIG. 11(b), for example, they may be arranged on the flow path Cy, or, although not shown, they may be arranged on the flow path Cx. The openings may also be arranged directly below the side spacer 30. In other words, the openings may be arranged on the flow path 42. The number of openings provided in the bottom 21 of the housing 20 may be one, or three or more.

In the above embodiment and modified example, as shown in FIG. 1, one side spacer 30 made of an insulating material is disposed between the battery group 2 and the side 22 of the housing 20. However, as shown in FIG. 12, the side spacer 30 may be configured to include a plurality of insulating members 130 stacked along a direction perpendicular to the side 22 of the housing 20 with which the side spacer 30 contacts. In this configuration, the side spacer 30 can be formed by inserting, for example, a number of insulating members 130 according to the size of the gap between the side 22 of the housing 20 and the battery group 2. This allows many types of battery packs 100 to be manufactured even when the type of housing 20 is limited.

In this case, the side spacer 30 may have a fixing portion 141 that fixes the multiple insulating members 130 together. In this configuration, the insulating members 130 do not protrude from between the housing 20 and the battery group 2, so that the function of the side spacer 30 can be well maintained.

1...storage battery (lead storage battery), 2...battery group, 6...water supply valve, 8a...bottom (second bottom), 8b...side (second side), 8c...chamfered portion, 9...lid, 9a...top, 20...housing, 21...bottom (first bottom), 21a, 21b...opening, 22...side (first side), 30 (30A-30J)...side spacer, 31...first side spacer, 32...second side spacer, 33...third side spacer, 34...fourth side spacer, 40...connecting passage, 100...battery assembly, 141...fixing portion, G...gap.

Claims (14)

a conductive housing having a first bottom and a first side portion standing upright from an edge of the first bottom, the first bottom having an opening;
A lead-acid battery having a second bottom and a second side portion standing upright from an edge of the second bottom, the lead-acid battery being accommodated in the housing such that the second bottom faces the first bottom;
an insulating side spacer that is disposed between an outer periphery of a battery group consisting of a plurality of the lead-acid batteries and the first side portion and that is disposed so as to be in contact with the first side portion and the second side portion;
The side spacer is provided in plurality along the first side portion,
a communication passage extending along a vertical direction perpendicular to the first bottom portion is formed by a gap between the adjacent side spacers. The side spacer has a gap extending in one direction,
The battery pack according to claim 1 , wherein the side spacers are disposed such that the extending direction of the gap is aligned vertically. The battery pack according to claim 1 or 2, wherein the communication passage is formed by a gap between the side spacer arranged in contact with one of the first sides and the side spacer arranged in contact with the other first side at a corner of the housing where the first sides intersect. a conductive housing having a first bottom and a first side portion extending from an edge of the first bottom, the first bottom having an opening;
A lead-acid battery having a second bottom and a second side portion standing upright from an edge of the second bottom, the lead-acid battery being accommodated in the housing such that the second bottom faces the first bottom;
an insulating side spacer that is disposed between an outer periphery of a battery group consisting of a plurality of the lead-acid batteries and the first side portion and that is disposed so as to be in contact with the first side portion and the second side portion;
The side spacer has a gap extending in one direction,
The side spacers are arranged such that the extension direction of the gap is along the vertical direction. The lead-acid battery has an upper surface opposite to the second bottom in a vertical direction,
5. The battery pack according to claim 1, wherein an upper end of the side spacer is located vertically below the upper surface of the lead-acid battery. The battery pack according to claim 5, wherein a water supply tap for refilling water into the lead-acid battery is provided on the top surface of the lead-acid battery. The battery pack according to any one of claims 1 to 6, wherein a gap is provided between the lower end of the side spacer and the first bottom of the housing. the lead-acid battery has a chamfered portion between the second bottom portion and the second side portion,
The battery pack according to any one of claims 1 to 7, wherein a flow path is formed by a space surrounded by the chamfered portion and the first bottom of each of the lead-acid batteries adjacent to each other. The battery pack according to claim 8, wherein the opening is formed on the flow path. The battery pack according to any one of claims 1 to 9, wherein the opening is formed so as to overlap the boundary between adjacent lead-acid batteries in a plan view seen from the vertical direction. In the battery group, the lead-acid batteries are arranged in a first direction and a second direction perpendicular to each other in a plan view seen from a vertical direction,
The opening is formed so as to overlap an intersection between a boundary portion between the lead-acid batteries adjacent to each other in the first direction and a boundary portion between the lead-acid batteries adjacent to each other in the second direction. The battery pack according to any one of claims 1 to 10. The battery pack according to any one of claims 1 to 11, comprising a fastening portion for fastening the side spacer to the housing. The battery pack according to any one of claims 1 to 12, wherein the side spacer has a plurality of insulating members stacked along a direction perpendicular to the first side of the housing with which the side spacer is in contact. The battery pack according to claim 13, wherein the side spacer has a fixing portion that fixes the insulating members together.

Images