JP2016096080A - Storage battery unit and power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage battery unit etc. which makes misalignment of a seal member less likely to occur during product assembly and enables a worker to check if the seal member is correctly placed.SOLUTION: A storage battery unit includes: secondary batteries; a housing storing the secondary batteries and having a first battery case and a second battery case, the housing in which a flange part of the first battery case and a flange part of the second battery case are fixed to each other; and a seal member 110 disposed between the flange parts. The seal member 110 includes: a thick part 111 sandwiched between the flange parts and having a planar shape formed into a closed annular shape; and a protruding part 115 for positioning the seal member 110 relative to the flange part of one of the battery cases.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a storage battery unit or the like in which a secondary battery is sealed and accommodated in a housing, and more particularly to a seal member that seals the housing and a peripheral structure thereof.

  In recent years, for example, power storage devices have been used to charge storage batteries in the middle of the night when electricity charges are cheap and use the electricity during the day, or use the electricity charged during the day by solar power generation at night. It has become to. There are various types of power storage devices, from large ones installed in factories and offices to medium and small ones installed in stores, ordinary houses, and the like. Moreover, a lithium ion secondary battery etc. are mainly utilized as a storage battery (for example, refer patent document 1).

JP 2013-196851 A

  By the way, since the power storage device is sometimes used outdoors, it is required to prevent rainwater and dust from entering the device.

  In this regard, it is conceivable to use a seal member such as an O-ring, for example, in order to ensure the airtightness and watertightness of the storage body that stores the secondary battery. However, depending on the shape and size of the seal member, or the shape of the portion where the seal member is disposed, it may be difficult to place the seal member in a predetermined position during product assembly, or the position may be displaced. There is sex. Further, at the time of manufacturing a product, it is desirable from the viewpoint of improving the assembly accuracy of the product that it can be confirmed afterwards whether the seal member is correctly attached.

  The present invention has been made in view of the above-described problems, and its purpose is to confirm that the seal member is less likely to be misaligned during product assembly and that the seal member is correctly arranged. It is in providing the storage battery unit etc. which can also be performed.

In order to achieve the above object, a storage battery unit according to an embodiment of the present invention is as follows:
A secondary battery,
A housing for housing the secondary battery, comprising a first battery case and a second battery case, wherein a flange portion of the first battery case and a flange portion of the second battery case are fixed. A housing
A seal member disposed between the flange portions,
The sealing member is
An annular thick part sandwiched between flange parts,
A storage battery unit comprising: a projecting portion for positioning the seal member with respect to a flange portion of one of the battery cases.

(Explanation of terms)
In the present specification, the “battery cell” refers to an electrochemical cell that is a unit of a battery, such as a film-clad battery.
The “battery module” refers to a module that includes one or a plurality of battery cells and a case that houses the battery cells and outputs predetermined power.
“Storage battery unit” refers to a battery cell or battery module housed in a case (housing).
“Power storage device” refers to the entire device including at least one storage battery unit (battery unit) and its control circuit. It can also be called a power storage system.

  ADVANTAGE OF THE INVENTION According to this invention, the storage battery unit etc. which can confirm that it is hard to generate | occur | produce the position shift of a sealing member at the time of a product assembly, and can arrange | position the sealing member correctly can be provided.

It is a typical perspective view of the electrical storage apparatus of the state which removed the exterior cover. It is a typical exploded perspective view of a storage battery unit. It is typical sectional drawing of a storage battery unit. It is the top view which looked at the battery cover from the opening part upper direction. It is a partial cross section perspective view which expands and shows typically the structure of the flange part of a battery cover. It is a schematic diagram for demonstrating the shape of the gas flow path formed between flange parts. It is the top view of the storage battery unit which looked at the state where battery cases were fixed from the upper part. (A) is sectional drawing in the aa line of FIG. 7A, (b) is sectional drawing in the bb line. It is sectional drawing in the cc line of FIG. 7A. It is a top view of the storage battery unit of a 2nd embodiment. It is sectional drawing which shows the specific example of an elastic fixing | fixed part. It is a perspective view of the sealing member used in 3rd Embodiment. It is a top view of the battery cover with which a sealing member is mounted | worn. It is a partial cross section perspective view which shows the sealing member pinched | interposed between flange parts.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings. Note that the configuration shown in the drawings is merely an embodiment of the present invention, and the present invention is not limited to the specific configuration, and can be appropriately changed without departing from the gist of the present invention. .

  Hereinafter, several embodiments of the present invention will be described, but the respective technical features disclosed in each embodiment can be appropriately combined.

(1. About the entire device)
As illustrated in FIG. 1, the power storage device 1 of the present embodiment includes a storage battery unit 10, a junction box 200, a power conditioner 300 (PCS: Power Conditioner System), and a frame 80 that holds them. Yes. As an example, the power storage device 1 may be configured as a stationary power storage system used in a store or a home.

  The power storage device 1 can be used to supply surplus power to a commercial power supply as backup power or auxiliary power at the time of a power failure or the like. In addition, when household distributed power sources, such as a solar cell system and a micro wind power generator, are provided, these household distributed power sources may also be connected to the power storage system.

  The junction box 200 is a part having devices such as various cable connection parts and wiring breakers, and these are housed in the storage box 201. Although detailed illustration is omitted, the junction box 200 is connected to a cable connected to the system power, a cable connected to the home (an example) power system, and the like.

  The power conditioner 300 includes a device that converts direct current and alternating current from each other and a device that controls charging / discharging operations of the power storage device. Specifically, the power conditioner 300 converts an alternating current from a commercial power source into a direct current in order to charge the storage battery (during charging), and a direct current from the storage battery when using the stored power. Is stored in the storage case 301. Moreover, devices such as a battery management system (BMU: Battery Management System) which is a control circuit are also incorporated. The predetermined device in the power conditioner 300 and the predetermined device in the junction box 200 are electrically connected by a wiring (signal line, power line) (not shown).

  In addition, a conventionally well-known thing can also be utilized regarding these apparatuses. The battery management system has, for example, a function of managing the battery by controlling charge / discharge of each battery cell, monitoring voltage, temperature, and the like. Specifically, the total voltage and the remaining capacity of each cell may be calculated in real time and displayed on a predetermined display device as necessary. Further, a warning for overdischarge and overcharge may be performed.

  The frame 80 includes a frame main body portion 85 that holds the device, and leg portions 89L and 89R provided below the frame main body portion 85. The material of the frame 80 is not particularly limited, but is made of metal, for example. In the present embodiment, as an example, the junction box 200 and the power conditioner 300 are held in the upper stage of the frame main body 85, and the two storage battery units 10 are held in the lower stage. Since the storage battery unit 10 is a heavy object with a built-in battery as will be described later, disposing these in a low position is advantageous in that the center of gravity of the entire apparatus can be lowered. However, the present invention is not limited to such an arrangement.

  The leg portions 89L and 89R may be provided as portions that are fixed with respect to a predetermined installation position. For example, one or a plurality of bolt through holes (not shown) for passing through anchor bolts (not shown) provided at the installation positions of the power storage devices may be formed in the legs 89L and 89R.

  Although illustration is omitted, the power storage device 1 may include an exterior cover that covers the entire device. The exterior cover may be attached to the frame 80 as an example.

(2. Storage battery unit)
As shown in the schematic diagram of FIG. 2, the storage battery unit 10 includes a plurality of battery modules 20 and a sealed housing 50 that houses the battery modules 20. The housing 50 includes a pair of battery cases 51 and 61. Since the inside of the housing 50 is hermetically sealed, even if the internal battery is ignited for some reason, the housing 50 can be self-digested. By adopting such a fire prevention structure, the safety of the power storage device 1 becomes very good.

  The shape and size of the battery module 20 are not particularly limited, and the structure thereof may be arbitrary, but in the present embodiment, the battery module 20 is an example of a thin rectangular parallelepiped. It is configured. Although detailed illustration is omitted, the battery module 20 may be one in which one or more film-clad batteries (battery cells) are housed in the housing case 21.

  Various materials can be selected as the material of the storage case 21 of the battery module 20. However, as an example, the storage case 21 may be made of resin, may be made of metal, or may be made of metal in addition to the resin case. It may be like a cover made of metal. As the built-in film-clad battery (battery cell), a conventionally known general battery can be used. The film-clad battery has a battery element in which a positive electrode plate and a negative electrode plate are alternately laminated via a separator, and the battery element is enclosed in an outer film such as a laminate film together with an electrolyte. Good. Although the voltage of one film-clad battery is not limited at all, it may be in the range of 3.0V to 4.5V, for example.

  The number of battery cells used and the number of battery modules 20 may be appropriately set according to product specifications and the like. As a specific example, four battery-clad batteries are stacked in one battery module 20. It may be built in the state.

  The battery modules 20 thus configured may be stacked in the thickness direction to form an assembly (assembled battery) as shown in FIG. Specifically, a plurality of battery modules 20 are stacked (eight in this example), side plates 31 and 31 are arranged on both sides, and the whole is fixed with fixing bolts 33 and nuts (not shown). The fixing bolts 33 may be arranged at the four corners of the battery module 20. The fixing bolt 33 has a length that penetrates all the battery modules 20, and the entire module 20 and the side plate 31 are fixed by tightening a nut (not shown) at the tip side.

  The shape of the side plate 31 can be variously changed and is not limited to a simple plate shape as schematically illustrated in FIG. In addition to the side plate 31, if necessary, an additional intermediate plate (not shown) may be provided between the stacked battery modules 20. The assembly thus assembled is fixed at a predetermined position of the housing 50.

  Any method may be used for fixing the assembly of the battery module 20 and the battery cover. For example, as schematically shown in FIG. 3, the battery case is provided via fixing stays 25 and 26. It is good also as a structure attached to 61. FIG. The stays 25 and 26 are formed by bending a sheet metal member as an example, and are fixed to the battery case 61 by welding. The assembly of the battery module 20 may be positioned and arranged with respect to the stays 25 and 26, and the assembly may be fixed by screwing at a predetermined location.

  Note that the shapes of the stays 25 and 25 can be changed as appropriate in consideration of the shape and size of the internal assembly, the position to be screwed, and the like.

(Outline of film-clad battery)
With respect to the battery element of the film-clad battery, the battery element may be a laminated type composed of a positive electrode side active electrode and a negative electrode side active electrode laminated via a separator. As another aspect, the power generation element includes a belt-like positive electrode side active electrode and a negative electrode side active electrode that are stacked via a separator, wound, and then compressed into a flat shape to compress the positive electrode side active electrode and the negative electrode side active electrode. And a wound type having a structure in which and are alternately stacked.

  Battery elements in a typical lithium ion secondary battery are: a positive electrode plate in which a positive electrode active material is applied on both sides of an aluminum foil, and a negative electrode plate in which a carbon material capable of doping and undoping lithium is applied on both sides of a copper foil. Are stacked via a separator. As the positive electrode active material, lithium / manganese composite oxide, lithium cobaltate, or the like is used. The battery element is enclosed in the film outer package together with the electrolytic solution.

  As the electrolyte solvent, for example, ester solvents such as propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), and methyl ethyl carbonate can be used. In particular, examples of the volatile nonaqueous electrolytic solvent having combustibility include carbonate solvents such as cyclic carbonates such as diethyl carbonate (DEC).

  In addition to the above, examples of the battery element include other types of chemical batteries such as a nickel metal hydride battery, a nickel cadmium battery, a lithium metal primary battery or secondary battery, and a lithium polymer battery.

(3. Housing & gas release mechanism)
Next, the structure of the housing (housing body) and the structure for releasing gas will be described in detail.

  As shown in FIG. 2, the housing 50 includes a pair of battery cases 51 and 61. The battery covers 51 and 61 may have any shape as long as they can form a sealed space, and may not necessarily have the same or symmetric shape, but in the present embodiment, the battery covers 51 and 61 have the same or symmetric shape. A typical configuration will be described as an example.

  Hereinafter, in order to avoid duplication of explanation, description may be made by taking one battery cover as an example. In addition, for example, “a predetermined structure is formed on the battery covers 51 and 61” is described. However, such a description does not necessarily require that both battery covers have such a configuration. Only includes such a configuration.

  The battery cover 51 has a cup portion 58 and a flange portion 53 provided at the periphery on the opening side. The battery cover 61 is the same, and has a cup portion 68 and a flange portion 63. The battery covers 51 and 61 are shaped like a bathtub as a whole.

  The battery covers 51 and 61 are preferably made of a material having a high melting temperature so that the battery inside the battery covers 51 and 61 does not spread by fire even if the internal battery runs out of heat. In addition, when gas is generated, the internal pressure of the sealed housing 50 increases (the gas release mechanism will be described later), but the battery cover itself is not damaged before the gas release mechanism is activated. It is configured to have sufficient strength.

  The material of the battery covers 51 and 61 may be metal, for example. A rolled steel plate, a stainless steel plate, etc. can be used. The thickness of the material may be, for example, in the range of 1.0 mm to 3.0 mm. If the material is within this range, a highly reliable fire-proof structure can be realized without significantly degrading the workability of the battery cover.

  The battery covers 51 and 61 may be manufactured by any method, but for example, a single plate material may be integrally formed by pressing (in one example, deep drawing). Alternatively, it may be formed by joining by welding. When formed by deep drawing, the ridge line portion of the cup portion and the connection portion between the cup portion and the flange portion can be formed seamlessly, which is preferable from the viewpoint of sealing performance and high strength. Moreover, since operations such as welding are unnecessary, it is preferable from the viewpoint of manufacturing cost.

  The depth of the cup parts 58 and 68 is set to such a depth that both the cup parts 58 and 68 can cooperate to form an internal space in which the battery module 20 can be stored. According to the configuration in which the cup portions 58 and 68 are formed in both the battery covers 51 and 61 as in the present embodiment, it is not necessary to form a deep cup portion in only one battery cover, and it is manufactured by pressing. Is preferable in that it is easy to perform.

  In FIG. 2, the ridge line portions of the cup portions 58 and 68 are schematically shown in a squared state, but it goes without saying that when the battery cover is manufactured by pressing or the like, it is easy to manufacture. It may be formed in a gentle curved shape (R shape). FIG. 2 and the like are schematic views for explaining the basic configuration. For example, the outer peripheral portion of the flange portion is configured to extend flat (see FIG. 2, FIG. 3, etc.) or curved. It should be noted that the rising wall (see FIG. 7B and the like) is not an essential difference and may take any form.

(Gas release mechanism)
Next, a structure for releasing gas from the battery covers 51 and 61 will be described. In this embodiment, since the same structure is formed in both the flange parts 53 and 63, it demonstrates fundamentally taking one battery cover 61 as an example.

  As shown in FIGS. 4 and 5, the flange portion 63 of the battery cover 61 is formed with a concave surface portion 65 formed on the radially inner side and a convex surface portion 64 formed on the outer side so as to be one step higher. ing. As shown in FIG. 4, the concave surface portion 65 and the convex surface portion 64 are formed in a substantially rectangular ring shape surrounding the cup portion 68.

  As shown in FIG. 5, the annular concave surface portion 65 is provided so as to form a surface that extends substantially horizontally (in a direction substantially perpendicular to the depth direction of the cup portion) from the upper end of the opening of the cup portion 68. ing.

  As shown in FIGS. 4 and 5, a plurality of gas discharge grooves 65 a are formed on one side of the flange portion 63. The gas discharge groove 65a is formed to communicate the concave surface portion 65 and the outside of the case. The number and position of the gas discharge grooves 65a can be variously changed. In this example, three gas discharge grooves 65a are formed. The gas discharge grooves 65a may be formed in parallel to each other, or may be formed in a substantially radial shape.

  One, two, or four or more gas discharge grooves 65a may be formed. When three or more are formed, the distance (pitch) between the gas discharge grooves 65a may be an equal interval or may be a separate interval. In this example, the gas discharge groove 65a is formed on only one side, but may be formed on two or more sides.

  Although not limited, the concave surface portion 65 and the gas discharge groove 65a may be formed to have the same depth (that is, the surface of the concave surface portion 65 and the bottom surface of the discharge groove 65a are the same surface). As another form, it may be formed with different depths (for example, the gas discharge groove 65a is shallower).

  In FIG. 5, for convenience of illustration, the stepped portion of the concave surface portion 65 and the outer peripheral flange portion 64 of the concave portion 65, the portion corresponding to the side wall of the gas discharge groove 65a, and the like are depicted as square shapes. In the case where such a structure portion is formed in 63, it may actually be formed in an inclined surface or curved surface as shown in FIGS. 7B and 7C.

  The concave surface portion 65, the convex surface portion 64, and the gas discharge groove 65a as described above are similarly formed in the other battery cover 51 (see the concave surface portion 55, the convex surface portion 54, and the gas discharge groove 55a in FIG. 7B). .

  The flange portions 53 and 63 formed in this manner are overlapped with each other so that the gas discharge extending between the annular inner space 75 and one side thereof outward as schematically shown in FIG. A hole 75a is formed. The internal space 75 is a portion where the seal member R1 is disposed.

(Flange fixing)
By the way, in this embodiment, since the fixing structure of the flange parts 53 and 63 is also characteristic, this is first demonstrated with reference to FIG. 7A-FIG. The space 75 and the gas discharge hole 75a will be described again in detail.

  FIG. 7A is a plan view of the state in which the battery cases are fixed as viewed from above. 7A is a cross-sectional view taken along the line aa in FIG. 7A, and FIG. 7B is a cross-sectional view taken along the line bb. FIG. 7C is a cross-sectional view taken along line cc of FIG. 7A.

  In the present embodiment, the flange portions 53, 63 of the battery case are connected by a plurality of fixing portions f1, and the flange portions 53, 63 are fixed. Examples of the fixing means (fixing tool) include screws, bolts and nuts, rivets, and welding. In the present embodiment, basically, each of the fixing portions f1 may be rigidly fixed (“rigid fixation” means that an elastic body as described in the second embodiment is interposed. This means that the flange portions 53 and 63 are fixed so as not to be separated from each other.

  The specific types of screws, bolts, and the like are not limited in any way. For example, as shown in FIG. 7C, an opening is formed in the flange portion 53 and a female screw portion is formed in the flange portion 63. The connection may be performed by tightening the screw 91 from the part 53 side. Or you may connect a flange part with a volt | bolt and a nut (not shown).

  Referring to FIG. 7A again, in the present embodiment, the short sides of the flange portions 53 and 63 where the gas discharge holes 75a are formed are connected by two fixing portions f1, and the other sides are connected by three or more locations. ing.

  The pitch d1 between the fixed portions f1 on both sides of the gas discharge hole 75a is formed wider than any other pitch. Thus, the effect | action by having formed the pitch of the said part widely shall be mentioned later. The pitches d2 and d3 between the other fixed parts are only required to be smaller than the pitch d1, and the pitches d2 and d3 may be the same or different.

  More specifically, in one embodiment, the pitch d1 between the fixed portions is preferably, for example, a length in the range of 40% to 70% with respect to the length of the side where the fixed portion is provided. . If the pitch d1 is too long, the deformation of the flange portion due to the reaction force of the seal member may not be corrected, and if it is too short, the assembly process may be complicated.

(Normal state)
In the state where the flange portions 53 and 63 are connected by the plurality of fixing portions f1 as described above, the seal member R1 is sandwiched in a compressed state between the concave surface portions 55 and 65 of the flange portions 53 and 63. Is obtained. That is, the inner space of the case is sealed in a watertight and airtight manner.

  As the sealing member R1 (see FIG. 2), basically any material and shape may be used as long as the sealing between the battery cases can be performed in an airtight and watertight manner. The seal member R1 has a closed annular shape, and specifically, may have a shape corresponding to the planar shape (that is, a substantially square shape) of the concave surface portion 65 of the flange portion.

  In the present embodiment, a general seal member (for example, an O-ring) may be used as the seal member R1. In the present embodiment, the cross-sectional shape of the seal member R1 may be any shape such as a circle, an ellipse, a substantially semicircle, a rectangle, and a polygon. Another example of the seal member will be described later as a third embodiment with reference to other drawings.

(When gas is generated)
As described above, the storage battery unit 10 of the present embodiment is kept in a sealed state by a seal member in a normal state, but when gas is generated, the pitch d1 on the gas discharge hole 75a side is formed most widely, On the basis of the following principle, gas is discharged from between the fixed portions f1 having a wide pitch.

  That is, as shown in FIG. 7C, since the pitch d1 between the pair of fixing portions f1 is wide, when the pressure inside the case rises, the flange portions 53 and 63 are relatively deformed in this portion. As a result, when the internal pressure exceeds a predetermined level, this portion is slightly opened. As a result, the internal gas exceeds the seal R1 (see FIG. 7B) and is discharged to the outside via the gas discharge hole 75a.

  Although the gas discharge direction varies depending on the posture in which the frame 80 holds the storage battery unit 10, as a preferred embodiment, the storage battery unit 10 is oriented in such a direction that the side on which the gas discharge hole 75 a is formed is downward. May be attached to the frame 80. According to this, since the internal gas (high temperature, high pressure) is released toward the ground plane, the gas is blown to other equipment and is not damaged or damaged, and it is safe. .

  In the storage battery unit 10, when the gas is released to some extent and the internal pressure decreases, the flange portions 53 and 63 return to the original shape and the housing returns to the sealed state again.

As described above, an example of the present invention has been described as one embodiment with reference to the drawings. However, the present invention is not limited to the above, and various modifications can be made.
(1a) Although an example of a film-clad battery has been given as the battery, the present invention can be applied to any secondary battery that can generate gas when it is abnormal.
(1b) Although the battery cover has been described as an example having a square flange portion, it may have a polygonal shape other than that or a contour shape such as a combination of several sides and curves. In such a case, as one form of the invention “increase the pitch between the fixed portions”, the pitch (d1) of the fixed portions on a predetermined one side of the flange portion may be provided wider than the others. As a result, the flange portion can be deformed most freely between the fixed portions, and when the internal pressure rises, the flange portion can be deformed to release the gas from the portion.
(1c) With respect to the case of the battery module 20 and the film-clad battery inside the battery module 20, a structure portion that is preferentially broken to release gas when gas is generated may be formed.

(Second Embodiment)
In the first embodiment, the gas is released from between the fixed portions having a wide pitch by changing the pitch of the fixed portions f1, but other modes for regulating the gas discharge direction are as follows. It may be anything.

  In this embodiment, a part of the plurality of fixing parts of the flange parts 53 and 63 is a rigid fixing part f1, and the fixing part on the side where the gas is to be released is opened when a predetermined pressure or more is applied. It is an elastic fixing part f1 ′ (see FIG. 8).

  For example, as shown in FIG. 9, the “elastic fixing part f1 ′” includes a screw 91 and a spring 92, and the spring 92 is compressed in a tightened state of the screw 91 (specifically, the screw A spring is attached to the shaft portion of the screw and the spring is compressed between the screw head and the flange portion), and one flange portion 53 is pressed against the other flange portion 63 with a predetermined urging force. May be. For example, as shown in FIG. 8, the position where such a fixing portion f1 ′ is used is the side on the side where the gas discharge hole 75a is formed and the side on the side where the gas discharge hole 75a is formed among the long sides. It is good also as one or more of the side close to. In FIG. 8, the number of the fixed portions f1 and f1 ′ per long side is three as an example, but this number can be changed as appropriate.

  All the long sides may be rigid fixing portions f1, and only the side on which the gas discharge hole 75a is formed may be such a fixing portion f1 '.

  As the urging force of the spring 92 at the time of tightening, (i) during normal use, the flange portions can be pressed with sufficient force to ensure airtightness and watertightness, while (ii) internal pressure When the gas rises, the gas discharge hole 75a side is opened, and the gas can be discharged through the gas discharge hole 75a.

  As shown in FIG. 9, in the configuration in which the gap between the flange portion 53 and the flange portion 63 opens as necessary, for example, the opening amount is within a range of about 0.5 mm to 5.0 mm as an example, or It is preferably within a range of about 1.0 mm to 3.0 mm. This is because if the opening amount is too small, the internal gas cannot be discharged satisfactorily, and if it is excessively large, there is a possibility that the fixing portion f1 ′ becomes large and complicated.

  According to such a configuration, when gas is generated and the pressure in the battery case is increased, a force in a direction to separate the flange portions 53 and 63 is applied. When the internal pressure becomes a predetermined value or more, the flange portions 53 and 63 are opened against the urging force of the spring 92, and thereby gas is released to the outside of the case. When the internal pressure is released by the release of this gas and the pressure is reduced, the flange portions 53 and 63 are closed again by the biasing force of the spring 92, and the sealed state is restored again.

  According to the configuration of the present embodiment as described above, the screw 91 interposing the spring 92 is used, and a configuration in which a part on the gas discharge hole side of the battery case is connected by such a fixing portion f1 ′. Therefore, when the internal pressure rises above a predetermined level, the gas discharge hole side is preferentially opened, and the gas can be discharged to the outside from there.

As described above, the invention according to this embodiment is not limited to the above, and various modifications can be made.
(2a) In FIG. 8, the arrangement pitch of the fixed portions is the same as that in FIG. 4 (connection by rigid fixed portions). However, the pitch of the fixed portions is not limited to this, for example, is constant over the entire circumference of the flange (or left and right sides The elastic fixing part f1 ′ as described above may be used only for a part of the side where the gas is to be released.
(2b) The gas discharge hole 75a is preferably provided, but may be omitted.
(2c) Although the spring 92 has been exemplified above, any elastic body (biasing means) can be used as long as one flange portion can be biased toward the other.

(Third embodiment)
Next, another example of a seal member that seals between the flange portions 53 and 63 will be described. FIG. 10 is a perspective view of a seal member used in the present embodiment. FIG. 11 is a plan view of the battery case in which the seal member is disposed as viewed from above the opening of the cup portion. FIG. 12 is a cross-sectional perspective view showing a state in which the seal portion is interposed between the flange portions.

  In the storage battery unit according to one aspect of the present invention, basically any sealing member may be used as long as it can seal between the flange portions 53 and 63 of the battery cover. Therefore, for example, a general O-ring having a circular cross-sectional shape can also be used.

  However, in the case of such a general O-ring, it may take time to arrange the O-ring at a predetermined position of the flange portion 63 (one example) during assembly. In this regard, for example, a groove (for example, a recess having a semicircular cross section) may be formed in the flange portion 63 so as to fit the O-ring shape, and the O-ring may be fitted into the groove.

  However, when the battery cover is formed by drawing (pressing), it may be difficult to form such a groove, or secondary processing may be required. Then, it is preferable as one form of this invention to solve the problem regarding workability by devising the shape of the seal member while using the concave surface portion 65 which is a flat concave portion as shown in FIG. The present inventors have found that.

  Therefore, in this embodiment, a seal member 110 as shown in FIG. 10 is used. The seal member 110 is disposed on the concave surface portion 65 of the flange portion 63, and the overall shape is formed in a substantially quadrangular ring like the concave surface portion 65.

  Specifically, as shown in FIGS. 10 and 12, the seal member 110 includes a thick portion 111 sandwiched between the flange portions 53 and 63, a plurality of pins 115 for positioning the seal member 110, and a thickness. And an extending portion 113 extending inward from the portion 111.

  The cross-sectional shape of the thick portion 111 is not particularly limited, and may be, for example, a circle, a semicircle, an ellipse, a semielliptic, a triangle, a quadrangle, a polygon, or a combination thereof. The thickness of the thick portion 111 is formed to be thicker than the thickness t75 between the recesses (see FIG. 7B) (the compressed state is shown in FIG. 12). In the present embodiment, for example, the thick portion 111 has a circular cross section, and one top side (the upper part in the figure) protruding in an arc shape is in close contact with the flange part of one battery case, and the other top side (the lower part in the figure) ) Is in close contact with the flange portion of another battery case.

  In this example, the pin 115 is formed in a columnar shape, and is provided so as to be outside the thick portion 111 (on the right side in FIG. 12) via the connection portion 114. Although not limited, the pin 115 may be formed in a vertical direction substantially orthogonal to the radial direction of the entire seal member 110 when the radial direction is the horizontal direction. In other words, the pin 115 may be formed in an orientation that is substantially perpendicular to the flange portion 63.

  The pin 115 is inserted into a hole 65 h (see FIG. 11) formed in advance in the flange portion 63 to position the seal member 110 at a predetermined position of the flange portion 63. The pin 115 is also preferably formed in a tapered shape (for example, chamfered or rounded) so that the pin 115 can be easily inserted into the hole 65h.

  The inner diameter of the hole 65h may be the same as or slightly larger than the diameter of the pin 115. All the holes 65 h are formed in the region of the concave surface portion 65.

  Although the length of the pin 115 can be changed as appropriate, for example, it is also preferable in one embodiment that the length of the protrusion from the flange portion 63 when inserted is in the range of 5 to 15 mm. Even if the pin is relatively short and the amount of protrusion is, for example, less than a few millimeters, the positioning effect due to the provision of the pin 115 can be obtained in the same manner, but a relatively long protrusion as described above. In the case of a quantity, there is an advantage that it is possible to visually confirm whether or not the seal member is normally attached during work. In addition, if the length of the pin is too short, it is difficult to insert the pin into the hole.

  In the present embodiment, the pin 115 is described, but any shape may be used as long as it can be attached to the battery cover. For example, it may be configured as a columnar or plate-like protrusion, and a part of the protrusion may be inserted into a hole or an opening formed in the battery cover for positioning.

  In the case of a columnar protrusion, the cross-sectional shape can be any shape, and may be circular, semicircular, elliptical, semielliptical, triangular, quadrangular, polygonal, or a combination thereof.

  Refer to FIG. 10 again. The relationship between the overall shape of the seal member 110 and the number of pins 115 will be described. In the example of FIG. 10, a plurality of pins 115 are provided on each of the short side and the long side of the substantially square seal member 110. Yes.

  Specifically, in this example, the pins 115 are formed at three locations on the short side, and the pins 115 are formed at four locations on the long side. As shown in FIG. 11, a plurality of holes 65 h are formed in the flange portion 63 of the battery cover 61 so as to correspond to the pins 115.

  Note that the pins 115 are not necessarily formed on all sides, and may be provided at only one place on the seal member 110 in some cases. In addition, one or more pins 115 may be provided on at least two sides so that the seal member 110 can be positioned more easily. For example, the pins 115 may be provided only on two opposite sides.

  Next, the extension part 113 will be described. The extending portion 113 is not necessarily essential, but in the configuration in which the seal member 110 is disposed on the flat concave surface portion 65 as in the present embodiment, the seal member 110 may be stably formed on the concave surface portion 65 in some cases. There is also concern that it will be difficult to place. Therefore, in the present embodiment, the extending portion 113 extends from the thick portion 111 toward the inside of the case.

  The extension portion 113 is formed thinner than the thick portion 111 and thinner than the thickness t75 between the recesses. In the example of FIG. 12, the extending portion 113 is formed in a flat plate shape having a uniform thickness, and is formed over the entire circumference of the seal member 111. As shown in FIG. 10, two portions 113 a and 113 a that are partially larger in protruding amount may be formed on a part of the extending portion 113.

  In addition, the extension part 113 does not necessarily need to be formed over the perimeter of the sealing member 110, and may be formed only in part or intermittently.

  The thickness of the extension portion 113 does not need to be constant. In another aspect, the extension portion 113 includes a plurality of portions having different thicknesses (for example, the thickness is gradually or stepwise on the base end side and the tip end side). It may be different, for example, a tapered shape with a tapered tip.

  According to the storage battery unit 10 using the seal member 110 as described above, the pin 115 is inserted into the hole 65h of the battery case at the time of assembly, so that the seal member 110 is attached to the battery case. Therefore, it is possible to perform the assembling work satisfactorily without the seal member 110 being displaced or dropping from the predetermined position in the subsequent work.

  Moreover, since the pin 115 can be visually confirmed from the back side of the flange portion if it is correctly inserted, it is easy to confirm whether or not the seal member 110 is normally attached.

  If the pin 115 is disposed on the inner side of the thick part 111 that provides a sealing action, the hole 65h through which the pin 115 is passed is also formed on the inner side of the thick part 111, and as a result, When the pressure in the case rises, gas may leak from the hole 65h. On the other hand, when the pin 115 is arrange | positioned outside the thick part 111 like this embodiment, a sealing performance is not impaired.

  Furthermore, according to the seal member 110 of the present embodiment, the extending portion 113 is formed even when the seal member 110 is placed on the planar concave surface portion 65. Thus, the seal member 110 can be efficiently installed.

As described above, the invention according to this embodiment is not limited to the above, and various modifications can be made.
(3a) In the above embodiment, the extending portion 113 extends from the thick portion 111 toward the inside of the case. However, the present invention is not limited thereto, and the extending portion 113 extends from the thick portion 111 toward the outside of the case. The structure which extends may be sufficient. Also in this case, the operational effect by providing the extending portion 113 can be obtained in the same manner as described above.
(3b) The pins 115 may all have the same length, but may have different lengths. For example, when the mounting direction of the seal member 110 with respect to the battery cover is determined, the length of the pin 115 on one side and the other side of the seal member 110 (for example, the right side and the left side, or the upper mold and the lower side). May be changed. Thereby, it is possible to check whether the mounting direction of the seal member 110 is correct by looking at the length of the pin 115.

(Appendix)
This application discloses the following inventions:
The reference numerals in parentheses are for reference only and do not limit the present invention.

1. A secondary battery (20);
A housing (50) for housing the secondary battery, comprising a first battery case (51) and a second battery case (61), the flange part (53) of the first battery case and the A housing (50) to which a flange portion (63) of the second battery case is fixed;
A seal member (110) disposed between the flange portions,
The seal member (110)
An annular thick part (111) sandwiched between flange parts,
A protrusion (115) for positioning the seal member with respect to the flange of one of the battery cases;
A storage battery unit (10) having

“Annular” means that the overall shape of the seal member is a closed ring. If another way of living is used, for example, it means that the planar shape of the entire sealing member viewed from above is annular.
The “secondary battery” may be a single battery cell (for example, a film-clad battery) or may be one in which it is housed in a predetermined case.

2. The sealing member (110) further includes
An extending portion (113) extending from the thick portion toward the inside or toward the outside is provided.
“Inside / outside” means inside / outside in the direction along the radial direction of the annular seal member. The “annular shape” is not necessarily limited to an annular shape, and includes a polygonal annular shape.

3. The protrusion (115) is formed outside the thick part.

4). The flange portions (53, 63) are substantially quadrangular, and the seal member (110) is also formed in a correspondingly quadrangular shape (for example, including a quadrilateral with a rounded corner shape), At least one protrusion (115) is formed on each of at least two sides of the seal member (110).

5. At least one protrusion (115) is formed on each of the four sides.

6). In the flange portion of the first or second battery case, a portion where the seal member (110) is disposed is formed as a flat concave surface portion (65). Such a flat surface is preferable in that it can be formed without requiring secondary processing or the like even if it is press working.

7). The protrusion is a pin having a circular cross section. In the case of a circular shape, there is an advantage that the pin can be easily inserted into the hole as compared with the case of a quadrangular shape or an elliptical shape.

8). In a state where the seal member is normally attached, the protrusion is inserted into the hole of the flange portion, and the tip side of the protrusion is the surface of the flange portion on the side where the protrusion is inserted It protrudes with a length of 5 mm to 15 mm from the opposite surface.

9. A power storage device (1) comprising a storage battery unit and at least a frame for holding the storage battery unit.

DESCRIPTION OF SYMBOLS 1 Power storage device 10 Storage battery unit 20 Battery module 21 Storage case 25, 26 Stay 31 Side plate 33 Fixing bolt 50 Sealing housing 51, 61 Battery cover 53, 63 Flange part 54, 64 Convex part 55, 65 Concave part 55a, 65a Gas release Grooves 58 and 68 Cup part 75 Internal space 75a Gas discharge hole 80 Frame 85 Frame body part 89L, 89R Leg part 91 Screw 92 Spring (coil spring)
110 Sealing member 111 Thick part 113 Extension part 114 Connection part 115 Pin (protrusion part)
200 Junction box 201 Storage box 300 Power conditioner 301 Storage case f1 Fixed part (rigid)
f1 'fixed part (elastic)

Claims (9)

A secondary battery,
A housing for housing the secondary battery, comprising a first battery case and a second battery case, wherein a flange portion of the first battery case and a flange portion of the second battery case are fixed. A housing
A seal member disposed between the flange portions,
The sealing member is
An annular thick part sandwiched between flange parts,
A protrusion for positioning the seal member with respect to the flange of one of the battery cases;
A storage battery unit. The sealing member further includes
From the thick part, it has an extending part that extends inward or outward.
The storage battery unit according to claim 1. The protruding portion is formed outside the thick portion,
The storage battery unit according to claim 1 or 2. The flange portion is substantially rectangular;
Correspondingly, the seal member is also formed in a substantially rectangular ring shape, and at least one protrusion is formed on each of at least two sides of the seal member.
The storage battery unit according to any one of claims 1 to 3.   The storage battery unit according to claim 4, wherein at least one protrusion is formed on each of the four sides. In the flange portion of the first or second battery case,
The storage battery unit according to any one of claims 1 to 5, wherein a portion where the seal member is disposed is formed as a flat concave surface portion.   The storage battery unit according to any one of claims 1 to 6, wherein the protrusion is a pin having a circular cross section. In a state where the seal member is normally attached, the protrusion is inserted into the hole of the flange portion, and the tip side of the protrusion is the surface of the flange portion on the side where the protrusion is inserted It is comprised so that it may protrude in the length of 5 mm-15 mm from the surface on the opposite side.
The storage battery unit according to any one of claims 1 to 7. The storage battery unit according to any one of claims 1 to 8,
At least a frame to hold it,
A power storage device comprising:

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