Battery watertight structure and method using blind nut or bolt

Abstract

An invention relating to a battery watertight structure and method for solving problems caused by bushings included in a gasket. According to the present invention, for watertightness in a battery using a blind nut or a blind bolt, a blind nut (103) or a blind bolt (111) is press-fitted into a case (101), and assembly hardware (109, 113) corresponding to the blind nut or blind bolt is fastened to the blind nut or blind bolt; the height of the head flange (104) or anchor portion (112) of the blind nut or blind bolt is set such that torque for compressing the gasket is maintained against the axial force when fastening the assembly hardware in the space between the case and the cover; and the gasket includes an inner extension portion (106) in which the gasket ribs are extended in a direction toward the blind nut or blind bolt, and as the gasket is compressed between the case and the cover, it expands toward the blind nut or blind bolt. A battery watertight structure and method are provided.

Description

Technology Field

[0001] The present invention relates to a battery for an electric vehicle, and specifically, to a technology for improving the watertightness of a battery using a blind nut / bolt. Background Technology

[0002] Gaskets are used for watertight sealing of batteries used in electric vehicles, electric vehicles, and various other fields. FIG. 1a is a schematic diagram of a battery watertight gasket. A gasket (3) is provided between the battery casings (2), and when assembled, the rubber gasket (3) is compressed to block the path of moisture penetration (watertight action).

[0003] However, if only the gasket (3) is used, there is a concern that the gasket (3) may not be firmly fixed and thus the watertightness may be poor. Therefore, a number of metal bushes (1) are combined with the gasket (3) for use.

[0004] FIG. 1b is an example of a bush (1) used in conjunction with a battery watertight gasket. The steel bush (1) fitted into the gasket (3) supports the axial force caused by the torque when fastening the hardware for assembly. Generally, the shape of the bush (1) is a cylindrical shape with flanges (4, 4') formed on the upper and lower surfaces and fitted into the gasket, and a hollow (5) in the center through which the assembly hardware passes. Prior art literature

[0005] Korean Registered Patent 10-1895870 (September 7, 2018) The problem to be solved

[0006] As described above, a bushing is attached to the gasket to generate torque; however, since the gasket and bushing are not a single integrated unit, the bushing must be manually press-fitted onto the gasket. This increases cycle time and costs, and leads to quality issues as the bushing frequently detaches during the logistics of the gasket. Furthermore, repeatedly tightening and loosening assembly hardware (bolts, nuts, etc.) can cause the flange portion of the bushing (the part fixed to the rubber gasket) to bend, resulting in damage to the rubber gasket and permanent deformation. These issues cause torque loosening, and since gasket compression cannot be guaranteed, moisture may enter the battery.

[0007] Therefore, the objective of the present invention is to propose a battery watertight structure to solve these problems. means of solving the problem

[0008] To solve the above problem, according to the present invention, for watertightness in a battery using a blind nut or a blind bolt, a blind nut or a blind bolt is press-fitted into a case, and assembly hardware corresponding to the blind nut or blind bolt is fastened to the blind nut or blind bolt; the height of the head flange of the blind nut or blind bolt is set such that a torque for compressing the gasket is maintained against the axial force when fastening the assembly hardware in the space between the case and the cover; and the gasket includes an inner extension portion in which the gasket ribs are extended in a direction toward the blind nut or blind bolt, so that as the gasket is compressed between the case and the cover, it expands toward the blind nut or blind bolt. A battery watertight structure and method are provided.

[0009] The structure and operation of the present invention will become clearer through specific embodiments described later together with the drawings. Effects of the invention

[0010] Since bushings are not used in the gasket, the joining process between the gasket and the bushing is eliminated, reducing cycle time and costs, and resolving the issue of defects occurring during the logistics of the gasket.

[0011] In addition, since the bushing is removed from the gasket, damage or deformation of the gasket does not occur even when the assembly hardware (fastening bolts, fastening nuts) is tightened and loosened multiple times, thereby strengthening the gasket's compression and effectively blocking moisture from entering the battery. Brief explanation of the drawing

[0012] Figure 1a is a schematic diagram of a battery watertight gasket. FIG. 1b is an example of a bushing used in conjunction with a gasket. FIG. 2 is an assembly diagram of a conventional battery system (BSA) for a PHEV before the battery watertight structure of the present invention is applied. FIG. 3 is an exploded view of a maintenance bay (40) in an upper cover (20) made of steel or aluminum extrusion material. FIG. 4 is a detailed view of the upper cover (20) portion where a blind nut (42) is pressed in. Figure 5 shows the bush (46) fitted into the gasket (43). FIG. 6 is a detailed cross-sectional view of the components of FIG. 2 to FIG. 5 assembled. FIG. 7 is a cross-sectional view showing the battery watertight structure of the present invention, which improves upon the conventional gasket / bush-based battery watertight structure. FIG. 8 shows that the present invention is applied when the case (101) is made of extruded aluminum and is relatively thicker than the upper cover (107). FIG. 9 is an embodiment in which the blind nut of FIG. 8 is replaced with a blind bolt (111). Specific details for implementing the invention

[0013] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the preferred embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments described below but may be implemented in various other forms. The embodiments are provided merely to fully disclose the present invention and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined by the contents of the claims. Furthermore, the terms used in this specification are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular form includes the plural form unless specifically stated otherwise. Also, the terms used in this specification, such as 'comprise,' 'comprising,' etc., are used in the sense that they do not exclude the presence or addition of one or more other components, steps, actions, and / or elements other than those mentioned.

[0014] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the embodiments, specific descriptions of related known components or functions are omitted if such detailed descriptions could obscure the essence of the present invention.

[0016] FIG. 2 is an assembly diagram of a conventional battery system assembly (BSA) for a plug-in hybrid electric vehicle (PHEV) before the application of the battery watertight structure of the present invention. A battery is installed in the space between the lower case (10) and the upper cover (20), and a metal bracket (30) is placed over the upper cover (20) to secure it to the lower case (10), and the two are fastened together with bolts. A gasket is fitted and fastened between the lower case (10) and the upper cover (20), although it is not visible in FIG. 2. Part number '40' in FIG. 2 is a maintenance bay where specific parts can be serviced without disassembling the entire BSA.

[0018] FIG. 3 is an exploded view of a maintenance bay (40) in an upper cover (20) made of steel or aluminum extrusion material. A rubber gasket (43) is placed around a maintenance bay hole (41) drilled in the upper cover (20), and a maintenance bay cover (44) is placed over it. A plurality of fastening bolts (45), which are assembly hardware, are fastened through the through holes formed therein. A plurality of blind nuts (42) are pressed into the maintenance bay hole (41) to fasten the bolts. Additionally, a steel bush (see FIG. 5) is fitted into the gasket (43) at each location where the bolt passes to support the upper and lower compression limits of the gasket against the axial force during torque fastening.

[0020] FIG. 4 is a detailed view of the upper cover (20) where a blind nut (42) is pressed in. The left side is a view from the top of the upper cover (20), and the right side is a view from the bottom of the upper cover (20). Instead of pressing in a blind nut (42) into the upper cover (20), a blind bolt (described later) may be pressed in.

[0022] FIG. 5 shows a bush (46) fitted into a gasket (43). A bolt through hole formed in a rubber gasket (43) is opened by elastic force, and a hollow cylindrical steel bush (46) with flanges on the upper and lower surfaces as shown in FIG. 1b is press-fitted into it.

[0024] FIG. 6 is a detailed cross-sectional view of the assembled components described above. FIG. 6 shows the structure of an embodiment for watertightness of the maintenance bay (40) of FIG. 2, but it is evident that the present invention is not limited to the watertight structure of the maintenance bay (40) but can also be applied to the watertight structure of the battery module itself.

[0025] As shown in FIG. 6, a blind nut (42) is pressed into the upper cover (20) of the BSA, and a bush (46) is fitted into the gasket (43). Accordingly, the upper part of the gasket (43) contacts the lower surface of the maintenance cover (44) above, and the lower part of the gasket (43) contacts the upper surface of the BSA upper cover (20) below, thereby providing a watertight seal.

[0026] Here, the upper flange portion of the bush (46) contacts the lower surface of the maintenance cover (44) above, and the lower flange portion of the bush (46) contacts the head flange (47) of the blind nut (42) below. Therefore, as mentioned in the 'problem to be solved' above, as the fastening of the fastening bolt (45) and the blind nut (42) is repeated several times, the flange portion of the bush (46) may bend or deform, and the gasket (43) may be damaged or permanently deformed. Consequently, the torque of the fastening portion of the bolt (45) and the blind nut (42) is loosened ('A' marked portion), and since the gasket compression is not guaranteed, moisture may enter the battery ('B' marked portion).

[0028] FIG. 7 is a cross-sectional view showing the battery watertight structure of the present invention, which improves upon the conventional gasket / busher-based battery watertight structure described above.

[0029] Similar to what is shown in FIG. 6, a blind nut (103) is pressed into the case (101) of the BSA (made of steel), and a gasket (105) is fitted between the case (101) and the upper cover (107). Then, assembly hardware (i.e., a bolt (109)) passes through the through hole of the upper cover (107) and the gasket (105) and enters the blind nut (103) to fasten these components.

[0030] However, in the present invention, the gasket (105) does not have a bush. Instead, the thickness (height) of the head flange (104) of the blind nut (103) is extended to correspond to the position where the existing bush was located between the case (101) and the upper cover (107). This overcomes the problem of deformation of the bush's flange portion when fastening assembly hardware due to the bush's relatively weak flange structure, and allows the blind nut (103) to withstand (counter) the axial force when fastening assembly hardware (i.e., the fastening bolt (109)) instead of the bush, thereby maintaining the torque for compressing the gasket.

[0031] In addition, an inner extension (106) is added so that the gasket material goes further into the through hole of the gasket (105) and wraps around the head flange (104) of the blind nut (103). As the gasket (105) is compressed between the case (101) and the upper cover (107), this inner extension (106) enters and expands further into the through hole, allowing it to come close to or be in close contact with the side of the head flange (104) of the blind nut (103). Furthermore, since there is no bushing in the gasket (105), the watertightness between the case (101) and the upper cover (107) is maintained entirely by the compression of the gasket (105), thereby blocking moisture from penetrating into the space between them ('C' marked section) ('D' marked section).

[0033] FIG. 8 shows the application of the present invention when the case (101) is made of extruded aluminum and is relatively thicker than the upper cover (107) (Fig. 7 shows the case when the case (101) is made of steel). That is, it shows an embodiment in which the present invention is applied when the lower case (101) is thicker than the upper cover (107) above, and the configuration and principle of operation are the same as the embodiment shown in FIG. 7.

[0035] FIG. 9 is an embodiment in which a blind bolt (111) is used instead of the blind nut used in the embodiment of FIG. 8.

[0036] A blind bolt (111) is pressed into a case (101) made of aluminum extrusion material, an upper cover (107) is placed over the blind bolt (111) and a fastening nut (113) is fastened to the blind bolt (111).

[0037] Similar to the cases in FIGS. 7 and 8, the thickness of the blind bolt (111) is extended so that the anchor portion (112) of the blind bolt (111) occupies the space between the case (101) and the upper cover (107) instead of the bushing being removed. Then, the case (101) and the upper cover (107) are fastened using a nut (113) as assembly hardware. The watertight action of the gasket (105) and the improvement of its effect are the same as in the case of the blind nut (103) in FIGS. 7 and 8.

[0039] Although the present invention has been described in detail through preferred embodiments thereof, those skilled in the art will understand that the present invention may be implemented in a specific form different from that disclosed herein without changing its technical concept or essential features.

[0040] As such, the embodiments described above should be understood as illustrative in all respects and not restrictive. Furthermore, the scope of protection of the present invention is determined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the claims and their equivalents should be interpreted as being included within the technical scope of the present invention.

Claims

Claim 1 A battery watertight structure comprising: a case in which a battery is installed; a cover covering the case; and a gasket located between the case and the cover, wherein a blind nut is press-fitted into the case, and assembly hardware corresponding to the blind nut penetrates the cover, the gasket, and the case and is fastened to the blind nut, wherein the height of the head flange of the blind nut is set such that torque for compressing the gasket is maintained against the axial force when fastening the assembly hardware in the space between the case and the cover, and the gasket includes an inner extension portion in which the gasket rib extends into the inner side of the hole through which the assembly hardware penetrates the gasket, and the gasket expands toward the blind nut as it is compressed between the case and the cover, wherein the maximum thickness of the gasket is greater than the height of the head flange, the thickness of the inner extension portion is smaller than the height of the head flange, and the inner extension portion is spaced apart from the head flange by a predetermined distance. Claim 2 A battery watertight structure comprising: a case in which a battery is installed; a cover covering the case; and a gasket located between the case and the cover, wherein a blind bolt is press-fitted into the case and penetrates the gasket and the case and protrudes through the cover, and assembly hardware corresponding to the blind bolt is fastened to the blind bolt, and the height of the anchor portion of the blind bolt is set such that torque for compressing the gasket is maintained against the axial force when fastening the assembly hardware in the space between the case and the cover, and the gasket includes an inner extension portion in which the gasket rib extends into the inner side of the hole through which the blind bolt penetrates the gasket, so that the gasket expands toward the blind bolt as it is compressed between the case and the cover, and the maximum thickness of the gasket is greater than the height of the anchor portion, the thickness of the inner extension portion is smaller than the height of the anchor portion, and the inner extension portion is spaced apart from the anchor portion by a predetermined distance. Claim 3 In claim 1 or 2, the case is a battery watertight structure made of steel. Claim 4 In claim 1 or 2, the case is a battery watertight structure made of aluminum extrusion material. Claim 5 A battery watertight structure according to claim 1 or 2, characterized in that the case is a lower case of a BSA (battery system assembly) for an electric vehicle, and the cover is an upper cover of the BSA. Claim 6 A battery watertight structure according to claim 1 or 2, characterized in that the case is an upper case of a BSA (battery system assembly) for an electric vehicle, and the cover is a maintenance bay of the BSA. Claim 7 A method for watertightening a battery, comprising: a case in which a battery is installed; a cover covering the case; and a gasket located between the case and the cover, wherein a blind nut is press-fitted into the case, and assembly hardware corresponding to the blind nut penetrates the cover, the gasket, and the case and is fastened to the blind nut, thereby watertightening the battery, wherein the height of the head flange of the blind nut is set such that a torque for compressing the gasket is maintained against the axial force when fastening the assembly hardware in the space between the case and the cover; and the gasket ribs are extended inwardly into the hole through which the assembly hardware penetrates the gasket to form an inner extension, so that the gasket expands toward the blind nut as it is compressed between the case and the cover, wherein the maximum thickness of the gasket is greater than the height of the head flange, the thickness of the inner extension is smaller than the height of the head flange, and the inner extension is spaced apart from the head flange by a predetermined distance. Claim 8 A method for watertightening a battery, comprising: a case in which a battery is installed; a cover covering the case; and a gasket located between the case and the cover, wherein a blind bolt is pressed into the case and penetrates the gasket and the case and protrudes through the cover, and assembly hardware corresponding to the blind bolt penetrates the cover, the gasket, and the case and is fastened to the blind bolt, thereby watertightening the battery, wherein the height of the anchor portion of the blind bolt is set such that a torque for compressing the gasket is maintained against the axial force when fastening the assembly hardware in the space between the case and the cover; and the gasket ribs are extended inwardly into the hole through which the blind bolt penetrates the gasket to form an inner extension portion, so that the gasket expands toward the blind bolt as it is compressed between the case and the cover, wherein the maximum thickness of the gasket is greater than the height of the anchor portion, the thickness of the inner extension portion is smaller than the height of the anchor portion, and the inner extension portion is spaced apart from the anchor portion by a predetermined distance. Claim 9 A battery watertight method according to claim 7 or 8, wherein the case is made of steel material. Claim 10 A battery watertight method according to claim 7 or 8, wherein the case is made of aluminum extrusion material. Claim 11 A battery watertight sealing method according to claim 7 or 8, wherein the case is a lower case of a BSA (battery system assembly) for an electric vehicle and the cover is an upper cover of the BSA. Claim 12 A battery watertight method according to claim 7 or 8, characterized in that the case is an upper case of a BSA (battery system assembly) for an electric vehicle, and the cover is a maintenance bay cover of the BSA.

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