Vehicle substructure

Abstract

The present invention provides a vehicle lower structure capable of suppressing damage to battery units during a frontal collision even when a transmission is configured to partially intrude into a floor tunnel. The vehicle lower structure comprises: a transmission (4) configured to intrude into a floor tunnel (10); a rear drive shaft (9) for transmitting power from the transmission (4) to rear wheels (7); and left and right battery units (40L, 40R) arranged on the left and right sides of the floor tunnel (10). A rear portion of the transmission (4) (transfer case (4a)) is arranged close to the front and upper sides of each battery unit (40L, 40R). An inner protective member (70L, 70R) covering the battery unit (40L, 40R) from the inner side in the vehicle width direction is mounted on the front end portion of the inner face (45L, 45R) of each battery unit (40L, 40R).

Description

Technical Field

[0001] The technology disclosed here belongs to the technical field related to the lower structure of a vehicle. Background Art

[0002] In recent years, hybrid vehicles and electric vehicles have been produced in large numbers, and many vehicles are equipped with large-capacity batteries for operating electric motors as driving sources.

[0003] For example, the hybrid vehicle described in Patent Document 1 has a structure in which a battery for driving a motor and an inverter are arranged facing each other in the vehicle width direction with a floor tunnel interposed therebetween, and a wiring harness connecting the battery and the inverter is arranged across the floor tunnel.

[0004] The hybrid vehicle described in Patent Document 2 is a rear-wheel driven vehicle having a structure in which two battery packs are disposed opposite each other in the vehicle width direction with a floor tunnel interposed therebetween, and a rear portion of a transmission and a propeller shaft are disposed in the floor tunnel.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-103535

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2013-67334

[0009] Technical problem to be solved by the invention

[0010] However, in order to absorb the impact load during a frontal collision, it is preferable to maximize the travel of the engine and transmission. To address this, a configuration in which the rear portion of the transmission intrudes into the floor tunnel is conceivable. This allows the transmission to enter the floor tunnel during a frontal collision, thereby maximizing the travel of the engine and transmission.

[0011] Here, as in Patent Documents 1 and 2, when the battery units are arranged on the left and right sides of a floor tunnel, if the rear portion of the transmission is positioned so as to intrude into the floor tunnel, the battery units and the transmission become close. Consequently, if the transmission moves backward in the vehicle width direction relative to the vehicle's fore-aft direction during a frontal collision, the inner portion of the battery unit in the vehicle width direction may contact the transmission, damaging the battery unit. Summary of the Invention

[0012] The technology disclosed herein has been developed in view of this point, and its object is to suppress damage to the battery unit during a frontal collision of the vehicle even when the transmission is arranged so that a portion thereof intrudes into the floor tunnel.

[0013] Technical means for solving technical problems

[0014] To solve the above technical problems, the technology disclosed herein is directed to an undercarriage structure of a vehicle having rear wheels as drive wheels, and comprises: a transmission arranged such that at least a portion of the transmission on the vehicle rear side intrudes into a floor tunnel formed by a tunnel panel; a drive shaft extending from the transmission toward the vehicle rear side and transmitting power from the transmission to the rear wheels; and left and right battery units arranged under a floor panel on the vehicle left and right sides of the floor tunnel, wherein a portion of the transmission on the vehicle rear side is arranged close to a portion of each battery unit on the vehicle front side and above the battery unit, each battery unit having an inner side surface extending in the vehicle front-rear direction along both side ends of the floor tunnel in the vehicle width direction, and an inner guard member attached to each battery unit, the inner guard member covering a front end portion of the inner side surface from the vehicle width inner side.

[0015] With this structure, the rear-side portion of the transmission intrudes into the floor tunnel, so in a frontal collision, the transmission will enter the floor tunnel. The inner side of the battery unit is located in the floor tunnel. Furthermore, the rear-side portion of the transmission is positioned close to and above the front-side portion of the battery unit. Therefore, there is a concern that the transmission may come into contact with the inner side of the battery unit in a frontal collision.

[0016] In this regard, in the above-described structure, an inner protective member is attached to the battery cell, covering the front end of the inner side surface. This prevents direct contact between the transmission and the inner side surface of the battery cell during a frontal collision, even if the transmission moves backward toward one of the left and right battery cells. Consequently, damage to the battery cell is minimized.

[0017] In the lower structure of the vehicle, it can also be constructed so that each of the inner protective components respectively has: a protective part, which actually covers the inner side surface; and a body connection part, which is connected to the body component of the vehicle, and the body connection part of each of the inner protective components is smaller in width in the front and rear direction of the vehicle than the protective part.

[0018] According to this structure, since the inner protective component is connected to the vehicle body components, it also serves as a bracket for mounting and supporting the battery unit on the vehicle body. Furthermore, by connecting the inner protective component to the vehicle body components, the vehicle body can bear the impact load input when the transmission and the inner protective component come into contact. Furthermore, the body connection portion of the inner protective component is narrower in the vehicle's front-to-rear direction than the protective portion, thereby achieving vehicle weight reduction. This prevents damage to the battery unit and further contributes to vehicle weight reduction.

[0019] In one embodiment of the vehicle lower structure, a reinforcement rib is formed on a surface portion of each of the inner guard members on an outer side in the vehicle width direction.

[0020] This structure can prevent the inner guard member from being damaged even if the inner guard member contacts the transmission during a frontal collision, thereby inputting the collision load into the inner guard member. As a result, damage to the battery cells can be more effectively suppressed.

[0021] In the above-mentioned embodiment, the reinforcing rib may include a plurality of longitudinal ribs extending in the up-down direction.

[0022] Specifically, because the transmission's rear-side portion is positioned near the front and upper side of the battery unit, in a frontal collision, the transmission moves backward while advancing from the upper side toward the lower side. Consequently, there is a high probability that the collision load will be vertically transmitted to the inner guard component. Therefore, the inclusion of multiple longitudinal ribs effectively prevents damage to the inner guard component.

[0023] In the embodiment described above, the reinforcement rib includes a transverse rib extending in the vehicle front-rear direction, and at least a portion of the transverse rib is located at the same height as the channel plate.

[0024] With this structure, when a collision load in the vehicle width direction is applied to the inner shield, the transverse ribs abut against the channel plate, allowing the vehicle body to absorb the collision load. This prevents the collision load from being transferred to the battery cells, effectively preventing damage to the battery cells.

[0025] In the lower structure of the vehicle, it can also be constructed so that the inner side surface of each battery unit has a protrusion protruding inward in the vehicle width direction, each inner protective component is respectively arranged in an area above the protrusion in each inner side surface, and is respectively fixed to each protrusion by an axial fastening component, and each axial fastening component is fastened in a manner extending in the up and down directions.

[0026] According to this structure, even if the transmission abuts against the inner guard member and a collision load is input to the inner guard member, the shaft-shaped fastening portion can appropriately bear the load, thereby appropriately preventing the inner guard member from being separated from the battery cell.

[0027] In the vehicle lower structure having a protrusion formed on the inner side surface of the battery unit, the inner surface of each inner shield member in the vehicle width direction may be located at substantially the same position as the inner end of each protrusion in the vehicle width direction.

[0028] This configuration can prevent the transmission from getting caught on the protruding portion and causing the battery unit to fall out during a frontal collision, thereby more effectively preventing damage to the battery unit.

[0029] In the vehicle lower structure, a front guard member that covers a front end portion of each inner guard member from a vehicle front side may be attached to each of the battery units.

[0030] This configuration can prevent the transmission from getting caught on the front end of the inner guard member and causing the inner guard member to separate from the battery unit during a frontal collision, thereby more effectively preventing damage to the battery unit.

[0031] In the lower structure of the vehicle, a portion of the transmission on the rear side of the vehicle may constitute a transfer case.

[0032] According to this configuration, even in a four-wheel drive configuration, for example, damage to the battery cells can be appropriately suppressed.

[0033] Effects of the Invention

[0034] As described above, according to the technology disclosed herein, even if the transmission is arranged so that a portion thereof intrudes into the floor tunnel, damage to the battery unit during a frontal collision of the vehicle can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram showing a drive system of a vehicle having a lower structure according to an exemplary embodiment.

[0036] Figure 2 This is a bottom view of the vehicle's driver's seat and passenger seat area as viewed from below.

[0037] Figure 3 This is a view of the floor tunnel from the right side of the vehicle.

[0038] Figure 4 This is a plan view of the periphery of the vehicle rear side portion of the transmission as viewed from above.

[0039] Figure 5 This is a diagram of the left and right battery units as viewed from the front.

[0040] Figure 6 This is a diagram of the left battery cell viewed from the right.

[0041] Figure 7 It is a perspective view showing the front guard member and the inner guard member.

[0042] Figure 8 It is a perspective view showing the outer surface of the left inner guard member in the vehicle width direction.

[0043] Figure 9 is equivalent to Figure 4 The cross-sectional view taken along line IX-IX is a cross-sectional view including the section from the channel plate to the lower side sill on the left side.

[0044] Figure 10 is equivalent to Figure 4 The cross-sectional view taken along line XX is a cross-sectional view including the section from the channel plate to the lower side beam on the left side.

[0045] Figure 11 It is a perspective view showing the outer surface of the left inner guard member in the vehicle width direction.

[0046] Explanation of symbols

[0047] 1 vehicle

[0048] 2 engines

[0049] 4. Transmission (speed gear)

[0050] 4a Transfer case (transmission)

[0051] 9 rear drive shaft

[0052] 10 Floor Passage

[0053] 30 Floor

[0054] 33 Transmission support member (support component)

[0055] 40L, 40R left battery unit, right battery unit

[0056] 41aL, 41aR flange (protrusion)

[0057] 42aL, 42aR flange (protrusion)

[0058] 43L, 43R Left front, right front

[0059] 45L, 45R left inner face, right inner face

[0060] 60L, 60R left front guard, right front guard

[0061] 70L, 70R left inner guard, right inner guard

[0062] 71L, 71R left and right guards

[0063] 72L, 72R left and right body connection parts

[0064] 74L, 74R left longitudinal rib, right longitudinal rib

[0065] 75L, 75R left side transverse rib, right side transverse rib

[0066] 102 Bolt (shaft-shaped fastening part)

[0067] 104 Bolt (shaft-shaped fastening part) DETAILED DESCRIPTION

[0068] Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. In the following description, the front, rear, top, and bottom of the vehicle 1 will be referred to simply as front, rear, top, and bottom, respectively. Furthermore, left and right, when viewed from the rear, will be referred to simply as left and right, respectively.

[0069] Figure 1 A drive system of a vehicle 1 to which the lower structure of the present embodiment is applied is schematically shown. Figure 2 The bottom surface around the driver's seat and the passenger seat of the vehicle 1 is shown in detail. Figure 1 The configuration of the vehicle 1 is shown when viewed from below.

[0070] Vehicle 1 is a hybrid vehicle having an engine 2 and a motor 3 as drive sources, and a transmission 4 for changing the speed of the drive force transmitted from at least one of the engine 2 and motor 3. Engine 2 is positioned longitudinally in the approximate center of the vehicle width direction within an engine compartment located forward of the vehicle interior. Motor 3 is positioned rearward of engine 2 via a damper 5. Transmission 4 is positioned longitudinally behind motor 3.

[0071] The vehicle 1 is a vehicle that uses the left and right rear wheels 7 as drive wheels. More specifically, it is a four-wheel drive structure that uses both the left and right front wheels 6 and the left and right rear wheels 7 as drive wheels. The rear portion of the transmission 4 is a transfer case 4a for transmitting driving force to the front wheels 6 and the rear wheels 7. The front drive shaft 8 extends from the transfer case 4a toward the front side. The rear drive shaft 9 extends from the transfer case 4a toward the rear side. The front drive shaft 8 is arranged slightly to the right of the center in the vehicle width direction, and the rear drive shaft 9 is arranged approximately in the center in the vehicle width direction. Although details are omitted, the driving force after the speed change by the transmission 4 is transmitted to the front drive shaft 8 and the rear drive shaft 9 respectively through the transfer case 4a. In addition, the driving force is transmitted to the front wheels 6 and the rear wheels 7 via the front drive shaft 8 and the rear drive shaft 9.

[0072] like Figure 2 As shown, the transmission 4 is arranged to incline downward from the front to the rear while intruding into the floor tunnel 10. The transfer case 4a of the transmission 4 is arranged near the front and upper side of the battery units 40L and 40R described later.

[0073] The floor tunnel 10 is formed by a tunnel plate 11. Figure 3 As shown in FIG. 1 , the upper end portion of the tunnel plate 11 is inclined downward from the front side toward the rear side. Therefore, the floor tunnel 10 becomes narrower in the vertical direction toward the rear side.

[0074] A rear propeller shaft 9 is positioned within the floor tunnel 10. The rear propeller shaft 9 is connected to the transfer case 4a via a rubber cover 4b. The rear propeller shaft 9 extends from the rubber cover 4b toward the rear and then extends obliquely downward. A universal joint 9a is provided at the center of the rear propeller shaft 9 in the front-to-back direction. This universal joint 9a allows the rear propeller shaft 9 to rotate vertically and horizontally during a frontal collision.

[0075] A rubber cover 9b is provided in front of a universal joint 9a in the rear propeller shaft 9. A support bracket 9c is provided in place of the rubber cover 9b to support the rear propeller shaft 9. The support bracket 9c is U-shaped, covering the rubber cover 9b from below, and its left and right ends are connected to an upper tunnel reinforcement 12 provided on the tunnel plate 11 for reinforcement by bolts.

[0076] Side channel reinforcements 13 extending in the front-to-rear direction are provided at the left and right ends of the channel plate 11. Each side channel reinforcement 13 is used to reinforce the channel plate 11. Each side channel reinforcement 13 is connected to the inner portion of the channel plate 11 by welding, forming a closed cross-section between each side channel reinforcement 13 and the channel plate 11.

[0077] A pair of left and right floor panels 30 constituting the vehicle interior floor are provided on the left and right sides of the tunnel panel 11. The floor panels 30 extend horizontally in the front-rear direction and the vehicle width direction (left-right direction). Figure 9 and Figure 10 As shown, the right side end of the left floor panel 30 is welded to the left side end of the tunnel panel 11. The left side end of the right floor panel 30 is also welded to the right side end of the tunnel panel 11. The left and right floor panels 30 are connected side by side via the tunnel panel 11. The connection portions between each floor panel 30 and the tunnel panel 11 and the connection portion between the tunnel panel 11 and the side tunnel reinforcement 13 are located at the same location or are located outward in the vehicle width direction relative to these connection portions.

[0078] The left and right running boards 32 are welded to the front ends of the left and right floor panels 30, respectively. The left and right running boards 32 extend upward and tilted from the front ends of the left and right floor panels 30 toward the front. The upper ends of the left and right running boards 32 are joined to the lower end of the dash panel (not shown) that divides the vehicle interior from the engine compartment. The right end of the left running board 32 is welded to the left end of the tunnel panel 11. The left end of the right running board 32 is also welded to the right end of the tunnel panel 11.

[0079] A pair of left and right floor frames 21 extending in the front-rear direction are connected to the lower surfaces of the left and right floor panels 30 and the lower surfaces of the left and right footboards 32. The left and right floor frames 21 extend in a manner that is separated from each other in the vehicle width direction, tilt outward in the vehicle width direction, and then extend straight in parallel to the rear side. Figure 9 and Figure 10 As shown, each floor frame 21 has a U-shaped cross-section with an open top. The floor frames 21 are connected to the lower surfaces of the left and right floor panels 30 and the lower surfaces of the left and right footboards 32 by welding, so as to form a closed cross-section between the floor frames 21, the floor panels 30, and the footboards 32.

[0080] A pair of left and right side rails 22 extending in the front-rear direction are connected to the ends of the left and right floors 30 on the outside in the vehicle width direction. The left and right side rails 22 are located on the outside in the vehicle width direction relative to the left and right floor frames 21. Figure 9 and Figure 10 As shown, the left rocker 22 is connected to the left end portion of the left floor panel 30 by welding. The right rocker 22 is connected to the right end portion of the right floor panel 30 by welding.

[0081] like Figure 2 As shown, the front ends of the left and right floor frames 21 and the front ends of the left and right rocker sills 22 are connected to each other on the left and right sides, respectively, by left and right corner braces 23 .

[0082] like Figure 1 and Figure 2As shown, battery cells 40L and 40R, which store power for driving motor 3, are positioned on the left and right sides of the floor tunnel, respectively, in an area further rearward than transfer case 4a. Left battery cell 40L is positioned below the passenger seat, while right battery cell 40R is positioned below the driver's seat. The left and right battery cells 40L and 40R are electrically connected via connectors. When viewed from above, the right end of left battery cell 40L and the left end of right battery cell 40R slightly overlap floor tunnel 10. Battery cells 40L and 40R will be described in detail later.

[0083] like Figure 2 As shown in FIG. 1 , a transmission support member 33 supporting the transfer case 4a (ie, the transmission 4) is provided slightly in front of the left and right battery units 40L and 40R. Figure 4 As shown, the transmission support member 33 is positioned adjacent to the left and right front portions 43L and 43R of the battery units 40L and 40R (hereinafter referred to as the left and right front portions 43L and 43R). When viewed from the front-to-back direction, the transmission support member 33 has a U-shape that extends upward and outward in the vehicle width direction. When viewed from the front-to-back direction, the transmission support member 33 is mounted to the vehicle body so as to straddle the floor tunnel 10.

[0084] The U-shaped portion of the transmission support member 33 is wide in the front-rear direction. The upper left and right ends of the transmission support member 33 serve as mounting portions 33a for mounting the transmission support member 33 on the vehicle body. Figure 4 As shown, the left and right mounting portions 33a protrude forward and rearward relative to the rest of the transmission support member 33. Each mounting portion 33a is provided with a plurality of holes 33b (here, three holes each, for a total of six holes) through which the bolts 101 pass.

[0085] like Figure 2 and Figure 4 As shown, an exhaust pipe 28 for exhaust gas from the engine 2 is arranged on the right side of the transmission support member 33. The exhaust pipe 28 extends from the engine 2 to the right side of the transmission 4 and the transmission support member 33 toward the floor tunnel 10, passes through the floor tunnel 10, and extends toward the rear side. The exhaust pipe 28 has an exhaust purification device 29 at a position on the right side of the transmission support member 33. The exhaust purification device 29 has a laterally long elliptical shape and has an exhaust purification catalyst inside. The exhaust pipe 28 is configured to penetrate into the floor tunnel 10 at the same height as the front surface 43R of the right battery unit 40R (more specifically, the right front guard component 60R described later) and the transmission support member 33, passing between the front surface 43R of the right battery unit 40R and the transmission support member 33.

[0086] Next, the peripheral structures of the left battery unit 40L and the right battery unit 40R will be described in detail.

[0087] First, the peripheral structure of the left battery unit 40L will be described. Figure 2 and Figure 5 As shown, the left battery unit 40L is box-shaped, roughly rectangular in plan view. The left battery unit 40L includes a left front portion 43L; a left outer side portion 44L extending forward and backward from the vehicle widthwise outer end of the left front portion 43L; a left inner side portion 45L extending forward and backward from the vehicle widthwise inner end of the left front portion 43L; a left upper side portion 46L extending horizontally from the upper end of the left front portion 43L toward the vehicle rear; a left lower portion 47L extending vertically from the lower end of the left front portion 43L and facing the left upper side portion 46L; and a left rear side portion 48L facing the left front portion 43L in the front and rear directions. The end edges of each of the side portions 43L-48L of the left battery unit 40L are integrally formed. The vehicle widthwise inner portion of the left front portion 43L is positioned rearward of the vehicle widthwise outer portion. This maximizes the size of the left battery unit 40L while creating space for the transmission support member 33.

[0088] like Figure 5 and Figure 6 As shown, the left battery unit 40L includes a first left side housing 41L and a second left side housing 42L, which are divided vertically. The first left side housing 41L includes a left upper portion 46L and is located relatively above. The second left side housing 42L includes a left lower portion 47L and is located relatively below. The first left side housing 41L has a flange 41aL extending along the edge at its lower end, and the second left side housing 42L has a flange 42aL extending along the edge at its upper end. The first left side housing 41L and the second left side housing 42L are connected by bolts, with their flanges abutting each other in the vertical direction. A sealing member is disposed at the abutting portion between the first left side housing 41L and the second left side housing 42L. Each flange 41aL and 42aL corresponds to a protrusion that protrudes inward from the left inner side surface 45L in the vehicle width direction.

[0089] The left battery unit 40L is supported on the vehicle body via multiple brackets. Specifically, a first left bracket 51L and a second left bracket 52L are attached to the left outer side 44L of the left battery unit 40L. Furthermore, a third left bracket 53L is attached to the left inner side 45L of the left battery unit 40L.

[0090] The first left side bracket 51L is mounted at the middle position in the front-rear direction of the left side outer surface portion 44L, and the second left side bracket 52L is mounted at the rear end position of the left side outer surface portion 44L. Figure 5 As shown, the lower portion of the first left bracket 51L is mounted to the second left housing 42L by bolts. Although not shown, the lower portion of the second left bracket 52L is mounted to the second left housing 42L by bolts. The upper ends of the first left bracket 51L and the second left bracket 52L are fixed to the lower surface of the left floor frame 21 (at Figure 9 , only the connection portion between the first left bracket 51L and the left floor frame 21 is shown).

[0091] The third left bracket 53L is installed at the middle position of the left inner side surface 45L in the front-back direction. Figure 6 As shown, the lower portion of the third left bracket 53L is mounted to the flange 41aL of the first left housing 41L and the flange 42aL of the second left housing 42L from the upper side by bolts. The upper end portion of the third left bracket 53L is fixed to the upper channel reinforcement 12 by bolts. Figure 3 , a connection portion between a third right bracket 53R and the upper tunnel reinforcement 12 described later is shown, and a connection portion between the third left bracket 53L and the upper tunnel reinforcement 12 overlaps with the upper tunnel reinforcement 12 and cannot be seen.

[0092] like Figures 2 to 6 As shown, a left inner guard member 70L is attached to the front portion of the left inner side portion 45L, covering the left inner side portion 45L from the vehicle widthwise inner side. The left inner guard member 70L is used to prevent the transfer case 4a from contacting the left inner side portion 45L of the left battery unit 40L when the transmission 4 and transfer case 4a enter the floor tunnel 10 during a frontal collision. Furthermore, the left inner guard member 70L is used to prevent the transfer case 4a from being caught on the flange portion of the first left case 41L, causing the collision load to be applied downward to the left battery unit 40L and thereby causing the left battery unit 40L to separate from the vehicle body. The left inner guard member 70L is made of, for example, cast iron.

[0093] The left inner guard member 70L includes a left guard portion 71L that substantially covers the left inner side surface 45L, and a left vehicle body connecting portion 72L that is connected to a vehicle body component. The left vehicle body connecting portion 72L is provided at the upper end of the left guard portion 71L.

[0094] The left side shield portion 71L covers a portion of the first left side housing 41L of the left inner side surface 45L. Figures 6 to 8As shown, the width of the left side guard portion 71L in the front-to-back direction gradually narrows toward the upper side. Specifically, the front end of the left side guard portion 71L tilts rearward toward the left side vehicle body connecting portion 72L. The rear end of the left side guard portion 71L extends straight upward, bends toward the front, and then extends obliquely toward the left side vehicle body connecting portion 72L. Therefore, the left side vehicle body connecting portion 72L has a smaller width in the vehicle front-to-back direction than the left side guard portion 71L.

[0095] like Figure 9 and Figure 10 As shown, the vehicle width direction inner surface (ie, the right side surface) of the left guard portion 71L is located at substantially the same position as the vehicle width direction inner ends of the upper and lower flanges 41aL and 42aL.

[0096] like Figure 7 and Figure 8 As shown, two left mounting portions 73L are provided on the outer surface of the left side guard portion 71L in the vehicle width direction (i.e., the left side surface). These two left mounting portions 73L are used to mount the left inner guard component 70L to the left battery unit 40L. The left mounting portions 73L are respectively provided at the front and lower end portion and the rear and lower end portion of the left side guard portion 71L. The bolt 102 (axial fastening component) is inserted into each left mounting portion 73L in a manner extending in the vertical direction. As shown Figure 9 As shown, the bolts 102 are fastened to the upper and lower flanges 41aL and 42aL (in the vertical direction) while being maintained in an extended position. Figure 9 (Only the left mounting portion 73L on the rear side is shown in the figure). Thus, the left inner shield member 70L is fixed to the upper and lower flanges 41aL and 42aL of the left battery unit 40L.

[0097] A plurality of reinforcing ribs are provided on the outer surface of the left side guard portion 71L in the vehicle width direction (i.e., the left side surface). The reinforcing ribs include a plurality of (five in this case) left side longitudinal ribs 74L extending in the up-down direction and a left side transverse rib 75L extending in the front-back direction. The width of each left side longitudinal rib 74L increases as it approaches the left side transverse rib 75L. The left side longitudinal rib 74L located at the frontmost side among the plurality of left side longitudinal ribs 74L is integrated with the left side mounting portion 73L on the front side. The left side longitudinal rib 74L located at the rearmost side among the plurality of left side longitudinal ribs 74L is integrated with the left side mounting portion 73L on the rear side.

[0098] The left transverse rib 75L extends straightly from the position of the left longitudinal rib 74L located at the rearmost side through the middle portion of the left longitudinal rib 74L in the vertical direction toward the front side, and then becomes one with the upper end of the left longitudinal rib 74L located at the frontmost side along the front end of the left guard portion 71L. The left transverse rib 75L becomes one with each left longitudinal rib 74L. Figure 10As shown, the left side transverse rib 75L is located at the same height as the tunnel plate 11. The left side transverse rib 75L protrudes outward in the vehicle width direction compared to the left side longitudinal rib 74L, and its top end is located near the tunnel plate 11.

[0099] like Figure 7 and Figure 8 As shown, the left body connection portion 72L extends upward from the upper end portion of the left guard portion 71L and then bends approximately at a right angle toward the inner side in the vehicle width direction. The left body connection portion 72L is fixed to the upper tunnel reinforcement 12 by bolts 103. Figure 10 As shown, the bolts 103 are fastened to the weld nuts provided on the upper tunnel reinforcement 12 in a posture extending in the vertical direction.

[0100] Each left mounting portion 73L is mounted on the left battery unit 40L, and the left vehicle body connection portion 72L is connected to the upper tunnel reinforcement 12. Thus, the left battery unit 40L is supported on the vehicle body via the left inner guard member 70L. In other words, the left inner guard member 70L also functions as a bracket. Figure 3 The figure shows a connection portion between a right inner guard component 70R and the upper tunnel reinforcement 12 , which will be described later. A connection portion between a left inner guard component 70L and the upper tunnel reinforcement 12 overlaps with the upper tunnel reinforcement 12 and cannot be seen.

[0101] like Figures 4 to 7 As shown, a left front guard member 60L is provided on the left front portion 43L of the left battery unit 40L to cover the inner portion of the left front portion 43L in the vehicle width direction from the front side. The left front guard member 60L is a member that prevents the left battery unit 40L from directly colliding with the transmission support member 33 when the transmission support member 33 moves backward during a frontal collision.

[0102] The vehicle widthwise inner end of the left front guard member 60L is located inward of the front end of the left inner guard member 70L in the vehicle width direction. Thus, when viewed from the front, a portion of the front end of the left inner guard member 70L is covered by the vehicle widthwise inner end of the left front guard member 60L. Furthermore, the vehicle widthwise inner end of the left front guard member 60L is inclined rearward toward the vehicle widthwise inner end. In other words, the left front guard member 60L also covers the front end of the left inner guard member 70L in the vehicle width direction.

[0103] The left front guard member 60L is attached to the left battery unit 40L via two left front attachment portions 61L and 62L.

[0104] Next, the peripheral structure of the right battery cell 40R will be described. While the detailed shape of the peripheral structure of the right battery cell 40R differs from that of the left battery cell 40L, the basic structure is bilaterally symmetrical with the left battery cell 40L. Therefore, regarding the peripheral structure of the right battery cell 40R, only the parts that differ from the peripheral structure of the left battery cell 40Ls will be described in detail, and the detailed description of the parts that are common with the peripheral structure of the left battery cell 40L will be omitted as appropriate.

[0105] like Figure 2 and Figure 5 As shown, the right battery unit 40R is box-shaped and generally rectangular in plan view. The right battery unit 40R includes a right front portion 43R; a right outer side portion 44R extending forward and backward from the vehicle widthwise outer end of the right front portion 43R; a right inner side portion 45R extending forward and backward from the vehicle widthwise inner end of the right front portion 43R; a right upper side portion 46R extending horizontally from the upper end of the right front portion 43R toward the vehicle rear; a right lower portion 47R extending vertically from the lower end of the right front portion 43R and facing the right upper side portion 46R; and a right rear side portion 48R facing the right front portion 43R in the front and rear directions. The end edges of each of the side portions 43R to 48R of the right battery unit 40R are integral with each other. The vehicle widthwise inner portion of the right front portion 43R is located rearward of the vehicle widthwise outer portion.

[0106] like Figure 5 、 Figure 9 as well as Figure 10 As shown, the right battery unit 40R includes a first right case 41R and a second right case 42R, which are divided vertically. The first right case 41R has a flange 41aR extending along the edge at its lower end, and the second right case 42R has a flange 42aR extending along the edge at its upper end. The first and second right cases 41R, 42R are connected by bolts, with their flanges abutting each other vertically. A sealing member is disposed at the abutting portion between the first and second right cases 41R, 42R. Each flange 41aR, 42aR corresponds to a protrusion that projects inward in the vehicle width direction from the right inner side surface 45R.

[0107] The right battery unit 40R is supported on the vehicle body via multiple brackets. Specifically, a first right bracket 51R and a second right bracket 52R are attached to the right outer side surface 44R of the right battery unit 40R. Furthermore, a third right bracket 53R is attached to the right inner side surface 45R of the right battery unit 40R. The structures of the first through third right brackets 51R, 53R are bilaterally symmetrical with the first through third left brackets 51L, 53L, so detailed descriptions are omitted.

[0108] like Figure 4 and Figure 5 As shown, a right inner guard member 70R is attached to the front portion of the right inner side portion 45R, covering the right inner side portion 45R from the vehicle widthwise inner side. The right inner guard member 70R functions similarly to the left inner guard member 70L for the left battery unit 40L, and therefore a detailed description thereof will be omitted. The right inner guard member 70R is made of, for example, cast iron.

[0109] The right inner guard member 70R includes a right guard portion 71R that substantially covers the right inner side surface 45R and a right vehicle body connecting portion 72R that is connected to a vehicle body component. The right vehicle body connecting portion 72R is provided at the upper end portion of the right guard portion 71R.

[0110] The right side shield portion 71R covers a portion of the first right side housing 41R of the right inner side surface portion 45L. Figure 7 As shown, the right side guard 71R has a front-to-rear symmetric shape and extends straight from the bottom to the top, with its width gradually narrowing toward the right vehicle body connecting portion 72R. The right vehicle body connecting portion 72R has a smaller width in the vehicle front-to-rear direction than the right side guard 71R.

[0111] like Figure 9 and Figure 10 As shown, the vehicle width direction inner surface (ie, the left side surface) of the right guard portion 71R is located at substantially the same position as the vehicle width direction inner ends of the upper and lower flanges 41aR and 42aR.

[0112] like Figure 4 、 Figure 7 as well as Figure 8 As shown, two right side mounting portions 73R for mounting the right inner guard member 70R to the right battery unit 40R are provided on the outer side of the right side guard member 71R in the vehicle width direction (i.e., the right side surface). The right side mounting portions 73R are provided at the front and lower end and the rear and lower end of the right side guard member 71R, respectively. A bolt 104 (axial fastening member) is inserted into each right side mounting portion 73R in a manner extending in the vertical direction. Figure 9 As shown, the bolts 104 are fastened to the upper and lower flanges 41aR and 42aR (in the vertical direction) while maintaining the posture of extending in the vertical direction. Figure 9 (Only the rear right mounting portion 73R is shown in the figure). Thus, the right inner shield member 70R is fixed to the upper and lower flanges 41aR and 42aR of the right battery unit 40R.

[0113] like Figure 11As shown, a plurality of reinforcing ribs are provided on the outer surface of the right side guard portion 71R in the vehicle width direction (i.e., the left side surface). The reinforcing ribs include a plurality of (five in this case) right side longitudinal ribs 74R extending in the up-down direction and a right side transverse rib 75R extending in the front-back direction. The width of each right side longitudinal rib 74R increases as it approaches the right side transverse rib 75R. The right side longitudinal rib 74R located at the frontmost side among the plurality of right side longitudinal ribs 74R is integrated with the right side mounting portion 73R on the front side. The right side longitudinal rib 74R located at the rearmost side among the plurality of right side longitudinal ribs 74R is integrated with the right side mounting portion 73R on the rear side.

[0114] The right transverse rib 75R extends straight from the upper end of the right longitudinal rib 74R located at the rearmost side through the middle portion of the right longitudinal rib 74R in the vertical direction toward the front side, and then becomes one with the upper end of the right longitudinal rib 74R located at the frontmost side. The right transverse rib 75R becomes one with each right longitudinal rib 74R. Figure 10 As shown, the right side transverse rib 75R is located at the same height as the tunnel plate 11. The right side transverse rib 75R protrudes outward in the vehicle width direction compared to the right side longitudinal rib 74R, and its top end is located near the tunnel plate 11.

[0115] like Figure 7 As shown, the right vehicle body connecting portion 72R extends upward from the upper end portion of the right side guard portion 71R and then bends and extends substantially at a right angle toward the inner side in the vehicle width direction. The right vehicle body connecting portion 72R is fixed to the upper tunnel reinforcement 12 by bolts 105. Figure 10 As shown, the bolts 105 are fastened to the weld nuts provided on the upper tunnel reinforcement 12 in a posture extending in the vertical direction.

[0116] Each right mounting portion 73R is mounted on the right battery unit 40R, and the right vehicle body connecting portion 72R is connected to the upper tunnel reinforcement 12. Thus, the right battery unit 40R is supported on the vehicle body via the right inner guard member 70R. In other words, the right inner guard member 70R also functions as a bracket.

[0117] like Figure 4 、 Figure 5 as well as Figure 7 As shown, a right front guard member 60R is provided on the right front portion 43R of the right battery unit 40R to cover the inner portion of the right front portion 43R in the vehicle width direction from the front side. The right front guard member 60R is a member that prevents the right battery unit 40R from directly colliding with the transmission support member 33 when the transmission support member 33 moves backward during a frontal collision.

[0118] The vehicle widthwise inner end of the right front guard member 60R is located inward of the front end of the right inner guard member 70R in the vehicle width direction. Thus, when viewed from the front, a portion of the front end of the right inner guard member 70R is covered by the vehicle widthwise inner end of the right front guard member 60R. Furthermore, the vehicle widthwise inner end of the right front guard member 60R is inclined rearward toward the vehicle widthwise inner end. In other words, the right front guard member 60R also covers the front end of the right inner guard member 70R in the vehicle width direction.

[0119] The right front guard member 60R is attached to the right battery unit 40R via two right front attachment portions 61R and 62R.

[0120] Here, in the case where the transfer case 4a of the transmission 4 is configured to intrude into the floor tunnel 10 as in the present embodiment, in the event of a frontal collision, the transfer case 4a will move backward while entering the floor tunnel 10. In addition, since the universal joint 9a is provided on the rear propeller shaft 9, the rear propeller shaft 9 may rotate in the left-right direction (vehicle width direction) in the event of a frontal collision. When the rear propeller shaft 9 rotates in the left-right direction, the transfer case 4a moves backward diagonally to the left or right. Therefore, the transfer case 4a may come into contact with the left battery unit 40L or the right battery unit 40R. In particular, since the transfer case 4a is configured to be close to the front and upper portion of the left battery unit 40L or the right battery unit 40R and is tilted downward toward the rear, in the event of a frontal collision, it may move backward while rubbing against the left inner side surface 45L or the right inner side surface 45R diagonally downward.

[0121] In contrast, in this embodiment, the left and right inner side surfaces 45L and 45R are provided with a left guard member 70L and a right inner side surface 70R, thereby preventing the transfer case 4a from contacting the left and right inner side surfaces 45L and 45R during a frontal collision. Consequently, damage to the left and right battery units 40L and 40R can be prevented during a frontal collision.

[0122] Furthermore, in this embodiment, the left and right inner side surfaces 45L and 45R are provided with flanges 41aL, 42aL, 41aR, and 42aR that protrude inward in the vehicle width direction. Therefore, in the event of a frontal collision, the transfer case 4a could become caught on these flanges 41aL, 42aL, 41aR, and 42aR, causing the left and right inner side surfaces 45L and 45R to fall off. However, in this embodiment, the vehicle width inward surfaces of the guard portions 71L and 71R of the left and right inner guard members 70L and 70R are located at substantially the same positions in the vehicle width direction as the vehicle width inward ends of the flanges 41aL, 42aL, 41aR, and 42aR. This effectively prevents the transfer case 4a from becoming caught on these flanges 41aL, 42aL, 41aR, and 42aR.

[0123] Furthermore, in this embodiment, the left and right inner guard members 70L and 70R have reinforcing ribs comprising a plurality of left and right longitudinal ribs 74L and 74R extending in the vertical direction, as well as left and right transverse ribs 75L and 75R extending in the front-to-back direction. This prevents damage to the left and right inner guard members 70L and 70R, even when the collision load is input from the transfer case 4a during a frontal collision. Consequently, damage to the left and right battery units 40L and 40R can be more effectively prevented.

[0124] Furthermore, in this embodiment, the left and right transverse ribs 75L and 75R are located at the same height as the channel plate 11. Specifically, when the transfer case 4a tilts backward and abuts the left inner guard component 70L or the right inner guard component 70R, a collision load in the vehicle width direction (left-right direction) is input to the abutted inner guard component. When the inner guard component is deformed by this collision load, the collision load is borne by the vehicle body through the left and right transverse ribs 75L and 75R abutting the channel plate 11. This suppresses deformation of the left and right battery cells 40L and 40R. Consequently, damage to the left and right battery cells 40L and 40R can be more effectively suppressed.

[0125] Furthermore, in this embodiment, the left inner guard member 70L is secured to the upper and lower flanges 41aL and 42aL of the left inner side portion 45L by bolts 102, and the right inner guard member 70R is secured to the upper and lower flanges 41aR and 42aR of the right inner side portion 45R by bolts 104. Bolts 102 and 104 are tightened so as to extend vertically. Consequently, even if the left inner guard member 70L or the right inner guard member 70R abuts the transfer case 4a during a frontal collision, and a collision load is applied to the left inner guard member 70L or the right inner guard member 70R, the collision load can be absorbed by the bolts 102 or 104. As a result, the left inner guard member 70L and the right inner guard member 70R are prevented from peeling off from the left inner side portion 45L and the right inner side portion 45R, respectively, during a frontal collision. Consequently, damage to the left battery unit 40L and the right battery unit 40R can be more effectively suppressed.

[0126] Furthermore, in this embodiment, a left front guard member 60L and a right front guard member 60R are attached to the left battery unit 40L and the right battery unit 40R, respectively, to cover the front ends of the left inner guard member 70L and the right inner guard member 70R from the vehicle front. This prevents the transfer case 4a from becoming caught on the front ends of the left inner guard member 70L or the right inner guard member 70R, thereby preventing the left inner guard member 70L or the right inner guard member 70R from being separated from the left battery unit 40L or the right battery unit 40R, respectively. As a result, damage to the left battery unit 40L and the right battery unit 40R can be more effectively suppressed.

[0127] Furthermore, in this embodiment, the left and right inner guard members 70L and 70R are connected to the vehicle body component (the upper tunnel reinforcement 12) via the left and right vehicle body connecting portions 72L and 72R. This allows the vehicle body to absorb the impact load applied when the transfer case 4a contacts the left and right inner guard members 70L and 70R. Consequently, damage to the left and right battery units 40L and 40R can be minimized.

[0128] Furthermore, in this embodiment, the left and right vehicle body connecting portions 72L and 72R have smaller widths in the front-to-rear direction than the left and right guard portions 71L and 71R. This prevents damage to the left and right battery units 40L and 40R, while also reducing the weight of the vehicle 1.

[0129] (Other embodiments)

[0130] The technology disclosed here is not limited to the above-described embodiment, and can be replaced within the scope of the gist of the invention.

[0131] For example, in the above embodiment, vehicle 1 is a four-wheel drive vehicle. This is not limiting and vehicle 1 may also be a four-wheel drive vehicle, for example. In the case of a four-wheel drive vehicle 1, the transfer case 4a and the front propeller shaft 8 are omitted. Alternatively, vehicle 1 may be an electric vehicle that does not include the engine 2 but only includes the motor 3 as a driving source.

[0132] In the above embodiment, the left and right inner guard members 70L and 70R include the left and right vehicle body connecting portions 72L and 72R, respectively, and also function as brackets. However, the present invention is not limited thereto and the left and right vehicle body connecting portions 72L and 72R may be omitted.

[0133] The above embodiments are merely examples and should not be construed as limiting the scope of the present invention. The scope of the present invention is defined by the scope of the invention to be protected, and modifications and variations within the scope of the invention to be protected are all included in the scope of the present invention.

[0134] Industrial Application Possibilities

[0135] The technology disclosed herein is useful as an understructure of a vehicle having rear wheels as drive wheels.

Claims

1. A lower structure of a vehicle having rear wheels as driving wheels, characterized in that: have: a transmission arranged such that at least a portion of the transmission on the rear side of the vehicle intrudes into a floor tunnel formed by the tunnel panel; a propeller shaft extending from the transmission toward the rear side of the vehicle and transmitting power from the transmission to the rear wheels; and Left and right battery units are arranged on the lower side of the floor on the left and right sides of the vehicle of the floor tunnel, The portion of the transmission on the rear side of the vehicle is arranged close to the portion on the front side and above the battery cells of the vehicle. Each of the battery cells has an inner side surface portion extending in the vehicle front-rear direction along both side ends of the floor tunnel in the vehicle width direction. An inner protection member is mounted on each of the battery cells, and covers the front end of the inner side surface from the inner side in the vehicle width direction. During a frontal collision, the inner guard member prevents the portion of the transmission on the vehicle rear side from contacting the inner side surface. Each of the battery cells is supported on the vehicle body via a plurality of brackets. Each of the inner protective components has: a guard portion that substantially covers the inner face; and a vehicle body connecting portion connected to a vehicle body component; The vehicle body connecting portion of each inner guard member has a smaller width in the vehicle front-rear direction than the guard portion. Side channel reinforcements extending in the front-rear direction are respectively provided at the left and right ends of the channel plate. The inner side surface of each battery unit is mounted to an upper tunnel reinforcement provided on the tunnel plate on the inner side of the side tunnel reinforcement in the vehicle width direction via the vehicle body connection portion of the inner protection member. Reinforcement ribs are formed on the outer surface of each inner guard member in the vehicle width direction. The reinforcing ribs include transverse ribs extending in the front-rear direction of the vehicle. At least a portion of the transverse rib is located at the same height as the channel plate.

2. The vehicle lower structure according to claim 1, wherein: The reinforcement ribs include a plurality of longitudinal ribs extending in the up-down direction.

3. The vehicle lower structure according to claim 1, wherein: The inner side surface of each battery cell has a protrusion protruding toward the inner side in the vehicle width direction. Each of the inner guard members is disposed in an area above the protruding portion of each of the inner side surfaces and is fixed to each of the protruding portions via a shaft-shaped fastening member. The shaft-shaped fastening members are fastened so as to extend in the vertical direction.

4. The vehicle lower structure according to claim 3, wherein: The inner surface of each inner guard member in the vehicle width direction is located at substantially the same position as the inner end portion of each protrusion in the vehicle width direction.

5. The vehicle lower structure according to claim 1, wherein: A front guard member is attached to each of the battery units so as to cover a front end portion of each of the inner guard members from the front side of the vehicle.

6. The lower structure of a vehicle according to any one of claims 1 to 5, characterized in that: The portion of the transmission on the rear side of the vehicle constitutes a transfer case.

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