Battery cooling apparatus for electric vehicle and method of manufacturing same

Disclosed are battery cooling apparatus for electric vehicle, method of manufacturing, and an insulator structure for the apparatus including an insulator having a side wall of the insulator define an upper open part, a tube inserted into the upper open part of the insulator, and a gap filler disposed in a space between an upper surface of the tube and the battery cell, wherein the side wall comprises an inner inclined surface inclined inward and a tube accommodation part formed in an inner surface of the side wall to accommodate an outer part of the tube, and a gap filler application space is formed between the battery cell and the tube, when the tube is inserted between the tube accommodation part of the insulator and an inner bottom surface of the insulator, and a top of the side wall being located higher than the upper surface of the tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119(a) of Korean Patent Application No. 10-2020-0153196, filed on Nov. 16, 2020 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes.

BACKGROUND

The following description relates to a water cooling type or refrigerant type battery cooling apparatus that cools a battery of an electric vehicle using a cooling fluid.

2. Discussion of Related Art

In recent years, the supply of electric vehicles that drive motors using batteries is increasing. The batteries are important components that determine lifetimes and mileages of the electric vehicles. Such batteries generate heat during charging and discharging and require cooling to a predetermined temperature. Currently, an air cooling type using air, a water cooling type using cooling water, and a refrigerant type using a refrigerant are used as such cooling methods. In a cooling method using a cooling fluid, such as the water cooling type or the refrigerant type, a battery cooling apparatus having a cooling passage is mounted in a lower end surface of a battery pack to cool the batteries while the batteries are charged or discharged.

The concept and main configuration of the battery cooling apparatus according to the related art are illustrated inFIGS.1A(front view) and1B (plan view). A coolant or a cooling fluid (refrigerant or cooling water) flows in a tube10below a battery cell30to exchange heat with a cooling/heating target (that is, the battery cell30). In/out pipes12and14are passages through which the cooling fluid is introduced into and discharged from the tube10. A header20connects a plurality of tubes10so that the cooling fluid introduced into and discharged from the in/out pipes12and14flows through the tubes10.

In addition, although not illustrated inFIGS.1A and1B(however, as illustrated inFIG.2), an insulator that insulates the tube10below the battery cell30from external elements, an elastic support that is located on a lower surface of the insulator to support the insulator and to increase surface adhesion between the tube10and the battery cell30, and a pipe connector for assembling the in/out pipes12and14and the header20are added.

In this way, a tube-type battery cooling apparatus according to the related art roughly includes the tube10, the insulator, and the elastic support, and a thermal interface material (TIM) is attached to an upper surface of the tube10and disposed between the tube10and the battery cell30to cool the battery cell30through the heat transfer between the battery cell30and the tube10. The TIM is used to increase a surface adhesion force between the tube10and the battery cell30and to achieve electrical insulation. The TIM has a pad type and liquid type gap filler.

When the pad-type TIM is used, the tube10is supported with a constant force by the elastic support connected to a bottom surface of the tube10for uniform surface adhesion between the tube10and the battery cell30, and the insulator is interposed between the tube10and the elastic support to insulate the tube10. When a gap filler that is the liquid type TIM is used, a separate structure is required so that the gap filler is cured in a state in which a constant thickness is maintained after application.

In the tube-type battery cooling apparatus according to the related art, since a flat surface of the tube is required when the TIM is used, the area of the TIM is increased more than necessary, and thus a weight thereof increases. Further, when the gap filler is used as the TIM, a separate spread plate should be used, and thus there is a risk that more of the filler is used than necessary. Thus, in the current tube-type battery cooling apparatus, when the gap filler is applied, the elastic support is not maintained in the constant thickness, and thus a separate configuration is required.

SUMMARY

In one general aspect, there is provided an apparatus for cooling a batter cell of an electric vehicle, the apparatus including an insulator having an upper open part, and a side wall of the insulator define the upper open part, a tube inserted into the upper open part of the insulator, and a gap filler disposed in a space between an upper surface of the tube and the battery cell, wherein the side wall comprises an inner inclined surface inclined inward and a tube accommodation part formed in an inner surface of the side wall and below the inner inclined surface, the tube accommodation part being configured to accommodate an outer part of the tube, and wherein a gap filler application space is formed between the battery cell and the tube, in response to the tube being inserted between the tube accommodation part of the insulator and an inner bottom surface of the insulator, and a top of the side wall being located higher than the upper surface of the tube.

A compression material may be attached to an upper surface of the side wall.

The compression material may be attached to the upper surface of the side wall by one of bonding, fitting, or simultaneous molding with the insulator.

The battery cooling apparatus may include an excess gap filler discharge hole formed in the side wall, the excess gap filler discharge hole being configured to allow the gap filler to pass through an exterior of the insulator.

The battery cooling apparatus may include a condensed water passage formed in the inner bottom surface of the insulator and through which condensed water generated in the tube flows.

The battery cooling apparatus may include a condensed water discharge hole formed in the condensed water passage, the condensed water discharge hole being configured to discharge condensed water externally.

In another general aspect, there is provided an insulator of a battery cooling apparatus for an electric vehicle, the insulator including a tube for cooling a battery cell and the insulator configured to insulate the tube, wherein the insulator comprises a side wall defining an upper open part of the insulator, and the side wall comprises an inner inclined surface inclined inward and a tube accommodation part formed in an inner surface of the side wall and below the inner inclined surface, the tube accommodation part being configured to accommodate an outer part of the tube, and wherein a gap filler application space is formed between the battery cell and the tube, in response to the tube being accommodated between the tube accommodation part and an inner bottom surface of the insulator, and a top of the side wall being located higher than the upper surface of the tube.

A compression material may be attached to an upper surface of the side wall.

The compression material may be attached to the upper surface of the side wall of the upper open part of the insulator by one of bonding, fitting, or simultaneous molding with the insulator.

In another general aspect, there is provided a method of manufacturing a battery cooling apparatus for a battery cell of an electric vehicle, the method including forming an insulator having an upper open part and a side wall defining the upper open part, the side wall including an inner inclined surface inclined inward and a tube accommodation part formed in an inner surface below the inner inclined surface and being configured to accommodate an outer part of the tube, inserting the tube in the tube accommodation part formed between the inner inclined surface and an inner bottom surface of the insulator to form a gap filler application space in an upper surface of the tube, applying a gap filler to the gap filler application space, and assembling a battery on the upper surface of the tube to which the gap filler is applied.

The forming of the insulator may include attaching a compression material to an upper surface of the side wall.

The attaching of the compression material may include attaching the compression material to the upper surface of the side wall by one of bonding, fitting, or simultaneous molding with the insulator.

The forming of the insulator may include forming an excess gap filler discharge hole in the side wall to allow the gap filler to pass through an exterior of the insulator.

The forming of the insulator may include forming a condensed water passage in the inner bottom surface of the insulator and through which condensed water generated in the tube flows.

The forming of the insulator may include a condensed water discharge hole formed in the condensed water passage, and the condensed water discharge hole being configured to discharge the condensed water externally.

DETAILED DESCRIPTION

Also, in the description of the components, terms such as first, second, A, B, (a), (b) or the like may be used herein when describing components of the present disclosure. These terms are used only for the purpose of discriminating one constituent element from another constituent element, and the nature, the sequences, or the orders of the constituent elements are not limited by the terms. When one constituent element is described as being “connected”, “coupled”, or “attached” to another constituent element, it should be understood that one constituent element can be connected or attached directly to another constituent element, and an intervening constituent element can also be “connected”, “coupled”, or “attached” to the constituent elements.

Advantages and features of the present disclosure and a method of achieving the advantages and the features will become apparent with reference to embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments described below and may be implemented in various different forms. The embodiments are merely provided to completely disclose the present disclosure and to completely inform the scope of the disclosure of those skilled in the art to which the present disclosure pertains, but the present disclosure is defined by the appended claims. Further, terms used in the present specification are intended to describe the embodiments and are not intended to limit the present disclosure. In the present specification, a singular form also includes a plural form unless specifically mentioned. Further, terms (“comprise, comprising, and the like”) used herein do not exclude the presence or addition of one or more other components, steps, operations, and/or elements other than components, steps, operations, and/or elements mentioned above. Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In description of the embodiments, when a detailed description of related widely known configurations or functions makes the subject matter of the present disclosure unclear, the detailed description will be omitted.

FIG.2is a view illustrating a configuration of a tube-type battery cooling apparatus according to the present disclosure.

A tube10in contact with a battery cell30or a cooling fin (not illustrated) is assembled so that a lower surface thereof is covered with an insulator50for heat insulation from the outside. The insulator50has a shape having an upper open part having an open upper side and thus the tube10is seated on the insulator50through the upper open part. A lower surface of the insulator50is connected to an elastic support70through a connector60. When the elastic support79is mounted on an external component (a housing, a vehicle body, or the like), the elastic support70pushes the insulator50assembled with the tube10upward with a constant force, thereby increasing a surface adhesion force between the battery cell30and the tube10. Meanwhile, after the tube10is seated through the upper open part of the insulator50, a liquid gap filler45is applied or a pad-type thermal interface material (TIM) is inserted between an upper surface of the tube10and a lower surface of the battery cell30. thereby further increasing the surface adhesion force.

As illustrated in an enlarged view on a right side ofFIG.2, an edge surface of a side wall defining the upper open part of the insulator50forms an inner inclined surface52inclined inward, and a tube accommodation part54accommodating an outer part of the tube10is formed in an inner surface below the inner inclined surface52. The tube accommodation part54is recessed inward so that the tube10is accommodated between the inner inclined surface52of the side wall of the upper open part of the insulator50and an inner bottom surface of the insulator50(seeFIG.6for a state in which the tube10is assembled with the insulator50).

When the tube10is assembled inside the insulator50with such a structure, the side wall of the upper open part of the insulator50is located higher than the upper surface of the tube10. Accordingly, when the liquid gap filler45is applied to the upper surface of the tube10, the gap filler45may be cured between the upper surface of the tube10and the lower surface of the battery cell30while being maintained in a constant thickness. Further, even when not a liquid pad-type TIM but a solid pad-type TIM is attached, the side wall of the upper open part of the insulator50may serve as a guide for the TIM.

FIG.3illustrates that a compression material56is attached to an upper surface of the side wall of the upper open part of the insulator50, that is, a surface in contact with the lower surface of the battery cell30. The compression material56serves as a buffer for absorbing an assembly step of the battery cell30or the cooling fin (not illustrated) (seeFIG.4) and allows the gap filler45to maintain a constant thickness after the gap filler45is cured.

FIG.4illustrates a principle that the compression material56serves as a buffer for absorbing the assembly step of the battery cell30. As illustrated inFIG.4, the compression material56absorbs the positional deviation between respective cells constituting the battery cell30, and thus the side wall of the insulator50may come into contact with the battery cell30with a constant force on an entirety of an upper side wall of the insulator50.

The compression material56may be adhesively attached to the upper surface of the side wall defining the upper open part or may be fastened to the upper surface of the side wall through a fitting structure in a predetermined manner. Alternatively, the compression material56may be manufactured at the same time as the insulator50by a method such as insert injection during injection molding of the insulator50.FIGS.5A-5Cillustrate examples of various attachment/formation methods of the compression material56.

FIG.5Aillustrates a state in which the compression material56is attached to the upper portion of the side wall of the upper open part of the insulator50from an outer side to an upper side of the upper portion in an L shape, andFIG.5Billustrates that a groove is formed in the upper surface of the side wall of the upper open part of the insulator50and the compression material56is fitted and attached to the groove. Further,FIG.5Cillustrates that the compression material56is simultaneously insert-injected and molded on the upper surface of the side wall of the upper open part of the insulator50during the injection molding of the insulator50.

FIG.6is a perspective view illustrating a state in which the tube10is assembled inside the insulator50.FIG.6also illustrates an excess gap filler discharge hole57formed in the side wall of the upper open part of the insulator50to allow the liquid gap filler45to pass through the exterior of the insulator50. Even when an excessive amount of the gap filler45is applied to the upper surface of the tube10, since the excess gap filler45is discharged through the gap filler discharge hole5when the battery cell30is assembled, a constant amount of the gap filler45always remains and is cured between the tube10and the battery cell30. At least one gap filler discharge hole57may be formed to discharge the excess gap filler.

FIG.7illustrates the inner bottom surface of the insulator50before the tube10is assembled in order to describe components formed on the inner bottom surface of the insulator50. A condensed water passage58, through which condensed water generated by a cooling operation of the tube10flows, is formed in the inner bottom surface of the insulator50. Further, a condensed water discharge hole59through which the condensed water is discharged externally is formed in a bottom surface of the condensed water passage58. That is, the condensed water generated in the tube10falls down, is collected and flows in the condensed water passage58, and is discharged externally through the condensed water discharge hole59. In order to increase the effect of the condensed water discharge action, a plurality of condensed water passages58and a plurality of condensed water discharge holes59may be installed.

Described above are a battery cooling apparatus for an electric vehicle, a method of manufacturing the same, and an insulator structure for a battery cooling apparatus which, in a system for cooling a battery using a cooling fluid, increase surface adhesion between a tube and a battery cell so as to increase the cooling efficiency and prevent the degradation of the battery.

Described above are a battery cooling apparatus including a configuration in which a gap filler is applied between a tube and a battery cell and is cured and a constant interval is then maintained between the tube and the battery cell and a configuration in which a compression material is attached to an insulator so that the assembly deviation between the insulator and the battery cell is absorbed, a method of manufacturing the same, and an insulator used therein.

According to the present disclosure, by improving a structure of an insulator assembled with a tube, a side wall of an upper open part of the insulator is configured to accommodate a liquid gap filler, and thus a constant amount of the gap filler can be easily applied to a required part. Further, a compression material is attached to an upper surface of the side wall, thereby absorbing the assembly step of a battery cell and thus increasing the surface adhesion properties. In this way, the gap filler is applied only to the required part, and thus the application amount can be reduced and the weight of the entire cooling apparatus can be reduced. Further, a configuration for discharging condensed water is added to the insulator, and thus problems caused by the condensed water can be easily solved.