JP2017185948A - Battery mounting structure for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery mounting structure for a vehicle which is capable of absorbing an impact force caused by a side collision or the like while suppressing an increase in vehicle body weight.SOLUTION: A battery mounting structure 1 for a vehicle 10 comprises hollow skeleton members 24, 25 respectively arranged at each of both ends of the floor panel 43 in the vehicle width direction while being oriented in the vehicle longitudinal direction and battery packs 16-20 arranged between the arranged skeleton members 24, 25. Impact absorbing members 50, 60, 70, 80, 90, 100 for absorbing impact energy are arranged inside the skeleton members 24, 25, and surfaces 48 of the battery packs 16-20 facing outward in the vehicle width direction and surfaces of the impact absorbing members 50, 60, 70, 80, 90, 100 facing inward in the vehicle width direction are arranged so as to face each other in a horizontal direction at least partially.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a structure in which a battery for running a vehicle is mounted on a lower member of a vehicle body such as a floor panel.

  Patent Document 1 describes a battery support structure for an electric vehicle in which a battery for running a vehicle is attached to the lower side of a floor panel. In this battery support structure, a floor panel is provided between a pair of left and right side sills, and a battery storage portion is attached to the lower surface side of the floor panel. Moreover, the side panel which protrudes below is attached to each left and right side sill, and each side panel has opposed the side surface of the battery accommodating part. In each side panel, an impact absorbing member is held in a state facing the side surface of the battery storage unit.

JP2013-014276A

  In the structure described in Patent Document 1, the battery or the battery housing portion is not a strength member that constitutes the vehicle body, but even if the side sill is deformed due to an impact load from the side of the vehicle body, the battery housing Since the impact absorbing member is brought into contact with the portion to reduce the impact force, damage to the battery or the battery housing portion can be reduced. However, in the structure of Patent Document 1, since the side panel is additionally installed in order to provide the shock absorbing member, the number of members constituting the vehicle body increases, and the vehicle body weight increases. There is. Further, in the structure described in Patent Document 1, since the battery storage portion is arranged to be offset downward with respect to the side sill, an impact load from the side of the vehicle body is not easily applied to the battery storage portion, Although it is effective in protecting the battery in that respect, if the battery has high rigidity and can withstand a certain amount of load, the battery or the battery compartment may not function as a member for maintaining the rigidity of the vehicle body. is there.

  The present invention has been made paying attention to the above technical problem, and provides a vehicle battery mounting structure capable of reducing the impact force due to a side collision while suppressing an increase in the weight of the vehicle body. It is intended to do.

  In order to achieve the above object, the present invention provides a hollow skeleton member disposed on both side ends in the vehicle width direction of a floor panel in the vehicle longitudinal direction, and the skeleton member disposed between the hollow skeleton members. In the battery mounting structure of the vehicle including the battery pack disposed in the vehicle, a shock absorbing member that absorbs impact energy is disposed inside the skeleton member, and the surface of the battery pack that faces outward in the vehicle width direction and the shock absorption The member is arranged so that at least a part of the surface facing the inner side in the vehicle width direction is opposed in the horizontal direction.

  In this invention, an impact absorbing member that absorbs impact energy is provided inside a hollow skeleton member that is arranged in the vehicle longitudinal direction on both side ends in the vehicle width direction. That is, in the structure according to the present invention, since the member for maintaining the strength of the vehicle body also serves as a shock absorbing member, for example, a member for holding a buffer member such as a foam material, the shock absorbing member is used. As a result, the impact absorbing member can be provided while suppressing an increase in the vehicle weight. In particular, in the present invention, at least a part of each of the side surface of the battery pack in the vehicle width direction and the side surface of the shock absorbing member disposed inside the skeleton member is opposed to each other in the horizontal direction. Therefore, the load in the side direction acting on the skeleton member in the vehicle width direction acts to press and deform the impact absorbing member against the side surface of the battery pack, and as a result, the deformation of the impact absorbing member is ensured. And exhibit an excellent buffer function.

It is explanatory drawing which shows an example of the vehicle to which the battery mounting structure in embodiment of this invention is applied. It is a perspective view which shows an example of a battery module. It is sectional drawing which shows the connection state of a battery pack and a side sill. It is a figure for demonstrating the 1st example of an impact-absorbing member. It is a figure for demonstrating the 2nd example of an impact-absorbing member. It is a figure for demonstrating the 3rd example of an impact-absorbing member. It is a figure for demonstrating the 4th example of an impact-absorbing member. It is a figure for demonstrating the 5th example of an impact-absorbing member. It is a figure for demonstrating the 6th example of an impact-absorbing member.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an example of a vehicle 10 to which a vehicle battery mounting structure 1 according to an embodiment of the present invention is applied. In FIG. 1, the vehicle 10 is viewed from the bottom side, the arrow FR indicates the front direction of the vehicle 10, and the arrow RH indicates the outside in the vehicle width direction (right side of the vehicle body). As shown in FIG. 1, a vehicle 10 includes, for example, a converter 12, an inverter 13, a motor 14, and a power transmission mechanism 15 mounted in a front compartment 11, and five battery packs (batteries) 16 to 20 on the bottom surface of the vehicle 10. It is equipped with. The battery packs 16 to 20 have a configuration in which a battery module 21 including an assembly of single cells is accommodated in a rectangular parallelepiped case 22. Converter 12 boosts the voltage output from battery module 21, absorbs fluctuations in the voltage output from battery module 21, and supplies a stable voltage to inverter 13. The inverter 13 converts the direct current output from the battery module 21 into an alternating current and controls the frequency. The power transmission mechanism 15 increases or decreases the driving force output from the motor 14 and transmits the driving force to the driving wheels 23. The converter 12 may be omitted and the inverter 13 may be directly connected to the battery module 21.

  The vehicle 10 includes a pair of side sills (rockers) 24 and 25 extending in the front-rear direction of the vehicle 10 at both ends in the vehicle width direction. Between the portions of the pair of side sills 24 and 25 that are parallel to each other, the battery packs 16 to 20 are arranged side by side in the front-rear direction of the vehicle 10 at a predetermined interval. Each of the battery packs 16 to 20 has a rectangular shape in which the length in the vehicle width direction is longer than the length in the front-rear direction of the vehicle 10 in a bottom view, and a pair of the battery packs 16 to 20 is oriented in the longitudinal direction in the vehicle width direction. It is fixed between the side sills 24 and 25. The pair of side sills 24 and 25 is an example of a skeleton member that is disposed on both side ends in the vehicle width direction of the floor panel 43 (see FIG. 3) in the vehicle longitudinal direction. Each of the battery packs 16 to 20 functions as a reinforcing material that compensates for the resistance against an impact load when a side collision occurs. Floor crosses 26 and 27 that extend in the vehicle width direction are arranged on the front and rear sides of the vehicle 10 with respect to the battery pack 18 that is arranged at substantially the center of the parallel portions of the pair of side sills 24 and 25. . Both ends of the floor cloths 26 and 27 are fixed to a pair of side sills 24 and 25. In the embodiment of the present invention, five battery packs 16 are used. However, the present invention is not limited to this, and six or more or four or less including the singular may be used. Further, either one or both of the floor cloths 26 and 27 may be omitted.

  FIG. 2 is a perspective view showing an example of the battery module 21. In FIG. 2, the arrow FR indicates the front direction of the vehicle 10, the arrow LH indicates the outside in the vehicle width direction (the left side of the vehicle body), and the arrow UP indicates the upward direction of the vehicle 10. As shown in FIG. 2, the battery module 21 includes a first end plate 30, a second end plate 31, a first tension plate 32, a second tension plate 33, and a battery stack (stacked body) 34. The battery module 21 is, for example, a rectangular parallelepiped whose length along the vehicle width direction is longer than the length along the front-rear direction of the vehicle 10 and whose length along the height direction of the vehicle 10 is shorter than the length along the front-rear direction of the vehicle 10. It has a shape.

  The battery stack 34 is formed by laminating a plurality of single cells 35 in the vehicle width direction. The single cell 35 is formed in a thin flat plate shape in which the length in the front-rear direction of the vehicle 10 is longer than the length (thickness) in the vehicle width direction and the length in the height direction of the vehicle 10 is longer than the thickness length, for example. Yes. The battery stack 34 is stacked in the thickness direction of the single cell 35, that is, in the vehicle width direction.

  The single cell 35 has a solid electrolyte and a positive electrode and a negative electrode provided on both sides along the stacking direction of the solid electrolyte. Although not shown, the plurality of single cells 35 are electrically connected to each other by a harness. The harness has a structure in which a plurality of strands centered on a copper wire are wound together, and the surface thereof is coated with an insulating resin having high heat resistance and wear resistance. The battery module 21 is configured by connecting a plurality of single cells 35 in series, and outputs a voltage corresponding to the number of single cells 35 through a positive electrode terminal and a negative electrode terminal exposed to the outside. Each single cell 35 is electrically connected to a battery ECU (not shown) via a harness. The battery ECU measures the voltage of each single cell 35 and performs voltage equalization control for equalizing the voltage of the single cell 35 based on the measured voltage. The battery ECU is arranged before or after the vehicle 10 with respect to the battery stack 34. Battery packs 16 to 20 are each electrically connected in parallel. A current capacity necessary for driving the motor 14 is obtained by connecting the battery packs 16 to 20 in parallel.

  The first end plate 30 and the second end plate 31 are disposed at both ends of the battery stack 34 in the stacking direction. The first tension plate 32 is fixed between the first end plate 30 and the second end plate 31 on the upper side of the battery stack 34 by fastening fastening members, for example, a plurality of bolts 36 and 37. The second tension plate 33 is fixed below the battery stack 34 between the first end plate 30 and the second end plate 31 by fastening fastening members, for example, a plurality of bolts 36 and 37. The first end plate 30, the second end plate 31, the first tension plate 32, and the second tension plate 33 are made of a material having hardness or rigidity. The battery stack 34 is restrained in the stacking direction between the first end plate 30 and the second end plate 31 by fastening bolts 36 and 37. Since such a battery module 21 is made of a solid electrolyte, there is no fear of leakage of the electrolyte, and the main members constituting the single cell 35 are made so as to satisfy a high impact resistance requirement. Has the advantage of high impact resistance in the direction. The first tension plate 32, the second tension plate 33, and the bolts 36 and 37 are examples of restraining members. Further, the first end plate 30 and the second end plate 31 are provided with a fixing plate 38 for fixing to the case 22 made of an insulating material. The fixing plate 38 is fixed to a fixing portion (not shown) of the housing portion 40 (see FIG. 3) to which the battery module 21 is fixed by a fastening member. Although one fixing plate 38 is not shown, four fixing plates 38 are provided for one module.

  FIG. 3 is a cross-sectional view showing a state where the battery pack 18 and the side sill 25 are connected. In FIG. 3, the arrow LH indicates the vehicle width direction outside (the left side of the vehicle body), and the arrow UP indicates the vehicle upward direction. As shown in FIG. 3, the battery pack 18 includes a battery module 21 and a case 39. The case 39 includes a housing part 40 to which the battery module 21 is fixed and a lid part 41 that closes the housing part 40. A connecting portion 42 is attached to the case 39. For example, the connecting portion 42 is a tubular member having a rectangular cross section extending in the front-rear direction of the vehicle 10. A floor panel 43 is disposed on the upper surface of the battery pack 18. The floor panel 43 is joined to the side sills 24 and 25 at both ends in the vehicle width direction. Further, with the battery module 21 fixed to the case 39, the inner wall surface 44 in the vehicle width direction of the housing portion 40 and the outer surface 45 in the vehicle width direction of the first end plate 30 face each other in parallel in the front-rear direction of the vehicle 10. doing. Here, “parallel” is a concept that includes “substantially parallel” as well as “substantially parallel”, which is viewed in parallel from the viewpoint of technical common sense. “Parallel” referred to below has the same or similar concept as described above.

  The side sill 25 is integrally formed so as to have a hollow part (cross-section closed hollow part) 46 whose cross-sectional shape is closed by, for example, extrusion processing of an aluminum light alloy material for the purpose of reducing the weight of the vehicle body and ensuring rigidity. Yes. The side sill 25 has a cross-sectional shape having a concave portion 47 that is recessed in a rectangular shape on the lower side of the vehicle 10 and on the inner side in the vehicle width direction. The recess 47 and the connecting portion 42 are connected by a fastening member such as a bolt (not shown). In a state where the battery pack 18 is fixed to the side sill 25 by the connecting portion 42, the outer end surface 48 in the vehicle width direction of the battery pack 18 and the inner side surface 49 in the vehicle width direction of the side sill 25 are parallel to each other. The battery pack 18 is also fixed to the right side sill 24 in the vehicle width direction with the same or similar configuration as described above.

  An impact absorbing member (buffer member) 50 that absorbs impact energy is provided in the cross-section closed hollow portion 46 of the side sill 25. The shock absorbing member 50 is formed long in the vehicle front-rear direction, and the surface facing the vehicle width direction inner side of the shock absorbing member 50 and the inner side surface 49 of the side sill 25 in the vehicle width direction are in the vehicle front-rear direction. It extends in parallel. That is, the end surface 48 facing the outer side in the vehicle width direction of the battery pack 18 and the surface facing the inner side in the vehicle width direction of the shock absorbing member 50 are arranged so as to face each other with the side sill 25 interposed therebetween. As shown in FIG. 1, the length of the shock absorbing member 50 along the vehicle front-rear direction is the length from the front end of the battery pack 16 positioned at the frontmost side to the rear end of the battery pack 20 positioned at the rearmost side. In addition, it is formed longer.

  Next, the structure of the shock absorbing member 50 will be described. FIG. 4 is a perspective view for explaining a first example of the impact absorbing member 50. As shown in FIG. 4, the first example of the impact absorbing member 50 is a rectangular parallelepiped that is long in the vehicle front-rear direction, and the inside of the rectangular parallelepiped has a plurality of hexagonal holes 53 that are opened in the vehicle width direction. A so-called honeycomb structure is provided. The impact absorbing member 50 of the first example is in contact with the inner surface of the side sill 25. Specifically, the shock absorbing member 50 is formed between the first inner wall surface 51 facing the vehicle width direction outer side (the vehicle left direction) inside the side sill 25 and the second inner wall surface 52 facing the first inner wall surface 51. Are in contact. The shock absorbing member 50 is attached to the first inner wall surface 51 and the second inner wall surface 52 by bonding, welding, or fastening members such as bolts. The shock absorbing member 50 of the first example is attached to at least one inner wall surface among the inner wall surfaces forming the closed cross-section hollow portion 46 including the first inner wall surface 51 and the second inner wall surface 52. Good. Further, an impact absorbing member 50 having the same or similar configuration as the above configuration is also arranged on the right side sill 24 in the vehicle width direction.

  According to this configuration, the impact absorbing member 50 that absorbs impact energy is provided inside the hollow side sills 24 and 25 that are disposed in the vehicle longitudinal direction on both side ends in the vehicle width direction. That is, in the structure according to the embodiment of the present invention, since the member for maintaining the strength of the vehicle body also serves as the member for holding the shock absorbing member 50, the structural member accompanying the use of the shock absorbing member 50 As a result, the impact absorbing member 50 can be provided while suppressing an increase in vehicle weight. In particular, in the present invention, at least a part of each of the end surface (side surface) 48 in the vehicle width direction of the battery pack 18 and the side surface of the shock absorbing member 50 disposed inside the side sills 24 and 25 is mutually in the horizontal direction. Opposite. Therefore, a load in the side direction acting on the side sills 24 and 25 in the vehicle width direction acts to press and deform the shock absorbing member 50 against the side surface of the battery pack 18, and as a result, the shock absorbing member. It is possible to reliably produce 50 deformations and to exhibit an excellent buffer function.

  Moreover, according to this structure, the vehicle width of the whole vehicle body can be shortened compared with the case where the impact absorbing member 50 is provided outside the side sills 24, 25 in the vehicle width direction. Therefore, a space is formed on the outer side in the vehicle width direction of the vehicle body corresponding to the reduction of the vehicle width of the entire vehicle body, so that the battery packs 16 to 20 to be mounted can be enlarged. Furthermore, when the vehicle 10 in the embodiment of the present invention receives a side collision from another vehicle, the impact absorbing member 50 reduces the impact when the other vehicle collides with the battery pack 18. Therefore, damage to other vehicles due to collision with the battery pack 18 can be reduced.

  Hereinafter, another example of the impact absorbing member will be described with reference to FIGS. First, the shock absorbing member 60 of the second example shown in FIG. 5 includes a U-shaped portion 61 whose section when opened in the vehicle width direction is open to the vehicle compartment side, and a vehicle in the U-shaped portion 61. It is comprised by the two attachment surfaces 62 and 63 formed in the edge part of the chamber side so that the 1st inner wall surface 51 might be opposed. The two attachment surfaces 62 and 63 are fixed to the first inner wall surface 51 by bonding, welding, or fastening members such as bolts. That is, the shock absorbing member 60 is fixed to the first inner wall surface 51. Further, the shock absorbing member 60 of the second example is formed such that the distance between the faces 64 and 65 facing each other in the up-down direction increases from the outside toward the inside in the vehicle width direction. Therefore, when receiving a side collision from the outside in the vehicle width direction, the impact absorbing member 60 can absorb the impact while being deformed inward in the vehicle width direction.

  Next, similarly to the shock absorbing member 60 of the second example, the shock absorbing member 70 of the third example shown in FIG. 6 includes a portion formed in a U-shaped cross section that opens to the inner side in the vehicle width direction. . And the site | part formed in the cross-sectional U-shape has the 1st site | part 71 with the wide space | interval of the surfaces which face in the vehicle up-down direction, and the 2nd site | part 72 with a narrow space | interval. The first portions 71 and the narrow second portions 72 having a wide interval are alternately formed in the vehicle front-rear direction of the shock absorbing member 70. And the impact-absorbing member 70 of the 3rd example is provided with the two attachment surfaces 73 and 74 facing the 1st inner wall surface 51 similarly to the impact-absorbing member 60 of a 2nd example. The shock absorbing member 70 is fixed to the first inner wall surface 51 by attaching the two attachment surfaces 73 and 74 to the first inner wall surface 51. The impact absorbing member 70 of the third example has ridge lines formed in the vehicle width direction by alternately forming the first portions 71 and the second portions 72. Therefore, compared with the impact absorbing member 60 of the second example, impact energy can be further absorbed.

  Next, the shock absorbing member 80 of the fourth example shown in FIG. 7 is formed in a rectangular parallelepiped that is long in the front-rear direction of the vehicle. Two flat plate-like members 81 and 82 that are long in the vehicle front-rear direction are formed inside the rectangular parallelepiped. The flat plate members 81 and 82 are integrally formed by, for example, extrusion, and are provided so that the plane faces both sides in the vehicle width direction. Further, the outer surface of the shock absorbing member 80 of the fourth example is attached to at least one inner wall surface among the inner wall surfaces forming the closed cross-section hollow portion 46 including the first inner wall surface 51 and the second inner wall surface 52. The means for attaching is adhesion, welding, or fastening. The flat plate members 81 and 82 may be configured such that the plane faces the vehicle front-rear direction. Moreover, you may adjust the magnitude | size of the impact which can be absorbed by changing the number of flat members.

  Next, the shock absorbing member 90 of the fifth example shown in FIG. 8 includes a quadrilateral thrust box-like crash box 92 having a surface facing the second inner wall surface 52 as an upper surface 91, and a first lower surface side of the crash box 92. And a bottom surface portion 93 facing the inner wall surface 51. The bottom surface portion 93 is attached to the first inner wall surface 51 by bonding, welding, or a fastening member such as a bolt. The shock absorbing member 90 is fixed to the first inner wall surface 51 by attaching the bottom surface portion 93 to the first inner wall surface 51. It should be noted that any number of crash boxes 92 may be provided as long as at least a part of the end face 48 facing the vehicle width direction outside of the battery pack 18 and the bottom face portion 93 are in the horizontal direction and face each other via the side sill 25.

  And in the impact-absorbing member 100 of the 6th example shown in FIG. 9, the side sill 25 is comprised as a member which absorbs an impact. Specifically, first, the front end portion of the cross-section closed hollow portion 46 is closed by the wall portion 101, and the inflator 103 is attached so as to supply gas from the hole 102 formed in the wall portion 101. Further, the rear end portion (not shown) of the cross-section closed hollow portion 46 is also closed. A hole 104 is provided in the surface 104 of the side sill 25 facing outward in the vehicle width direction so as to communicate with the closed hollow portion 46. A plurality of punch holes 105 are provided at predetermined intervals in the vehicle front-rear direction. By adjusting the number and size of the punched holes 105, it is possible to adjust the amount of gas discharged to the outside from the closed cross-section hollow portion 46, and thus it is possible to adjust the amount of absorption of impact energy.

  When a vehicle including the impact absorbing member 100 of the sixth example receives a side collision from the outside in the vehicle width direction, a sensor (collision detection sensor) (not shown) detects the side collision and an ECU (airbag ECU) (not shown) ). The ECU that has received the signal issues an ignition instruction to the inflator 103 when it determines that it is necessary to generate gas in the closed hollow portion 46. When ignition is received in response to the ignition instruction, the explosive explodes (combusts) in the inflator 103 to generate gas, and the gas is supplied to the cross-section closed hollow portion 46. The internal pressure of the cross-section closed hollow portion 46 is instantaneously increased by the gas, and the cross-section closed hollow portion 46 is compressed inward in the vehicle width direction by a load due to an impact. When the cross-section closed hollow portion 46 is compressed, the gas is discharged from the punched hole 105 while absorbing the above-described impact. Therefore, it has the same effect as the impact absorbing members 50, 60, 70, 80, 90 of the first to fifth examples described above.

  Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications are made without departing from the spirit of the present invention. For example, the shock absorbing member may be a foam material. Further, the outer surface 45 facing the outer side in the vehicle width direction of the battery stack 34 and the surface facing the inner side in the vehicle width direction of the shock absorbing member 50 may be arranged so as to be at least partially opposed to each other. With such an arrangement, a plurality of the impact absorbing members 50, 60, 70, 80, 90 of the first to fifth examples may be arranged at a predetermined interval in the vehicle front-rear direction. . Further, the impact absorbing members 50, 60, 70, 80, 90 of the first to fifth examples may be made of resin, aluminum light alloy material, iron, or the like. Furthermore, in the above embodiment, a battery module in which single cells having a solid electrolyte are stacked is used. However, the present invention is not limited to this, and for example, a single cell having a liquid electrolyte may be stacked.

  DESCRIPTION OF SYMBOLS 1 ... Battery mounting structure, 10 ... Vehicle, 16, 17, 18, 19, 20 ... Battery pack, 24, 25 ... Side sill, 43 ... Floor panel, 48 ... End face, 50, 60, 70, 80, 90, 100 ... Shock absorbing member.

Claims (1)

A hollow skeleton member disposed on both side ends in the vehicle width direction of the floor panel in the vehicle longitudinal direction;
In the battery mounting structure of the vehicle comprising the battery pack disposed between the skeleton members disposed respectively.
An impact absorbing member that absorbs impact energy is disposed inside the skeleton member,
The battery mounting of a vehicle, wherein at least a part of a surface facing the vehicle width direction outside of the battery pack and a surface facing the vehicle width direction inside of the shock absorbing member are opposed to each other in the horizontal direction Construction.

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