Battery cover

Abstract

The battery cover (1) has a side wall (2) covering the side surface (S3) of the battery (100). The side wall (2) has: a first surface layer (11) in contact with the side surface (S3) of the battery (100); a second surface layer (12) arranged on the side opposite to the side surface (S3) of the battery (100) relative to the first surface layer (11) in the thickness direction of the side wall 2; a heat insulating layer (13) arranged between the first surface layer (11) and the second surface layer (12) in the thickness direction; and a buffer layer (14) arranged between the first surface layer (11) and the heat insulating layer (13) in the thickness direction.

Description

Technical Field

[0001] The invention relates to a battery cover. Background Art

[0002] Conventionally, a battery cover to be mounted on a battery has been proposed that includes a side wall covering the side of the battery, the side wall including a porous layer having heat insulation properties and protective layers arranged on one side and the other side of the porous layer in a thickness direction (see, for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2019 / 098231 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In the battery cover described in Patent Document 1, when there is a protrusion on the side surface of the battery, the battery cover may get caught on the protrusion, thereby preventing the battery cover from being attached to the battery.

[0008] Therefore, an object of the present invention is to provide a battery cover that can be smoothly mounted on a battery.

[0009] Solutions for solving problems

[0010] The present invention [1] includes a battery cover having a side wall, the side wall covering the side of the battery, the side wall having: a first surface layer, the first surface layer being in contact with the side of the battery; a second surface layer, the second surface layer being arranged on the side opposite to the side of the battery relative to the first surface layer in the thickness direction of the side wall; a heat insulating layer, the heat insulating layer being arranged between the first surface layer and the second surface layer in the thickness direction; and a buffer layer, the buffer layer being arranged between the first surface layer and the heat insulating layer in the thickness direction.

[0011] According to such a structure, the side wall of the battery cover includes the first surface layer in contact with the side surface of the battery and the buffer layer disposed between the first surface layer and the heat insulating layer.

[0012] When the battery cover is mounted on the battery, the side wall slides with the first surface layer relative to the side surface of the battery.

[0013] In this case, even if there is a protrusion on the side surface of the battery, the buffer layer disposed inside the side wall (between the first surface layer and the heat insulating layer) deforms according to the protrusion, thereby preventing the first surface layer from being caught by the protrusion.

[0014] Thus, even if there is a protruding portion on the side surface of the battery, the battery cover can smoothly go over the protruding portion.

[0015] As a result, the battery cover can be smoothly attached to the battery.

[0016] Furthermore, when the battery cover is completely attached to the battery, the first surface layer can be reliably brought into contact with the side surface of the battery due to the elasticity of the buffer layer.

[0017] Thus, the space between the side surface of the battery and the heat insulating layer can be filled with the buffer layer and the first surface layer.

[0018] As a result, it is possible to suppress the air around the battery from flowing into between the side surfaces of the battery and the heat insulating layer, and to suppress the transfer of ambient heat to the battery.

[0019] The present invention [2] comprises the battery cover of the above-mentioned [1], wherein the 50% compression hardness of the buffer layer is lower than the 50% compression hardness of the heat insulating layer.

[0020] According to such a structure, the buffer layer can be easily deformed while maintaining the shape of the heat insulating layer.

[0021] The present invention [3] comprises the battery cover of the above [2], wherein the 50% compression hardness of the heat insulating layer is 10.0 kPa or more, and the 50% compression hardness of the buffer layer is 1.0 kPa or more and less than 10.0 kPa.

[0022] According to such a structure, the shape of the heat insulating layer can be further maintained, and the buffer layer can be deformed more easily.

[0023] The present invention [4] comprises the battery cover according to any one of the above [1] to [3], wherein the thermal conductivity of the heat insulating layer is 0.045 W / (m·K) or less.

[0024] According to such a configuration, the heat insulating layer can suppress the transfer of ambient heat to the battery.

[0025] The present invention [5] comprises the battery cover of any one of the above [1] to [4], wherein the heat insulating layer and the buffer layer each comprise a foam-based heat insulating material or a fiber-based heat insulating material.

[0026] According to such a structure, the battery cover can be easily attached to the battery, and the heat insulation property can be improved.

[0027] The present invention [6] includes any one of the battery covers [1] to [5] above, wherein the battery has a first surface on which a terminal is arranged, a second surface separated from the first surface in a first direction, and the side surface is arranged between the first surface and the second surface in the first direction and extends along the first direction, and the buffer layer extends from one end of the side wall to the other end in the first direction.

[0028] According to such a configuration, when the battery cover is completely attached to the battery, the space between the side surface of the battery and the heat insulating layer can be filled in the entire range from one end to the other end of the side wall of the battery cover in the first direction.

[0029] The present invention [7] includes any one of the battery covers [1] to [6] above, wherein the side wall has an inner surface and an outer surface, the inner surface is in contact with the side surface of the battery in the thickness direction, and the outer surface is arranged on the side opposite to the side surface of the battery relative to the inner surface in the thickness direction, and the outer surface has: a recessed portion that is recessed in the thickness direction; and a bulging portion that bulges out more than the recessed portion in the thickness direction.

[0030] According to such a structure, the heat insulation can be ensured in the bulging part, and the side wall can be easily bent in the recessed part. In addition, the interference between the member arranged around the battery and the side wall can be avoided in the recessed part.

[0031] The present invention [8] includes the battery cover of the above-mentioned [7], wherein, in a state where the battery cover is removed from the battery, the thickness of the heat insulating layer in the recessed portion is thinner than the thickness of the heat insulating layer in the bulging portion.

[0032] According to such a configuration, by molding the heat insulating layer, the thickness of the buffer layer can be ensured and the recessed portion can be formed.

[0033] The present invention [9] includes the battery cover of the above-mentioned [7] or [8], wherein, when the battery cover is removed from the battery, the heat insulating layer in the recessed portion is compressed in the thickness direction more than the heat insulating layer in the bulging portion.

[0034] According to such a configuration, the recessed portion can be easily formed by compressing the heat insulating layer.

[0035] The present invention

[10] includes the battery cover of any one of the above [7] to [9], wherein the recessed portion extends along a corner of the battery.

[0036] According to such a structure, the side wall can be bent according to the corner of the battery, and the side wall can be made to follow the side surface of the battery.

[0037] Effects of the Invention

[0038] According to the battery cover of the present invention, it is possible to smoothly attach the battery cover to the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a perspective view of a battery to which a battery cover according to one embodiment of the present invention is attached.

[0040] Figure 2 yes Figure 1 A perspective view of the battery shown.

[0041] Figure 3 yes Figure 1 A perspective view of the battery cover is shown.

[0042] Figure 4 yes Figure 3 A-A cross-sectional view of the battery cover shown.

[0043] Figure 5 yes Figure 3 BB cross-sectional view of the battery cover shown.

[0044] Figure 6 In Figure 6 A and Figure 6 B is an explanatory diagram for explaining a method for manufacturing a battery cover. Figure 6 A represents the lamination process, Figure 6 B represents a forming process.

[0045] Figure 7 yes Figure 6 B is a top view of the stacked body.

[0046] Figure 8 In Figure 8 A and Figure 8 B is an explanatory diagram for explaining a method of mounting the battery cover relative to the battery. Figure 8 A represents the case where the battery cover deforms the cushioning material and is installed on the battery. Figure 8 B shows a state where the battery cover is completely attached to the battery.

[0047] Fig. 9 is an explanatory diagram for explaining the first modification example, Fig. 9 A is a perspective view of a battery cover according to a first modification example. Fig. 9 B is Fig. 9 A is a CC sectional view of the battery cover.

[0048] Fig.10 It is an explanatory diagram for explaining the second modification example.

[0049] Fig.11 It is an explanatory diagram for explaining the third modified example.

[0050] Fig.12 This is a top view of a test piece for evaluating thermal insulation properties.

[0051] Fig.13 yes Fig.12 DD cross-sectional view of the test piece shown.

[0052] Fig.14 This is a schematic diagram of the structure of an evaluation device for evaluating thermal insulation properties.

[0053] Fig.15 yes Fig.14 A side view of the jig shown, viewed from opposite directions.

[0054] Fig.16 This is a top view of a test piece for evaluating mounting performance.

[0055] Fig.17 This is a schematic diagram of the structure of an evaluation device for evaluating the installability.

[0056] Fig.18 This is an explanatory diagram for explaining a method of evaluating mountability. DETAILED DESCRIPTION

[0057] like Figure 1 As shown in FIG. 1 , a battery cover 1 according to one embodiment of the present invention is mounted on a battery 100 .

[0058] 1. Battery 100

[0059] Reference Figure 2 The battery 100 is described.

[0060] In the present embodiment, the battery 100 is a lead acid battery. However, the battery 100 is not limited to a lead acid battery, and may be a secondary battery such as a lithium ion secondary battery.

[0061] The battery 100 has a substantially rectangular parallelepiped shape and includes a battery case 101 , a cover 102 , a positive electrode plate (not shown), a negative electrode plate (not shown), a positive electrode terminal 103 as an example of a terminal, and a negative electrode terminal 104 as an example of a terminal.

[0062] The battery case 101 has an opening (not shown). The opening is arranged at one end portion in the first direction of the battery case 101. The battery case 101 accommodates a positive electrode plate, a negative electrode plate, and an electrolyte.

[0063] The cover 102 is attached to one end portion of the battery case 101 in the first direction. The cover 102 closes the opening of the battery case 101 .

[0064] The positive electrode terminal 103 and the negative electrode terminal 104 are attached to the cover 102. The positive electrode terminal 103 is electrically connected to the positive electrode. The negative electrode terminal 104 is electrically connected to the negative electrode. The negative electrode terminal 104 is arranged with a gap from the positive electrode terminal 103 in the second direction. The second direction is orthogonal to the first direction.

[0065] The battery 100 has a first surface S1, a second surface S2, and a side surface S3. In the present embodiment, the first surface S1 is the outer surface of the upper side of the cover 102. The positive terminal 103 and the negative terminal 104 are arranged on the first surface S1. The second surface S2 is the outer surface of the lower side of the battery case 101. That is, the second surface S2 is separated from the first surface S1 in the first direction. The side surface S3 is a side surface of the battery case 101. The side surface S3 is arranged between the first surface S1 and the second surface S2 in the first direction. The side surface S3 extends along the first direction. In the present embodiment, the side surface S3 includes a first side surface S31, a second side surface S32, a third side surface S33, and a fourth side surface S34.

[0066] The first side surface S31 is an outer surface of the battery case 101 on one side in the third direction. The third direction is perpendicular to the first direction and the second direction. The first side surface S31 extends along the first direction and the second direction.

[0067] The second side surface S32 is the other outer surface of the battery case 101 in the third direction. The second side surface S32 extends along the first direction and the second direction.

[0068] The third side surface S33 is an outer surface of one side of the battery case 101 in the second direction. The third side surface S33 extends along the first direction and the third direction. One end of the third side surface S33 in the third direction is connected to one end of the first side surface S31 in the second direction. The portion where one end of the third side surface S33 in the third direction is connected to one end of the first side surface S31 in the second direction is a corner C1. The other end of the third side surface S33 in the third direction is connected to one end of the second side surface S32 in the second direction. The portion where the other end of the third side surface S33 in the third direction is connected to one end of the second side surface S32 in the second direction is a corner C2.

[0069] The 4th side surface S34 is the outer surface of the other side of the battery case 101 in the 2nd direction. The 4th side surface S34 extends along the 1st direction and the 3rd direction. One end of the 4th side surface S34 in the 3rd direction is connected to the other end of the 1st side surface S31 in the 2nd direction. The portion where one end of the 4th side surface S34 in the 3rd direction is connected to the other end of the 1st side surface S31 in the 2nd direction is a corner C3. The other end of the 4th side surface S34 in the 3rd direction is connected to the other end of the 2nd side surface S32 in the 2nd direction. The portion where the other end of the 4th side surface S34 in the 3rd direction is connected to the other end of the 2nd side surface S32 in the 2nd direction is a corner C4.

[0070] 2.Battery cover 1

[0071] Next, refer to Figure 1 to Figure 5 The battery cover 1 will be described.

[0072] like Figure 1 As shown, when the battery cover 1 is mounted on the battery 100 , the battery cover 1 covers the outer surface of the battery 100 . When the battery cover 1 is mounted on the battery 100 , the battery cover 1 suppresses the transfer of ambient heat to the battery 100 .

[0073] In addition, the battery cover 1 may also partially expose the outer surface of the battery 100. In this embodiment, when the battery cover 1 is mounted on the battery 100, the battery cover 1 covers the side surface S3 of the battery 100, so that the first surface S1 and the second surface S2 of the battery 100 (see Figure 2 When the battery cover 1 is mounted on the battery 100 , the battery cover 1 surrounds the battery 100 .

[0074] (1) Shape of battery cover 1

[0075] like Figure 3 As shown in FIG. 1 , the battery cover 1 has a cylindrical shape. The battery cover 1 extends in a first direction. The battery cover 1 has a side wall 2. In the present embodiment, the battery cover 1 includes only the side wall 2. When the battery cover 1 is mounted on the battery 100 (see FIG. 1 ), the battery cover 1 is provided with a cylindrical shape. Figure 1 ), the side wall 2 covers the side surface S3 of the battery 100. In this embodiment, the side wall 2 includes a first side wall 2A, a second side wall 2B, a third side wall 2C and a fourth side wall 2D.

[0076] The first side wall 2A is disposed at one end of the battery cover 1 in the third direction. The first side wall 2A extends in the first direction and the second direction. The first side wall 2A has a flat plate shape. When the battery cover 1 is mounted on the battery 100, the first side wall 2A covers the first side surface S31 of the battery 100 (see Figure 2 ).

[0077] The second side wall 2B is arranged at the other end of the battery cover 1 in the third direction. The second side wall 2B is arranged at a distance from the first side wall 2A in the third direction. When the battery cover 1 is installed on the battery 100, the second side wall 2B is arranged on the side opposite to the first side wall 2A with respect to the battery 100 in the third direction. The second side wall 2B extends in the first direction and the second direction. The second side wall 2B has a flat plate shape. When the battery cover 1 is installed on the battery 100, the second side wall 2B covers the second side surface S32 of the battery 100 (see Figure 2 ).

[0078] The third side wall 2C is disposed at one end of the battery cover 1 in the second direction. The third side wall 2C extends in the first direction and the third direction. The third side wall 2C has a flat plate shape. When the battery cover 1 is mounted on the battery 100, the third side wall 2C covers the third side surface S33 of the battery 100 (see Figure 2 ). One end of the third side wall 2C in the third direction is connected to one end of the first side wall 2A in the second direction. The other end of the third side wall 2C in the third direction is connected to one end of the second side wall 2B in the second direction.

[0079] The fourth side wall 2D is arranged at the other end of the battery cover 1 in the second direction. The fourth side wall 2D is arranged at a distance from the third side wall 2C in the second direction. When the battery cover 1 is mounted on the battery 100, the fourth side wall 2D is arranged on the side opposite to the third side wall 2C with respect to the battery 100 in the second direction. The fourth side wall 2D extends in the first direction and the third direction. The fourth side wall 2D has a flat plate shape. When the battery cover 1 is mounted on the battery 100, the fourth side wall 2D covers the fourth side surface S34 of the battery 100 (see Figure 2 ). One end of the fourth side wall 2D in the third direction is connected to the other end of the first side wall 2A in the second direction. The other end of the fourth side wall 2D in the third direction is connected to the other end of the second side wall 2B in the second direction.

[0080] In addition, the side wall 2 has an inner surface S11 and an outer surface S12.

[0081] When the battery cover 1 is mounted on the battery 100, the inner surface S11 is aligned with the side surface S3 of the battery 100 (see FIG. Figure 2 ) are in contact. In addition, in the present embodiment, in the first side wall 2A and the second side wall 2B, the “thickness direction” is the third direction. In addition, in the third side wall 2C and the fourth side wall 2D, the “thickness direction” is the second direction.

[0082] When the battery cover 1 is mounted on the battery 100, the outer surface S12 is arranged at a position closer to the side surface S3 of the battery 100 (see FIG. Figure 2 ) on the opposite side.

[0083] The side wall 2 has edge portions 3A, 3B, outer bulging portions 4A to 4D as a plurality of bulging portions, a plurality of recessed portions 5A to 5D, and an inner bulging portion 6 (see Figure 4 ).

[0084] (1-1) Edges 3A, 3B

[0085] like Figure 3 and Figure 4 As shown, the edge 3A is arranged at one end (upper end) of the battery cover 1 in the first direction. The edge 3A extends over the entire circumference of the battery cover 1. In the present embodiment, the edge 3A extends in the second direction at the first side wall 2A and the second side wall 2B, and extends in the third direction at the third side wall 2C and the fourth side wall 2D.

[0086] The edge 3B is arranged at a distance from the edge 3A in the first direction. The edge 3B is arranged at the other end (lower end) of the battery cover 1 in the first direction. The edge 3B extends over the entire circumference of the battery cover 1 similarly to the edge 3A.

[0087] (1-2) Outer bulges 4A to 4D

[0088] like Figure 3 and Figure 4 As shown in FIG. 1 , the plurality of outer bulges 4A to 4D are arranged between the edge 3A and the edge 3B in the first direction. The plurality of outer bulges 4A to 4D bulge outward from the edge 3A and the edge 3B in the thickness direction. Figure 8 B), the plurality of outer bulges 4A to 4D are respectively disposed in the thickness direction relative to the edge 3A and the edge 3B and are adjacent to the side S3 (refer to Figure 1 ) is bulging on the opposite side.

[0089] like Figure 3 and Figure 5 As shown, the outer bulge 4A is arranged on the outer surface S12 of the first side wall 2A. The outer bulge 4B is arranged on the outer surface S12 of the second side wall 2B. The outer bulge 4C is arranged on the outer surface S12 of the third side wall 2C. The outer bulge 4D is arranged on the outer surface S12 of the fourth side wall 2D.

[0090] (1-3) Recessed portions 5A to 5D

[0091] like Figure 3As shown, a plurality of recesses 5A to 5D are arranged between the edge 3A and the edge 3B in the first direction. The recess 5A is arranged at the connection portion between the first side wall 2A and the third side wall 2C. The recess 5B is arranged at the connection portion between the second side wall 2B and the third side wall 2C. The recess 5C is arranged at the connection portion between the first side wall 2A and the fourth side wall 2D. The recess 5D is arranged at the connection portion between the second side wall 2B and the fourth side wall 2D. The plurality of recesses 5A to 5D extend in the first direction, respectively. When the battery cover 1 is mounted on the battery 100, the recess 5A extends along the corner C1 (refer to Figure 2 ) extends, the recess 5B extends along the corner C2 (refer to Figure 2 ) extends, the recess 5C extends along the corner C3 (refer to Figure 2 ) extends, the recess 5D extends along the corner C4 (refer to Figure 2 )extend.

[0092] like Figure 5 As shown, the plurality of recesses 5A to 5D are respectively recessed from the outer surface S12 toward the inner surface S11 in the thickness direction. Specifically, the plurality of recesses 5A to 5D are respectively recessed than the plurality of outer bulges 4A to 4D in the thickness direction. In other words, the plurality of outer bulges 4A to 4D are respectively bulged than the plurality of recesses 5A to 5D. The plurality of recesses 5A to 5D are formed on the outer surface S12. That is, the outer surface S12 has the plurality of recesses 5A to 5D.

[0093] (1-4) Inner bulge 6

[0094] like Figure 4 As shown in FIG. 1 , the inner bulge 6 is arranged on the inner surface S11 of the side wall 2. The inner bulge 6 is arranged between the edge 3A and the edge 3B in the first direction. The inner bulge 6 bulges inwardly than the edge 3A and the edge 3B in the thickness direction. Figure 8 B), the inner bulging portion 6 bulges from the edge portion 3A and the edge portion 3B toward the side surface S3 of the battery 100 in the thickness direction.

[0095] like Figure 5 As shown, the inner bulging portion 6 is arranged in the entire range from the first side wall 2A to the fourth side wall 2D.

[0096] (2) Layer structure of battery cover 1

[0097] like Figure 4 and Figure 5 As shown, the battery cover 1 includes a first surface layer 11 , a second surface layer 12 , a heat insulating layer 13 , and a buffer layer 14 . In other words, the side wall 2 includes a first surface layer 11 , a second surface layer 12 , a heat insulating layer 13 , and a buffer layer 14 .

[0098] (2-1) First surface layer 11

[0099] The first surface layer 11 is the innermost layer of the side wall 2 in the thickness direction. Figure 8 B), in the thickness direction, the first surface layer 11 is arranged between the side surface S3 of the battery 100 and the buffer layer 14, or between the side surface S3 of the battery 100 and the heat insulating layer 13. The first surface layer 11 protects the heat insulating layer 13 and the buffer layer 14 on the inner side in the thickness direction. The first surface layer 11 is arranged on the entire side wall 2. When the battery cover 1 is installed on the battery 100, the first surface layer 11 contacts the side surface S3 of the battery 100. The first surface layer 11 has an inner surface S11.

[0100] Examples of the material of the first surface layer 11 include nonwoven fabrics, woven fabrics, plastic sheets, and plastic films.

[0101] As materials for nonwoven fabrics and textiles, natural fibers such as cotton, hemp, pulp, wool, silk, and mineral fibers, and chemical fibers such as polyester fibers, polyethylene fibers, polypropylene fibers, nylon fibers, aromatic polyamide fibers, acrylonitrile fibers, vinylon fibers, rayon, and glass fibers can be cited. Nonwoven fabrics and textiles can be composed of a single type of fiber or a plurality of types of fibers.

[0102] As materials for the plastic sheet and the plastic film, there can be mentioned thermosetting resins such as polyester resin, polyurethane resin, polycarbonate resin, and thermoplastic resins such as polyolefin resin, polyvinyl chloride, styrene-butadiene rubber, etc. The plastic sheet and the plastic film may be composed of a single type of resin or a plurality of types of resins.

[0103] The first surface layer 11 is preferably made of nonwoven fabric. When the first surface layer 11 is made of nonwoven fabric, the material of the nonwoven fabric preferably includes chemical fibers, more preferably polyester fibers and polypropylene fibers, and further preferably polyethylene terephthalate (PET) fibers and polypropylene fibers.

[0104] If the first surface layer 11 includes polyethylene terephthalate fibers, the heat resistance of the first surface layer 11 can be improved. If the first surface layer 11 includes polypropylene fibers, the first surface layer 11 can be easily thermally fused to the second surface layer 12. If the first surface layer 11 includes polyethylene terephthalate fibers and polypropylene fibers, the heat resistance of the first surface layer 11 and the thermal fusion properties of the first surface layer 11 to the heat insulating layer 13 or the second surface layer 12 can be achieved.

[0105] The method for producing the nonwoven fabric is not limited. Examples of the method for producing the nonwoven fabric include pile fabric forming methods such as dry method, wet method, spunbonding method, meltblowing method, and pile fabric bonding methods such as thermal bonding method, chemical bonding method, stitch bonding method, needle punching method, spun lace method, and steam jet method.

[0106] The nonwoven fabric may also be impregnated with a resin. The resin impregnated in the nonwoven fabric is not limited. As the resin impregnated in the nonwoven fabric, thermosetting resins such as phenolic resins and resorcinol resins, vinyl acetate resins such as ethylene-vinyl acetate copolymers (EVA), olefin resins such as amorphous olefin copolymers (APAO), and other thermoplastic resins can be cited.

[0107] In addition, the nonwoven fabric may be a laminate of a resin layer and a fiber layer. As the resin layer, for example, a layer composed of the above-mentioned vinyl acetate resin can be cited. As the fiber layer, a layer composed of the above-mentioned nonwoven fabric and textile materials can be cited. Specifically, a nonwoven fabric can be cited in which vinyl acetate resin, polyester fiber (more specifically, polyethylene terephthalate fiber) and polypropylene fiber are laminated in the order of vinyl acetate resin (resin layer), polyester fiber (fiber layer), polypropylene fiber (fiber layer), and vinyl acetate resin (resin layer).

[0108] The thickness of the first surface layer 11 is thinner than the thickness of the heat insulating layer 13 and the buffer layer 14. The thickness of the first surface layer 11 is, for example, 0.01 mm or more, preferably 0.1 mm or more, and, for example, 10.0 mm or less, preferably 5.0 mm or less.

[0109] (2-2) Second surface layer 12

[0110] The second surface layer 12 is the outermost layer of the side wall 2 in the thickness direction. The second surface layer 12 is arranged on the opposite side of the first surface layer 11 with respect to the heat insulating layer 13 and the buffer layer 14 in the thickness direction. The second surface layer 12 protects the heat insulating layer 13 and the buffer layer 14 on the outer side in the thickness direction. Figure 8 B), the second surface layer 12 is arranged on the side opposite to the side S3 of the battery 100 relative to the first surface layer 11 in the thickness direction. The second surface layer 12 is arranged on the entire side wall 2. The second surface layer 12 has an outer surface S12. The second surface layer 12 is bonded to the first surface layer 11 at the edge 3A and the edge 3B.

[0111] Examples of the material of the second surface layer 12 include the same materials as those of the first surface layer 11. The second surface layer 12 may be made of the same material as that of the first surface layer 11, or may be made of a material different from that of the first surface layer 11.

[0112] The thickness of the second surface layer 12 is thinner than the thickness of the heat insulating layer 13 and the buffer layer 14. The thickness of the second surface layer 12 is, for example, 0.01 mm or more, preferably 0.1 mm or more, and, for example, 10.0 mm or less, preferably 5.0 mm or less. In addition, the thickness of the second surface layer 12 may be the same as the thickness of the first surface layer 11, or may be different from the thickness of the first surface layer 11.

[0113] (2-3) Heat insulation layer 13

[0114] The heat insulating layer 13 is arranged between the first surface layer 11 and the second surface layer 12 in the thickness direction. The heat insulating layer 13 is arranged between the buffer layer 14 and the second surface layer 12 in the thickness direction. The heat insulating layer 13 is arranged in each outer bulge 4A to 4D. In the present embodiment, the heat insulating layer 13 is arranged in each outer bulge 4A to 4D and each concave portion 5A to 5C. The heat insulating layer 13 is bonded to the second surface layer 12. The heat insulating layer 13 is composed of a heat insulating material.

[0115] Examples of the heat insulating material include foam-based heat insulating materials such as polyurethane foam, phenolic foam, polyethylene foam, and polystyrene foam; and fiber-based heat insulating materials such as glass wool, rock wool, nonwoven fabric containing silica aerogel and cellulose fiber.

[0116] The heat insulating layer 13 preferably includes a foamed heat insulating material, and more preferably includes polyurethane foam.

[0117] The thermal conductivity of the heat insulating layer 13 is 0.045 W / (m·K) or less, preferably 0.043 W / (m·K) or less, more preferably 0.040 W / (m·K) or less, further preferably 0.035 W / (m·K) or less, further preferably 0.033 W / (m·K) or less, further preferably 0.030 W / (m·K) or less, for example 0.015 W / (m·K) or more. The thermal conductivity is measured by the hot wire method (probe method) based on JIS R2616:2001 or ASTM D 5930. Specifically, the thermal conductivity is measured at room temperature using a rapid thermal conductivity meter (manufactured by Kyoto Electronics Industries, trade name "QTM-500"). The thermal conductivity of the heat insulating layer 13 is a major factor affecting the thermal insulation of the battery cover 1. The thermal insulation of the battery cover 1 can be evaluated by the method described in the examples described later.

[0118] Here, as other factors affecting the thermal insulation of the battery cover 1, for example, the thermal conductivity of the buffer layer 14 described later, the air permeability of the heat insulating layer 13, the air permeability of the buffer layer 14, etc. If the air permeability of the heat insulating layer 13 is too high, it is difficult for the battery cover 1 to block the high-temperature airflow, so there is a tendency for the thermal insulation of the battery cover 1 to decrease.

[0119] The air permeability of the heat insulating layer 13 is preferably lower than the air permeability of the buffer layer 14. More preferably, the air permeability of the heat insulating layer 13 is lower than the air permeability of the first surface layer 11, the second surface layer 12, and the buffer layer 14. In addition, in the case of a foam, the air permeability can be measured by the B method specified in JIS K 6400-7:2012, and in the case of a nonwoven fabric, the air permeability can be measured by the Frazier method specified in JIS L1913:2010.

[0120] The air permeability of the heat insulating layer 13 is, for example, 160 ml / cm 2 / sec or less, preferably 100ml / cm 2 / sec or less, more preferably 75ml / cm 2 When the air permeability of the heat insulating layer 13 is equal to or less than the upper limit value described above, a decrease in the heat insulating property of the battery cover 1 can be suppressed.

[0121] The heat insulating layer 13 is harder than the buffer layer 14. The 50% compression hardness of the heat insulating layer 13 is higher than the 50% compression hardness of the buffer layer 14. The 50% compression hardness is measured based on JIS K 6767:1999. In detail, the size (width×length) of the test piece used for measuring the 50% compression hardness is 100 mm×100 mm. The 50% compression hardness is calculated as follows, that is, the test piece is placed between parallel flat plates of the testing machine, and 50% of the initial thickness is compressed at a compression speed of 5 mm / min and stopped, and the following formula is used to calculate based on the load P measured just after the compression is stopped.

[0122] Formula: 50% compression hardness = load P ÷ area of ​​test piece (100mm×100mm)

[0123] The 50% compression hardness of the heat insulating layer 13 is, for example, 10.0 kPa or more, preferably 11.0 kPa or more, and more preferably 12.0 kPa or more. When the 50% compression hardness of the heat insulating layer 13 is greater than the above lower limit, deformation of the heat insulating layer 13 can be suppressed after the forming process described later. In addition, the upper limit of the 50% compression hardness of the heat insulating layer 13 is not limited as long as the heat insulating layer 13 can be compressed in the forming process described later.

[0124] The compression hardness retention rate of the heat insulating layer 13 after 120 seconds is, for example, less than 75%, preferably 70% or less, for example, 10% or more.

[0125] The compression hardness retention rate after 120 seconds is measured by the method described in Examples below.

[0126] By keeping the compression hardness retention rate of the heat insulating layer 13 after 120 seconds below the upper limit (i.e., the compression hardness is easily reduced in the compressed state and is not easy to recover from the compressed state), the heat insulating layer 13 can be suppressed from being deformed after the forming step described later. As a result, the concave portions 5A to 5C and the concave portion 40 of the modified example described later (see Fig.10 ) shape. Therefore, the side wall 2 can be bent at the recesses 5A to 5C so that the recesses 5A to 5D are along the corners C1 to C4 of the battery 100. As a result, the battery cover 1 can be easily mounted on the battery 100. In addition, the recess 40 can be used to suppress the member M (see Fig.10 ) interferes with the side wall 2.

[0127] When the battery cover 1 is removed from the battery 100, the thickness of the heat insulating layer 13 in each outer bulging portion 4A to 4D is, for example, 3 mm or more, preferably 5 mm or more, for example, 25 mm or less, preferably 20 mm or less. When the thickness of the heat insulating layer 13 in each outer bulging portion 4A to 4D is greater than the above lower limit, the heat insulating property of the battery cover 1 can be ensured. When the thickness of the heat insulating layer 13 in each outer bulging portion 4A to 4D is less than the above upper limit, the battery cover 1 can be prevented from being excessively enlarged.

[0128] When the battery cover 1 is removed from the battery 100, the thickness of the heat insulating layer 13 in each recess 5A to 5C is thinner than the thickness of the heat insulating layer 13 in each outer bulge 4A to 4D. Specifically, the thickness of the heat insulating layer 13 in each recess 5A to 5C is, for example, 10 mm or less, preferably 5 mm or less, for example, 1 mm or more. By making the thickness of the heat insulating layer 13 in each recess 5A to 5C thinner than the thickness of the heat insulating layer 13 in each outer bulge 4A to 4D, the side wall 2 can be easily bent at each recess 5A to 5C. By bending the side wall 2 at each recess 5A to 5C, the side wall 2 can be made to follow the side surface S3 of the battery 100.

[0129] When the battery cover 1 is removed from the battery 100, the density of the heat insulating layer 13 in each of the outer bulging portions 4A to 4D is, for example, 100 kg / m 3 Below, preferably 50kg / m 3 Below, for example 1kg / m 3 Above, preferably 10kg / m 3 The density is measured based on JIS A 9521: 2017 or JIS K 6767: 1999. By setting the density to be less than or equal to the above upper limit, the thermal conductivity can be reduced.

[0130] When the battery cover 1 is removed from the battery 100, the heat insulating layer 13 in each of the recesses 5A to 5C is compressed in the thickness direction compared to the heat insulating layer 13 in each of the outer bulging portions 4A to 4D. In other words, the density of the heat insulating layer 13 in each of the recesses 5A to 5C is higher than the density of the heat insulating layer 13 in each of the outer bulging portions 4A to 4D. The density of the heat insulating layer 13 in each of the recesses 5A to 5C is, for example, 10 kg / m 3 Above and 70kg / m 3 the following.

[0131] (2-4) Buffer layer 14

[0132] The buffer layer 14 is arranged between the first surface layer 11 and the heat insulating layer 13 in the thickness direction. The buffer layer 14 is arranged in the inner bulge 6. The buffer layer 14 extends from one end of the side wall 2 to the other end in the first direction. In other words, the buffer layer 14 extends from the edge 3A to the edge 3B in the first direction. In the present embodiment, the buffer layer 14 is arranged between the edge 3A and the edge 3B in the first direction. In the present embodiment, the buffer layer 14 is bonded to the heat insulating layer 13.

[0133] The buffer layer 14 is elastically deformable. Figure 8 A), the buffer layer 14 is deformed (depressed) in accordance with the shape of the outer surface of the battery 100, which will be described later. As a result, the battery cover 1 can be smoothly installed on the battery 100. In addition, by deforming the buffer layer 14 when the battery cover 1 is installed on the battery 100, it is possible to suppress excessive stress on the heat insulating layer 13, and the heat insulating layer 13 can be protected. In addition, when the battery cover 1 is installed on the battery 100 (refer to Figure 8 B), the elasticity of the buffer layer 14 can be used to make the first surface layer 11 reliably contact the side surface S3 of the battery 100. As a result, when the battery cover 1 is installed on the battery 100, the buffer layer 14 and the first surface layer 11 can be used to fill the space between the side surface S3 of the battery 100 and the heat insulating layer 13. As a result, it is possible to prevent the air around the battery 100 from flowing into the space between the side surface S3 of the battery 100 and the heat insulating layer 13, and it is possible to prevent the surrounding heat from being transferred to the battery 100.

[0134] The above-mentioned heat insulating materials can be cited as the material of the buffer layer 14. The buffer layer 14 preferably includes a foam-based heat insulating material, and more preferably includes polyurethane foam.

[0135] The buffer layer 14 is softer than the heat insulating layer 13. The 50% compression hardness of the buffer layer 14 is lower than the 50% compression hardness of the heat insulating layer 13. The 50% compression hardness of the buffer layer 14 is, for example, less than 10.0 kPa, preferably less than 8.0 kPa, more preferably less than 6.0 kPa, for example, greater than 1.0 kPa, preferably greater than 1.5 kPa, more preferably greater than 2.0 kPa. By having the 50% compression hardness of the buffer layer 14 be less than the above upper limit value, the buffer layer 14 can be easily deformed when the battery cover 1 is mounted on the battery 100. Thus, the battery cover 1 can be smoothly mounted on the battery 100. By having the 50% compression hardness of the buffer layer 14 be greater than the above lower limit value, the shape of the buffer layer 14 can be maintained.

[0136] The compression hardness retention rate of the buffer layer 14 after 120 seconds is, for example, 75% or more, preferably 80% or more, for example, 95% or less.

[0137] The compression hardness retention rate of the buffer layer 14 after 120 seconds is above the above lower limit (that is, the compression hardness is not easy to decrease in the compressed state and it is easy to recover from the compressed state), so that the battery cover 1 can be reliably restored when it is installed on the battery 100 and the space between the side S3 of the battery 100 and the insulation layer 13 can be buried.

[0138] The thermal conductivity of the buffer layer 14 is 0.045 W / (m·K) or less, preferably 0.043 W / (m·K) or less, more preferably 0.040 W / (m·K) or less, further preferably 0.035 W / (m·K) or less, further preferably 0.033 W / (m·K) or less, further preferably 0.030 W / (m·K) or less, for example 0.015 W / (m·K) or more.

[0139] When the battery cover 1 is removed from the battery 100, the thickness of the buffer layer 14 is, for example, 1 mm or more, preferably 2 mm or more, for example, 7 mm or less, preferably 5 mm or less. When the thickness of the buffer layer 14 is greater than the lower limit, the amount of deformation of the buffer layer 14 can be ensured when the battery cover 1 is mounted on the battery 100, and the mountability of the battery cover 1 relative to the battery 100 can be improved. When the thickness of the buffer layer 14 is less than the upper limit, the battery cover 1 can be prevented from being excessively enlarged.

[0140] 3. Method for manufacturing battery cover 1

[0141] Next, refer to Figure 6 A~ Figure 7 , a method for manufacturing the battery cover 1 will be described.

[0142] In this embodiment, the method for manufacturing the battery cover 1 includes a lamination step (see Figure 6 A) and forming process (refer to Figure 6 B).

[0143] like Figure 6 As shown in A, in the lamination step, the first surface layer 11, the buffer layer 14, the heat insulating layer 13 and the second surface layer 12 are laminated in the order of the first surface layer 11, the buffer layer 14, the heat insulating layer 13 and the second surface layer 12 in the thickness direction to obtain a laminated body 21.

[0144] Here, when the first surface layer 11 and the second surface layer 12 are nonwoven fabrics formed by laminating vinyl acetate resin, polyester fiber (more specifically, polyethylene terephthalate fiber) and polypropylene fiber in the order of vinyl acetate resin (resin layer), polyester fiber (fiber layer), polypropylene fiber (fiber layer), and vinyl acetate resin (resin layer), the polypropylene fiber of the first surface layer 11 is arranged between the polyethylene terephthalate fiber of the first surface layer 11 and the buffer layer 14 in the thickness direction of the laminate 21. In addition, the polypropylene fiber of the second surface layer 12 is arranged between the polyethylene terephthalate fiber of the second surface layer 12 and the heat insulating layer 13 in the thickness direction of the laminate 21.

[0145] The laminate 21 has a flat belt shape extending in a predetermined direction. The laminate 21 has one end E1 and the other end E2 in the direction in which the laminate 21 extends.

[0146] Furthermore, as required, an adhesive tape or adhesive is disposed at the peripheral portion of the laminate 21 (the portion where the edge 3A and the edge 3B are formed, and the one end E1 and the other end E2), between the first surface layer 11 and the second surface layer 12, between the second surface layer 12 and the heat insulating layer 13, and between the buffer layer 14 and the heat insulating layer 13. As the adhesive, for example, a hot melt adhesive that can be bonded by heating can be cited.

[0147] Next, if Figure 6 B and Figure 7 As shown, in the forming step, the first surface layer 11 and the second surface layer 12 are bonded to each other at the peripheral portion of the laminate 21 by hot pressing the laminate 21, and the recesses 5A to 5C are formed at predetermined positions. The recesses 5A to 5C are formed by compressing the heat insulating layer 13.

[0148] Then, the laminate 21 is bent at each of the recesses 5A to 5C so that one end E1 and the other end E2 of the laminate 21 are connected. Figure 3 As shown, the battery cover 1 is completed. In addition, the recessed portion 5D is formed by connecting the one end portion E1 and the other end portion E2.

[0149] 4. Mounting of the battery cover 1 relative to the battery 100

[0150] Next, refer to Figure 8 A and Figure 8 B, illustrates the installation of the battery cover 1 relative to the battery 100.

[0151] like Figure 8 As shown in A, in this embodiment, the battery cover 1 is attached from above (on one side in the first direction) with respect to the battery 100 placed on a predetermined plane.

[0152] At this time, in a conventional battery cover, if there is a protrusion P (eg, the edge of the cover 102 of the battery 100 ) on the side surface S3 of the battery 100 , the inner surface of the battery cover may get caught on the protrusion P, thereby preventing the battery cover from being attached to the battery 100 .

[0153] In this aspect, the battery cover 1 has a buffer layer 14 covered by the first surface layer 11 on the inner surface S11 .

[0154] Therefore, when the battery cover 1 is mounted on the battery 100 , if the inner surface S11 of the battery cover 1 contacts the protrusion P, the buffer layer 14 deforms (is recessed) in the portion of the battery cover 1 that contacts the protrusion P (hereinafter referred to as the contact portion).

[0155] Then, as the battery cover 1 moves downward, the buffer layer 14 is deformed sequentially in the contact portion, and the first surface layer 11 slides relative to the protruding portion P.

[0156] Thus, the battery cover 1 can smoothly go over the protruding portion P. In the portion of the battery cover 1 that goes over the protruding portion P, the buffer layer 14 is restored by the elasticity of the buffer layer 14 .

[0157] Then, if Figure 8 As shown in FIG. 1B , if the entire battery cover 1 passes over the protruding portion P, the buffer layer 14 is restored in the entire battery cover 1, and the first surface layer 11 is pressed by the buffer layer 14 and contacts the side surface S3 of the battery 100. When the battery cover 1 is installed on the battery 100, the space between the side surface S3 of the battery 100 and the heat insulating layer 13 is filled with the buffer layer 14 and the first surface layer 11.

[0158] According to the above, the mounting of the battery cover 1 to the battery 100 is completed.

[0159] 5. Effect

[0160] (1) According to the battery cover 1, Figure 8 As shown in B, it includes a first surface layer 11 in contact with the side surface S3 of the battery 100 and a buffer layer 14 disposed between the first surface layer 11 and the heat insulating layer 13 .

[0161] like Figure 8As shown in A, when the battery cover 1 is mounted on the battery 100 , the side wall 2 of the battery cover 1 slides relative to the side surface S3 of the battery 100 with the first surface layer 11 .

[0162] At this time, even if there is a protrusion P on the side S3 of the battery 100, the buffer layer 14 arranged inside the side wall 2 (between the first surface layer 11 and the insulation layer 13) is recessed (elastically deformed) accordingly with the protrusion P, thereby preventing the first surface layer 11 from getting stuck in the protrusion P.

[0163] Thus, even if the side surface S3 of the battery 100 has the protruding portion P, the battery cover 1 can smoothly go over the protruding portion P.

[0164] As a result, the battery cover 1 can be smoothly attached to the battery 100 .

[0165] In addition, if Figure 8 As shown in FIG. 2B , when the battery cover 1 is completely attached to the battery 100 , the first surface layer 11 can be reliably in contact with the side surface S3 of the battery 100 due to the elasticity of the buffer layer 14 .

[0166] Thus, the space between the side surface S3 of the battery 100 and the heat insulating layer 13 can be filled with the buffer layer 14 and the first surface layer 11 .

[0167] As a result, it is possible to suppress the air around the battery 100 from flowing into between the side surface S3 of the battery 100 and the heat insulating layer 13 , and to suppress the transfer of ambient heat to the battery 100 .

[0168] (2) According to the battery cover 1 , the 50% compression hardness of the buffer layer 14 is lower than the 50% compression hardness of the heat insulating layer 13 .

[0169] Therefore, the shape of the heat insulating layer 13 can be maintained, and the buffer layer 14 can be easily deformed.

[0170] (3) According to the battery cover 1 , the 50% compression hardness of the heat insulating layer 13 is 10.0 kPa or more, and the 50% compression hardness of the buffer layer 14 is 1.0 kPa or more and less than 10.0 kPa.

[0171] Therefore, the shape of the heat insulating layer 13 can be further maintained, and the buffer layer 14 can be deformed more easily.

[0172] (4) According to the battery cover 1, the thermal conductivity of the heat insulating layer 13 is 0.045 W / (m·K) or less.

[0173] Therefore, the heat insulating layer 13 can suppress the transfer of ambient heat to the battery 100 .

[0174] (5) According to the battery cover 1 , the heat insulating layer 13 and the buffer layer 14 each include a foam-based heat insulating material or a fiber-based heat insulating material.

[0175] Therefore, the battery cover 1 can be easily attached to the battery 100 , and the heat insulation property can be improved.

[0176] (6) According to the battery cover 1, Figure 4 As shown, the buffer layer 14 extends from one end to the other end of the side wall 2 in the first direction.

[0177] Therefore, if Figure 8 As shown in FIG. 2B , when the battery cover 1 is mounted on the battery 100 , the first surface layer 11 can be securely in contact with the side surface S3 of the battery 100 over the entire range from one end to the other end of the side wall 2 of the battery cover 1 in the first direction.

[0178] (7) According to the battery cover 1, Figure 3 and Figure 5 As shown, the outer surface S12 of the side wall 2 has recessed portions 5A to 5C recessed in the thickness direction and outer bulging portions 4A to 4D bulging outward from the recessed portions 5A to 5C in the thickness direction.

[0179] Therefore, the side wall 2 can be easily bent at the recessed portions 5A to 5C while ensuring heat insulation properties at the outer bulging portions 4A to 4D.

[0180] (8) According to the battery cover 1, Figure 5 As shown, in a state where the battery cover 1 is removed from the battery 100 , the thickness of the heat insulating layer 13 in the recessed portions 5A to 5C is thinner than the thickness of the heat insulating layer 13 in the outer bulging portions 4A to 4D.

[0181] Therefore, by molding the heat insulating layer 13 , the thickness of the buffer layer 14 can be ensured and the recessed portions 5A to 5C can be formed.

[0182] (9) According to the battery cover 1, Figure 5 As shown, in a state where the battery cover 1 is removed from the battery 100 , the heat insulating layer 13 in the recessed portions 5A to 5C is compressed in the thickness direction more than the heat insulating layer 13 in the outer bulging portions 4A to 4D.

[0183] Therefore, by compressing the heat insulating layer 13 , the recessed portions 5A to 5C can be easily formed.

[0184] (10) According to the battery cover 1, Figure 1 As shown, the recesses 5A to 5C extend along the corners C1 to C3 of the battery 100 .

[0185] Therefore, the side wall 2 can be bent in accordance with the corners C1 to C3 of the battery 100 , and the side wall 2 can be arranged along the side surface S3 of the battery 100 .

[0186] 6. Modifications

[0187] Hereinafter, a modification of the battery cover 1 will be described. In the description of the modification, the same reference numerals are given to the same components as those of the above-described embodiment, and the description thereof will be omitted.

[0188] (1) It can also be, Fig. 9 A and Fig. 9 As shown in FIG. 3B , the battery cover 30 does not have the edges 3A and 3B and the recesses 5A to 5D.

[0189] (2) The shape of the battery cover is not limited. The shape of the battery cover can be appropriately changed according to the shape of the battery. For example, when the battery has a shape without corners such as a cylindrical shape, the battery cover may also be a cylindrical shape. In addition, when the battery has a flat shape such as a flat plate shape, the battery cover may have a first side wall and a second side wall, and the battery may be clamped between the first side wall and the second side wall.

[0190] (3) The corners C1 to C4 of the battery 100 may be curved surfaces. In this case, the recessed portions 5A to 5D may be along the curved surfaces.

[0191] (4) The recessed portions 5A to 5C may be formed by the first surface layer 11 and the second surface layer 12. The heat insulating layer 13 and the buffer layer 14 may not be present in the recessed portions 5A to 5C.

[0192] (5) It can also be, Fig.10 As shown, the battery cover 1 has a recessed portion 40 for preventing the member M disposed around the battery 100 from interfering with the side wall 2 .

[0193] (6) It can also be, Fig.11 As shown, the buffer layer 14 exists only at both ends of the side wall 2 in the up-down direction.

[0194] (7) The above-mentioned modifications can be combined as appropriate.

[0195] [Example]

[0196] Next, the present invention is described based on examples and comparative examples. The present invention is not limited by the following examples. In addition, the specific numerical values ​​such as the physical property values ​​and parameters used in the following descriptions can be replaced by the upper limit values ​​(defined as "below", "less than") or lower limit values ​​(defined as "above") of the physical property values ​​and parameters corresponding to them recorded in the above-mentioned "embodiment".

[0197] 1. Preparation of Materials

[0198] Prepare the following materials.

[0199] (1) TF1100R (polyurethane foam, manufactured by Wm.T.Burnett & Co.)

[0200] (2) UEI-3 (polyurethane foam, manufactured by Inoac Corporation)

[0201] (3) F2 (polyurethane foam, manufactured by Inoac Corporation)

[0202] 2. Measurement of physical properties of materials

[0203] (1) Thermal conductivity

[0204] The thermal conductivity of each of the above materials was measured at room temperature using a quick thermal conductivity meter (manufactured by Kyoto Electronics Industry Co., Ltd., trade name "QTM-500").

[0205] (2) 50% compression hardness

[0206] The 50% compression hardness of each material was measured using a testing machine (manufactured by Shimadzu Corporation, trade name "AG-X Plus").

[0207] The test piece (width: 100 mm, length: 100 mm) was placed between parallel flat plates of the tester, and the compression was stopped at a compression rate of 5 mm / min until 50% of the initial thickness was compressed, and the load P immediately after the compression was stopped was measured. Based on the obtained load P, the 50% compression hardness H1 was calculated using the following formula.

[0208] Formula: 50% compression hardness = load P ÷ area of ​​test piece (100mm×100mm)

[0209] (3) Compression hardness retention after 120 seconds

[0210] The compression hardness retention rate of each material after 120 seconds was measured using a testing machine (manufactured by Shimadzu Corporation, trade name “AG-X Plus”).

[0211] A test piece (width: 100 mm, length: 100 mm) was placed between parallel flat plates of a testing machine and compressed at a compression rate of 5 mm / min until 50% of the initial thickness was reached and the load P immediately after the compression was stopped was measured.

[0212] Next, the test piece is held in this state (in a state compressed to 50% of the initial thickness) for 120 seconds, the load P is measured, and then the load P2 after 120 seconds is measured.

[0213] Based on the obtained load P, the 50% compression hardness H1 was calculated by the above formula, and based on the obtained load P2, the 50% compression hardness H2 after holding for 120 seconds was calculated by the above formula.

[0214] The percentage of the 50% compression hardness H2 to the 50% compression hardness H1 (H2÷H1×100) is the compression hardness retention rate after 120 seconds.

[0215] 3. Manufacturing of battery cover

[0216] Example 1

[0217] The first surface layer, the buffer layer shown in Table 1, the heat insulating layer shown in Table 1, and the second surface layer are stacked in the order of the first surface layer, the buffer layer, the heat insulating layer, and the second surface layer in the thickness direction to obtain a laminate (stacking step, see Figure 6 A). The first surface layer and the second surface layer are made of non-woven fabric (vinyl acetate resin, polyethylene terephthalate fiber and polypropylene fiber (base fabric) according to the vinyl acetate resin (unit area weight 8g / m 2 ), polyethylene terephthalate fiber (weight per unit area 80g / m 2 ), polypropylene fiber (weight per unit area 17g / m 2 ), vinyl acetate resin (weight per unit area 8g / m 2 ) are stacked in the order of . The polypropylene fibers of the first surface layer are arranged between the polyethylene terephthalate fibers of the first surface layer and the buffer layer in the thickness direction of the laminate. In addition, the polypropylene fibers of the second surface layer are arranged between the polyethylene terephthalate fibers of the second surface layer and the thermal insulation layer in the thickness direction of the laminate. In addition, an adhesive tape (trade name "TW-Y01", manufactured by Nitto Denko Corporation) is arranged between the second surface layer and the thermal insulation layer and between the buffer layer and the thermal insulation layer.

[0218] Next, the laminate is hot pressed (molding step, see Figure 6 B). The first surface layer and the second surface layer are thermally fused at the periphery of the laminate to form an edge. In addition, the heat insulating layer is compressed at a predetermined position to form a recess. In addition, the second surface layer and the heat insulating layer are bonded with an adhesive tape, and the buffer layer and the heat insulating layer are bonded with an adhesive tape.

[0219] Thus, a sample of the battery cover was obtained.

[0220] Examples 2, 3 and Comparative Examples 1 to 3

[0221] Except that the heat insulating layer and the buffer layer were replaced with the heat insulating layer and the buffer layer shown in Table 1, a sample of a battery cover was obtained in the same manner as in Example 1.

[0222] 4. Performance evaluation of battery cover

[0223] (1) Thermal insulation

[0224] <Shape of test piece>

[0225] Test pieces A were cut out from the samples obtained in the above-mentioned examples and comparative examples.

[0226] like Fig.12 As shown, the test piece A is a square and has a bulging portion 4 and a recessed portion 5 .

[0227] The bulge 4 is arranged at the center of the test piece A. The bulge 4 is square. The length L of one side of the bulge 4 is 240 mm. Fig.13 As shown, the thickness T of the bulged portion 4 is 10 mm.

[0228] like Fig.12 As shown, the recessed portion 5 is arranged around the bulging portion 4. The width W of the recessed portion 5 is 10 mm.

[0229] <Structure of evaluation device>

[0230] like Fig.14 As shown, the evaluation device 110 includes a constant temperature chamber 111 , a jig 112 , a temperature sensor 113 , a cable 114 , and a data logger 115 .

[0231] The constant temperature bath 111 includes a fan 116. As the constant temperature bath 111, "SH-242" manufactured by Espec Corporation was used.

[0232] The jig 112 is arranged in the constant temperature chamber 111. The jig 112 is opposite to the fan 116 at a distance in the relative direction. The relative direction is the direction in which the jig 112 and the fan 116 are opposite to each other. The jig 112 is composed of a phenolic resin foam (trade name "Neoma foam", manufactured by Asahi Kasei Building Materials Co., Ltd.) with a thickness of 9 mm. The jig 112 has a housing 112A and a flange 112B.

[0233] The housing 112A has one end and the other end in the relative direction. The one end is arranged between the fan 116 and the other end in the relative direction. Fig.15 As shown, the housing 112A is square when viewed from the opposite direction. The outer dimension L11 of the housing 112A is 240 mm. The depth (inner dimension in the opposite direction) L12 of the housing 112A (see Fig.14 The housing 112A has an opening 112C.

[0234] like Fig.14 As shown, the opening 112C is disposed at one end of the housing 112A in the opposite direction. Fig.15As shown, the opening 112C is square when viewed from the opposite direction. The dimension L13 of one side of the opening 112C is 220 mm.

[0235] like Fig.14 As shown, the flange 112B extends from one end of the housing 112A in the opposite direction. The flange 112B extends in a direction orthogonal to the opposite direction. The flange 112B has a flat plate shape. Fig.15 As shown, the outer shape of the jig 112 including the flange 112B is a square when viewed from the opposite direction. The outer dimension L14 of the jig 112 including the flange 112B is 260 mm.

[0236] like Fig.14 As shown, the test piece A is fixed to the jig 112. When the test piece A is fixed to the jig 112, the bulge 4 of the test piece A closes the opening 112C of the jig 112. When the test piece A is fixed to the jig 112, the distance D1 between the test piece A and the fan 116 is 150 mm.

[0237] The temperature sensor 113 measures the temperature in the housing 112A. As the temperature sensor 113, a K thermocouple defined by JIS C 1602: 2015 is used. The temperature sensor 113 is arranged in the housing 112A. The temperature sensor 113 is arranged at the center of the housing 112A in the relative direction, and is the center of the housing 112A in the direction orthogonal to the relative direction.

[0238] The cable 114 electrically connects the temperature sensor 113 and the data logger 115. One end of the cable 114 is electrically connected to the temperature sensor 113 through a through hole 112D provided in the wall of the housing 112A. The through hole 112D through which the cable 114 passes is filled with clay or the like. The other end of the cable 114 is electrically connected to the data logger 115.

[0239] The data logger 115 records the temperature measured by the temperature sensor 113 .

[0240] <Evaluation method of thermal insulation>

[0241] The thermal insulation of the test piece A was evaluated using the evaluation device 110. Specifically, the temperature of the thermostatic bath 111 was set to 90°C from a state where the temperature in the thermostatic bath 111 was at room temperature (25°C), and the thermostatic bath 111 was operated at a constant value, and the temperature change in the housing 112A was measured. Based on the obtained measurement results, the thermal insulation of the test piece A of each embodiment and each comparative example was evaluated based on the following evaluation criteria. The results are shown in Table 1.

[0242] Furthermore, it is considered that in Comparative Example 2, the air permeability of the heat insulating layer was too high, and the performance of blocking the airflow generated by the rotation of the fan 116 was low, resulting in poor heat insulation.

[0243] <Evaluation Criteria>

[0244] ○: The temperature in the jig 112 was less than 65° C. 10 minutes after the start of the constant-value operation of the thermostatic bath 111 .

[0245] ×: The temperature in the jig 112 was 65° C. or higher 10 minutes after the start of the constant-value operation of the thermostatic bath 111 .

[0246] (2) Installation

[0247] <Shape of test piece>

[0248] Test pieces B were cut out from the samples obtained in the above-mentioned examples and comparative examples.

[0249] like Fig.16 As shown, the test piece B is rectangular and has a bulging portion 4 and a recessed portion 5 .

[0250] The bulge 4 is arranged at the center of the test piece B in the longitudinal direction of the test piece B. The bulge 4 extends in the width direction of the test piece B. The width direction of the test piece B is orthogonal to the longitudinal direction of the test piece B. The length L21 of the bulge 4 in the longitudinal direction of the test piece B is 50 mm. The length L22 of the bulge 4 in the width direction of the test piece B is 100 mm. In addition, the thickness of the bulge 4 is the same as the thickness T of the above-mentioned test piece A, which is 10 mm.

[0251] The recessed portion 5 is arranged around the bulging portion 4. The width W1 of the recessed portion 5 in the longitudinal direction of the test piece B is 150 mm. The width W2 of the recessed portion 5 in the width direction of the test piece B is 10 mm.

[0252] <Structure of evaluation device>

[0253] like Fig.17 As shown, the evaluation device 200 has two plates 201A and 201B and two pillars 202A and 202B.

[0254] The plate 201B is opposed to the plate 201A with a gap in the relative direction. The relative direction is the direction in which the plate 201A and the plate 201B are opposed to each other. The plates 201A and 201B extend in directions perpendicular to the relative direction. The distance D2 in the relative direction between the plate 201A and the plate 201B is greater than the bulge 4 of the test piece B (refer to Fig.16 ) has a small thickness of 7 mm. Each of the plates 201A, 201B comprises polypropylene.

[0255] The support column 202A supports the plate 201A. The support column 202A is arranged on the opposite side of the plate 201B with respect to the plate 201A in the opposing direction.

[0256] The support column 202B supports the plate 201B. The support column 202B is arranged on the opposite side of the plate 201B from the plate 201A in the opposing direction.

[0257] <Evaluation method of installability>

[0258] The evaluation device 200 is used to evaluate the installability of the test piece B. Specifically, Fig.18 As shown, one end of the test piece B in the longitudinal direction is disposed between the plates 201A and 201B. At this time, the surface of the test piece B on one side in the thickness direction faces the plate 201A, and the surface of the test piece B on the other side in the thickness direction faces the plate 201B.

[0259] Next, the test piece B was pulled in the longitudinal direction, and the attachability of the test piece B of each example and each comparative example was evaluated based on the following evaluation criteria.

[0260] <Evaluation Criteria>

[0261] ○: The bulging portion 4 can pass between the plate 201A and the plate 201B.

[0262] ×: The bulging portion 4 cannot pass between the plate 201A and the plate 201B.

[0263] [Table 1]

[0264]

[0265] In addition, the above invention is provided as an exemplary embodiment of the present invention, but this is only an example and should not be interpreted as limiting. Modifications of the present invention that are clear to those skilled in the art are included in the above claims.

[0266] Industrial Applicability

[0267] The battery cover of the present invention is used to suppress the transfer of ambient heat to the battery.

[0268] Description of Reference Numerals

[0269] 1. Battery cover; 2. Side wall; 4A~4D, outer bulge; 5A~5D, recess; 11, first surface layer; 12, second surface layer; 13, heat insulation layer; 14, buffer layer; 30, battery cover; 40, recess; 100, battery; C1~C4, corner; S1, first surface; S2, second surface; S3, side; S11, inner surface; S12, outer surface.

Claims

1. A battery cover, characterized in that: It can be installed on the battery, The battery cover has a side wall, and the side wall covers the side of the battery when the battery cover is installed on the battery. The side wall has: a first surface layer, the first surface layer being in contact with the side surface of the battery when the battery cover is mounted on the battery; a second surface layer disposed on a side opposite to the side surface of the battery relative to the first surface layer in a thickness direction of the side wall; a heat-insulating layer disposed between the first surface layer and the second surface layer in the thickness direction; as well as A buffer layer is arranged between the first surface layer and the heat insulating layer in the thickness direction.

2. The battery cover according to claim 1, characterized in that: The 50% compression hardness of the buffer layer is lower than the 50% compression hardness of the heat insulation layer.

3. The battery cover according to claim 2, characterized in that: The 50% compression hardness of the heat insulation layer is above 10.0 kPa, The buffer layer has a 50% compression hardness of 1.0 kPa or more and less than 10.0 kPa.

4. The battery cover according to claim 1, characterized in that: The thermal conductivity of the thermal insulation layer is less than 0.045 W / (m·K).

5. The battery cover according to claim 1, characterized in that: The heat insulating layer and the buffer layer each include a fiber-based heat insulating material or a foam-based heat insulating material.

6. The battery cover according to claim 1, characterized in that: The battery has a first surface on which a terminal is arranged, a second surface separated from the first surface in a first direction, and the side surface arranged between the first surface and the second surface in the first direction and extending along the first direction. The buffer layer extends from one end portion to the other end portion of the side wall in the first direction.

7. The battery cover according to claim 1, characterized in that: The side wall has an inner surface and an outer surface, the inner surface is in contact with the side surface of the battery in the thickness direction, and the outer surface is arranged on the side opposite to the side surface of the battery with respect to the inner surface in the thickness direction. The outer surface has: a concave portion that is concave in the thickness direction; as well as A bulging portion bulges out more than the recessed portion in the thickness direction.

8. The battery cover according to claim 7, characterized in that: In a state where the battery cover is removed from the battery, a thickness of the heat insulating layer in the recessed portion is thinner than a thickness of the heat insulating layer in the bulging portion.

9. The battery cover according to claim 7, characterized in that: In a state where the battery cover is removed from the battery, the heat insulating layer in the recessed portion is compressed in the thickness direction more than the heat insulating layer in the bulging portion.

10. The battery cover according to claim 7, characterized in that: The recess extends along a corner of the battery.

Images