Power storage device

Abstract

To provide a power storage device that can prevent the power storage device from becoming large due to the structure of a portion where an end plate and a band are connected.SOLUTION: A power storage device 100 includes a plurality of storage cells 10 arranged in the X direction, end plates 20a and 20b that sandwich the plurality of storage cells 10 in the X direction, and a band 30. The band 30 includes a band main body 31 and a contact plate 32 provided at an end of the band main body 31 in the X direction. A protrusion 33 and a protrusion 34 are formed on one end and the other end of the contact plate 32 in the Y direction, respectively. A recess 25 that fits with the protrusion 33 and a recess 26 that fits with the protrusion 34 are formed on the end plate 20a.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2013-069657 (Patent Document 1) discloses an energy storage device including a plurality of energy storage elements arranged side by side in a predetermined direction, a pair of end plates sandwiching the plurality of energy storage elements in the predetermined direction, and a connecting member extending in the predetermined direction and connecting the pair of end plates. Patent Document 1 describes an example in which the end plates and the connecting member are fastened together with rivets. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-069657 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above Patent Document 1, an example is described in which the end plates and the connecting members (bands) are fastened with rivets, as described above. In this case, space is required to arrange the rivets, which may result in an increase in the size of the electricity storage device.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide an energy storage device that can prevent the energy storage device from becoming larger due to the structure of the part where the end plate and the band are connected. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present disclosure includes a plurality of energy storage cells arranged in an arrangement direction, first and second end plates that sandwich the plurality of energy storage cells in the arrangement direction, and a band that connects the plurality of energy storage cells, the first end plate, and the second end plate. The band includes a band main body that extends in the arrangement direction along the plurality of energy storage cells, and a connection portion provided at an end of the band main body in the arrangement direction. The connection portion is formed to extend in a transverse direction that intersects the arrangement direction. A first fitting portion and a second fitting portion are formed at one end and the other end of the connection portion in the transverse direction, respectively. The first end plate is formed with a first fitted portion that fits with the first fitting portion and a second fitted portion that fits with the second fitting portion.

[0007] In the energy storage device according to one aspect of the present disclosure, as described above, the first and second fitting portions are formed at one and the other ends of the connection portion in the transverse direction, respectively, and the first end plate is formed with a first fitted portion that fits with the first fitting portion and a second fitted portion that fits with the second fitting portion. This allows the band to be fixed to the end plate by fitting the connection portion to the end plate. Therefore, the band can be fixed to the end plate without using rivets or the like. As a result, it is possible to prevent the energy storage device from becoming larger due to the structure of the portion where the end plate and the band are connected. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to prevent the size of the electricity storage device from increasing due to the structure of the portion where the end plate and the band are connected. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic perspective view showing a configuration of an electricity storage device according to an embodiment; [Figure 2] FIG. 2 is a partially enlarged perspective view showing a configuration in the vicinity of a contact plate according to an embodiment. [Figure 3]FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. [Figure 5] FIG. 10 is a perspective view showing a configuration of an end plate according to a first modified example of the embodiment. [Figure 6] FIG. 10 is a cross-sectional view showing the configuration of an end plate and a contact plate according to a second modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0011] An electricity storage device 100 according to an embodiment of the present disclosure will be described with reference to Figs. 1 to 4. Fig. 1 is a schematic exploded perspective view showing the configuration of the electricity storage device 100 according to this embodiment. The electricity storage device 100 is mounted, for example, in a hybrid electric vehicle (Hybrid Electric Vehicle), a plug-in hybrid electric vehicle (Plug-in Hybrid Electric Vehicle), an electric vehicle (Battery Electric Vehicle), etc. Note that the use of the electricity storage device 100 is not limited to vehicle use.

[0012] In this specification, the X direction, Y direction, and Z direction are directions that are perpendicular to each other. For example, the X direction and Y direction may be the width direction and the front-rear direction of the vehicle when the power storage device 100 is mounted on the vehicle, respectively. The X1 direction and X2 direction may be the left and right directions of the vehicle, respectively. The Y1 direction and Y2 direction may be the front and rear directions of the vehicle, respectively. The Z direction may be the up-down (vertical) direction. The X direction and Y direction are examples of the "arrangement direction" and "intersecting direction" of the present disclosure, respectively. The Z direction is an example of the "thickness direction" of the present disclosure.

[0013] The energy storage device 100 includes a plurality of energy storage cells 10, an end plate 20a, an end plate 20b, and a band 30. The end plate 20a and the end plate 20b have the same configuration. In FIG. 1, the structures of the end plates 20a and 20b are illustrated in a simplified form. The end plate 20a and the end plate 20b are examples of the "first end plate" and the "second end plate" of the present disclosure, respectively.

[0014] The plurality of energy storage cells 10 are arranged in the X direction. Each of the plurality of energy storage cells 10 includes a positive electrode terminal 11 and a negative electrode terminal 12. The positive electrode terminals 11 and the negative electrode terminals 12 of the energy storage cells 10 adjacent to each other in the X direction are electrically connected by a bus bar (not shown). Note that, although FIG. 1 illustrates an example in which the positive electrode terminal 11 and the negative electrode terminal 12 are arranged on the upper surface 10a of the energy storage cell 10, the locations where the positive electrode terminal 11 and the negative electrode terminal 12 are arranged are not limited to this example.

[0015] End plate 20a is arranged on the X1 side of the multiple storage cells 10. End plate 20b is arranged on the X2 side of the multiple storage cells 10. End plate 20a and end plate 20b sandwich the multiple storage cells 10 in the X direction.

[0016] The band 30 connects the multiple energy storage cells 10 and the end plate 20a and end plate 20b. The band 30 serves to prevent each of the multiple energy storage cells 10 from expanding in the X direction. Specifically, the band 30 applies a load to the end plate 20a on the X2 side. The band 30 applies a load to the end plate 20b on the X1 side. As a result, a load is applied to the multiple energy storage cells 10 from both sides in the X direction via the end plate 20a and end plate 20b.

[0017] The band 30 includes a band main body 31 and a pair of contact plates 32. The pair of contact plates 32 have the same configuration. The contact plates 32 are an example of a "connection portion" in the present disclosure.

[0018] The band main body portion 31 extends in the X direction along the multiple energy storage cells 10. The band main body portion 31 is arranged on the Z1 side of the multiple energy storage cells 10 and the end plate 20a. An end portion 31a of the band main body portion 31 on the X1 side is arranged above the end plate 20a. An end portion 31b of the band main body portion 31 on the X2 side is arranged above the end plate 20b. A central portion 31c of the band main body portion 31 between the end portions 31a and 31b extends in the X direction above the multiple energy storage cells 10.

[0019] One of the pair of contact plates 32 is connected to the end 31a of the band main body 31. The other of the pair of contact plates 32 is connected to the end 31b of the band main body 31. Each of the pair of contact plates 32 is joined (for example, welded) to the underside 31d of the band main body 31. Note that each of the pair of contact plates 32 and the underside 31d of the band main body 31 may be connected by adhesive, bolts, or the like.

[0020] Fig. 2 is a partially enlarged view showing the contact plate 32 and end plate 20a on the X1 side. Although not shown, the contact plate 32 and end plate 20b on the X2 side are configured identically to those shown in Fig. 2. For simplicity, the band main body 31 is not shown in Fig. 2.

[0021] 2, the contact plate 32 is formed to extend in the Y direction. The contact plate 32 is also formed to extend in the X direction. That is, the contact plate 32 has a flat plate shape extending in the XY plane. The width W1 of the contact plate 32 in the Y direction is greater than the width W2 of the contact plate 32 in the X direction.

[0022] The end plate 20a includes a raised portion 21 that is provided so as to rise upward (toward the Z1 side). The contact plate 32 is disposed on the raised portion 21.

[0023] The raised portion 21 has an upper stage portion 22 and a lower stage portion 23. The contact plate 32 is disposed in the lower stage portion 23. The upper stage portion 22 is provided higher than the lower stage portion 23. The upper stage portion 22 is formed continuously with the lower stage portion 23. The upper stage portion 22 is provided above a portion of the lower stage portion 23 near the end on the X2 side (the energy storage cell 10 side).

[0024] The raised portion 21 is provided with a pair of protruding portions 24. The pair of protruding portions 24 are arranged in the Y direction. Each of the pair of protruding portions 24 is formed to extend in the up-down direction. Each of the pair of protruding portions 24 protrudes upward from the lower stage portion 23. Each of the pair of protruding portions 24 is formed integrally (continuously) with the lower stage portion 23.

[0025] One of the pair of protrusions 24 is provided at the Y1-side end of the lower stage 23. The other of the pair of protrusions 24 is provided at the Y2-side end of the lower stage 23. The contact plate 32 is sandwiched between the pair of protrusions 24 in the Y direction.

[0026] Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Fig. 3 is a cross-section of the contact plate 32, the end plate 20a, etc. cut perpendicularly to the X direction. Note that Fig. 3 also shows the band main body 31, which is not shown in Fig. 2.

[0027] In conventional electricity storage devices, the bands are fixed to the end plates using rivets, bolts, etc. In this case, space is required to place the rivets, etc., which may result in an increase in the size of the electricity storage device.

[0028] Therefore, in this embodiment, the contact plate 32 is fixed to the end plate 20a by fitting into the end plate 20a. Note that the relationship between the contact plate 32 and the end plate 20a is the same as the relationship between the contact plate 32 and the end plate 20b, so the following will only describe in detail the contact plate 32 and the end plate 20a.

[0029] Specifically, the contact plate 32 includes a protrusion 33 and a protrusion 34. The protrusion 33 is formed at the end of the contact plate 32 on the Y1 side. The protrusion 34 is formed at the end of the contact plate 32 on the Y2 side. The protrusions 33 and 34 are each formed so as to protrude outward in the Y direction on the contact plate 32. The protrusions 33 and 34 have the same shape. The protrusion 33 is an example of a "first fitting portion" and a "first protrusion" in the present disclosure. The protrusion 34 is an example of a "second fitting portion" and a "second protrusion" in the present disclosure.

[0030] End plate 20a is formed with recess 25 that fits with protrusion 33. End plate 20a is formed with recess 26 that fits with protrusion 34. Recess 25 and recess 26 are each formed in the lower part (lower end) of protrusion 24. Recess 25 and recess 26 have the same shape. Note that recess 25 is an example of a "first fitted portion" and a "first recess" in the present disclosure. Also, recess 26 is an example of a "second fitted portion" and a "second recess" in the present disclosure.

[0031] That is, both ends of the contact plate 32 in the Y direction (the protrusions 33 and 34) are fitted to the end plate 20a. This more reliably prevents the contact plate 32 from falling off (disengaging from) the end plate 20a compared to when only one protrusion is provided to fit into the end plate 20a.

[0032] The contact plate 32 includes an upper surface 35 and a lower surface 36. The upper surface 35 is the upper end surface of the contact plate 32. The lower surface 36 is the lower end surface of the contact plate 32. The upper surface 35 is welded to the lower surface 31d of the band main body 31. The lower surface 36 is in contact with the end plate 20a (the upper surface 23a of the lower stage portion 23).

[0033] The contact plate 32 includes a connection surface 33a and a connection surface 34a. The connection surface 33a constitutes the side surface of the contact plate 32 on the Y1 side. The connection surface 34a constitutes the side surface of the contact plate 32 on the Y2 side. The connection surface 33a and the connection surface 34a each connect the upper surface 35 and the lower surface 36. The connection surface 33a is provided on the protrusion 33. The connection surface 34a is provided on the protrusion 34.

[0034] The connecting surface 33a is inclined toward the Y1 side (the outer side in the Y direction of the contact plate 32) from the upper surface 35 to the lower surface 36. The connecting surface 34a is inclined toward the Y2 side (the outer side in the Y direction of the contact plate 32) from the upper surface 35 to the lower surface 36.

[0035] Each of the connection surfaces 33a and 34a is provided so as to be covered from above by the protrusion 24. Each of the protrusions 33 and 34 is pressed from above (Z1 side) and from the side (Y1 side or Y2 side) by the protrusion 24. This prevents the contact plate 32 from coming off the pair of protrusions 24 (recesses 25, recesses 26).

[0036] The protrusion 33 includes a corner 33b connecting the lower surface 36 and the connection surface 33a. The corner 33b has a curved shape. The protrusion 34 includes a corner 34b connecting the lower surface 36 and the connection surface 34a. The corner 34b has a curved shape. The portion of the recess 25 facing the corner 33b is curved along the corner 33b. The portion of the recess 26 facing the corner 34b is curved along the corner 34b. A gap (play) may be formed between the corner 33b and the recess 25 (the corner 34b and the recess 26).

[0037] The protrusion 33 and the recess 25 extend in the X direction while fitting together. The protrusion 34 and the recess 25 extend in the X direction while fitting together. The fitting portion between the protrusion 33 and the recess 25 (the protrusion 34 and the recess 26) extends in the X direction by a length L (FIG. 2) in the X direction of the region where the protrusion 24 and the contact plate 32 overlap in the Y direction.

[0038] This allows the contact plate 32 and the end plate 20a to be fixed to each other over a relatively wide area, thereby enabling the contact plate 32 to be fixed to the end plate 20a more stably.

[0039] Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 2. Fig. 4 is a cross-section of the contact plate 32, the end plate 20a, etc. cut perpendicularly to the Y direction.

[0040] The contact plate 32 includes a protrusion 37. The protrusion 37 is provided at an end of the contact plate 32 on the side of the plurality of energy storage cells 10 in the X direction (X2 side). The protrusion 37 is formed on the contact plate 32 so as to protrude outward in the X direction.

[0041] The end plate 20a is formed with a recess 27 that fits onto the protrusion 37. The recess 27 is formed in a step between the upper stage 22 and the lower stage 23 of the end plate 20a. Specifically, the recess 27 is formed in the space between the surface 22a of the upper stage 22 on the lower stage 23 side (X1 side, opposite to the energy storage cell 10) and the upper surface 23a of the lower stage 23.

[0042] As a result, in addition to the protrusions 33 and 34 (FIG. 3), the protrusions 37 are also fitted to the end plate 20a, so that the contact plate 32 can be fixed to the end plate 20a more stably. Also, since the protrusions 37 are provided at the end of the contact plate 32 on the storage cell 10 side (X2 side), a restraining load can be easily applied to the storage cell 10 through the fitting portion between the protrusions 37 and the recesses 27.

[0043] The convex portion 37 may be formed continuously with the convex portion 33 and the convex portion 34 (FIG. 3). The concave portion 27 may be formed continuously with the concave portion 25 and the concave portion 26 (FIG. 3).

[0044] The contact plate 32 includes a connection surface 37a. The connection surface 37a connects the upper surface 35 and the lower surface 36. The connection surface 37a constitutes the side surface of the contact plate 32 on the X2 side (the side facing the energy storage cells 10). The connection surface 37a is provided on the protrusion 37. The connection surface 37a is inclined toward the X2 side from the upper surface 35 to the lower surface 36.

[0045] The connection surface 37a is provided so as to be covered from above by the surface 22a of the end plate 20a. The protrusion 37 is pressed from above (Z1 side) and from the side (X2 side) by the upper step portion 22 (surface 22a). This prevents the protrusion 37 of the contact plate 32 from coming out of the recess 27.

[0046] The protrusion 37 includes a corner 37b that connects the lower surface 36 and the connection surface 37a. The corner 37b has a curved shape. The portion of the recess 27 that faces the corner 37b is curved along the corner 37b. A gap (play) may be formed between the corner 37b and the recess 27.

[0047] The protrusions 37 and the recesses 27 extend in the Y direction while fitting together. In other words, the fitting portions between the protrusions 37 and the recesses 27 extend in the Y direction. This makes it possible to fix the contact plate 32 to the end plate 20a over a relatively wide range. As a result, the contact plate 32 can be fixed to the end plate 20a even more stably.

[0048] The contact plate 32 has a thickness t1 in the vertical direction (Z direction). The band main body 31 has a thickness t2 in the vertical direction. The thickness t1 is greater than the thickness t2. For example, the thickness t1 may be three times or more the thickness t2.

[0049] This increases the rigidity (for example, bending rigidity) of contact plate 32 compared to when thickness t1 is equal to or less than thickness t2. As a result, even when contact plate 32 is fitted with end plate 20a, deformation (breakage) of contact plate 32 can be suppressed.

[0050] As described above, in this embodiment, the protrusions 33 of the contact plate 32 fit into the recesses 25 of the end plate 20a, and the protrusions 34 of the contact plate 32 fit into the recesses 26 of the end plate 20a. This allows the contact plate 32 to be fixed to the end plate 20a without using rivets, bolts, or the like. As a result, space for rivets or the like is not required, and an increase in size of the energy storage device 100 can be suppressed. Furthermore, because rivets or the like are not required, the number of parts can be reduced and the configuration of the energy storage device 100 can be simplified. Furthermore, compared to when the contact plate 32 and the end plate 20a are welded together, the influence of heat on the contact plate 32 and the like can be suppressed.

[0051] [Variations] In the above embodiment, an example was shown in which each of the pair of protrusions 24 is formed to extend in the up-down direction, but the present disclosure is not limited to this. The shape of the pair of protrusions may be other than the shape in the above embodiment.

[0052] For example, in the example shown in FIG. 5, the end plate 120 includes a pair of protrusions 124. Each of the pair of protrusions 124 includes a vertical portion 124a extending upward from the lower stage portion 23 and a horizontal portion 124b extending in the Y direction from the upper end of the vertical portion 124a. The horizontal portions 124b of each of the pair of protrusions 124 extend in directions approaching each other. Each of the pair of protrusions 124 has an L-shape. Note that, for simplification, the contact plate is not shown in FIG. 5.

[0053] Therefore, recesses 125 and 126 are formed in the area surrounded by horizontal portion 124b, vertical portion 124a, and upper surface 23a of lower portion 23. Recess 125 is formed by protruding portion 124 on the Y1 side. Recess 126 is formed by protruding portion 124 on the Y2 side. Note that recess 125 is an example of a "first fitted portion" and a "first recess" in the present disclosure. Also, recess 126 is an example of a "second fitted portion" and a "second recess" in the present disclosure.

[0054] Furthermore, in the above embodiment, an example has been shown in which the contact plate 32 has the protrusion 37, but the present disclosure is not limited to this. For example, in the example shown in Fig. 6, the contact plate 132 has the protrusion 137. The protrusion 137 is provided so as to protrude from the lower end of the contact plate 132 toward the X2 side (the energy storage cell 10 side). The protrusion 137 has a flat plate shape.

[0055] A recess 227 is formed in the end plate 220. The protrusion 137 of the contact plate 132 is fitted into the recess 227. The recess 227 is formed so as to be recessed from a surface 222a of the upper step portion 222 of the end plate 220 on the lower step portion 223 side (X1 side) toward the X2 side. The recess 227 is formed at the lower end of the upper step portion 222. Note that the surface 222a may extend perpendicular to the X direction.

[0056] In the above embodiment, an example has been described in which each of the end plates 20a and 20b is fitted with the contact plate 32, but the present disclosure is not limited to this. For example, the end plate 20b does not have to be fitted with the contact plate 32.

[0057] In the above embodiment, an example was shown in which the protrusions (33, 34, 37) were formed on the contact plate 32 and the recesses (25, 26, 27) were formed on the end plate 20a (20b), but the present disclosure is not limited to this. The recesses may be formed on the contact plate and the protrusions may be formed on the end plate.

[0058] In the above embodiment, an example has been shown in which the protrusions 37 are formed only on the end of the contact plate 32 on the side of the energy storage cells 10 in the X direction, but the present disclosure is not limited to this. A protrusion may also be formed on the end of the contact plate on the opposite side of the energy storage cells 10 in the X direction.

[0059] In the above embodiment, the band main body 31 and the contact plate 32 are provided separately and joined (welded) to each other, but the present disclosure is not limited to this. The contact plate 32 may be formed integrally with the band main body 31.

[0060] In the above embodiment, an example was shown in which the contact plate 32 having a flat plate shape is included in the band 30, but the present disclosure is not limited to this. Instead of the contact plate 32, a portion (part of the band) having a shape other than a flat plate shape (for example, a spherical or cubic shape) may be fitted with the end plate 20a (20b).

[0061] The configurations of the above-described embodiment and the above-described modifications may be combined with each other.

[0062] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present disclosure is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0063] 10 Energy storage cell, 20a End plate (first end plate), 20b End plate (second end plate), 25, 125 Recess (first mating portion) (first recess), 26, 126 Recess (second mating portion) (second recess), 27 Recess, 30 Band, 31 Band main body, 32 Contact plate (connection portion), 33 Convex portion (first mating portion) (first convex portion), 34 Convex portion (second mating portion) (second convex portion), 37 Convex portion, 100 Energy storage device, t1 Thickness (thickness of connection portion), t2 Thickness (thickness of band main body).

Claims

1. A plurality of storage cells arranged in an arrangement direction; a first end plate and a second end plate that sandwich the plurality of storage cells in the arrangement direction; a band connecting the plurality of storage cells, the first end plate, and the second end plate, The band is a band main body portion extending in the arrangement direction along the plurality of storage cells; a connecting portion provided at an end of the band main body in the arrangement direction, the connection portion is formed to extend in an intersecting direction intersecting the arrangement direction, a first fitting portion and a second fitting portion are formed at one end and the other end of the connection portion in the intersecting direction, respectively; The first end plate has a first fitted portion that fits with the first fitting portion; and a second fitted portion that fits into the second fitting portion.

2. The connection portion is formed to extend in the arrangement direction, The first fitting portion and the first fitted portion are formed to extend in the arrangement direction while fitting together, The power storage device according to claim 1 , wherein the second fitting portion and the second fitted portion are formed to extend in the arrangement direction while fitting together.

3. the first fitting portion includes a first protrusion that protrudes outward in the intersecting direction, the second fitting portion includes a second protrusion that protrudes outward in the intersecting direction, the first fitted portion includes a first recess that fits into the first protrusion, The power storage device according to claim 1 , wherein the second fitted portion includes a second recess that fits with the second protrusion.

4. a protrusion that protrudes outward in the arrangement direction is formed at an end of the connection portion that is closer to the plurality of power storage cells in the arrangement direction, The power storage device according to claim 1 or 2, wherein the first end plate is formed with a recess that fits with the protrusion.

5. If a direction intersecting both the arrangement direction and the intersecting direction is defined as a thickness direction, The power storage device according to claim 1 , wherein a thickness of the connection portion in the thickness direction is greater than a thickness of the band body in the thickness direction.

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