JP5212085B2 - Battery case for electric vehicles - Google Patents

Description

  The present invention relates to a battery case for housing a battery module of an electric vehicle that is driven by a motor that uses a battery as a power source.

  A battery unit used in an electric vehicle includes a battery module and a battery case that houses the battery module. An example of the battery case includes a tray member that supports the battery module, a cover member that covers an upper portion of the tray member, and the like. For electric vehicles, how to increase the mileage is a major issue. Therefore, it is desired to mount a battery as large as possible. For example, in the electric vehicle described in Patent Document 1, a battery mounting frame is provided below the cross member under the floor of the vehicle body, and the battery case is held by the battery mounting frame.

  In order to fix the battery case to the vehicle body, it has been considered that an embedded nut is provided in an insert member embedded in the battery case, and a bolt for fixing the battery case is screwed into the embedded nut from the outside of the battery case. The insert member is set in the lower mold when the battery case is molded, and is molded together with the material (resin) of the battery case.

FIG. 17 shows an example of a mold 400 for molding the tray member of the battery case. The mold 400 includes a lower mold 401 and an upper mold 402. In the lower mold 401, a metal insert member 403 is set at a portion where the peripheral wall of the tray member is formed. The insert member 403 is provided with a nut 410 for fixing the tray member. When forming the tray member, the upper die 402 is lowered in the direction indicated by the arrow Z, and a cavity 404 is formed between the lower die 401 and the upper die 402, and the cavity 404 is filled with resin. In order to fix the tray member formed in a predetermined shape to the vehicle body, it is considered that a bolt (not shown) is screwed into the nut 410 from the outside of the tray member.
JP-A-6-32247

  However, when the nut 410 as described above is fixed to the insert member 403, the inner surface 411 of the upper mold 402 may touch the nut 410 when the upper mold 402 is lowered from above the lower mold 401. For this reason, a gap G of about several millimeters or more must be secured between the inner surface 411 of the upper mold 402 and the end surface 412 of the nut 410. If such a gap G exists, there is a problem that the material (resin) of the tray member enters the inside of the nut 410 from the gap G when the tray member is formed.

  In order to solve the above problem, the gap G between the upper die 402 and the end face 412 of the nut 410 may be made as small as possible. However, there is a limit to increasing the accuracy of the shape and dimensions of the insert member 403 and the nut 410, and the insert member 403 must be positioned with high accuracy with respect to the lower mold 401, and the work requires skill. Therefore, there is a natural limit to reducing the gap G.

  Accordingly, an object of the present invention is to provide a battery case for an electric vehicle in which a nut for fixing the tray member can be provided on the peripheral wall of the tray member without any problem.

  The present invention is a battery case that houses a battery module of an electric vehicle, and includes a tray member that supports the battery module, and a cover member that is stacked on the tray member and fixed to the tray member. Yes. The tray member has a bottom wall that supports the battery module and a peripheral wall formed around the bottom wall. The tray member further includes a resin portion formed by molding synthetic resin, a metal insert member fixed to the peripheral wall of the tray member, and a nut insertion hole formed in the peripheral wall and penetrating the peripheral wall in the horizontal direction. And a nut plate assembly. The nut plate assembly includes an outsert nut for fixing a tray member that is inserted into the nut insertion hole from the inside of the tray member, and a plate member to which one end of the outsert nut is fixed. The end surface on the other end side of the outsert nut is fixed to the insert member and faces the outer surface of the peripheral wall at the opening of the nut insertion hole. By screwing a tray member fixing bolt into the outsert nut from the outside of the tray member, the peripheral wall of the tray member and the support member are fastened to each other.

  In a preferred embodiment of the present invention, an insert nut embedded in the peripheral wall of the tray member is fixed to the insert member, and the nut plate assembly is provided by a plate fixing bolt that is screwed into the insert nut from the inside of the tray member. The plate member is fixed to the insert member.

  Preferably, in a state where the end surface of the outsert nut protrudes outside the outer surface of the peripheral wall, and the vertical wall of the support member overlaps the end surface, the peripheral wall and the vertical wall are separated by the tray member fixing bolt. Are fastened together. A sealing material may be provided between the inner surface of the nut insertion hole and the outsert nut.

  According to the present invention, by inserting the outsert nut into the nut insertion hole formed in the peripheral wall of the tray member, the outsert nut can function as a tray member fixing nut. Since this outsert nut is inserted into the nut insertion hole after the tray member is molded, the material (resin) of the tray member is prevented from entering the inside of the outsert nut.

  The tray member fixing bolt is screwed into the outsert nut from the outside of the tray member. Since the outsert nut receives the bolt tightening force (axial force), it is avoided that the bolt tightening force is directly applied to the peripheral wall of the resin tray member. For this reason, it is possible to prevent tightening of the resin due to the tightening force of the bolt, and it is possible to appropriately manage the tightening torque, such as suppressing the bolt tightening torque from decreasing with time.

An embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 shows an example of an electric vehicle 10. The electric vehicle 10 includes a traveling motor 12 and a charging device 13 disposed at the rear of the vehicle body 11, a battery unit 14 disposed under the floor of the vehicle body 11, and the like.

  FIG. 2 shows a frame structure 30 that forms the skeleton of the vehicle body 11. FIG. 3 is a plan view of the frame structure 30 as viewed from above. The frame structure 30 includes a pair of left and right side members 31, 32 extending in the front-rear direction of the vehicle body 11 and cross members 33, 34, 35 extending in the width direction of the vehicle body 11. The cross members 33, 34, 35 are fixed to predetermined positions of the side members 31, 32 by welding.

  Support brackets 40 and 41 are provided at the rear portions of the side members 31 and 32. The support brackets 40 and 41 are welded to predetermined positions of the side members 31 and 32, respectively. A pivot portion 42 is provided on the support brackets 40 and 41. A front end portion of a rear suspension arm is attached to the pivot portions 42.

  As shown in FIG. 4, the battery unit 14 is disposed on the lower surface side of the floor panel 45. The floor panel 45 extends in the front-rear direction and the width direction of the vehicle body 11 and constitutes a floor portion of the vehicle body 11. The floor panel 45 is fixed to a predetermined position of the frame structure 30 by welding.

  As shown in FIG. 5, the battery unit 14 includes a battery case 50. The battery case 50 includes a tray member 51 located on the lower side and a cover member 52 located on the upper side. FIG. 6 shows the tray member 51.

  The tray member 51 has a pair of left and right side walls 51a and 51b, a front wall 51c, a rear wall 51d, a bottom wall 51e, and partition walls 51f and 51g, and is formed in a box shape with the top surface open. . The front wall 51 c is located on the front side with respect to the front-rear direction of the vehicle body 11. The rear wall 51d is located on the rear side. The partition walls 51f and 51g extend in the front-rear direction. A peripheral wall 54 of the tray member 51 is constituted by the pair of side walls 51a, 51d, the front wall 51c, and the rear wall 51d. The peripheral wall 54 is formed around the bottom wall 51e. The tray member 51 is formed into a predetermined shape by stamping, for example.

  A front battery storage 55 is formed in the front half of the tray member 51. A rear battery storage portion 56 is formed in the rear half of the tray member 51. Between the front battery storage 55 and the rear battery storage 56, a central battery storage 57, an electric circuit storage 58, and the like are formed.

  Battery modules 60 (a part of which is indicated by a two-dot chain line in FIGS. 5 and 6) are stored in the battery storage portions 55, 56, and 57, respectively. The battery module 60 is supported by the bottom wall 51 e of the tray member 51. An example of the battery module 60 is obtained by connecting a plurality of cells made of lithium ion batteries in series.

  The electrical circuit storage 58 stores electrical components 61 (a part of which is schematically shown in FIG. 5) that controls the monitor and control for detecting the state of the battery module 60 and the like. The electrical component 61 is electrically connected to the battery module 60.

  A cover attachment surface 70 is formed on the upper surface of the peripheral wall 54 of the tray member 51, that is, on the joint portion between the tray member 51 and the cover member 52. The cover mounting surface 70 is continuous over the entire circumference of the tray member 51 and extends in the horizontal direction. A seal holding groove 71 is formed on the cover mounting surface 70. A waterproof and dustproof seal member 72 is arranged in the seal holding groove 71. The seal holding groove 71 and the seal member 72 are continuous over the entire circumference of the peripheral wall 54 of the tray member 51 without interruption.

  The cover member 52 is made of an integrally molded product of synthetic resin reinforced with fibers. A service plug opening 85 and a cooling air inlet 86 are formed at the front of the cover member 52. A bellows-like boot member 87 is attached to the opening 85 for the service plug. A bellows-like boot member 88 is also attached to the cooling air inlet 86. On the upper surface of the cover member 52, a bypass flow path portion 90 for allowing a part of the cooling air to flow, a cooling fan accommodating portion 91, and the like are provided.

  A flange portion 95 is formed on the peripheral edge portion of the cover member 52. The flange portion 95 is continuous over the entire circumference of the cover member 52. As will be described in detail later, the flange portion 95 of the cover member 52 is overlaid on the cover mounting surface 70 of the tray member 51, and the flange portion 95 and the cover mounting surface 70 are connected to each other via the seal member 72. The bolt 100 </ b> A and the second bolt 100 are fastened.

  The battery unit 14 is attached to the lower surface of the vehicle body 11 by a plurality of (for example, four) girder members 101, 102, 103, and 104 that function as support members. As shown in FIGS. 3 and 4, the beam members 101, 102, 103, and 104 have beam bodies 111, 112, 113, and 114 that extend in the width direction of the vehicle body 11, respectively. The girder members 101, 102, 103, 104 are made of a metal material (for example, a steel plate) having sufficient strength to support the load of the battery unit 14.

  Fastening portions 121 and 122 are provided at both ends of the first girder body 111 from the front. Fastening portions 123 and 124 are provided at both ends of the second girder body 112 from the front. Fastening portions 125 and 126 are provided at both ends of the third girder body 113 from the front. Fastening portions 127 and 128 are provided at both ends of the fourth (last) girder body 112 from the front. A pair of left and right front support members 130 and 131 are provided at the front end of the battery unit 14.

  Bolt insertion holes 143 (shown in FIGS. 2 and 5) penetrating in the vertical direction are formed in the fastening portions 121 and 122 provided at both ends of the first beam member 101 from the front. The side members 31 and 32 are provided with battery unit mounting portions 145 and 146 having nut members at positions facing the fastening portions 121 and 122, respectively. A bolt 147 (shown in FIGS. 2 and 5) is inserted into the bolt insertion hole 143 from below the fastening portions 121 and 122, and the bolt 147 is screwed into a nut member of the battery unit mounting portions 145 and 146 and tightened. Fastening portions 121 and 122 of the first girder member 101 are fixed to the side members 31 and 32.

  Bolt insertion holes 153 (shown in FIGS. 2 and 5) penetrating in the vertical direction are formed in the fastening portions 123 and 124 provided at both ends of the second beam member 102 from the front. The side members 31 and 32 are provided with battery unit mounting portions 155 and 156 provided with nut members at positions facing the fastening portions 123 and 124. A bolt 157 (shown in FIGS. 2 and 5) is inserted into the bolt insertion hole 153 from below the fastening portions 123 and 124, and the bolt 157 is screwed into a nut member of the battery unit mounting portions 155 and 156 and tightened. Accordingly, the fastening portions 123 and 124 of the second beam member 102 are fixed to the side members 31 and 32.

  Bolt insertion holes 163 (shown in FIGS. 2 and 5) penetrating in the vertical direction are formed in the fastening portions 125 and 126 provided at both ends of the third beam member 103 from the front. As shown in FIGS. 3 and 4, load transmission members 170 and 171 are fixed to the side members 31 and 32 by bolts 172. These load transmission members 170 and 171 are provided above the fastening portions 125 and 126 of the third girder member 103 from the front. One load transmission member 170 is welded to one support bracket 40. The other load transmission member 171 is welded to the other support bracket 41.

  That is, the load transmission members 170 and 171 are coupled to the side members 31 and 32 and the support brackets 40 and 41. These load transmission members 170 and 171 form a part of the frame structure 30. The load transmission members 170 and 171 are provided with battery unit attachment portions 175 and 176 having nut members.

  The bolt 177 is inserted into the bolt insertion hole 163 from the lower side of the fastening portions 125 and 126, and the bolt 177 is screwed into the nut members of the battery unit mounting portions 175 and 176 to be tightened. Fastening portions 125 and 126 are fixed to side members 31 and 32 via load transmission members 170 and 171.

  Bolt insertion holes 183 (shown in FIGS. 2 and 5) penetrating in the vertical direction are formed in the fastening portions 127 and 128 of the fourth beam member 104 from the front. Extension brackets 184 and 185 are provided on the side members 31 and 32 at positions facing the fastening portions 127 and 128, respectively. The extension brackets 184, 185 extend below the kick-up portions 31b, 32b of the side members 31, 32. The extension brackets 184 and 185 form a part of the frame structure 30. The extension brackets 184 and 185 are provided with battery unit mounting portions 186 and 187 having nut members.

  Bolts 188 (shown in FIGS. 2 and 3) are inserted into the bolt insertion holes 183 from below the fastening portions 127 and 128, and the bolts 188 are nut members of the battery unit mounting portions 186 and 187 of the extension brackets 184 and 185. The fastening portions 127 and 128 of the fourth girder member 104 are fixed to the side members 31 and 32 via the extension brackets 184 and 185, respectively.

  The front support members 130 and 131 located at the front end of the battery unit 14 protrude in front of the first girder member 101 from the front. The front support members 130 and 131 are coupled to the beam member 101. As shown in FIG. 2, the fastening portions 190 and 191 provided on the front support members 130 and 131 are fixed to the battery unit mounting portions 193 and 194 of the cross member 33 by bolts 192.

  In the electric vehicle 10 according to this embodiment, beam members 101, 102, 103, and 104 that function as support members are provided between the left and right side members 31 and 32, and the side members are formed by these beam members 101, 102, 103, and 104. 31 and 32 are connected. For this reason, the girder members 101, 102, 103, 104 of the battery unit 14 can also function as a rigid member corresponding to the cross member of the vehicle body 11.

  Further, the load transmitting members 170 and 171 are fixed to the support brackets 40 and 41, and the lateral load input to the support brackets 40 and 41 is input to the girder member 103 via the load transmitting members 170 and 171.

  For this reason, even if the cross member is not disposed in the vicinity of the support brackets 40 and 41, the rigidity in the vicinity of the support brackets 40 and 41 can be increased by the girder member 103, and the steering stability and the ride comfort are improved. In other words, a part of the large battery unit 14 can be disposed in the space between the pair of left and right support brackets 40 and 41. For this reason, it becomes possible to mount the large-sized battery unit 14, and the mileage of an electric vehicle can be lengthened.

  As shown in FIGS. 1 and 4, an under cover 195 is disposed below the battery unit 14. The upper surface of the under cover 195 faces the lower surface of the beam members 101, 102, 103, 104. An example of the material of the under cover 195 is a synthetic resin reinforced with glass fibers. The under cover 195 is fixed to the frame structure 30 and the girder members 101, 102, 103, and 104 by bolts (not shown) from the lower side of the vehicle body 11.

The tray member 51 will be described in detail below.
FIG. 6 shows the tray member 51. The tray member 51 includes a resin portion 200 that is integrally formed of an electrically insulating material, three insert members 210a, 210b, and 210c (shown in FIG. 7) disposed in the front half of the tray member 51, a tray It includes three insert members 210d, 210e, 210f (shown in FIG. 8) disposed in the rear half of the member 51. A cover mounting surface 70 is formed on the upper surface of the peripheral wall 54 of the tray member 51, that is, on the upper surface of the resin portion 200.

  The resin part 200 is obtained by reinforcing a resin matrix made of polypropylene, for example, with short glass fibers having a length of about several mm to several cm. In addition, the resin part 200 may be comprised only by the synthetic resin, and resin reinforced with carbon fibers, such as resin (FRP) reinforced with fiber and carbon fiber, may be used. In addition, when using carbon fibers, such as carbon fiber, it is necessary to perform an electrical insulation process on the inner wall.

  The insert members 210a to 210f are press-formed products of metal plates (for example, steel plates). The insert members 210a, 210b, and 210c shown in FIG. 7 are embedded in the side walls 51a and 51b and the front wall 51c of the tray member 51, respectively. The side walls 51a, 51b and the front wall 51c of the tray member 51 are reinforced by the insert members 210a, 210b, 210c. The side walls 51a, 51b and the rear wall 51d of the tray member 51 are reinforced by the insert members 210d, 210e, 210f shown in FIG. Reinforcing plates 210g and 210h are embedded in the partition walls 51f and 51g of the tray member 51, respectively.

  9 to 12 show the insert member 210 a provided on one side wall 51 a of the tray member 51. The upper end 220 of the insert member 210 a is at a position lower than the cover mounting surface 70. The other insert members 210b to 210f are also provided on the inner surface of the peripheral wall 54 of the tray member 51 so that the positions of the upper ends of the other insert members 210b to 210f are lower than the cover mounting surface 70.

  For this reason, the upper ends of the insert members 210 a to 210 f are not exposed to the cover mounting surface 70. That is, the cover mounting surface 70 is configured only by the resin portion 200 over the entire circumference of the peripheral wall 54 of the tray member 51. For this reason, the seal holding groove 71 also includes only the resin portion 200, and the metal insert members 210 a to 210 f are avoided from being exposed to the inner surface of the seal holding groove 71.

  As shown in FIG. 7 and the like, one nut structure 230 with a bracket is provided on each of the outer surfaces of the front insert members 210a, 210b, and 210c. As shown in FIG. 8 and the like, each of the insert members 210d, 210e, 210f on the rear side is also provided with one nut structure 230 with a bracket.

  9, FIG. 10, FIG. 14, and FIG. 15 show a nut structure 230 with a bracket provided on the insert member 210a. The nut structure 230 with a bracket is composed of a metal bracket 231 and a metal first embedded nut 232. The bracket 231 includes a pair of base portions 233 and a bridge portion 234 that protrudes from the base portion 233 in the horizontal direction.

  The base 233 is fixed to the outer surface of the insert member 210a by spot welding. A bottomed first embedded nut 232 extending in the vertical direction is welded to the bridge portion 234 of the bracket 231. The bridge portion 234 is formed in an arc shape when viewed from above in order to increase the welding area for the embedded nut 232.

  The nut structure 230 with bracket is embedded in the resin portion 200 of the peripheral wall 54 of the tray member 51. The first embedded nut 232 is fixed to the insert member 210a via the bracket 231, and the upper end 236 of the first embedded nut 232 is located above the upper end 220 of the insert member 210a. The upper end 236 of the first embedded nut 232 is positioned at the same height as the cover mounting surface 70 of the tray member 51, and the upper end 236 of the first embedded nut 232 is exposed to the cover mounting surface 70. Since the first embedded nut 232 has a bottom portion, the resin of the resin portion 200 does not enter the first embedded nut 232 when the peripheral wall 54 is formed.

  The insert members 210b to 210e other than the above are provided with one nut structure 230 with brackets having the same configuration as the nut structure 230 with brackets. A first tightening portion 240 shown in FIG. 10 and the like is configured by the first embedded nut 232 and the first bolt 100A screwed into the first embedded nut 232.

  In the flange portion 95 of the cover member 52, a metal collar 237 is inserted into a hole through which the bolt 100A is passed. The collar 237 prevents the resin of the flange portion 95 from sagging due to the tightening pressure of the bolt 100A.

  The cover mounting surface 70 is provided with a second embedded nut 250 (shown in FIG. 11) at a location other than the first embedded nut 232. The second embedded nuts 250 are arranged at a plurality of locations at predetermined intervals in the circumferential direction of the peripheral wall 54 of the tray member 51. The second embedded nut 250 is not fixed to the insert members 210 a to 210 e, and is press-fitted into a hole 251 formed in the cover mounting surface 70. The upper end of the second embedded nut 250 is exposed on the cover mounting surface 70. A second tightening portion 260 shown in FIG. 11 is configured by the second embedded nut 250 and the second bolt 100 screwed into the second embedded nut 250.

  When fixing the cover member 52 to the tray member 51, the flange portion 95 of the cover member 52 is overlapped on the cover mounting surface 70. A seal member 72 is provided in the seal holding groove 71 in advance. In the first tightening portion 240, the first bolt 100A is passed through the collar 237 from above the flange portion 95, and the first bolt 100A is screwed into the first embedded nut 232 and tightened with a prescribed torque.

  In the second tightening portion 260, the second bolt 100 is passed through the collar 237 from above the flange portion 95, and the second bolt 100 is screwed into the second embedded nut 250 and tightened. Thus, the tray member 51 and the cover member 52 are fastened to each other in a state where the seal member 72 is sandwiched between the cover mounting surface 70 and the cover member 52.

  As shown in FIGS. 7 and 8, through-holes 300 are formed in the insert members 210a to 210e. These through holes 300 are formed at positions corresponding to the fastening portions 121 to 128 of the beam members 101 to 104 functioning as support members and the fastening portions 190 and 191 of the front support members 130 and 131.

  A pair of insert nuts 310 are attached to the outer surfaces of the insert members 210 a to 210 e for each of the through holes 300. The insert nut 310 is welded to the insert members 210a to 210e. These insert nuts 310 are embedded in the peripheral wall 54 of the tray member 51 together with the insert members 210a to 210e. A hole 311 (a part of which is shown in FIG. 12) is formed in the insert member 210a to 210e at a position corresponding to the insert nut 310.

  A nut plate assembly 320 is provided for each through hole 300 of each of the insert members 210a to 210e. The shape of the nut plate assembly 320 is slightly different depending on the position where the nut plate assembly 320 is provided, but the basic configuration is common.

  FIG. 13 shows a nut plate assembly 320 provided at the front portion of the insert member 210 a as an example of the nut plate assembly 320. The nut plate assembly 320 includes a metal plate member 321 and an outsert nut 322. One end of the outsert nut 322 is fixed to the plate member 321 by projection welding or the like. A symbol W1 in FIG. 13 indicates the welded portion. The outsert nut 322 extends in the horizontal direction. The plate member 321 has a hole 324 into which the plate fixing bolt 323 is inserted.

  Outsert nuts 322 are inserted into the through holes 300 of the insert members 210 a to 210 e from the inside of the tray member 51. As shown in FIG. 12, the plate fixing bolt 323 is inserted into the hole 324 of the plate member 321, and the bolt 323 is screwed into the insert nut 310, whereby the nut plate assembly 320 is fixed to the insert member 210a. Similarly to the nut plate assembly 320, the nut plate assembly 320 is fixed to the other insert members 210 b to 210 e by plate fixing bolts 323.

  As shown in FIG. 6, a nut insertion hole 330 having a circular cross section penetrating in the horizontal direction is formed in the peripheral wall 54 of the tray member 51 at a position corresponding to the through hole 300. As shown in FIG. 12, the cylindrical outsert nut 322 is inserted into the nut insertion hole 330 from the inside of the tray member 51. That is, the outsert nut 322 is a retrofit component that is inserted into the peripheral wall 54 after the tray member 51 is formed.

  The end surface 322 a on the other end side of the outsert nut 322 is exposed to the outside at the opening 330 a outside the nut insertion hole 330 and faces the outer surface of the peripheral wall 54. In addition, the end surface 322a slightly protrudes (about 1 to 2 mm) outward from the outer surface of the peripheral wall 54 of the tray member 51. A seal member 335 (shown in FIGS. 12 and 16) is provided between the outsert nut 322 and the tray member 51.

  Between the nut plate assembly 320 provided on the side walls 51a and 51b of the tray member 51 and the battery module 60, a synthetic resin protective plate 340 (see FIG. 14) is provided at a position where the plate fixing bolt 323 can be covered. Some are shown). An insulating member 341 made of an electrically insulating material is provided on the side of the protective plate 340 facing the battery module 60. The protection plate 340 can prevent the plate member 321 and the bolt 323 from coming into direct contact with the battery module 60 when the tray member 51 is crushed to the inside of the vehicle body due to a side collision or the like. Can be reduced.

  One fastening part 123 of the girder member 102 is shown by FIGS. The fastening portion 123 includes a metal support plate 350 having the bolt insertion holes 153, a flange portion 351 formed at the end of the support plate 350, and a vertical wall 352 to which the flange portion 351 is welded. A hole 353 is formed in the vertical wall 352 so as to penetrate in the horizontal direction. A tray member fixing bolt 355 is inserted into the hole 353 from the outside of the vertical wall 352.

  By screwing the bolt 355 into the outsert nut 322 from the outside of the tray member 51, the vertical wall 352 of the girder member 102 is fastened to one side wall 51 a of the tray member 51. In this case, since there is no resin between the end surface 322 a of the outsert nut 322 and the vertical wall 352, the tightening force of the bolt 355 can be directly transmitted to the outsert nut 322.

  That is, the peripheral wall 54 of the tray member 51 is sandwiched between the metal insert member 210a and the metal vertical wall 352. In this case, the tightening force (axial force) of the tray member fixing bolt 355 is applied to the outsert nut 322, but it is possible to avoid the tightening force of the bolt 355 from being directly applied to the peripheral wall 54 made of resin. For this reason, the fall of the fastening torque of the volt | bolt 355 by the resin of the surrounding wall 54 can be avoided.

  Since the outsert nut 322 is inserted into the nut insertion hole 330 after the tray member 51 is formed, the resin of the material flows into the inside of the outsert nut 322 and is hardened when the tray member 51 is formed. There is no problem. Further, as shown in FIG. 12, since a sufficient distance X can be secured between the end surface 310a of the insert nut 310 and the outer surface of the side wall 54, the mold used when molding the tray member 51 is the insert nut. There is no fear of contacting the end surface 310a of 310. Further, since the end face 310a of the insert nut 310 is closed, there is no problem that the resin of the material flows into the insert nut 310 and hardens when the tray member 51 is formed.

  The other fastening portion 124 of the girder member 102 is also fixed to the other side wall 51 b of the tray member 51 by the nut plate assembly 320 and the tray member fixing bolt 355 similarly to the fastening portion 123. Further, the fastening portions 121, 122, 125 to 128 of the girder members 101, 103, 104 other than the girder member 102 and the fastening portions 190, 191 of the front support members 130, 131 are also similar to the fastening portion 123. The nut plate assembly 320 and the tray member fixing bolt 355 are fixed to the peripheral wall 54 of the tray member 51.

  In addition, although the said embodiment demonstrated the electric vehicle by which the driving motor was mounted in the vehicle body rear part, this invention is applicable also to the electric vehicle by which the driving motor is arrange | positioned at the vehicle body front part. In carrying out the present invention, the structure and arrangement of the components of the invention including the motor, support member (girder member, etc.), tray member, cover member, insert member, and nut plate assembly can be changed as appropriate. Needless to say.

The perspective view of the electric vehicle which has the battery case which concerns on one Embodiment of this invention. FIG. 2 is a perspective view of a frame structure and battery unit of the electric vehicle shown in FIG. 1. The top view which looked at the frame structure and battery unit of the electric vehicle shown by FIG. 1 from upper direction. The side view of the frame structure and battery unit of the electric vehicle which were shown by FIG. FIG. 3 is a perspective view of a tray member, a cover member, and a girder member of the battery unit shown in FIG. 2. FIG. 6 is a perspective view of the tray member shown in FIG. 5. The perspective view of the insert member of the front side embed | buried under the said tray member. The perspective view of the back side insert member embed | buried under the said tray member. The top view of a part of tray member shown by FIG. Sectional drawing of a part of tray member which follows F10-F10 line | wire in FIG. FIG. 10 is a partial cross-sectional view of the tray member along the line F11-F11 in FIG. 9; Sectional drawing of a part of tray member which follows F12-F12 line | wire in FIG. FIG. 8 is a perspective view of one example of the nut plate assembly shown in FIG. 7. The top view of the fastening part of the girder member of the battery unit shown by FIG. The side view of the fastening part shown by FIG. Sectional drawing of the fastening part which follows the F16-F16 line | wire in FIG. Sectional drawing which shows the reference example of a metal mold | die and an insert member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electric vehicle 11 ... Car body 14 ... Battery unit 50 ... Battery case 51 ... Tray member 52 ... Cover member 54 ... Peripheral wall 60 ... Battery module 101-104 ... Girder member (support member)
DESCRIPTION OF SYMBOLS 200 ... Resin part 210a-210f ... Insert member 320 ... Nut plate assembly 321 ... Plate member 322 ... Outsert nut 323 ... Plate fixing bolt 330 ... Nut insertion hole 355 ... Tray member fixing bolt

Claims (4)

A battery case that houses a battery module of an electric vehicle and is fixed to a vehicle body via a support member,
A tray member having a bottom wall that supports the battery module and a peripheral wall formed around the bottom wall;
A cover member that is stacked on the tray member and fixed to the tray member;
The tray member is
A resin part formed by molding a synthetic resin;
A metal insert member fixed to the peripheral wall of the tray member;
A nut insertion hole formed in the peripheral wall of the tray member and penetrating the peripheral wall in a horizontal direction;
An outsert nut to be inserted into the nut insertion hole from the inside of the tray member; and a plate member to which one end of the outsert nut is fixed; the plate member being fixed to the insert member; and the outsert A nut plate assembly in which an end surface on the other end side of the nut faces an outer surface of the peripheral wall at the opening of the nut insertion hole;
A tray member fixing bolt for fixing the peripheral wall of the tray member and the support member to each other by being screwed into the outsert nut from the outside of the tray member;
A battery case for an electric vehicle, comprising:   An insert nut embedded in the peripheral wall of the tray member is fixed to the insert member, and the plate member of the nut plate assembly is inserted into the insert member by a plate fixing bolt that is screwed into the insert nut from the inside of the tray member. The battery case for an electric vehicle according to claim 1, wherein the battery case is fixed to a member.   The peripheral wall and the vertical wall are fastened to each other by the tray member fixing bolt in a state where the end surface of the outsert nut protrudes outward from the outer surface of the peripheral wall and the vertical wall of the support member overlaps the end surface. The battery case for an electric vehicle according to claim 2, wherein   The battery case for an electric vehicle according to claim 1, wherein a sealing material is provided between an inner surface of the nut insertion hole and an outsert nut.

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