KR20210135785A - Sealed housing for battery pack of electric vehicles - Google Patents

Abstract

The present invention relates to a sealed battery pack housing for an electric vehicle, which comprises: a case formed in a container shape having the open upper part open as an inlet to include a lithium-ion battery module supplying power to a vehicle, a wiring for transmitting electricity from the battery module, and an electric device and control circuit required for controlling a battery; and a cover formed to cover the open upper part of the case from the outside. According to the present invention, a case-side joint part forming a flange shape bent and extended outward is provided on the open upper part of the case and a cover-side joint part forming a flange shape bent outwardly to face the case-side joint part is provided on the lower part of the cover. Coupling holes are installed at a plurality of places on at least one side of the case-side joint part and the cover-side joint part to be fastened by a fastening screw, and a sealing member is installed in a region, which includes a region forming a closed curve encompassing the inlet by turning inside at least the fastening screw, on a coupling surface where the case-side joint part and the cover-side joint part face each other, so that waterproofness is implemented between the joint parts and between the coupling holes and the fastening screws. Accordingly, the battery pack housing can prevent a problem that water flows into the housing and electrical devices and parts are submerged so that the battery is damaged or malfunction is caused.

Description

Sealed housing for battery pack of electric vehicles

The present invention relates to a battery for an electric vehicle, and more particularly, a sealed battery pack for an electric vehicle having a configuration capable of suppressing or preventing the inflow of water from the outside to the inside between the case and the cover in the battery pack for the electric vehicle It's about housing.

Due to the strengthening of international environmental regulations on automobile exhaust gas, the possibility of depletion of oil, and the continued high oil price, the global automobile market is turning from internal combustion engine vehicles to electric vehicles. In particular, pure electric vehicles (EVs) are emerging as an effective global greenhouse gas reduction means and a powerful alternative for a sustainable environment. Meanwhile, sales of electric vehicles (EVs) and hybrid vehicles (HEVs) are significantly increasing as consumers' preference for low-cost fueled vehicles increases due to the burden of rising fuel costs. As a result, advanced countries are strongly promoting electric vehicle supply policies.

Therefore, the capacity and efficiency of the battery, which are key components for operating an electric vehicle, are the most important factors for an electric vehicle, and the drivable distance according to the performance is a big issue. this is rising

Conventional vehicle electric vehicle batteries mainly used lead-acid batteries, but since lead-acid batteries are used as power sources for vehicles, the amount of electricity that can be accumulated compared to weight and volume, i.e., charge capacity, is low, so lithium, which can increase the charge capacity compared to weight, is a lithium battery for electric vehicles. This series of batteries is mainly used.

A battery is basically a device made to make chemical energy compatible with electrical energy, and the use of a secondary battery capable of charging and discharging together is a basic premise due to the characteristics of a vehicle.

In a lithium-ion battery widely used in electric vehicles, a plurality of battery cell units are closely coupled to each other to form a module in order to secure a stable capacity, and a plurality of modules are combined to form a battery pack having sufficient capacity.

However, in a battery pack for an electric vehicle, a housing is used to stably accommodate and mechanically protect a plurality of battery modules including a plurality of battery cells. Such housings therefore require a fairly high level of rigidity.

In addition, due to the nature of the electric device, when the battery for an electric vehicle is submerged, an abnormal current flows due to a short circuit between numerous terminals, resulting in failure or deterioration of a number of electrical components constituting the battery pack. It may cause damage or deterioration of difficult components.

In addition, even if the amount of water flowing into the housing is small and does not cause an electrical problem such as a short circuit, corrosion such as internal rust may occur, which may adversely affect the function or durability.

In particular, the battery pack for an electric vehicle is often installed low in the lower part of the electric vehicle for the purpose of keeping the vehicle's center of gravity low due to its heavy weight. In order to connect the battery pack to the outside of the housing, a passage through which the wiring passes is required, and in many cases, the heating medium of the cooling means passes through the inside and outside of the housing through the piping to dissipate the heat generated during operation of the internal battery, and the container of the housing. It is necessary to detach the upper cover or the side cover to install the module in the mold case.

Therefore, if the lower part of the electric vehicle is partially submerged, even if the battery pack is covered with the housing and the modules, circuit devices, and wiring terminals inside are not exposed to the outside, water flows into the housing and causes the battery to flood. There is a problem with the probability that it will continue.

And, in order to solve this problem, in order to prevent the inflow of water through the housing from the battery pack and the resulting battery inundation, the part in which the wiring for connecting to the outside or the passage of the medium material is formed in the housing, the battery pack cover and the container-type case There are cases where a sealing material is placed in the part where the body is joined to prevent water ingress, but even in this case, the sealing material is specialized for the relevant area and is limited in size and shape, so it is difficult in terms of manufacturing cost. It is responsible for permanent sealing and sealing, such as bonding to a part, and if it is necessary to open such a part, it is necessary to open these parts while destroying the sealing material. There was trouble.

In more detail, it is possible to adopt a sealing method by preparing an exclusive gasket by an injection method using a rubber material for a sealing material and implementing a shape such as a groove that can accommodate it in the housing structure. There may also be a method of coating with a sealing solution that can be applied to the housing assembly.

The sealing structure using a separate gasket mold for sealing the battery pack housing can guarantee sufficient waterproof performance because the method itself is designed as an exclusive structure tailored to the shape of the housing, but the initial mold investment cost and compatibility with other products , manufacturing cost, etc. should be considered.

The method of applying a sealing solution to the housing assembly part for sealing requires a gasket-type maintenance condition, and it is necessary to select a material that maintains waterproofness even when left for a long period of time, and has favorable heat resistance and cold resistance to ambient temperature.

In addition, general sealing solutions have adhesive strength and are attached to the housing member, and although the waterproof effect is excellent, there is a problem in that the assembly part is damaged or removed after re-coating in terms of reassembly and maintenance.

Korean Patent Application 10-2016-0148035

The present invention has a configuration capable of inhibiting and preventing the occurrence of internal corrosion or damage to the battery due to short circuit, etc. due to water inflow from the battery pack for an electric vehicle into the housing and submersion of electrical devices and parts, etc. An object of the present invention is to provide a sealed battery pack housing for an electric vehicle.

The present invention is a sealed battery pack for an electric vehicle having a configuration that does not self-damage and can be reinstalled and reused even when a part installed with a component that prevents water from flowing into the battery pack is opened for maintenance, repair, etc. The purpose is to provide a housing.

The sealed battery pack housing for an electric vehicle of the present invention for achieving the above object,

Lithium-ion battery module for supplying power to the vehicle, wiring for transmitting electricity from the battery module, electric device and control circuit required for battery control, and a case in the form of a container with an open top;

In the battery pack housing for an electric vehicle comprising a cover configured to cover the open upper part of the case from the outside,

The open upper portion of the case is provided with a case side joint in the form of a flange bent outwardly, and the lower portion of the cover is provided with a cover side joint in the form of a flange bent and extended outwardly to face the case side joint,

At least one side of the case-side junction and the cover-side junction is provided with a plurality of coupling holes provided in a plurality of places to be fastened by a fastening screw, and at least on the coupling surface where the case-side junction and the cover-side junction face face each other, at least the fastening screw is rotated inside the inlet. A sealing member is installed in the area including the area forming a closed curve encompassing the

It is made to block the water or other fluid flowing into the gap between the joint and between the coupling hole and the fastening screw.

In the present invention, in the sealing member, the portion exposed to air is dried or cured to solidify, and the contact surface with the joint is an adhesive type having adhesive strength or a non-adhesive type having no adhesive strength, and may be a liquid type gasket formed through liquid coating.

In the present invention, the sealing member may be a solid sheet-type gasket having a through-hole that can be aligned at the position of the coupling hole. In this case, the solid sheet-like sealing member may be formed by mutually fastening a plurality of parts installed for each section with a connecting portion (coupler) using a locking jaw structure.

In the present invention, the periphery of the coupling hole of one junction is bent upward or downward to contact the junction on the other side to secure a clearance space between the two junctions, and the gasket, which is a sealing member, is filled in this clearance space to form a case around the coupling hole. It may be installed to prevent movement of a fluid such as inflow water to the inside.

In the present invention, a packing washer that closely adheres to the screw is installed between the fastening screw head and the adjacent joint to prevent fluid from flowing into the gap between the coupling hole and the fastening screw in the fastening part made of the coupling hole and the fastening screw. In addition or separately, a packing nut that is in close contact with the screw or the end is in close contact with the surface of the joint part may be installed while acting as a nut that surrounds the screw end with a closed curved surface.

According to the present invention, it is possible to suppress or prevent the occurrence of internal corrosion or damage to the battery due to short circuit, etc. due to water inflow from the battery pack for an electric vehicle into the case or housing and flooding of electrical devices and parts. .

According to one aspect of the present invention, even when the part where the component that prevents the inflow of water into the battery pack is opened for maintenance, repair, etc., it is not damaged and can be reinstalled and reused, making it simple and easy Maintenance may be possible.

1 is an exploded perspective view of a first battery pack housing according to an embodiment of the present invention;
Figure 2 is an exploded perspective view of the battery cover shown in Figure 1;
Fig. 3 is a rear view partially showing the battery cover and gasket connection part shown in Fig. 1;
4 is a cross-sectional view of the sealing assembly of the battery pack housing shown in FIG. 1;
5 is an exploded perspective view of a second battery pack housing according to another embodiment of the present invention;
6 is an exploded perspective view of the battery cover shown in FIG. 5;
Fig. 7 is a rear view partially showing the battery cover and gasket connection part shown in Fig. 5;
8 is a cross-sectional view of the sealing assembly of the battery pack housing shown in FIG. 5;
9 is an exploded perspective view of a third battery pack housing according to another embodiment of the present invention;
10 is a rear view showing a gasket application state of the battery cover shown in FIG. 9;
11 is a cross-sectional view of the sealing assembly of the battery pack housing shown in FIG.

A battery pack for an electric vehicle consists of a plurality of battery modules surrounded by a battery pack housing in various forms when viewed schematically, a battery pack case including a battery module and electric devices, and a battery covering the battery pack case. In the case of a hermetic housing, which includes a pack cover, a connector mounting part or a module cover in which various connectors that enable power transmission and communication to the vehicle are installed, and in which the contacting parts of the elements constituting the housing such as the case and the cover are sealed, the housing It may be configured to include a vent device for releasing the pressure when the internal pressure of the battery is generated therein.

In the case of the hermetic housing, since watertightness must be secured between the components of the housing, various gasket members for sealing may be applied or ready-made parts suitable for watertightness may be adopted and used.

Hereinafter, the present invention will be described in more detail through three specific examples with reference to the drawings.

(Example 1)

1 to 4, first, in Example 1, the sealing material is made of a material excellent in environmental factors such as heat resistance and cold resistance and mechanical hardness, and is foamed to form a solid sheet-type gasket 10 having an appropriate thickness. . The sheet-shaped gasket is provided with through-holes 12a spaced apart from each other at a predetermined distance.

Here, the sheet gasket 10 is formed to correspond to the shape of the rim or the joint portion of the housing assembly in which the cover-side joint 30a and the case-side joint 20a come into contact with the sheet-like gasket 10 interposed therebetween, and the gasket member 11 , 12) are formed successively, but the connection portions 11a of the gasket members connected in a male/female form are positioned at appropriate distances. This shape processing can be implemented in an optimized shape so that the residual material of the raw material is not generated by cutting with a wooden die or mold punching processing.

The case side joint 20a of the battery case 20 is configured in the form of a flange bent outwardly from the edge, and a fastening member, here, the press-fitting nut 21, is coupled to the coupling hole 20b arranged at a predetermined distance. do.

The cover side bonding portion 30a of the cover 30 of the battery pack is configured in the form of a flange of a shape corresponding to the case side bonding portion 20a, and is arranged at a predetermined distance and has a coupling hole that can be aligned with the case side coupling hole. have

Here, the sheet-type gasket 10 can be formed of a foaming material having elasticity or elasticity by itself in order to have adhesion to the case side junction part and the cover side junction part. Deformation that is difficult to restore to its original state may result in poor sealing properties, so a space of a predetermined size needs to be secured between the case-side joint and the cover-side joint.

Therefore, here, the peripheral support part 30b is bent so that the periphery of the coupling hole is bent upward or downward to allow space maintenance at the junction of one side of the case 20 and the cover 30 of the battery pack so that the end thereof touches the junction of the other side. ) to form Such a peripheral support may be formed through press burring, etc. together after the formation of the coupling hole or when the coupling hole is formed.

The sheet-like gasket 10 is attached to the cover 30 or case 20 having such a structure, and assembly between the battery case 20 and the cover 30 is performed. The gasket 10 between the cover and the case is deformed to spread around the coupling hole by being compressed by the fastening force that tightens the fastening screw 40 against the press-fitting nut 21, and the coupling support part 30b is the battery case 20. to make contact around the fastening part. Due to the peripheral support portion 30b, the gasket 10 maintains an appropriate thickness or height and maintains adhesion to the surface of the case side joint portion and the cover side joint portion.

In the configuration of this embodiment, a junction part bent outwardly on the cover and the case is formed first, and a coupling hole is formed here to prevent external fluid such as influent water from entering directly into the inner space of the housing when passing through the coupling hole, and secondary As a result, the gasket seals the area around the coupling hole and the assembly area, thereby preventing inflow of water into the battery pack housing and ensuring watertightness.

In particular, when forming the gasket, as shown in FIG. 2 , while forming a rectangle like the rim of the assembly part of the housing, the corner part and the straight part of the side are separated, and the straight part is divided into several sections to form the gasket members 11 and 12. ) and combining them with each other using a clasp or the like to form the entire gasket, it is possible to form gaskets corresponding to various sizes and specifications at a relatively low mold cost.

(Example 2)

5 to 8, the sheet type gasket 50 punched out is used, and the assembly part of the battery pack case and the cover has a flange shape on the outer edge as in the first embodiment. A case-side bonding portion 60a and a cover-side bonding portion 70a are provided.

A welding bolt or welding stud 61 having a predetermined step height from the bonding surface is welded to the case-side bonding portion at a predetermined distance. A coupling hole is formed and arranged at a predetermined distance from the flange-type cover side joint 70a of the battery pack cover, and the coupling hole is installed at an alignment position that can be coupled to a welding stud when assembling the case and the cover.

The sheet-type gasket 50 is first attached to the case-side bonding surface, and the fastening nut 80 is fastened over the coupling hole in a state where the cover coupling hole is penetrated by a welding stud in order to assemble it with the battery pack cover.

Here again, the sheet gasket 50 is formed so as to correspond to the shape of the rim or the joint portion of the housing assembly in which the cover-side joint 70a and the case-side joint 60a come into contact with the sheet-like gasket 50 interposed therebetween, and the gasket member 51 , 52) are formed in succession, but the connecting portion 52a of the gasket member connected to the female/male form or by a locking protrusion is positioned.

The gasket between the cover and the case is compressed by the fastening force between the fastening nut and the welding stud and spreads so as to be in close contact with the outside of the welding stud step (head), and the upper part of the step of the welding stud 61 is Make sure that the surface abuts against the cover-side contact part around the cover-side coupling hole. Due to this step, the gasket maintains an appropriate thickness or height.

The assembly structure of this embodiment 2 has a substantially similar structure as a whole except for using the welding stud 61 instead of the fastening screw 40 of the first embodiment, and thus the action and effect for sealing are also similar. can

Also, here, when forming the gasket, as shown in FIG. 6 , the gasket members 51 and 52 are formed by dividing the short side, the corner part, and the long side straight part while forming a rectangle like the edge of the assembly part of the housing. By combining with each other to form the entire gasket, it is possible to form gaskets corresponding to various sizes and specifications at a relatively low mold cost.

(Example 3)

9 to 11, the configuration of Embodiment 3 uses a liquid gasket 90, and the case 110 of the battery pack housing is provided with a flange-shaped case-side junction outside the rim of the assembly part, A coupling hole (110a) is formed at a predetermined distance in this joint portion, and a rivet nut (111) forming a closed curved surface that is not penetrated is assembled to the coupling hole (110a). A coupling hole 100a is also provided at a predetermined distance from the cover side bonding portion configured in the form of a flange, in contact with the case side bonding portion of the cover 100, and this coupling hole is also formed at a position aligned with the case side bonding hole.

The liquid gasket 90 is applied to the coupling hole 100a and the bonding portion of the cover 100 using an application device, but the coating is applied in a path that goes around the inside of the coupling hole 100a and then cured. When the gasket-installed cover 100 and the case 110 are assembled using the fastening screw 120, the cured liquid gasket 90 is compressed by the fastening force between the fastening screw and the rivet nut, and is sealed while spreading around the application path. will keep

The assembly structure of this embodiment 3 primarily uses the rivet nut 111 that does not penetrate into the fastening part, so that water does not flow into the battery pack housing by using the gap space between the fastening screw and the coupling groove, and secondary As a result, the liquid gasket 90 seals around the coupling hole 100a and the assembly area to prevent water from flowing into the battery pack housing to secure watertightness.

Liquid-type gaskets can also be used by selecting materials that are excellent in environmental factors such as heat resistance and cold resistance, mechanical hardness, compression ratio, and restoring force. For example, the liquid gasket may be cured within a few minutes after application to the sealing portion, and may be applied by mixing a precursor that forms an appropriate hardness with a curing material.

When the contact surface with the joint is exposed to air due to curing and drying, the adhesive force is canceled to form a non-adhesive surface, and the gasket can be destroyed when the cover and case are separated for module replacement or housing internal repair. There is no need, and since the existing gasket can be used even when reassembling, the burden of reforming the liquid type gasket can be eliminated.

In the above, the present invention has been described with reference to limited embodiments, but these are only illustratively described to help the understanding of the present invention, and the present invention is not limited to these specific embodiments.

Accordingly, those of ordinary skill in the art to which the present invention pertains will be able to make various changes or application examples based on the present invention, and it is natural that such modifications or application examples belong to the appended claims.

10, 50: sheet gasket 11, 12, 51, 52: gasket member
11a, 51a: gasket member connection part 12a, 52a: through hole
20, 60, 110: Case 20a, 60a: Case side junction
20b, 100a, 110a: coupling hole 21: press-fit nut
30, 70, 100: cover 30a, 70a: cover side joint
30b: peripheral support 40, 120: fastening screw
61: welding stud (welding bolt) 80: fastening nut
90: liquid gasket 111: rivet nut

Claims (7)

A case comprising a lithium-ion battery module for supplying power to a vehicle, a wiring for transmitting electricity from the battery module, an electric device and a control circuit necessary for battery control, and a container having an open top therein; In the battery pack housing for an electric vehicle comprising a cover configured to cover the open upper part of the case body from the outside,
A case-side junction portion having a flange shape bent outwardly is provided on the upper part open to the inlet of the case, and a cover-side junction part forming a flange shape bent outwardly to face the case-side junction part on the lower part of the cover. provided,
At least one side of the case side junction part and the cover side junction part are provided with coupling holes in a plurality of places so that the coupling holes can be screwed together,
A sealing member is installed in an area including a region that forms a closed curve encompassing the rim of the inlet by at least revolving inside the fastening screw on the opposite coupling surface of the case side junction part and the cover side junction part, so that the case side junction part and A battery pack housing for an electric vehicle configured to block fluid flowing into a gap between the cover-side joint portion and a gap between the coupling hole and the fastening screw. The method of claim 1,
The sealing member is a battery pack for an electric vehicle, characterized in that the portion exposed to air is dried or hardened and solidified, and the contact surface with the cover-side joint portion or the case-side joint portion is non-adhesive, and is formed by applying a liquid gasket. housing. The method of claim 1,
The sealing member is a solid sheet-type gasket having a through hole formed at a position of the coupling hole. 4. The method of claim 3,
The battery pack housing for an electric vehicle, characterized in that the solid sheet-type gasket is formed in a closed curve shape by connecting a plurality of parts installed for each section using a male and female structure or a locking jaw structure. 5. The method according to claim 3 or 4,
The coupling hole of one side of the cover-side junction part or the case-side junction part is bent to the opposite side and made to touch the opposite side, thereby securing a gap space between the cover-side junction part and the case-side junction part,
The solid sheet-type gasket fills the gap space and prevents the fluid from flowing into the inner space of the housing around the coupling hole. 5. The method according to claim 3 or 4,
A fastening screw having a stepped part or a head part is fixed to one side of the cover side junction part or the case side junction part, and it passes through a coupling hole formed on the other side and is fastened to the nut,
The solid sheet gasket is fitted into a gap space secured between the cover-side junction part and the case-side junction part by the step portion to prevent fluid from flowing into the inner space of the housing around the coupling hole. battery pack housing. 3. The method of claim 2,
A rivet nut 111 forming a closed curved surface is fastened to the end of the fastening screw, so that one end of the rivet nut is in watertight contact with the case side junction part or the cover side junction part, or the fastening screw and the rivet A battery pack housing for an electric vehicle, characterized in that watertight adhesion is achieved by pressing between nuts.

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