assembly

Abstract

This instrument is applied to a battery pack (10) comprising a plurality of batteries (50) and a case (90) which is provided with a discharge hole (41) and a sealing member (43) for sealing the discharge hole (41) and which is for storing the batteries (50), and the instrument has a function of discharging a gas from the case (90) and comprises: a base (61) on which the battery pack is mounted; a gas inlet hole (41) formed in the base (61) at a position overlapping the discharge hole (41) of the battery pack; a discharge duct (64) that is a ventilation path formed in the base (61) and that is contiguous with the gas inlet hole (41) so as to guide the gas discharged from the battery pack (10) to the outside of the instrument; and a pressing part (63) that projects from the gas inlet hole (61) and presses the sealing member (43) of the battery pack (10).

Description

[Technical Field]

[0001] The present disclosure relates to a battery pack and an appliance having the ability to vent gas from the battery pack. [Background technology]

[0002] Non-aqueous electrolyte secondary batteries, such as lithium-ion batteries, are sometimes used in the form of a battery pack, in which multiple batteries are electrically connected and housed in a case. If an abnormality occurs in a battery in this battery pack, a large amount of high-temperature flammable gas may be generated from the battery. If this gas is not properly vented to the outside of the battery pack, the internal pressure of the battery pack may increase, which may damage the battery pack case. Generally, battery pack cases are required to have a sealed structure to prevent the intrusion of water and dust into the battery pack. However, if an abnormality occurs in a battery and the internal pressure of the case increases, the gas must be vented to the outside as quickly as possible.

[0003] Battery abnormalities often occur while the battery is being charged while attached to a charger. For example, Patent Document 1 discloses a charger that opens the vent holes of the battery pack when charging the battery pack. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 6-64360 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the charger of Patent Document 1, gas released from the battery pack is expected to accumulate in the gap between the battery pack and the charger, preventing the gas from being released smoothly. Furthermore, the electrode contacts for charging are located in the gap between the battery pack and the charger. If gas is released forcefully, poor contact may occur at the contacts, and since the generated gas is flammable, it may ignite and cause a fire.

[0006] An object of the present disclosure is to provide a means for smoothly and safely releasing gas from a battery pack when an abnormality occurs in the battery and the internal pressure of the battery pack rises. [Means for solving the problem]

[0007] The battery pack of the present disclosure comprises a plurality of batteries and a case that houses the plurality of batteries, the case having a discharge hole formed through the case, a partition wall formed in a cylindrical shape with a bottom so as to surround the discharge hole inside the case, a sealing member provided within the cylindrical partition wall and blocking the discharge hole, and a biasing member provided within the cylindrical partition wall and biasing the sealing member toward the discharge hole, the partition wall having an air vent that forms a gas discharge path together with the discharge hole, and the sealing member configured to move inward when pressed from the outside of the case to open the discharge hole.

[0008] The device with a gas exhaust function disclosed herein is applied to a battery pack including a plurality of batteries, a case that houses the plurality of batteries and has an exhaust hole and a sealing member that blocks the exhaust hole, and includes a base on which the battery pack is placed, a gas inlet hole that is a hole formed in the base and is located at a position that overlaps with the exhaust hole of the battery pack, an exhaust duct that is a ventilation path formed in the base and communicates with the gas inlet hole for guiding gas exhausted from the battery pack to the outside of the device, and a pressing portion that protrudes from the gas inlet hole and presses the sealing member of the battery pack. [Effects of the Invention]

[0009] According to the battery pack and the appliance having a gas exhaust function of the present disclosure, when an abnormality occurs in the battery and the internal pressure of the battery pack rises, gas can be smoothly and safely exhausted from the battery pack. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an external view of a battery pack and a charger according to an embodiment of the present disclosure. [Figure 2] 2 is a cross-sectional view of the battery pack taken along line AA in FIG. 1. [Figure 3] 10 is a cross-sectional view showing a portion of the charger of the present disclosure when the ejection mechanism of the battery pack is activated. FIG. [Figure 4] 1 is a cross-sectional view showing a portion of a battery pack according to the present disclosure when it is mounted on an electrical device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, specific shapes, materials, directions, numerical values, etc. are examples for facilitating understanding of the present disclosure, and can be appropriately changed according to the application, purpose, specifications, etc.

[0012] (First embodiment) FIG. 1 is an external view of a battery pack 10 according to a first embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. As shown in FIGS. 1 and 2, the battery pack 10 includes a plurality of batteries 50 and a case 90. The case 90 includes a case body 20 that houses the plurality of batteries 50, a case lid 30 that closes an opening of the case body 20, and a case bottom 40 that closes an opening of the case body 20. The case 90 has a rectangular cylindrical shape, and each opening of the case body 20 is closed by the case lid 30 and the case bottom 40, respectively, to seal the internal space. This prevents water and dust from entering the case 90. For ease of explanation, the case lid 30 side of the case 90 is referred to as the top, and the case bottom 40 side is referred to as the bottom, and the direction in which the case lid 30, case body 20, and case bottom 40 are aligned is referred to as the up-down direction.

[0013] The plurality of batteries 50 are electrically connected to each other to form a battery pack. The battery pack has a structure in which a plurality of battery groups, each of which is made up of a plurality of batteries 50 connected in parallel, are connected in series, and is configured to output a voltage suitable for the device being used. The battery 50 is, for example, a cylindrical battery. Note that while FIG. 2 illustrates a cylindrical battery as the battery 50, the battery is not limited to a cylindrical battery and may be a prismatic battery, a laminated battery, or the like. The battery 50 may be either an aqueous battery or a non-aqueous battery. An example of a non-aqueous battery is a lithium-ion battery.

[0014] The battery 50 is a cylindrical battery having a cylindrical outer can with a bottom and a sealing body that closes the opening of the outer can. An insulating gasket is provided between the outer can and the sealing body. In a cylindrical battery, the sealing body generally serves as the positive electrode terminal, and the outer can serves as the negative electrode terminal. The sealing body is provided with an exhaust valve for venting gas when an abnormality occurs in the battery 50 and the internal pressure rises. The exhaust valve may also be provided at the bottom of the outer can.

[0015] The plurality of batteries 50 are housed in a holder 51 within the case 90. The holder 51 fixes the arrangement of the batteries 50 and maintains the shape of the assembled battery. The battery pack 10 also includes, for example, terminal plates that electrically connect the plurality of batteries 50. The terminal plates include a positive terminal plate that is electrically connected to the sealing body, which is the positive terminal of each battery 50, and a negative terminal plate that is electrically connected to the outer can, which is the negative terminal of each battery 50. The terminal plates may be integrated with the holder 51.

[0016] The case 90 is provided with external terminals (not shown) electrically connected to each battery 50. The external terminals are provided, for example, on the case bottom 40, and are used as terminals for supplying DC voltage when the battery pack 10 is installed in a device that uses the battery pack 10. The external terminals are also used when charging the battery pack 10 (batteries 50).

[0017] The gas release function of the battery pack 10 will be described in detail with reference to FIGS.

[0018] As shown in FIGS. 1 and 2, the case 90 constituting the battery pack 10 has a case body 20, a case lid 30, and a case bottom 40, and is formed into a rectangular parallelepiped shape that is long in the vertical direction. The case 90 may be made of resin or metal. As described above, the case body 20 is formed into a rectangular cylindrical shape with both the top and bottom ends open. The case 90 has a structure in which the opening on the upper end side of the case body 20 is closed by the case lid 30, and the opening on the lower end side is closed by the case bottom 40. In the internal space of the sealed case body 20, multiple batteries 50 are arranged with their sealing bodies facing the case lid 30, but the number and arrangement of the batteries are not limited to those exemplified in FIG. 2.

[0019] A discharge hole 41 is formed in the case bottom 40, penetrating the case bottom 40. The discharge hole 41 is, for example, a circular hole. A cylindrical partition wall 44 with a bottom is formed inside the case bottom 40, facing the case body 20, so as to surround the discharge hole 41. A spring (biasing member) 42 and a sealing member 43 are housed in the partition wall 44. The spring 42 presses the sealing member 43 toward the discharge hole 41. The sealing member 43 has the same shape as the discharge hole 41 in a plan view but is slightly larger, and closes the discharge hole 41. A vent hole 45 is formed in the partition wall 44, above the sealing member 43 and from the discharge hole 41 upward in the partition wall 44 when the sealing member 43 is pressed against it.

[0020] In the case bottom 40, a spring 42 urges a sealing member 43 to close the exhaust hole 41 in a normal state, thereby preventing gas from being exhausted from the case bottom 40.

[0021] The sealing member 43 can be pushed in from the outside against the elastic force of the spring 42. When the sealing member 43 is pushed in beyond the position of the vent hole 45, the exhaust hole 41 is opened, and together with the vent hole 45, a gas exhaust path is formed.

[0022] As described above, the battery pack 10 is normally kept sealed, and can form a gas discharge means when pressed from the outside.

[0023] The sizes of the exhaust hole 41 and the vent hole 45 are determined so that the gas is appropriately discharged. The gas discharge rate is determined by the pressure in the case 90 and the opening area of the exhaust hole 41 and the vent hole 45. Note that, because the discharged gas contains flammable components, it is necessary to prevent ignition when the gas is discharged from the case 90. As a result of studies by the inventors, it has been found that the gas discharge rate is an important factor in suppressing ignition, and that the ignition suppression effect increases when the gas discharge rate exceeds a certain threshold. For this reason, it is preferable to set the opening area of the exhaust hole 41 and the vent hole 45 so that the gas discharge rate exceeds this threshold.

[0024] In the battery pack 10 of this embodiment, as will be described later, the discharge hole 41 is an opening that receives a pressing portion from the outside, and therefore it is preferable to adjust the opening area of the vent hole 45. By appropriately setting the discharge area of the vent hole 45, it is possible to set the discharge speed.

[0025] The ventilation hole 45 may be formed as a mesh structure in part of the partition wall 44. The mesh structure is a lattice or net-like structure having periodically arranged fine line partitions. The gaps between the fine line partitions serve as openings for gas discharge. For example, the width of the partitions is smaller than the width of the openings, and the opening ratio of the mesh structure (total area of the openings) is set to be greater than 50%. The mesh structure is preferably made of metal.

[0026] By forming the ventilation holes 45 with a mesh structure, it is possible to easily trap sparks while ensuring smooth gas discharge performance. When sparks are efficiently trapped by the mesh structure, the effect of suppressing ignition is further enhanced.

[0027] (Second embodiment) Next, a device having a function of releasing gas from a battery pack will be described with reference to Figures 1 and 3. In this embodiment, a battery pack charger will be described as an example of the device.

[0028] 1 shows a charger 60 for charging a battery pack 10. The charger 60 includes a base 61 for placing the battery pack 10 thereon and a connection terminal 67 for connecting to the charging terminal of the battery pack 10.

[0029] Base 61 serves as a base on which battery pack 10 is placed during charging. Base 61 is provided with gas inlet hole 62. At the bottom of base 61, exhaust duct 64 is provided, which is connected to gas inlet hole 62, passes through the inside of charger 60, and has an opening to the outside.

[0030] It is preferable that the base 61 has a shape corresponding to the bottom surface of the case bottom 40 of the battery pack 10. By forming it in this way, when the battery pack 10 is placed, no gap is formed between the case bottom 40 and the base 61, and gas can be smoothly discharged from the gas inlet hole 62, which will be described next.

[0031] When the battery pack 10 is placed, the gas inlet hole 62 overlaps with the exhaust hole 41 of the battery pack 10 , and introduces gas exhausted from the gas exhaust path of the battery pack 10 and leads it to the exhaust duct 64 .

[0032] The exhaust duct 64 exhausts the gas introduced from the gas inlet hole 62 to the outside of the charger 60. In this embodiment, an opening 66 is provided on a side surface of the charger 60. The opening 66 may be provided on both opposing side surfaces of the charger 60, or on only one side surface.

[0033] A pressing portion 63 for pressing up the sealing member 43 of the battery pack 10 protrudes from the gas inlet hole 62 toward the battery pack 10 above the surface of the base 61. In this embodiment, the pressing portion 63 extends from the exhaust duct 64 through the gas inlet hole 62 and penetrates through to the surface of the base 61. However, the configuration of the pressing portion 63 is not limited to this, and the gas inlet hole 62 may be configured with a pressing portion 63 that protrudes toward the battery pack 10.

[0034] By having the above-described configuration, when the battery pack 10 is placed on the charger 60, the gas exhaust path of the battery pack 10 is opened, and the gas can be exhausted to the outside of the charger 60 through the path shown by the arrow in Fig. 3. This prevents the generated gas from remaining in the gap between the battery pack and the charger, and there is no risk of fire.

[0035] A fire extinguishing agent 65 may be installed in the exhaust duct 64. The location of the fire extinguishing agent 65 is preferably near the opening 66. This allows the fire to be quickly extinguished even if the gas ignites, and prevents the fire from spreading into the battery pack 10. Examples of the fire extinguishing agent 65 include fire extinguishing agents made of bicarbonates or phosphates.

[0036] The exhaust duct 64 may be provided with a mesh-type flame-extinguishing structure at the opening 66. The mesh structure is preferably made of metal. By providing the exhaust duct 64 with a mesh-type flame-extinguishing structure, sparks can be easily trapped while ensuring smooth gas discharge performance. If sparks are efficiently trapped by the mesh structure, the fire suppression effect is further enhanced. Note that although the flame-extinguishing structure is provided at one of the openings 66 of the exhaust duct 64 in FIG. 3, it may be provided at both openings 66. It may also be provided inside the exhaust duct 64, or at multiple locations.

[0037] (Other application examples) Another application example will be described with reference to Fig. 4. Fig. 4 shows a case where the battery pack 10 is installed in an electric device 80 in which the battery pack 10 is used, and is a cross-sectional view including the electric device 80 and a gas discharge mechanism of the battery pack 10.

[0038] When the battery pack 10 is installed in the electrical device 80, the gas discharge mechanism of the battery pack 10 is usually not operating. Therefore, as shown in FIG. 4, the sealing member 43 closes the discharge hole 41, and the battery pack 10 remains sealed.

[0039] An abnormality may occur in the battery pack 10 due to an abnormality in the electrical device 80 or the influence of the ambient temperature, causing an increase in the internal pressure of the battery pack 10. In this case, it is preferable that the gas generated inside the battery pack 10 can be discharged to the outside by pushing up the sealing member 43, which is a gas discharge mechanism provided in the battery pack 10.

[0040] In this case, the pressing portion that pushes up the sealing member 43 is usually housed inside the electrical device 80, and is preferably configured as a movable portion that appears when an abnormality is detected in the battery pack 10. There are no particular limitations on this configuration.

[0041] Regarding abnormalities in the battery pack 10, for example, the temperature of the battery pack 10 can be measured by the electrical device 80, and if the temperature exceeds a predetermined range, an abnormality can be detected. The temperature of the battery pack 10 can be estimated by measuring the temperature of the surface outside the case or at another location. Abnormalities in the battery pack 10 can also be detected by detecting the output voltage of the battery pack 10, etc.

[0042] The above describes embodiments of the present disclosure, but these are merely examples and do not exclude other configurations. For example, in the above embodiments, the battery pack has a rectangular parallelepiped exterior. However, the exterior may be cylindrical, and other shapes are not excluded. Furthermore, while each side of the rectangular parallelepiped has a substantially identical shape, adjacent sides may have different sizes and shapes. The dimensional ratio between the case lid and the case body is not limited to that disclosed in the drawings. Furthermore, the shape of the battery pack when actually used may include protrusions, recesses, handles, terminals, etc., on the periphery. However, these are provided within a range that does not affect the operation of the ejection mechanism described in this disclosure and does not affect the function of the ejection mechanism of this embodiment.

[0043] The battery pack according to the present disclosure can be used as a power supply component for electronic devices. Examples include battery packs for laptops, cleaners, and power tools. It can also be used as a battery for electrically assisted bicycles. It can also be used for battery packs other than those listed here.

[0044] It should be noted that the present disclosure is not limited to the above-described embodiments and their variations, and it goes without saying that various modifications and improvements are possible within the scope of the matters described in the claims of the present application. [Explanation of symbols]

[0045] 10 battery pack, 20 case body, 30 case lid, 40 case bottom, 41 discharge hole, 42 spring (biasing member), 43 sealing member, 44 partition wall, 45 vent hole, 50 battery, 51 holder, 60 charger, 61 base, 62 gas inlet hole, 63 pressing part, 64 discharge duct, 65 extinguishing agent, 66 opening, 67 connection terminal, 70 gas discharge device, 80 electrical equipment, 90 case

Claims

1. An assembly of a battery pack and a charger for charging the battery pack, comprising: The battery pack Multiple batteries and a case that houses the plurality of batteries; Equipped with The case is a discharge hole formed through the case; a partition wall formed in a cylindrical shape with a bottom so as to surround the discharge hole inside the case; a sealing member provided inside the partition wall and closing the discharge hole; a biasing member provided inside the partition wall and biasing the sealing member toward the discharge hole; and the partition wall has a vent hole which forms a gas discharge path together with the discharge hole; the sealing member is configured to move inward when pressed from the outside of the case to open the discharge hole, The charger includes: a base on which the battery pack is placed; a gas introduction hole formed in the base at a position overlapping the exhaust hole of the battery pack; an exhaust duct, which is a ventilation path formed in the base and communicates with the gas inlet hole, for guiding gas exhausted from the battery pack to the outside of the appliance; a pressing portion that protrudes from the gas introduction hole and presses the sealing member of the battery pack; Equipped with an opening communicating with the exhaust duct is provided on a side surface of the charger; an assembly wherein, when the battery pack is placed on the charger, the surface of the case on which the exhaust hole is formed is in contact with the surface of the charger on which the gas introduction hole is formed without any gaps.

2. a part of the partition wall of the battery pack is formed with a mesh structure and forms the ventilation hole; The assembly of claim 1 .

3. The exhaust duct is provided with an anti-inflammatory agent. The assembly of claim 1 .

4. The exhaust duct is provided with a mesh flame-extinguishing structure. The assembly of claim 1 .

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