Underbody for vehicles

Abstract

The present invention relates to an underbody for a vehicle, comprising: a tray member secured to the lower portion of a chassis frame and including a receiving portion with an open lower surface for receiving a battery module; and a cover member covering the open lower surface of the receiving portion, wherein the cover member includes a fluid channel through which a refrigerant flows. This underbody ensures sufficient space for receiving the battery module, eliminating the need for a separate battery tray assembly after vehicle manufacture, and effectively cooling the received battery module.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2019-0096006, filed on August 7, 2019, and the entire contents of the Korean Patent Application are incorporated herein by reference.

[0002] The present invention relates to an underbody for a vehicle, and more particularly, to an underbody that is directly fastened to a lower portion of a vehicle body frame and is capable of storing a battery module therein. Background Art

[0003] As energy prices rise due to the depletion of fossil fuels and people's concerns about environmental pollution increase, the demand for environmentally friendly alternative energy sources is also increasing. In particular, conventional cars that use fossil fuels emit pollutants, which are a major cause of environmental pollution.

[0004] In recent years, environmentally friendly vehicles that can reduce environmental pollution are attracting attention as a means to replace conventional vehicles that use only fossil fuels. Environmentally friendly vehicles include those that obtain driving power from secondary batteries, such as hybrid or electric vehicles.

[0005] Hybrid or electric vehicles have a structure in which a battery pack or battery module, consisting of multiple secondary batteries, is mounted on the vehicle body. To increase the vehicle's range and power, a relatively large-capacity battery pack is required. However, mounting large-capacity battery modules on the vehicle body presents the problem of requiring sufficient mounting space.

[0006] Korean Patent Publication No. 10-2019-0029954 discloses an underbody for an electric vehicle in which a battery pack can be installed. In this document, a center floor panel is assembled between two side sills, consisting of an inner and outer side sill panel. A mounting member installed inside the side seals secures a battery pack storage space beneath the center floor panel. However, even according to this document, replacing all or part of the secondary batteries after the vehicle is delivered is not easy.

[0007] Furthermore, Korean Patent Registration No. 10-1565980 discloses a floor panel assembly for an electric vehicle. However, this document discloses cooling the battery modules using air cooling, but this cooling method is limited in that it does not effectively reduce the temperature of the battery modules while the vehicle is in use. Furthermore, the air cooling method disclosed in this document requires a separate space to create an air flow path. Summary of the Invention

[0008]

Technical Issues

[0009] The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to provide an underbody for a vehicle that is capable of directly fastening a battery module to a vehicle body frame.

[0010]

Technical Solution

[0011] The underbody of a vehicle according to the present invention includes a tray member secured to the lower portion of a vehicle body frame and including a receiving portion having an open lower surface for accommodating a battery module; and a cover member covering the open lower surface of the receiving portion. The cover member includes a flow path through which refrigerant flows.

[0012] According to an embodiment of the present invention, the covering member has a structure in which irregularities are formed on one or both surfaces of the plate-shaped panel, and the irregularities of the covering member form protrusions or recesses along the flow path on the surface of the plate-shaped panel.

[0013] According to an embodiment of the present invention, the protrusions or recesses are arranged at regular intervals and include curved areas on the same plane.

[0014] According to an embodiment of the present invention, the protrusions or recesses are arranged at regular intervals and include a patterned area oriented in one direction.

[0015] According to an embodiment of the present invention, the covering member of the present invention includes a cooling layer in which a flow path is formed, through which a refrigerant flows, and a covering layer that protects a lower surface of the cooling layer.

[0016] Furthermore, according to an embodiment of the present invention, in the covering member, irregularities are formed on the cooling layer and the covering layer, the irregularities of the cooling layer having a form of protrusions formed along the flow path on the surface of the plate-shaped panel,

[0017] The irregularities of the cover layer have a form of recesses formed on the surface of the plate-shaped panel to correspond to the protrusions of the cooling layer, and the cooling layer and the cover layer have a structure in which the protrusions of the cooling layer are inserted into the recesses of the cover layer to be in close contact.

[0018] According to an embodiment of the present invention, the cooling layer is formed of a metal material, and the covering layer is formed of a plastic material.

[0019] According to an embodiment of the present invention, the vehicle body bottom further comprises a vibration-proof layer, which is interposed between the cooling layer and the covering layer. The vibration-proof layer can be formed of a fiber layer, such as a non-woven fabric or a resin foam layer.

[0020] According to an embodiment of the present invention, the covering member has a single-layer plate-shaped panel structure, and the flow path may be formed on one surface of the plate-shaped panel or recessed inside the plate-shaped panel.

[0021] According to an embodiment of the present invention, the covering member includes a region for opening and closing a part or all of the open surface of the receiving portion.

[0022] According to an embodiment of the present invention, the receiving portion has an outer wall member that surrounds a side surface of a battery module to be accommodated, and a partition wall member that divides the interior of the receiving portion into a plurality of compartments.

[0023] According to an embodiment of the present invention, the receiving portion includes an outer wall member that surrounds the side surface of the battery module to be accommodated, and a partition wall member that divides the interior of the receiving portion into a plurality of compartments. Here, each compartment has a structure that receives a separate battery module.

[0024] According to an embodiment of the present invention, the outer wall member has a rectangular structure covering four surfaces based on a planar cross-sectional structure. Furthermore, the outer wall member includes: a first front-to-back outer wall member and a second front-to-back outer wall member, the first and second front-to-back outer wall members being arranged perpendicular to the front-to-back direction of the vehicle; and a first left-to-right outer wall member and a second left-to-right outer wall member, the first and second left-to-right outer wall members being arranged perpendicular to the left-to-right direction of the vehicle. Furthermore, according to an embodiment of the present invention, at least one of the first and second left-to-right outer wall members has a structure capable of changing its position in the front-to-back direction of the vehicle.

[0025] According to an embodiment of the present invention, the outer wall member has a structure that covers three surfaces based on a planar cross-sectional structure. Furthermore, the outer wall member includes: a first front-to-back outer wall member and a second front-to-back outer wall member, the first and second front-to-back outer wall members being arranged perpendicular to the front-to-back direction of the vehicle; and a first left-to-right outer wall member being arranged perpendicular to the left-to-right direction of the vehicle. Furthermore, according to an embodiment of the present invention, the first left-to-right outer wall member has a structure that allows its position in the front-to-back direction of the vehicle to change.

[0026] According to an embodiment of the present invention, the covering member is in the form of a curved panel and covers the lower side and the open surface of the receiving portion.

[0027] Furthermore, the present invention provides a battery pack, and in the battery pack, a battery module may be accommodated in the underbody for the vehicle.

[0028] Furthermore, the present invention provides a vehicle including the battery pack, and the vehicle may be a hybrid vehicle or an electric vehicle.

[0029]

Beneficial effects

[0030] The underbody for a vehicle according to the present invention can sufficiently ensure a space for accommodating a battery module, can omit a process of separately assembling a battery tray after manufacturing a vehicle, and can effectively cool the accommodated battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is an exploded perspective view illustrating a coupling structure for an underbody of a vehicle according to an embodiment of the present invention.

[0032] Figure 2 and Figure 3 1 and 2 are schematic diagrams of a covering member for an underbody of a vehicle according to an embodiment of the present invention, viewed from below and above, respectively.

[0033] Figure 4 FIG. 1 is a schematic diagram of a covering member for an underbody of a vehicle according to another embodiment of the present invention.

[0034] Figure 5 and Figure 6 1 and 2 are sectional views each showing a cross section of a covering member for an underbody of a vehicle according to an embodiment of the present invention.

[0035] Figure 7 is a schematic diagram showing a main configuration of a battery module according to an embodiment of the present invention.

[0036] Figure 8 is a perspective view showing a tray member for an underbody of a vehicle according to an embodiment of the present invention.

[0037] Figure 9 is a schematic diagram showing a state in which a battery module according to an embodiment of the present invention is mounted on a tray member for an underbody of a vehicle.

[0038] Figure 10 is a view showing an underbody for a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. The terms and words used in this specification and claims should not be construed as limited to common terms or dictionary terms, and the inventors may appropriately define the concepts of the terms to best describe their invention. The terms and words should be interpreted as having meanings and concepts consistent with the technical ideas of the present invention.

[0040] Therefore, the embodiments described in the specification and the configurations described in the drawings are only the most preferred embodiments of the present invention and do not represent all technical ideas of the present invention. It should be understood that various equivalent solutions and changes can replace them when submitting this application.

[0041] In the present invention, the longitudinal direction of the vehicle body is defined as the "front-rear direction," the width direction of the vehicle body is defined as the "left-right direction," and the height of the vehicle body is defined as the "up-down direction." The longitudinal direction, width direction, and height direction are defined based on the shape of a general vehicle.

[0042] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[0043] The present invention relates to an underbody for a vehicle, comprising: a tray member that is fastened to a lower portion of a vehicle body frame and includes a receiving portion having a structure with an open lower surface while accommodating a battery; and a covering member that covers the open lower surface of the receiving portion, wherein the covering member includes a flow path through which a refrigerant flows.

[0044] The underbody has a structure that is directly fastened to the lower part of the body frame. In the present invention, "direct fastening" refers to fastening without using a separate intermediate material or part for fastening. For example, the underbody can be directly fastened to the lower part of the body frame by welding or bolting. Conventionally, a battery pack is assembled from the outside, in which the battery modules are housed in a tray member, and the assembled battery pack is connected to the lower part of the body through an additional assembly process. Specifically, in the related art, the battery pack and the vehicle are manufactured separately, and the battery pack assembled on one surface of the underbody of the vehicle is installed in a separate process.

[0045] When separately manufactured battery packs are installed in vehicles, separate fixing members are used to secure the battery pack to the vehicle body. This requires space for the fixing members, and the number of parts and assembly process increases. Furthermore, the need for a separate battery pack cover and tray to house the battery modules reduces space efficiency and increases weight. In particular, there is a problem with the rigidity overlap between the vehicle body frame and the lower tray, which is inefficient in a robust design.

[0046] The present invention provides an underbody that includes a battery module receiving portion. The underbody is a component that forms the body of a vehicle. Specifically, the underbody forms the bottom surface of the vehicle body and also constitutes one surface of the battery module receiving portion. This reduces the number of parts and assembly steps, improves space efficiency, and ensures robustness against overlap.

[0047] An underbody for a vehicle according to the present invention includes a tray member and a cover member.

[0048] In one example, a covering member has a structure in which irregularities are formed on one or both surfaces of a plate-shaped panel. The irregularities of the covering member are formed on the surface of the plate-shaped panel and have a structure that forms protrusions or recesses along the flow path. The covering member has the effect of increasing rigidity by forming an uneven structure. In addition, by integrating the irregularities of the covering member with the shape of the flow path for cooling the battery module, the volume required to form the covering member can be minimized.

[0049] In one example, the protrusions or recesses are arranged at regular intervals and include curved areas on the same plane. The protrusions or recesses may increase resistance to impacts applied in unspecified or various directions by including curved areas.

[0050] In another example, the protrusions or recesses are arranged at regular intervals and include patterned areas oriented in a single direction. The protrusions include a pattern oriented in a single direction, thereby increasing the rigidity of the vehicle body. For example, the protrusions or recesses may include patterned areas oriented in the front-to-back direction or in the width direction. In this case, resistance to forces applied perpendicular to the pattern direction of the protrusions or recesses can be increased.

[0051] For example, the irregularities of the covering member according to the present invention include a pattern in which uneven structures oriented in one direction are repeated, and ends of the irregularities oriented in each direction may have shapes connected by curved uneven structures.

[0052] In this regard, Figure 1 is an exploded perspective view of an underbody according to an embodiment of the present invention, and illustrates a coupling structure of the underbody.

[0053] refer to Figure 1 The underbody for a vehicle according to the present invention includes a tray member 300 that is fastened to a lower portion of a vehicle body frame and accommodates a battery module, a battery module 210 that is accommodated in a receiving portion of the tray member 300, and a cover member 100 that covers the receiving portion of the tray member 300. The tray member 300 is located at the uppermost portion of the underbody for the vehicle based on the vehicle body, and the cover member 100 is located at the lowermost portion of the underbody for the vehicle.

[0054] As needed, one or more electrical devices 230 are mounted on one surface of the battery module 210. The electrical devices 230 include: a battery management system (BMS), which is mounted adjacent to the battery module 210 and monitors and controls the operation of the battery module 210; a battery disconnect unit (BDU), which is mounted adjacent to the battery module 210 and the BMS and controls the electrical connection of the battery module 210; a fuse, which is located between the battery module 210 and the BMS and provides an overcurrent blocking function; a bus bar, which is connected to the module terminals of the battery module 210 to electrically connect the battery module 210; and an LV wire, which electrically connects the electrical devices.

[0055] The BMS may also include components such as a current sensor or a relay. The current sensor is a component that senses the charge / discharge current of the battery pack, and the relay is a switching component that selectively opens and closes the charge / discharge path through which the charge / discharge current of the battery pack flows, and can be controlled while exchanging information with the BMS.

[0056] In addition, a thermal interface material (TIM) 231 may be interposed between the battery module 210 and the cover member 100. The TIM 231 includes a material having excellent thermal conductivity, and a thermally conductive pad or a thermally conductive resin may be used. The TIM 231 fills the empty space caused by the surface roughness of the contact surface between the battery module 210 and the cover member 100 to reduce the contact thermal resistance between the battery module 210 and the cover member 100. Heat generated from the battery module 210 can be quickly discharged toward the cover member 100 below.

[0057] The TIM 231 directly contacts the battery module 210 and one surface of the cover member 100 and may have a size corresponding to an area of ​​the battery module 210 accommodated in the tray member 300. The TIM 231 may have a structure separated to correspond to each battery module, but is not limited thereto.

[0058] In addition, the battery module 210 can be fastened to the tray member 300 by a predetermined method and mechanically fastened using, for example, mounting bolts 220 and mounting nuts (not shown). The above structure can be collectively referred to as a battery pack 200 including the battery module 210 and the electrical device 230, and can further include mounting bolts 220 for fixing the battery module 210.

[0059] As described above, the underbody for a vehicle according to the present invention may include the battery module 210 and the electric device 230 mounted on one surface of the battery module 210. In addition, the tray member 300 serves as both a lower tray of a conventional battery module and a bottom cover of a vehicle.

[0060] In the present invention, the covering member includes the flow path through which the refrigerant moves.

[0061] The battery module generates a large amount of heat during operation, and cooling is essential to maintaining battery performance and safety. The cooling of the battery module can be performed by forming an air flow path on one surface of the battery module or attaching a cooling plate for heat radiation. However, when the cooling of the battery module is performed by forming an air flow path, there is a problem in that the cooling efficiency is lower than when the cooling is performed using a cooling plate, and in particular, a separate space should be ensured to form the flow path. When the cooling of the battery module is performed by attaching a cooling plate to one surface of the battery module, space is required to form a separate cooling plate. In addition, the cooling plate should be located below the battery module. This is because, when the cooling plate is located above the battery module, if the cooling plate is damaged, the refrigerant may leak from the cooling plate and cause a short circuit while contacting the terminals of the battery.

[0062] Therefore, in the present invention, by integrating the refrigerant flow path with the cover member, the space wasted by installing the cooling plate is minimized, and cooling can be performed at the lowest part of the vehicle body. Furthermore, by forming the cover member including the flow path, the cover member is positioned below the battery module. This strengthens the contact force between the cover member and the battery module due to the load of the battery module, thereby improving cooling efficiency.

[0063] In one embodiment, the covering member of the present invention includes: a cooling layer having a flow path formed therein, through which the refrigerant flows; and a covering layer that protects the lower surface of the cooling layer. In this case, in the covering member, the cooling layer and the covering layer are formed with irregularities, the irregularities of the cooling layer have a shape forming a protrusion along the flow path on the surface of the plate-shaped panel, and the irregularities of the covering layer have a shape forming a recess on the surface of the plate-shaped panel to correspond to the protrusion of the cooling layer. In addition, the cooling layer and the covering layer may have a structure in which the protrusion of the cooling layer is inserted into the recess of the covering layer to be in close contact. As described above, the covering member has a structure in which the rigidity is supplemented by forming irregularities. In the present invention, by integrating the arrangement of the irregularities and the flow path of the covering member, cooling and space efficiency can be improved at the same time.

[0064] When the covering member has a structure in which a cooling layer and a covering layer are stacked, each of these layers can be formed of a different material. Specifically, the cooling layer is formed of a metal material and the covering layer is formed of a plastic material. The metal material forming the cooling layer is not particularly limited as long as it is a metal material having thermal conductivity, but can be, for example, at least one selected from copper, aluminum, iron and alloys thereof. The material of the covering layer is not particularly limited as long as it is a plastic material having a certain level of rigidity, but for example, a plastic material including at least one of PP, PE and PET can be used, and if necessary, dispersed fibers and the like can be included in this layer.

[0065] The present invention may further include an anti-vibration layer positioned between the cooling layer and the cover layer. The anti-vibration layer is used to block vibration and noise from the lower portion of the vehicle body during driving. The anti-vibration layer may be formed, for example, from one or more of a non-woven fabric layer, a resin fiber layer, a resin layer, and a foam layer.

[0066] In another embodiment, the covering member has a single-layer plate-shaped panel structure, and the flow path can be formed on one surface of the plate-shaped panel or recessed in the interior of the plate-shaped panel. When the flow path is attached to one surface of the plate-shaped panel, the flow path is formed on one surface of the plate-shaped panel. In this case, based on the cross-section of the flow path, the flow path has a shape attached to the surface of the covering member or partially recessed in the interior of the covering member, and a protrusion is formed in the covering member along the flow path. The form in which the flow path is recessed in the interior of the plate-shaped panel is a case in which the flow path is recessed in the covering member. In this case, based on the cross-section of the flow path, the flow path is partially or completely embedded in the covering member, and a protrusion is formed on one or both surfaces of the covering member along the flow path.

[0067] When the covering member of the present invention has a single-layer plate-shaped panel structure, the covering member can be formed of a metal material. The metal material is not particularly limited as long as it is a metal material with excellent thermal conductivity, but can be, for example, at least one selected from copper, aluminum, iron and alloys thereof.

[0068] Furthermore, the cover member may include an area for opening and closing a portion or all of the open surface of the receiving portion formed on the tray member. The cover member covers the open surface of the receiving portion and has a structure that can be opened when necessary. During the use of the battery module, there may be situations where repair or replacement is required. In this case, the battery module can be repaired or replaced by simply removing the cover member. The cover member is detachably attached to the tray member and has a structure such as a bolt connection.

[0069] Figure 2 and Figure 31 and 2 are schematic diagrams of a covering member for an underbody of a vehicle according to an embodiment of the present invention, viewed from below and above, respectively.

[0070] Figure 2 Schematic diagram of a cover member viewed from below. Cover member 100 has a plate-shaped panel structure with a flow path formed therein, and irregularities 111 are formed on the surface of cover member 100. A central fixing point 112 for intermediate fastening is formed in a specific area of ​​irregularity 111 of cover member 100, and bolt through holes 113 for fastening are formed at the edge of cover member 100.

[0071] Specifically, the covering member 100 has a plate-shaped structure having a size that covers the open surface of the receiving portion, and bolt through holes 113 for connection are formed to be spaced apart from each other at regular intervals on the outer periphery of the covering member 100. In addition, the outer periphery of the covering member 100 may have an irregular portion having a shape corresponding to the uneven shape of the end portion of the outer wall member. By forming the irregular portion on the outer periphery of the covering member 100 and the end portion of the outer wall member, when the outer periphery of the covering member 100 and the end portion of the outer wall member are accurately engaged through the irregular portion, the connection force between the covering member 100 and the outer wall member can be strengthened, and the covering member 100 can be prevented from being separated due to external vibration or impact.

[0072] Furthermore, irregularities 111 are formed on the outer surface of the cover member 100. These irregularities 111 are formed on the surface of the cover member 100 and are recessed along the flow path. These irregularities 111 have a shape that protrudes or recesses from the outer surface in the direction of contact with the battery module. Thus, the cover member 100 can more effectively and safely protect the battery module from external physical impact or stress in various operating environments.

[0073] Furthermore, one side surface of the cover member 100 is vertically curved. The vertically curved cover member 100 can cover the open surface and / or the side surface. By using the L-shaped cover member 100 described above, the number of outer wall members located in the front-to-back direction of the tray member can be reduced. Furthermore, the cover member 100 simplifies the number of parts and the assembly process, and can form a structure that is resistant to external impact.

[0074] One side surface of the vertically bent cover member 100 is further bent vertically to form a connection surface with the tray member 300. Holes for fastening bolts to the vehicle body frame are formed on this connection surface. The central portion of the vertically bent side may have a structure that protrudes outward to improve the coupling force and rigidity with the tray member 300. The width of the protruding portion may be the same as the distance between the spaced-apart battery module assemblies.

[0075] Furthermore, the cover member 100 has a central fixing point 112 formed at a portion of the partition wall member contacting the tray member in the central portion, enabling additional coupling with the partition wall member by bolts or the like.

[0076] Figure 3 This is a schematic diagram of the cover member viewed from above. Figure 3 , an inlet port 121 and an outlet port 122 through which the refrigerant flows in or out of a flow path are formed on one side of the cover member 100. A refrigerant flow path connected to the inlet port 121 and the outlet port 122 is formed so that the refrigerant introduced through the inlet port 121 cools the battery module through heat exchange. In addition, a valve capable of adjusting the refrigerant flow rate may be installed at the inlet port 121 and the outlet port 122. In addition, referring to Figure 3 , the inlet port 121 and the outlet port 122 are located at the end of the cover member in one direction. Therefore, a through hole through which the inlet port 121 and the outlet port 122 can pass is formed on one side of the tray member, and the inlet port 121 and the outlet port 122 are connected to the external refrigerant storage space through the through hole.

[0077] In the present invention, as the refrigerant, a fluid that easily flows in the flow path and has excellent cooling properties can be used, and water, antifreeze, gas refrigerant or air can be used, but water is most preferred because it can maximize cooling efficiency due to high latent heat.

[0078] The refrigerant flow path has a structure in which temperature distribution is made uniform by adopting a serpentine hairpin ring structure, and several straight and curved sections coexist.

[0079] Figure 4 FIG. 1 is a schematic diagram of a covering member for an underbody of a vehicle according to another embodiment of the present invention. Figure 4 This is a schematic diagram of a cover member viewed from below. The cover member 100 has a plate-shaped panel structure with a flow path formed therein, and irregularities 111 are formed on the surface of the cover member 100. The irregularities 111 formed on the surface of the cover member 100 have a shape in which a pattern of straight lines extending in the left-right direction is repeated, and this shape follows the straight line pattern in the area where the flow path is formed. A central fixing point 112 for intermediate fastening is formed in a specific area of ​​the irregularity 111 of the cover member 100, and bolt holes 113 for fastening are formed at the edge of the cover member 100.

[0080] Figure 5 and Figure 61 and 2 are sectional views each showing a cross section of a covering member for an underbody of a vehicle according to an embodiment of the present invention.

[0081] As an example, refer to Figure 5 , the covering member 100 has a structure in which the cooling layer 103 and the covering layer 104 are formed with irregularities. A flow path 101 is formed in the cooling layer 103, and protrusions are formed on the surface along the flow path 101. The covering layer 104 has a shape in which recesses are formed on the plate-shaped panel surface to correspond to the protrusions of the cooling layer 103, and the covering layer 104 has a structure in which the protrusions of the cooling layer 103 are inserted into the recesses of the covering layer 104 to make close contact. The cooling layer 103 can be formed of an aluminum alloy, and the covering layer 104 can be formed of a plastic material.

[0082] As another example, see Figure 6 The cross section of the covering member disclosed in FIG. 1 is a diagram showing a covering member 100 having a single-layer plate-shaped panel structure, and a flow path 102 is formed in the panel structure. The flow path 102 is located inside the plate-shaped panel structure in a partially recessed form. The plate-shaped panel can be formed of aluminum alloy or the like.

[0083] One region for forming the flow paths 101 and 102 of the cover member 100 may be provided for each battery module, but in order to simplify the number of parts and the assembly process, it is preferable to manufacture the cover member 100 as an integrated type covering all battery modules.

[0084] In the present invention, the receiving portion includes an outer wall member that surrounds the side surfaces of the battery modules to be accommodated, and a partition wall member that divides the interior of the receiving portion into multiple compartments. Individual battery modules are accommodated in each of the subareas defined by the partition wall member. The outer wall member divides the area for accommodating the battery modules, and when accommodating two or more battery modules, the partition wall member divides the interior of the receiving portion. Furthermore, the outer wall member and the partition wall member serve to secure the accommodated battery modules from the side surfaces.

[0085] In one example, the outer wall member has a rectangular structure covering four surfaces based on a plane cross-sectional structure. In this case, the outer wall member includes: a first front-to-back direction outer wall member and a second front-to-back direction outer wall member, the first front-to-back direction outer wall member and the second front-to-back direction outer wall member being arranged perpendicular to the front-to-back direction of the vehicle; and a first left-to-right direction outer wall member and a second left-to-right direction outer wall member, the first left-to-right direction outer wall member and the second left-to-right direction outer wall member being arranged perpendicular to the left-to-right direction of the vehicle. In addition, at least one of the first left-to-right direction outer wall member and the second left-to-right direction outer wall member may have a structure capable of changing its position in the front-to-back direction of the vehicle. By forming at least one of the first left-to-right direction outer wall member and the second left-to-right direction outer wall member into a structure capable of changing its position in the front-to-back direction of the vehicle, the area of ​​the receiving portion can be flexibly adjusted according to the insertion size or number of the battery modules.

[0086] In yet another example, the outer wall member forms a structure that surrounds three surfaces based on a plane cross-sectional structure. Specifically, the outer wall member forms a "c"-shaped structure in which three surfaces are continuously wrapped and the other surface is open. In this case, the outer wall member includes: a first front-to-back direction outer wall member and a second front-to-back direction outer wall member, the first front-to-back direction outer wall member and the second front-to-back direction outer wall member being arranged perpendicular to the front-to-back direction of the vehicle; and a first left-to-right direction outer wall member, the first left-to-right direction outer wall member being arranged perpendicular to the left-to-right direction of the vehicle. In addition, the first left-to-right direction outer wall member may have a structure that can change its position in the front-to-back direction of the vehicle. By forming the first left-to-right direction outer wall member into a structure that can change its position in the front-to-back direction of the vehicle, the area of ​​the receiving portion can be flexibly adjusted according to the insertion size or number of the battery modules.

[0087] In one example, when the outer wall member has a structure in which three surfaces are surrounded based on a planar cross-sectional structure, the covering member has a curved panel shape. Thus, the covering member forms a structure covering the lower surface and the open side surface of the receiving portion.

[0088] Figure 7 is a schematic diagram showing a main configuration of a battery module according to an embodiment of the present invention.

[0089] refer to Figure 7 The battery module 210 includes a housing in which a plurality of separate battery modules are assembled, and each battery module may include a secondary battery (not shown). In particular, the secondary battery may be a pouch-type secondary battery, and the pouch-type secondary battery may include an electrode assembly, an electrolyte solution, and a pouch housing.

[0090] Here, the electrode assembly is an assembly of electrodes and separators, and can be constructed in a form in which one or more positive electrode plates and one or more negative electrode plates are arranged with a separator interposed therebetween. In addition, each electrode plate of the electrode assembly is provided with an electrode tab, and the one or more electrode tabs can be connected to an electrode lead. In addition, the electrode lead is interposed between the bag shells, and one end is exposed to the outside, and the exposed portion can be used as an electrode terminal of the secondary battery. The bag shell can contain an electrolyte solution as well as an electrode assembly in the internal space. In addition, the bag shell can be constructed in a form in which the edge portion is sealed by a method such as hot melting. The bag shell can be composed of an upper bag and a lower bag, and each bag includes an outer insulating layer, a metal layer and an inner adhesive layer, so that the inner adhesive layers can be fused to each other.

[0091] The configuration of such a secondary battery is obvious to those skilled in the art to which the present invention pertains, and thus a more detailed description thereof will be omitted. In addition, various secondary batteries known at the time of filing the present invention may be used in the battery module according to the present invention.

[0092] The battery module 210 may include a plurality of secondary batteries. Specifically, a plurality of secondary batteries (e.g., pouch-type secondary batteries) may be stacked vertically or horizontally with their wide surfaces facing each other, thereby forming a secondary battery laminate. To facilitate stacking, such a secondary battery may include a box in the shape of a square ring surrounding the edges of the secondary battery, or may be installed in a state where the secondary batteries are stacked in a module housing 211. In this case, it is more preferable to use a module housing in terms of ensuring space for the secondary batteries.

[0093] The module housing 211 can be formed of a metal material with high mechanical strength and excellent thermal conductivity. The shape of the module housing 211 is not particularly limited, but it can be formed as a single frame in the form of a square column tube. After the U-shaped frame is bonded to both sides of the secondary battery laminate, the U-shaped frame can be connected to a separate plate-shaped frame. A groove for mounting the secondary battery can be formed inside the module housing 211. This module housing can prevent the secondary battery from flowing by holding it.

[0094] The battery module is completed by attaching covers to the open front and rear of the module housing 211. A duct for air to flow between the inside and outside of the battery module, and a sensing assembly connected to the electrode leads of the secondary batteries to sense the voltage of the secondary batteries may also be provided. The sensing assembly may include a plurality of bus bars, connectors, wiring harnesses, printed circuit boards, and the like, each of which is individually connected to the pouch-type secondary batteries.

[0095] In the present invention, one or more battery modules 210 are mounted on a tray member 300, described later. The battery module 210 includes a housing in which a plurality of battery modules 210 form a pack. That is, the plurality of battery modules 210 can be connected in series and / or in parallel, depending on the output and capacity required for the battery pack.

[0096] Figure 8 is a perspective view showing the structure of a tray member 300 according to an embodiment of the present invention, Figure 9 is a perspective view illustrating a state in which the battery module 210 is coupled to the tray member 300 according to an embodiment of the present invention.

[0097] Reference Figure 8 and Figure 9 The tray member 300 includes outer wall members 320 and 340 that surround the side surfaces of the receiving portion 310, which is a battery module storage space; and partition wall members 330 that extend in the front-to-back direction and the left-to-right direction to divide the receiving portion 310 into a plurality of compartments. In addition, the outer wall members 340, which are positioned perpendicular to the front-to-back direction, are formed in the form of side covers and can be moved in the front-to-back direction as needed. In addition, the outer wall members 320 and 340 form three or four walls from the bottom of the tray member 300 and form the receiving portion 310, into which the battery modules 210 are inserted.

[0098] The tray member 300 has a bottom surface of a certain area, and the battery module is mounted on the bottom surface of the tray member 300. The bottom surface is formed with a plurality of uneven portions or ribs 311 so that the battery module does not move due to external shock or vibration and maintains a stable mounting state.

[0099] The outer wall members 320 and 340 protrude from the bottom surface of the tray member 300 to a predetermined height and to a length corresponding to the height of the battery module 210. As a result, the outer wall members 320 and 340 have a shape surrounding the battery module 210 by extending along the front and rear sides or the left and right sides of the battery module 210. The outer wall member 320, which is formed to extend along the left and right sides of the battery module 210, has a bolt insertion groove 321 for fastening to the frame of the vehicle body.

[0100] Irregularities are formed at the ends of the outer wall member 320 to enhance coupling force with the vehicle body frame. In more detail, the portion where the bolt insertion groove 321 is formed protrudes, and the portion where the bolt insertion groove 321 is not formed may have a recessed structure.

[0101] The partition wall member 330 is mounted on the tray member 300, the battery modules 210 are fastened to the tray member 300, and the receiving portion 310 is divided to fasten a plurality of battery modules 210 in units of a predetermined number of battery modules. The partition wall member 330 has a shape extending in the front-rear and left-right directions of the tray member 300.

[0102] A plurality of battery modules 210 according to the present invention may be applied. Figure 8 and Figure 9 Due to the presence of a first partition wall member 331 extending in the front-to-back direction and a second partition wall member 332 extending in the left-to-right direction, the battery module 210 is divided into a battery module assembly consisting of two battery modules, and each of the four battery module assemblies is installed. However, there are no particular limitations on the number of partition wall members, the number of battery module assemblies, the number of battery modules included in the battery module assembly, and the arrangement of the battery modules. For example, two or more first partition wall members extending in the front-to-back direction may be installed, two or more second partition wall members extending in the left-to-right direction may be installed, and the battery modules may be arranged in parallel in the left-to-right direction or in parallel in the front-to-back direction.

[0103] In addition, reference Figure 9 Because a predetermined space is formed between the side surfaces of battery modules 210, electrical equipment such as a battery management system (BMS) and battery management unit (BDU) can be placed in this space, improving space utilization. Wires and connectors extending from the BMS and BDU are secured to the lower portion of the battery modules, based on the vehicle body. Furthermore, electrical equipment such as bus bars and connectors can be mounted on the upper end of partition wall member 330 in the space between the battery modules.

[0104] Meanwhile, in the tray member 300, an outer wall member 340 located in the front-to-back direction is formed on one side of the battery module 210 to fix and protect the battery module 210. The outer wall member 340 located in the front-to-back direction has a structure that can be detached from the tray member 300, and a mounting surface 341 for coupling with a cover member is formed in the outer wall member 340 located in the front-to-back direction by being bent, and bolt through holes are formed in the mounting surface 341 to achieve bolt coupling.

[0105] In addition, a support portion 343 for supporting the outer wall member 340 protrudes from the center of the outer wall member 340 in the front-rear direction. The support portion 343 includes a support piece 344 extending from the center of the outer wall member 340 in the front-rear direction at an oblique angle toward the tray member 300, and a support plate 345 connected to the support piece 344 and in contact with the tray member 300.

[0106] In a more specific example, the support piece 344 and the support plate 345 form a flange structure. Since the outer wall member 340 located in the front-to-rear direction is connected to the tray member 300 and the cover member through the narrow mounting surface 341, the portion bent due to external impact may be easily bent in the front-to-rear direction and damaged, so the outer wall member 340 can be stably fixed to the vehicle body frame by the support portion 343.

[0107] In more detail, the portion of the tray member 300 that contacts the support portion may have a structure that is recessed according to the shape of the support portion 343. Figure 8 and Figure 9 The support plate 345 constituting the support portion 343 may have a plate-shaped structure, and the portion of the tray member 300 contacting the support plate 345 may be recessed relative to the left-right side portions of the support plate 345. In other words, the support plate 345 has a shape such that the support portion 343 is fixed between the recessed portions of the tray member 300, and this prevents horizontal flow of the outer wall member 340 located in the front-back direction.

[0108] In addition, a mounting bracket (not shown) for fixing the battery module to the receiving portion 310 may be mounted on the tray member 300 .

[0109] As described above, the underbody for a vehicle according to the present invention exhibits excellent performance compared to separately manufacturing and then assembling a battery pack by directly fastening the battery modules to the vehicle body frame.

[0110] As described above, the underbody for a vehicle according to the present invention exhibits excellent performance compared to separately manufacturing and then assembling a battery pack by directly fastening the battery modules to the vehicle body frame.

[0111] In short, reference Figure 10 In the underbody according to the present invention, battery module 210 is directly fastened to receiving portion 310 formed in tray member 300. External wall members 320 and 340 surrounding the sides of battery module 210 and partition wall member 330 are mounted on tray member 300. Electrical equipment is mounted on the battery module, and then cover member 100, which incorporates a cooling flow path, is positioned. This increases the battery module's footprint ratio, improves the efficiency and safety of the battery module installation process, and facilitates repair or replacement of the battery module by opening and closing the cover member as needed.

[0112] In addition, the present invention provides a battery pack including an underbody, and a battery module is housed in the underbody for a vehicle. More specifically, the battery pack includes an underbody for a vehicle, and the underbody for a vehicle includes: a tray member including a receiving portion having an open lower surface below a vehicle body frame; and a covering member and a battery module, the covering member covering the open lower surface of the receiving portion, and the battery module is housed in the receiving portion. A flow path through which a refrigerant flows is formed in the covering member. That is, in the present invention, since the battery module is directly fastened to the vehicle body frame, the vehicle body frame and the battery module housed therein form a battery pack.

[0113] Furthermore, the present invention provides a vehicle including the battery pack, the vehicle including an underbody below the vehicle body and a battery module accommodated in a receiving portion. The vehicle may be a hybrid vehicle or an electric vehicle.

[0114] In the above, preferred embodiments of the present invention have been shown and described, but the present invention is not limited to the above-mentioned specific preferred embodiments, and any ordinary technician in the technical field of the present invention can implement various modifications without departing from the subject matter of the invention claimed for protection in the claims, and these changes will fall within the scope of the description of the claims.

[0115] On the other hand, although terms indicating directions such as up, down, front, back, left and right have been used in this specification, it is obvious to those skilled in the art that these terms are for convenience of description and may be expressed differently depending on the viewing position of the observer or the position of the object.

[0116] <Description of Reference Signs>

[0117] 100: Covering component

[0118] 101, 102: Flow path

[0119] 103: Cooling layer

[0120] 104: Overlay

[0121] 111: Irregular part

[0122] 112: Central fixing point

[0123] 113: Bolt through hole

[0124] 121: Ingress port

[0125] 122: egress port

[0126] 200: Battery pack

[0127] 210: Battery module

[0128] 211: Module housing

[0129] 220: Mounting bolts

[0130] 230: Electrical equipment

[0131] 231:TIM

[0132] 300: Tray components

[0133] 310: Reception Department

[0134] 311: Rib

[0135] 320, 340: outer wall components

[0136] 321: Bolt inserted into groove

[0137] 330: Partition wall component

[0138] 331: First partition wall member

[0139] 332: Second partition wall member

[0140] 341: Mounting surface

[0141] 343: Support

[0142] 344: Support

[0143] 345: Support plate

Claims

1. An underbody for a vehicle, comprising: a tray member that is fastened to a lower portion of the vehicle body frame and includes a receiving portion having a structure with an open lower surface while accommodating the battery module; and a covering member covering the open lower surface of the receiving portion, wherein the cover member includes a flow path through which the refrigerant flows, wherein the covering member has a structure in which irregularities are formed on one or both surfaces of a plate-shaped panel, and wherein the irregular portion of the covering member is formed with protrusions or recesses along the flow path on the surface of the plate-shaped panel, wherein the covering member is detachably attached to the tray member, and the covering member has a plate-shaped structure sized to cover an open surface of the receiving portion, The receiving portion includes: an outer wall member that surrounds a side surface of a battery module to be housed; and a partition wall member that divides the interior of the receiving portion into a plurality of compartments, Each compartment has a structure for receiving a separate battery module. The covering member comprises: a cooling layer having a flow path formed thereon, through which the refrigerant flows; and a cover layer, the cover layer protecting the lower surface of the cooling layer, wherein in the covering member, irregularities are formed on the cooling layer and the covering layer, wherein the irregularities of the cooling layer have the form of protrusions formed on the surface of the plate-shaped panel along the flow path, wherein the irregularities of the cover layer have the form of recesses formed on the surface of the plate-shaped panel to correspond to the protrusions of the cooling layer, and wherein the cooling layer and the cover layer have a structure in which the protrusions of the cooling layer are inserted into the recesses of the cover layer to be in close contact. 2 . The underbody according to claim 1 , wherein the protrusions or recesses are arranged at regular intervals and include curved areas on the same plane. 3 . The underbody according to claim 1 , wherein the protrusions or recesses are arranged at regular intervals and include a patterned area oriented in one direction.

4. The underbody according to claim 1, wherein: The cooling layer is formed of a metal material, and the cover layer is formed of a plastic material. 5 . The underbody according to claim 1 , further comprising a vibration-isolating layer interposed between the cooling layer and the covering layer.

6. The underbody according to claim 1, wherein the covering member has a single-layer plate-shaped panel structure, and The flow path is formed on one side of the plate-shaped panel or is recessed into the plate-shaped panel. 7 . The underbody according to claim 1 , wherein the covering member includes a region for opening and closing a part or all of an open surface of the receiving portion.

8. The underbody according to claim 1, wherein the outer wall member has a rectangular structure covering four surfaces based on a planar cross-sectional structure, The outer wall component comprises: a first front-rear outer wall member and a second front-rear outer wall member, the first front-rear outer wall member and the second front-rear outer wall member being arranged perpendicular to the front-rear direction of the vehicle; and a first left-right outer wall member and a second left-right outer wall member, the first left-right outer wall member and the second left-right outer wall member being arranged perpendicular to the left-right direction of the vehicle, and At least one of the first left-right outer wall member and the second left-right outer wall member has a structure capable of changing its position in the front-rear direction of the vehicle.

9. The underbody according to claim 1, wherein the outer wall member has a structure covering three surfaces based on a planar cross-sectional structure, The outer wall component comprises: a first front-rear direction outer wall member and a second front-rear direction outer wall member, the first front-rear direction outer wall member and the second front-rear direction outer wall member being arranged perpendicular to the front-rear direction of the vehicle; and a first left-right outer wall member arranged perpendicular to the left-right direction of the vehicle, and The first left-right outer wall member has a structure capable of changing its position in the front-rear direction of the vehicle.

10. The underbody according to claim 9, wherein: The covering member is in the form of a curved panel and covers the lower side and the open surface of the receiving portion. 11 . A battery pack in which a battery module is housed in the underbody for a vehicle according to claim 1 .

12. A vehicle comprising the battery pack according to claim 11.

13. The vehicle according to claim 12, wherein: The vehicle is a hybrid vehicle or an electric vehicle.

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