Battery case to which mechanical coupling of different materials ensuring watertight performance is applied and chassis frame integrated with battery case

Abstract

The present invention relates to: a battery case to which mechanical coupling of different materials ensuring watertight performance is applied and a chassis frame integrated with the battery case, and, more specifically, to a battery case comprising: a cross member which partitions an internal space of a battery case and has an insertion recess formed on the lower end thereof with a predetermined gap and an insertion hole passing through at a position where the insertion recess is formed; a cooling plate positioned below the cross member and having an insertion protrusion end which protrudes to be inserted into the insertion recess, and has a through hole corresponding to the insertion hole; a body mounting pipe having a lower end which is inserted into the insertion hole and having, formed inside the lower end thereof, a lower end female screw; and a lower bolt fastened to the lower end female screw through the through hole to allow the body mounting pipe and the cooling plate to be in surface contact with each other.

Description

Battery case and battery case-integrated chassis frame with mechanical bonding of dissimilar materials that ensures watertight performance

[0001] The present invention relates to a battery case with a combined structure of different materials (steel, aluminum) that ensures watertight performance.

[0002] Existing aluminum battery cases are joined using MIG welding, friction stir welding (FSW), and mechanical fastening methods (bolting, etc.).

[0003] Figure 1 illustrates the joint structure of a conventional aluminum battery case. Figure 2 illustrates a perspective view of a body mounting pipe. Figure 3 also illustrates a cross-sectional view of Figure 1.

[0004] As shown in FIGS. 1 to 3, the inside of the battery case (1) can be seen to have a fastening structure in which a body mounting pipe (9) penetrates the cross member (2) of the battery case (1). The body mounting pipe (9) is manufactured through aluminum extrusion and is joined to a press-formed aluminum base (11) at the bottom.

[0005] The body mounting pipe (9), cross member (2), and cooling plate (20) of the aluminum battery case (1) are made of aluminum. Therefore, the body mounting pipe (9) and the cooling plate (20) are made of the same material and are joined through a MIG welding part (80). In addition, the upper plate (30) of the battery case (1) made of steel and the body mounting pipe (9) are made of different materials and are joined with bolts.

[0006] Fig. 4 is a perspective view of the battery case mounted on the body, and Fig. 5 shows bolts for fastening the body and the battery pack. As shown in Figs. 4 and 5, the body mounting pipe (9) penetrates the battery case (1) to prevent sagging of the battery case top plate (30) at the top, and provides a hole (functioning as a nut) at the bottom for assembly with the body, and is assembled to the assembled body.

[0007] However, the existing aluminum battery case (1) has problems with thermal deformation and leakage because it secures watertight performance through MIG welding and friction stir welding (FSW) of the same material. In addition, the aluminum battery case (1) is more expensive than the steel battery case, which is a factor that increases the cost of electric vehicles. The role of the cooling plate (20) is thermal conductivity, and aluminum is mainly used as a raw material because aluminum has superior thermal conductivity compared to steel.

[0008] Therefore, when the cooling plate (20) is made of aluminum and the battery case including the remaining body mounting pipe (9) is made of steel, a new fastening structure and method that can secure watertight performance are required.

[0009] Accordingly, the present invention has been devised to solve the above-mentioned conventional problems, and according to an embodiment of the present invention, the purpose is to provide a battery case and a battery case-integrated chassis frame to which a mechanical bond of different materials is applied, which secures watertight performance.

[0010] According to an embodiment of the present invention, the purpose is to provide a battery case and a battery case-integrated chassis frame with a mechanical joint of dissimilar materials that can assemble an aluminum cooling plate inside a steel battery case without welding (assembly of dissimilar materials), secure thermal deformation and watertightness and airtightness performance by removing MIG welding, and secure cost competitiveness by applying a steel battery case compared to an aluminum battery case, and secure watertightness performance.

[0011] And according to an embodiment of the present invention, it is possible to reduce the cost of a battery case by mechanically joining dissimilar materials (steel, aluminum), to enable low-cost use in vehicles based on a steel frame structure including an electric vehicle-only platform, to simplify the process (manufacturing process) through mechanical fastening, to secure watertightness performance by mechanically fastening a steel battery case and an aluminum cooling plate, to adjust the fastening force by applying upper and lower separate counter-rotating fastening bolts (H / W, left and right rotation), and to prevent thermal deformation of the cooling plate (ensuring quality) by removing the MIG welding part, and to provide a battery case and a battery case-integrated chassis frame applied with dissimilar materials mechanical fastening that secure watertightness performance.

[0012] Meanwhile, the technical tasks to be achieved in the present invention are not limited to the technical tasks mentioned above, and other technical tasks not mentioned can be clearly understood by a person having ordinary knowledge in the technical field to which the present invention belongs from the description below.

[0013] The object of the present invention is to provide a battery case, which comprises a cross member that divides the internal space of the battery case, has insertion grooves formed at a lower end at predetermined intervals, and has insertion holes penetrating at positions where the insertion grooves are formed; a cooling plate positioned at the lower end of the cross member, protruding to be inserted into the insertion grooves, and having insertion protrusions formed with through holes corresponding to the insertion holes; a body mounting pipe having a lower end inserted into the insertion hole, and a lower female screw formed on the inner side of the lower end; and a lower bolt that is fastened to the lower female screw through the through hole so that the body mounting pipe and the cooling plate are brought into contact.

[0014] Additionally, the body mounting pipe may further form an upper female screw portion on the inside of the upper portion, and may further include an upper bolt that is fastened to the upper female screw portion while the top plate is assembled to the upper portion.

[0015] Additionally, an upper watertight gasket may be further included between the upper surface of the body mounting pipe and the upper plate.

[0016] Additionally, the tightening directions of the upper bolt and the lower bolt are opposite to each other.

[0017] Additionally, a lower watertight gasket may be further included between the lower surface of the insertion protrusion and the lower bolt.

[0018] Additionally, the cooling plate may be made of aluminum, and the crossmember and body mounting pipe may be made of steel.

[0019] The above-described object of the present invention can also be achieved by a battery case-integrated chassis frame to which a mechanical bond of different materials is applied, as another embodiment, characterized by including the battery case described above; a side frame integrally coupled to the periphery of the battery case; a front frame coupled to one side of the side frame; and a rear frame coupled to the other side of the side frame.

[0020] In addition, the side frame is arranged to form a closed cross-sectional curve by overlapping the folded outer panel and the folded inner panel, and may further include an assembly means for simultaneously and integrally assembling the outer panel, the inner panel, and the cooling plate of the battery case.

[0021] In addition, the assembly means includes a rivet nut assembled to penetrate the outer panel hole of the outer panel and the inner panel hole of the inner panel; and a frame bolt that integrally fastens the cooling plate and the rivet nut.

[0022] Additionally, it further includes a lower cover that is assembled to the lower part of the cooling plate, and the frame bolts integrally fasten the cooling plate, rivet nuts, and lower cover.

[0023] Additionally, a foam gasket is added between the cooling plate and the side frame to maintain watertightness.

[0024] According to an embodiment of the present invention, a battery case and a battery case-integrated chassis frame to which a mechanical bond of different materials is applied, which secures watertight performance, can be provided.

[0025] According to an embodiment of the present invention, an aluminum cooling plate can be assembled within a steel battery case without welding (assembly of dissimilar materials), and thermal deformation and watertightness and airtightness can be secured through MIG welding, and cost competitiveness can be secured by applying a steel battery case compared to an aluminum battery case.

[0026] And according to an embodiment of the present invention, the cost of the battery case can be reduced through mechanical joining of dissimilar materials (steel, aluminum), and it can be used at low cost in vehicles based on a steel frame structure, including an electric vehicle-only platform. In addition, the process simplification (manufacturing process) is possible through mechanical fastening, and watertight performance can be secured through mechanical fastening of the steel battery case and the aluminum cooling plate. In addition, the fastening force can be adjusted by applying upper and lower separate counter-rotating fastening bolts (H / W, left and right rotation), and it has the effect of preventing thermal deformation of the cooling plate (ensuring quality) through removal of the MIG welded part.

[0027] Meanwhile, the effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0028] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0029] Figure 1 is a diagram of the joint structure of a conventional aluminum battery case.

[0030] Figure 2 is a perspective view of the body mounting pipe;

[0031] Figure 3 is a cross-sectional view of Figure 1;

[0032] Figure 4 is a perspective view of the battery case body mounting.

[0033] Figure 5 is a perspective view of the body and battery pack fastening bolts.

[0034] Figure 6 is an exploded perspective view (excluding the top plate) of a battery case to which a mechanical bond of different materials is applied to ensure watertight performance according to an embodiment of the present invention.

[0035] Figure 7 is a combination diagram of a cooling plate (part), a cross member, and a body mounting pipe according to an embodiment of the present invention.

[0036] Figure 8 is a cross-sectional view of a battery case to which a mechanical bond of different materials is applied to ensure watertight performance according to an embodiment of the present invention.

[0037] Figure 9 is an exploded perspective view of a chassis frame in which a battery case according to the present invention is integrally assembled.

[0038] Fig. 10 is a cross-sectional view of part AA of Fig. 9.

[0039] The above-described purposes, other purposes, features, and advantages of the present invention will be readily understood through the following preferred embodiments, illustrated in the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments presented herein are provided to ensure that the disclosure is thorough and complete, and to ensure that the spirit of the present invention is fully conveyed to those skilled in the art.

[0040] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. In addition, in the drawings, the thicknesses of the components are exaggerated for the purpose of effectively explaining the technical contents.

[0041] Embodiments described herein will be described with reference to cross-sectional and / or plan views, which are ideal illustrative illustrations of the present invention. In the drawings, the thicknesses of films and regions are exaggerated for effective explanation of the technical content. Therefore, the shapes of the illustrative drawings may be modified due to manufacturing techniques and / or tolerances. Therefore, embodiments of the present invention are not limited to the specific shapes illustrated, but also include variations in shapes resulting from the manufacturing process. For example, regions illustrated at right angles may be rounded or have a predetermined curvature. Therefore, the regions illustrated in the drawings have properties, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of regions of the device and are not intended to limit the scope of the invention. Although terms such as "first" and "second" are used to describe various components in various embodiments of the present invention, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. The embodiments described and illustrated herein also include complementary embodiments.

[0042] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the words "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components.

[0043] In describing the specific embodiments below, various specific details have been included to more specifically explain the invention and facilitate understanding. However, readers with sufficient knowledge of the field to understand the present invention will recognize that the present invention can be used without these specific details. In some cases, it is noted in advance that commonly known but largely irrelevant aspects of the invention have been omitted to avoid unnecessary confusion in describing the invention.

[0044] Below, the configuration and fastening structure of a battery case to which a mechanical bond of different materials is applied to ensure watertight performance according to an embodiment of the present invention will be described.

[0045] First, FIG. 6 is an exploded perspective view (excluding the top plate) of a battery case to which a mechanical joint of different materials with watertight performance is applied according to an embodiment of the present invention, FIG. 7 is a joint diagram of a cooling plate (part), a cross member, and a body mounting pipe according to an embodiment of the present invention, and FIG. 8 is a cross-sectional view of a battery case to which a mechanical joint of different materials with watertight performance is applied according to an embodiment of the present invention.

[0046] In the method for fastening a battery case according to an embodiment of the present invention, MIG welding and friction stir welding are not applied, and only the upper bolt and the lower bolt are fastened by a mechanical method.

[0047] In an embodiment of the present invention, a battery case (100) is configured to include an upper bolt (5), a top plate (30), an upper watertight gasket (12), a body mounting pipe (10), a cross member (2), a cooling plate (60), a lower watertight gasket (13), a lower bolt (6), etc. The upper plate (30), the body mounting pipe (10), and the cross member (2) are configured of a steel material, and the cooling plate (60) is configured of an aluminum material.

[0048] In an embodiment of the present invention, dissimilar materials are applied, welding is not applied, and only a mechanical fastening method using bolting is applied. That is, a mechanical connection of dissimilar materials (steel and aluminum) using a body mounting pipe (10), an upper bolt (5), and a lower bolt (6) is applied.

[0049] The body mounting pipe (10) is hollow and made of steel. A top plate (30) is fitted into the upper part (14) of the body mounting pipe (10), and the lower part (15) is fitted into the insertion hole (3). An upper female screw (16) is formed on the inner diameter of the upper part (14), and a lower female screw (17) is formed on the inner diameter of the lower part (15). The screw directions of the upper female screw (16) and the lower female screw (17) may be opposite to each other.

[0050] An upper watertight gasket (12) is interposed between the upper surface of the body mounting pipe (10) and the upper plate (30). The lower surface of the body mounting pipe (10) makes contact with the area around the through hole (64) of the cooling plate (60). Sufficient heat transfer and heat dissipation are achieved through this contact.

[0051] The cross member (2) divides the internal space of the battery case, and the battery cell is positioned in the divided battery space (50). As shown in FIGS. 6 and 7, the cross member (2) according to the embodiment of the present invention has insertion grooves (4) formed at a specific interval at the bottom, and insertion holes (3) penetrating at positions where the insertion grooves (4) are formed. The insertion grooves (4) are formed to have a tapered shape so that an insertion protrusion (62) can be inserted. Optionally, the insertion grooves (4) may be formed to match the shape of the insertion protrusion (62). The insertion holes (3) penetrate vertically from the upper surface of the cross member (2) toward the insertion grooves (4).

[0052] And the cooling plate (60) has a rectangular shape that covers the bottom of the battery, and forms a plurality (e.g., 6 to 12) of insertion protrusions (62) at regular intervals. The cooling plate (60) is positioned to contact the lower part of the cross member (2), and the insertion protrusions (62) are inserted into the insertion grooves (4). The insertion protrusions (62) have a rounded protrusion shape, and a through hole (64) is formed at the upper part. That is, by forming a lower female screw (17) at the lower end (15) of the body mounting pipe (10), the lower end of the body mounting pipe (10) contacts the cooling plate (60). Therefore, when fastening, each insertion protrusion (62) is positioned at each insertion groove (4) of the cross member (2), making it easy to determine the fastening position.

[0053] And when fastening, the lower part (15) of the body mounting pipe (10) is fitted into the insertion hole (3) of the cross member (2). Accordingly, the lower bolt (6) is passed through the through hole (64) of the cooling plate (60) and then fastened to the body mounting pipe (10) by bolting. That is, in the fastening structure according to the embodiment of the present invention, the upper bolt (5) is fastened to the upper female screw (16) in a state where the upper plate (30) is assembled to the upper part (14) of the body mounting pipe (10).

[0054] And the lower bolt (6) is bolted to the lower female screw (17) of the body mounting pipe (10), so that the body mounting pipe (10), cross member (2), and cooling plate (60) are connected as one piece.

[0055] In addition, the upper watertight gasket (12) is placed between the upper end (14) of the body mounting pipe (10) and the upper plate (30). And the lower watertight gasket (13) is placed between the lower surface of the insertion protrusion (62) and the lower bolt (6). The upper watertight gasket (12) and the lower watertight gasket (13) may be a rubber ring, an O-ring, a silicone ring, etc. As a result, the battery case (100) can secure both the rigidity of the bolt fastening and the watertight performance.

[0056] And in an embodiment of the present invention, the tightening direction of the upper bolt (5) and the tightening direction of the lower bolt (6) can be made opposite to each other. That is, the upper bolt (5) can use a right-hand screw bolt and the lower bolt (6) can use a left-hand screw bolt to secure fastening force.

[0057] Therefore, according to the embodiment of the present invention mentioned above, it is possible to provide a steel battery case to which a mechanical bond of dissimilar materials (steel, aluminum) is applied to ensure watertight performance.

[0058] Furthermore, according to an embodiment of the present invention, an aluminum cooling plate within a steel battery case can be assembled without welding (assembly of dissimilar materials). Furthermore, the elimination of MIG welding ensures thermal deformation, watertightness, and airtightness, and the application of a steel battery case provides cost competitiveness compared to an aluminum battery case.

[0059] Furthermore, according to an embodiment of the present invention, the cost of the battery case can be reduced through mechanical joining of dissimilar materials (steel, aluminum). Furthermore, according to the present invention, it can be used at low cost in vehicles based on a steel frame structure, including electric vehicle-only platforms, and the manufacturing process can be simplified through mechanical fastening. Furthermore, watertightness can be ensured through mechanical fastening of the steel battery case and the aluminum cooling plate, and the fastening force can be adjusted by applying separate upper and lower counter-rotating fastening bolts (H / W, left and right rotation). Furthermore, thermal deformation of the cooling plate can be prevented (quality secured) through the removal of the MIG welded portion.

[0060] Fig. 9 is an exploded perspective view of a chassis frame into which a battery case according to the present invention is integrally assembled. As illustrated in Fig. 9, the chassis frame is a battery case-integrated chassis frame (Cell To Frame, CTF) and is largely composed of a battery case (100), a front frame (70), and a rear frame (75).

[0061] The battery case (100) has a rectangular prism shape in the shape of a plate, and a cooling plate (60) is assembled at the bottom. In addition, a side frame (88) is integrally assembled around the perimeter of the battery case (100). A front frame (70) is assembled to one side (front of the vehicle) of the side frame (88), and a rear frame (75) is assembled to the other side (rear of the vehicle) of the side frame (88).

[0062] Fig. 10 is a cross-sectional view of portion AA of Fig. 9. As shown in Fig. 10, the side frame (88) is arranged so that the outer panel (82) and the inner panel (84) are folded in a ㄷ shape and face each other, and then overlapped on the cooling plate (60). That is, the cross-section of the side frame (88) is a hollow rectangle.

[0063] First, a rivet nut (86) is assembled so as to penetrate the outer panel hole (92) of the outer panel (82) and the inner panel hole (94) of the inner panel (84). Next, a foam gasket (85) is applied along the perimeter of the cooling plate (60).

[0064] Next, the frame bolt (87) integrally fastens the lower cover (80), the cooling plate (60), and the rivet nut (86). The frame bolt (87) can form a female thread in the inner diameter of the rivet nut (86) during fastening. At the same time, the foam gasket (85) is pressed against the lower cover (80) to form a watertight seal. Through this process, the assembly of the battery (90), the battery case (100), and the side frame (88) is completed. Although Fig. 10 illustrates the lower part of the side frame (88), the upper part of the side frame (88) is also assembled with the same structure. Optionally, the frame bolt (87) may be replaced in whole or in part by welding in the assembled structure.

[0065] In addition, the devices and methods described above are not limited to the configurations and methods of the embodiments described above, and the embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made.

[0066] Description of the symbol

[0067] 1: Conventional aluminum battery case,

[0068] 2: Cross member,

[0069] 3: Insertion hole,

[0070] 4: Insertion groove,

[0071] 5: Top bolt,

[0072] 6: Lower bolt,

[0073] 7: Battery pack fastening bolts,

[0074] 8: MIG weld,

[0075] 9: Body mounting pipe,

[0076] 10: Body mounting pipe,

[0077] 11: Base,

[0078] 12: Upper watertight gasket,

[0079] 13: Lower watertight gasket,

[0080] 14: Top,

[0081] 15: Bottom,

[0082] 16: Upper female screw part,

[0083] 17: Lower female screw,

[0084] 20: Cooling plate,

[0085] 30: Top,

[0086] 40: Undercover,

[0087] 50: Battery space,

[0088] 60: Cooling plate,

[0089] 62: Insertion protrusion,

[0090] 64: Through hole,

[0091] 70: Front frame,

[0092] 75: Rear frame,

[0093] 80: Lower cover,

[0094] 82: Outer panel,

[0095] 84: Inner panel,

[0096] 85: Foam gasket,

[0097] 86: Rivet nut,

[0098] 87: Frame bolts,

[0099] 90: Battery,

[0100] 92: Outer panel hole,

[0101] 94: Inner panel hole,

[0102] 100: Battery case.

Claims

1. As a battery case, A cross member that divides the internal space of a battery case, has insertion grooves formed at the bottom at regular intervals, and has insertion holes that penetrate the positions where the insertion grooves are formed; A cooling plate positioned at the bottom of the cross member, having an insertion protrusion formed to protrude so as to be inserted into the insertion groove and having a through hole corresponding to the insertion hole; A body mounting pipe having a lower portion inserted into the insertion hole and a lower female screw formed on the inside of the lower portion; and A battery case with a mechanical joint of different materials that ensures watertight performance, characterized by including a lower bolt that is fastened to the lower female screw through the through hole to allow the body mounting pipe and the cooling plate to be in contact.

2. In paragraph 1, A battery case with a mechanical joint of different materials that ensures watertight performance, characterized in that the body mounting pipe further forms an upper female screw portion on the inside of the upper portion, and further includes an upper bolt that is fastened to the upper female screw portion while the upper plate is assembled to the upper portion.

3. In paragraph 2, A battery case with a mechanical bonding of different materials that ensures watertight performance, characterized in that it further includes an upper watertight gasket placed between the upper surface of the body mounting pipe and the upper plate.

4. In paragraph 2, A battery case with a mechanical bonding of different materials that ensures watertightness, characterized in that the tightening directions of the upper bolt and the lower bolt are opposite to each other.

5. In paragraph 1, A battery case with a mechanical joint of different materials that ensures watertight performance, characterized in that it further includes a lower watertight gasket interposed between the lower surface of the insertion protrusion and the lower bolt.

6. In paragraph 1, A battery case with a watertight performance and a mechanical bonding of different materials, characterized in that the cooling plate is made of aluminum and the cross member and the body mounting pipe are made of steel.

7. A battery case according to any one of paragraphs 1 to 6; A side frame integrally connected to the periphery of the above battery case; a front frame coupled to one side of the above side frame; and A battery case-integrated chassis frame with a mechanical bond of different materials, characterized in that it includes a rear frame coupled to the other side of the side frame.

8. In paragraph 7, The above side frame is arranged to form a closed cross-sectional curve by overlapping the folded outer panel and the folded inner panel, and A battery case-integrated chassis frame with a mechanical bond of dissimilar materials, characterized in that it further includes an assembly means for simultaneously and integrally assembling the outer panel, the inner panel, and the cooling plate of the battery case.

9. In paragraph 8, The above assembly means, A rivet nut assembled to penetrate the outer panel hole of the outer panel and the inner panel hole of the inner panel; and A battery case-integrated chassis frame with a mechanical bond of dissimilar materials, characterized in that it includes a frame bolt that integrally fastens the cooling plate and the rivet nut.

10. In paragraph 9, Further comprising a lower cover assembled to the lower portion of the cooling plate; A battery case-integrated chassis frame with a mechanical bond of dissimilar materials, characterized in that the frame bolt integrally fastens the cooling plate, the rivet nut, and the lower cover.

11. In paragraph 8, A battery case-integrated chassis frame with a mechanical bond of dissimilar materials, characterized in that a foam gasket is further included between the cooling plate and the side frame to maintain watertightness.

Images