KR102528689B1 - Venting device for battery pack - Google Patents

Abstract

The present invention relates to a venting device for a battery pack and, more specifically, to a venting device for a battery pack, which not only can resolve a pressure difference between the inside and outside of the battery pack in normal times, but also rapidly discharge erupted gas to the outside when the gas is erupted due to an event generated in the battery pack. The venting device for a battery pack according to the present invention comprises a housing means, a cover means, a packing seal, and an elastic restraint unit. The housing means has a housing with a ventilation hole passed through in an axial direction to communicate with the inside of the battery pack and a bolt unit for mounting the housing to the battery pack, so that the housing means is mounted on the battery pack. The cover means has a membrane that allows air to pass between the inside and outside of the battery pack, but blocks the passage of moisture, so that the cover means is detachably mounted on the ventilation hole. The packing seal seals a gap between the cover means and the ventilation hole when the cover means is inserted into the ventilation hole. The elastic restraint unit has one side joined to the cover means and the other side joined to the inside of the housing means to elastically support the cover means such that the cover means deviates by a certain distance from the ventilation hole when the inside of the battery pack is pressurized above a certain pressure.

Description

Venting device for battery pack {Venting device for battery pack}

The present invention relates to a venting device for a battery pack, and more particularly, can relieve the pressure difference between the inside and outside of the battery pack in normal times, and rapidly expel the ejected gas when gas is ejected due to the generation of an event in the battery pack. It is about a venting device for a battery pack that can be discharged to the outside.

In the secondary battery, an internal short-circuit due to overcharging or failure may occur or gas may be generated from the inside during repeated charging and discharging, which is referred to as venting gas. For example, when an overcurrent flows, the temperature of the secondary battery inside rises rapidly. Such a rapid increase in temperature may cause a decomposition reaction of the electrolyte solution and thus gas may be generated. When gas is generated inside the battery pack, the battery pack may be deformed, damaged, or exploded if the gas is collected inside the pack. To this end, a venting device is provided in the battery pack to reduce internal pressure by discharging internal gas to the outside.

On the other hand, since the pressure of the battery pack increases or decreases when the temperature of the battery cell increases or decreases, the pressure difference as well as heat exchange must be resolved through exchange with external air. Therefore, the battery pack requires a breathing device that can communicate with outside air.

Patent Publication No. 10-2022-0008602 (published on January 21, 2022) Patent Publication No. 10-2021-0091514 (published on July 22, 2021) Registered Patent No. 10-2181521 (Registered on November 16, 2020) Patent Publication No. 10-2020-0107214 (published on September 16, 2020)

Since the conventional venting device has only a discharge passage through which gas can be discharged when gas is ejected due to an abnormality of the battery pack, there is a problem in that a breathing device capable of resolving the temperature or pressure difference between the inside and outside of the battery is separately required.

The present invention is to solve the above problems. An object of the present invention is to provide a venting device capable of exchanging air with the outside as well as rapidly discharging gas to the outside when gas is ejected due to an abnormality in a battery pack.

A venting device for a battery pack according to the present invention includes a housing means, a lid means, a packing seal, and an elastic restraint. The housing means includes a housing formed with an axially penetrating ventilation hole so as to communicate with the inside of the battery pack, and bolts for attaching the housing to the battery pack, and is mounted on the battery pack. The lid member has a membrane membrane that allows air to pass between the inside and outside of the battery pack but blocks moisture from passing therethrough, and is detachably mounted in the ventilation hole. The packing seal seals a gap between the lid member and the ventilation hole when the lid member is inserted into the ventilation hole. One side of the elastic constraining part is coupled to the lid member so as to elastically support the lid member so that the lid member can deviate from the ventilation hole by a predetermined distance when the inside of the battery pack is pressurized to a predetermined pressure or more. The other side is coupled to the inside of the housing means.

In addition, in the above venting device for a battery pack, it is preferable that the lid means further includes a lower lid and an upper lid. In the lower lid, a through hole closed by the membrane is formed in a central portion to close the ventilation hole, and one side is coupled to the other side of the elastic restraining part. The upper cover is coupled to the lower cover to form an exhaust passage communicating with the outside by being spaced apart from the top of the lower cover at a predetermined interval so that air passing through the membrane from the inside can be discharged to the outside.

In addition, in the venting device for a battery pack, the lower cover includes a lower disc portion having a through hole formed in a central portion to close the ventilation hole, and a predetermined distance from the through hole in the upper surface of the lower disc portion in a radial direction. It is preferable to include a plurality of coupling protrusions protruding at regular intervals in the circumferential direction at a spaced distance from each other, and a locking protrusion protruding so that the elastic limiting portion is coupled to the lower surface of the lower disc portion. In this case, the membrane is bonded to and bonded to the upper surface of the lower lid to block the through hole. The upper lid includes an upper disk part coupled to the coupling protrusion to cover the member lane film at a predetermined interval so as to form the exhaust passage, and an edge of the member lane film so that the member lane film does not separate from the lower disc part. It is provided with a pressing protrusion protruding at a predetermined interval along the circumferential direction from the lower surface of the upper disc portion so as to be able to press.

In addition, in the venting device for a battery pack, the packing seal is inserted between the ventilation hole and the lower disk portion so that the upper end can protrude, and a ring portion for sealing the ventilation hole and the lower disk portion, and an end portion It is preferable to have a roof portion extending in a radial direction to be tapered from an upper end of the ring portion to an end portion so as to contact and seal the upper surface of the housing.

In addition, in the venting device for a battery pack, the housing preferably has a stopper protrusion protruding from an inner circumferential surface to support a bottom surface of the upper lid so that the upper lid can be inserted only to a certain depth. In this case, the upper lid has a central portion penetrated and is spaced apart from the upper disk portion at a predetermined interval so that the outside and the inside can communicate, a roof disk portion for pressing the upper end of the roof portion, and the roof disk portion to the upper disk portion. In order to fix it, one end is coupled to the roof disc portion and the other end is coupled to the upper disc portion to further include a plurality of supports formed along the circumferential direction.

Further, in the venting device for a battery pack, it is preferable that fixing grooves into which both ends of the elastic restraining part are inserted are further formed on an inner circumferential surface of the housing along a circumferential direction. In this case, the elastic restraining part is a plate spring whose central portion is coupled to the restraining protrusion and both ends of which are inserted into the fixing groove so as to be bent to apply force to the lower lid in a direction to close the ventilation hole.

According to the present invention, air can flow from the inside to the outside or from the outside to the inside of the battery pack through the membrane attached to the lower lid in normal times. In addition, when an emergency ventilation is required to discharge the gas to the outside due to a gas ejection inside the battery pack due to an abnormality of the battery pack, the cover means is opened from the housing means to eject the gas generated inside the battery pack to the outside. Therefore, the venting device according to the present invention can perform gas discharge as well as breathing without a separate device.

1 is a cross-sectional view of an embodiment of a venting device for a battery pack according to the present invention;
Figure 2 is a cross-sectional view at the time of emergency ventilation in the embodiment of Figure 1;
3 and 4 are conceptual views of the lower lid of the embodiment shown in Figure 1;
5 and 6 are conceptual views of the upper lid of the embodiment shown in FIG.

An embodiment of a venting device for a battery pack according to the present invention will be described with reference to FIGS. 1 to 6 .

A venting device for a battery pack according to the present invention includes a housing means 10, a lid means 20, a packing seal 40, and an elastic restraining part 50.

The housing means 10 includes a housing 11 and a bolt part 15 and is mounted on the battery pack 1 . The housing 11 is formed with a ventilation hole 12 for discharging gas ejected from the battery pack 1 as well as allowing air to be introduced and discharged in order to eliminate the pressure difference of the battery pack 1 . Thus, the ventilation hole 12 is formed to penetrate in the axial direction so that the inside and outside of the battery pack 1 can communicate with each other. In addition, a stopper protrusion 13 is formed on an inner circumferential surface of the housing 11 to support the cover means 20 so that the cover means 20 can only be inserted to a certain depth when the cover means 20 is inserted into the ventilation hole 12. That is, when the lid means 20 is inserted into the ventilation hole 12 to block the ventilation hole 12, it can be inserted only as much as the stopper protrusion 13 exists. In addition, the housing 11 has a fixing groove 14 formed along the circumferential direction so that both ends of the elastic restraining portion 50 can be inserted into the inner circumferential surface.

The bolt part 15 mounts the housing 11 to the battery pack 1 . The bolt unit 15 includes bolts and nuts to fix the outer circumferential surface of the housing 11 to the battery pack 1 . At this time, when the housing 11 is mounted on the battery pack 1 with the bolt part 15, the O-ring 16 may be used to block leakage.

The lid means 20 closes the ventilation hole 12 to allow air to pass through the ventilation hole 12 in normal times and to prevent external moisture from penetrating into the inside, but gas is ejected from the battery pack 1 When the internal pressure increases to a certain pressure or higher, it serves to open the ventilation hole 12 so that gas can be discharged. To this end, the lid means 20 includes a membrane 21, a lower lid 23, and an upper lid 27.

The membrane 21 allows air to pass through, but does not pass moisture.

The lower lid 23 is inserted into the ventilation hole 12 to close the ventilation hole 12, and includes a lower disk 24, a coupling protrusion 25 and a restraining protrusion 26. The lower disc 24 has a through hole 24a formed in the center thereof and is inserted to close the vent hole 12. When the lower disc 24 is inserted into the vent hole 12, it is supported by the stopper protrusion 13. . The through hole 24a is closed by the membrane 21 . The membrane film 21 is bonded with an adhesive on the top of the lower lid 23 to close the through hole 24a. That is, the edge of the lower surface of the membrane 21 is bonded to the upper portion of the lower lid 23 with an adhesive to close the through hole 24a. So, when the lower lid 23 is inserted into the ventilation hole 12, air can pass through the membrane 21, but moisture is blocked. The coupling protrusion 25 is a portion coupled with the upper lid 27. To this end, the coupling protrusions 25 are spaced apart at regular intervals in the circumferential direction so as to surround the through-holes 24a at regular intervals in the radial direction from the through-holes 24a on the upper surface of the lower disc portion 24. do. Since the coupling protrusions 25 protrude at regular intervals along the circumferential direction, a passage is formed between the coupling protrusions 25 . The air discharged through the membrane membrane 21 goes out through the passage between the coupling protrusions 25, or the outside air flows in through the passage between the coupling protrusions 25 to break the membrane 21. can pass

The restraining protrusion 26 protrudes so that the elastic restraining part 50 is coupled to the lower surface of the lower disk part 24 .

The upper cover 27 is an exhaust passage 35 spaced apart from the upper part of the lower cover 23 at a predetermined interval and communicating with the outside so that air passing through the membrane 21 inside the battery pack 1 can be discharged to the outside. ) is coupled to the lower lid 23 to form, and serves to protect the membrane 21. To this end, the upper lid 27 includes an upper disc portion 28, a pressing protrusion 29, a roof disc portion 23, and a support 33.

The upper disc portion 28 is coupled to the coupling protrusion 25 to cover the member lane film 21 at a predetermined interval so as to form an exhaust passage 35 . That is, since the coupling protrusion 25 protrudes on the upper surface of the lower disc portion 24, when the upper disc portion 28 is coupled to the coupling protrusion 25, it is spaced apart from the lower disc portion 24 at a predetermined interval, and the exhaust passage 35 ) is formed. When the pressure inside the battery pack 1 increases, the air inside is discharged to the membrane 21 and is discharged to the outside through the exhaust passage 35 between the upper disc part 28 and the lower disc part 24. may be discharged. When the upper disc portion 28 is coupled to the coupling protrusion 25, it may be coupled by a method such as ultrasonic welding. In addition, since the upper disc portion 28 is located above the member lane film 21, it can prevent external foreign substances from impacting the member lane film 21, thereby protecting the member lane film 21. .

The pressing protrusion 29 is a part of the upper disc portion 28 to press the edge of the member lane film 21 adhered to the lower disc portion 24 when the upper disc portion 28 is coupled to the coupling protrusion 25. The protrusions are spaced apart at regular intervals along the circumferential direction from the lower surface. Since the pressing protrusions 29 are also spaced at regular intervals along the circumferential direction, a gap is formed between the pressing protrusions 29 like the coupling protrusions 25 to form an exhaust passage 35 . That is, the air discharged to the member lane film 21 is emitted from the gap between the pressing protrusions 24, the space between the upper disc portion 28 and the lower disc portion 24, and the gap between the coupling protrusions 25. It can be discharged to the outside through, or it can be introduced through the opposite path. Since the pressing protrusion 29 presses the edge of the member lane film 21, the member lane film 21 is prevented from being separated from the lower lid 23.

The roof disc portion 31 serves to press the packing seal 40. To this end, the central portion of the roof disc portion 31 penetrates and is spaced apart from the upper disc portion 28 at a predetermined interval so that the outside and the inside can communicate. That is, there is a gap between the roof disk part 31 and the upper disk part 28 so that air can exchange with each other.

The support 33 has one end coupled to the roof disk portion 31 and the other end coupled to the upper disk portion 28 so as to fix the roof disk portion 31 to the upper disk portion 28. dogs are formed

The packing seal 40 seals between the lower lid 23 and the ventilation hole 12 when the lower lid 23 is inserted into the ventilation hole 12 . At this time, the packing seal 40 includes a ring portion 41 and a roof portion 43 .

The ring part 41 is inserted between the vent hole 12 and the lower disk part 24 so that the upper end can protrude, and seals the space between the vent hole 12 and the lower disk part 24. The roof portion 43 extends radially from the upper end of the ring portion 41 to the end so that the end portion contacts the upper surface of the housing 11 to be sealed. The roof portion 43 is spaced apart from the upper surface of the housing 11 and is attached to the upper surface of the housing 11 while gradually decreasing in thickness toward the end. Since it has a shape in which the thickness gradually decreases, it can be adhered to the upper surface of the housing 11 with a small force, and when water pressure is generated from the outside, the contact area increases and the airtightness can be improved.

The elastic restraining part 50 elastically applies force so that the cover means 20 comes into close contact with the housing 11, and when the inside of the battery pack 1 is pressurized above a certain pressure, the cover means 20 opens the ventilation hole. Supports the lid means 20 so that it can be opened at (12). To this end, in the case of this embodiment, the elastic restraining part 50 is implemented as a leaf spring, both ends are inserted into the fixing groove 14 of the housing 11, and the central part is coupled to the restraining protrusion 26 of the lower lid 23. Combined with (51). At this time, the elastic restraining part 50 is bent to apply force in the direction in which the lid member 20 is inserted into the ventilation hole 12, as shown in FIG. 1 in normal times. Therefore, since the elastic restraining part 50 applies force to the lid member 20 in the closing direction, the lid member 20 does not escape from the ventilation hole 12 . However, when gas is ejected from the inside of the battery pack 1 and rises above a certain pressure, the cover means 20 receives force, and as shown in FIG. 2, the cover means 20 is separated from the ventilation hole 12 and elastic. The restricting portion 50 is bent in a direction opposite to that of FIG. 1 . In this case, since the ventilation hole 12 is opened, gas ejected from the battery pack 1 can be rapidly discharged to the outside. In the case of this embodiment, a pair of elastic restraints 50 cross each other in a cross shape and are coupled to the restraining protrusions 26 .

In the case of the present embodiment, as shown in FIG. 1 , the cover member 20 receives force by the elastic restraining part 50 and closes the ventilation hole 12 of the housing 11 in normal times. At this time, since the membrane film 21 can pass air, air can flow into or flow out of the battery pack 1 through the exhaust passage 35 as shown by arrow A. Thus, the pressure inside the battery pack 1 can be adjusted. Meanwhile, since the membrane 21 allows air to pass through but does not pass moisture, it is possible to block moisture from entering the inside of the battery pack 1 from the outside. In addition, the upper disc portion 28 is positioned above the membrane 21 to prevent external foreign substances from impacting the membrane 21 .

When abnormal gas is generated in the battery pack 1 due to an abnormality of the battery pack 1 and the pressure is increased, the abnormal gas must be ejected to the outside to prevent the battery pack 1 from exploding. In this case, the cover means 20 is opened as shown in FIG. 2 by the gas pressure. Then, the generated gas can be rapidly discharged to the outside as indicated by arrow B.

Therefore, according to the present embodiment, it is possible to keep the internal pressure of the battery pack 1 constant by enabling the flow of air to the inside and outside of the battery pack 1 in normal times, and to keep the battery pack 1 constant in an emergency. The generated gas can be released.

1: battery pack 10: housing means
11: housing 12: ventilation hole
13: stopper protrusion 14: fixing groove
15: bolt part 20: lid means
21: membrane membrane 22: lower lid
24: lower disc portion 24a: through hole
25: coupling protrusion 26: restraining protrusion
27: upper lid 28: upper disk part
29: pressing protrusion 31: roof disk part
33: support 35: exhaust passage
40: packing seal 41: ring part
43: roof part 50: elastic restraint part

Claims (6)

A housing having a housing formed with an axially penetrating ventilation hole so as to communicate with the inside of the battery pack, and a housing means mounted on the battery pack including a bolt unit attaching the housing to the battery pack;
a lid means detachably mounted to the ventilation hole and having a membrane membrane that allows air to pass between the inside and outside of the battery pack but blocks moisture from passing therethrough;
a packing seal for sealing between the lid member and the ventilation hole when the lid means is inserted into the ventilation hole;
When the inside of the battery pack is pressurized to a predetermined pressure or higher, one side is coupled to the lid member and the other side is coupled to the housing so as to elastically support the lid member so that the lid member can deviate from the ventilation hole by a predetermined distance. A venting device for a battery pack, characterized in that it comprises an elastic restraint coupled to the inside of the means. The method of claim 1, wherein the lid means
A lower lid having a through hole closed by the membrane formed in the central portion to close the ventilation hole and having one side coupled to the other side of the elastic restraining portion;
Further comprising an upper lid coupled to the lower lid to form an exhaust passage communicating with the outside by being spaced apart from the top of the lower lid at a predetermined interval so that air passing through the membrane from the inside can be discharged to the outside. A venting device for a battery pack characterized by According to claim 2,
The lower lid includes a lower disc portion having the through hole formed in the central portion to close the ventilation hole, and a predetermined interval along the circumferential direction at a distance from the through hole in the radial direction to the upper surface of the lower disc portion. A plurality of protruding coupling protrusions and a protruding restraining protrusion so that the elastic limiting portion is coupled to the lower surface of the lower disc portion,
The membrane film is bonded to and bonded to the upper surface of the lower lid to block the through hole,
The upper lid includes an upper disk portion coupled to the coupling protrusion to cover the member lane membrane at a predetermined interval so as to form the exhaust passage, and an edge of the member lane membrane to prevent the member lane membrane from being separated from the lower disk portion. A venting device for a battery pack, characterized in that it includes pressing protrusions spaced apart from the lower surface of the upper disc portion at a predetermined interval in a circumferential direction so as to be pressurized. According to claim 3,
The packing seal is inserted between the ventilation hole and the lower disc portion so that the upper end can protrude, and a ring portion for sealing between the ventilation hole and the lower disc portion, and an end portion can contact the upper surface of the housing to seal it. A venting device for a battery pack, characterized in that it has a roof portion extending in the radial direction tapering from the top of the ring portion to the end. According to claim 4,
The housing has a stopper protrusion protruding from the inner circumferential surface to support the lower end of the upper lid so that the upper lid can be inserted only to a certain depth,
The upper cover has a central portion penetrated and is spaced apart from the upper disk portion at a predetermined interval so that the outside and the inside can communicate, a roof disk portion for pressing the upper end of the roof portion, and the roof disk portion being fixed to the upper disk portion. In order to do so, the venting device for a battery pack, characterized in that it further includes a plurality of supports formed along the circumferential direction with one end coupled to the roof disc portion and the other end coupled to the upper disc portion. According to claim 5,
The housing is further formed with a fixing groove for inserting both ends of the elastic restraining part along the circumferential direction on the inner circumferential surface,
The elastic restraining part is a plate spring whose central portion is coupled to the restraining protrusion and both ends of which are inserted into the fixing groove so as to be bent to apply force to the lower lid in a direction of closing the ventilation hole.

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