Vehicle underbody structure

Abstract

The present disclosure relates to a vehicle underbody structure. The vehicle underbody structure includes a floor panel; a bracket fixed to the floor panel; and a component mounted on the lower side of the floor panel to be fastened to the bracket by a fastener. The floor panel has a raised portion. The bracket is arranged to cover the raised portion from the lower side. The fastener includes a bolt and a nut. The bolt has a head located on the lower side of the bracket and a shaft extending upward from the head and inserted into a hole formed in the bracket. The distal end of the shaft is located in the internal space of the raised portion.

Description

Technical Field

[0001] The present invention relates to a vehicle underbody structure in which components such as a battery are mounted on the lower side of a floor panel. Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2013 - 067334 (JP 2013 - 067334 A) describes a technique for mounting a battery on the lower side of a floor panel by fastening the battery to a bracket protruding downward from the floor panel using fasteners.

[0003] However, the technique of JP 2013 - 067334 A has the following inconveniences. Since the bracket protrudes downward from the floor panel, when removing the currently mounted battery on the lower side of the floor panel and newly mounting a battery having a different shape from the removed battery or a larger battery than the removed battery on the lower side of the floor panel, the bracket may interfere with the new battery, or the bracket may impair the installation of the new battery. It is also conceivable that the new battery is mounted on the lower side of the bracket protruding downward from the floor panel. In this case, the ground height of the new battery is reduced, and as a result, the new battery is more likely to interfere with the road surface. Summary of the Invention

[0004] The present invention provides a vehicle underbody structure capable of suppressing damage caused by a bracket to the installation of a new component on the lower side of a floor panel.

[0005] The solution of the present invention relates to a vehicle underbody structure. The vehicle underbody structure includes a floor panel; a bracket fixed to the floor panel; and a component mounted on the lower side of the floor panel so as to be fastened to the bracket by a fastener. The floor panel has a raised portion that bulges upward such that the internal space opens downward. The bracket has a flat plate shape and is arranged to cover the raised portion from the lower side. The fastener includes a bolt and a nut located on the upper side of the bracket, at least a part of the nut being located in the internal space of the raised portion, and the bolt being threadedly fixed to the nut. The bolt has a head located on the lower side of the bracket and a shaft that extends upward from the head and is inserted into a hole formed in the bracket. The distal end of the shaft is located in the internal space of the raised portion.

[0006] Using the above vehicle underbody structure, the floor panel has a raised portion that bulges upward, such that the interior space is open downward, and the bracket has a flat plate shape and is arranged to cover the raised portion from below. Accordingly, compared with the case where the bracket is arranged to protrude downward from the floor panel, the protrusion of the bracket downward from the floor panel can be reduced. Therefore, when removing a currently installed component such as a battery from the bracket and newly installing a component having a different shape from the removed component or a larger component than the removed component on the lower side of the floor panel, interference between the new component and the bracket can be reduced. Therefore, damage caused to the installation of the new component due to the bracket can be suppressed.

[0007] At least a part of the nut is located in the interior space of the raised portion, and a distal end of the shaft of the bolt is located in the interior space of the raised portion, so that the nut and the shaft of the bolt can be received in the interior space of the raised portion. Accordingly, even when the bracket has a flat plate shape, damage caused to the fastening of the fastener due to the floor panel can be suppressed.

[0008] In the vehicle underbody structure of the above solution, a lateral member can be joined to the top surface of the floor panel. The lateral member can have a top wall, a pair of side walls, and flanges provided at lower ends of the respective side walls. The raised portion of the floor panel can bulge in a direction approaching the top wall between the two side walls of the lateral member.

[0009] Using the above vehicle underbody structure, since the raised portion of the floor panel bulges in a direction approaching the top wall between the two side walls of the lateral member, the raised portion of the floor can be received in the interior space of the lateral member. Accordingly, the raised portion of the floor panel does not appear in the passenger compartment of the vehicle, thus ensuring a wide foot space in the passenger compartment.

[0010] In the vehicle underbody structure of the above solution, the bracket can be joined to the floor panel together with the flange of the lateral member.

[0011] Using the above vehicle underbody structure, since the bracket is joined to the floor panel together with the flange of the lateral member, the connection stiffness between the bracket and the floor is increased.

[0012] The vehicle underbody structure of the above solution can further include a reinforcing patch provided on the top surface of the bracket to suppress deformation of the bracket.

[0013] Using the above vehicle underbody structure, since the reinforcing patch is provided on the top surface of the bracket, deformation of the bracket in the vertical direction is reduced even when the bracket has a flat plate shape.

[0014] In the vehicle underbody structure of the above-described solution, the reinforcing patch may have upright portions extending upward on both sides of the fastener.

[0015] With the above vehicle underbody structure, since the reinforcing patch includes upright portions extending upward on both sides of the fastener, the stiffness of the reinforcing patch is increased compared to the case where the reinforcing patch does not include upright portions, and the deformation of the bracket in the vertical direction is effectively reduced through the reinforcing patch. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Hereinafter, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described with reference to the drawings, in which the same reference numerals denote the same elements, and in which:

[0017] Figure 1 is a sectional view of a vehicle underbody structure according to an embodiment of the present invention;

[0018] Figure 2 is a schematic partial plan view of a vehicle underbody structure according to an embodiment of the present invention;

[0019] Figure 3 is a perspective view of a bracket and its vicinity in a vehicle underbody structure according to an embodiment of the present invention when viewed from the lower side of the vehicle; and

[0020] Figure 4 is a sectional view of a vehicle underbody structure in a comparative example different from the embodiment of the present invention. DETAILED DESCRIPTION

[0021] Hereinafter, a vehicle underbody structure 10 according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, "UP" indicates the upper side of the vehicle, "FR" indicates the front side of the vehicle, and "W" indicates the width direction of the vehicle.

[0022] As Figure 1 and Figure 3 shown, the vehicle underbody structure 10 according to an embodiment of the present invention is a structure in which a component 100 is mounted on the lower side of a floor panel 20 so as to be fastened to a bracket 30 fixed to the floor panel 20 of the vehicle through a fastener 40. The component 100 is not limited, and for example, is a battery.

[0023] As Figure 2 shown, the floor panel 20 is a panel constituting the floor at the lower part of the vehicle. The floor panel 20 is, for example, a front floor panel, which is provided so as to extend from the lower end of a front bulkhead (not shown) toward the rear side of the vehicle. Although not shown in the drawings, the floor panel 20 is not limited to the front floor panel and may be a rear floor panel or the like.

[0024] The floor panel 20 may be composed of a single part or may be composed of multiple parts. When the floor panel 20 is composed of multiple parts, all these parts are joined to form a single floor panel 20. An inner sill panel 21, a central reinforcement 22, an outer reinforcement 23, and a transverse member 24 are provided on the floor panel 20.

[0025] The inner sill panel 21 is provided at both ends in the vehicle width direction of the floor panel 20 and extends in the vehicle front-rear direction respectively. Each inner sill panel 21 is provided to be continuous throughout the range in the vehicle front-rear direction of the floor panel 20. Each inner sill panel 21 is joined to an outer sill panel (not shown) provided outside the inner sill panel 21 in the vehicle width direction to form a sill having a closed cross-sectional shape.

[0026] The central reinforcement 22 is provided at the center in the vehicle width direction of the floor panel 20. The central reinforcement 22 is joined to the top surface 20a of the floor panel 20. The central reinforcement 22 is provided to extend from the front end in the vehicle front-rear direction of the floor panel 20 to the middle in the vehicle front-rear direction of the floor panel 20. The top surface 22a of the central reinforcement 22 is inclined rearward and downward of the vehicle.

[0027] The outer reinforcement 23 is provided to extend in the vehicle front-rear direction inside the inner sill panel 21 in the vehicle width direction and outside the central reinforcement 22 in the vehicle width direction. Each outer reinforcement 23 is provided to be continuous throughout the range in the vehicle front-rear direction of the floor panel 20. The outer reinforcement 23 is joined to the top surface 20a of the floor panel 20.

[0028] The transverse member 24 is provided to extend in the vehicle width direction between the left and right inner sill panels 21. Each transverse member 24 is provided to be continuous throughout the range in the vehicle width direction of the floor panel 20. The number of transverse members 24 provided on the floor panel 20 may be one or may be two or more. Figure 2 The case where two transverse members 24 are provided is shown. The two transverse members 24 include a front transverse member 25 and a rear transverse member 26. The front transverse member 25 is provided to extend in the vehicle width direction through the middle in the vehicle front-rear direction of the central reinforcement 22. The rear transverse member 26 is located on the vehicle rear side of the front transverse member 25 and is joined to the rear end portion 22b in the vehicle front-rear direction of the central reinforcement 22.

[0029] As Figure 1 shown, the transverse member 24 has a hat-shaped cross section and is open downward, and includes a top wall 24a, a pair of side walls 24b, and flanges 24c provided at the lower ends of the respective side walls 24b. The transverse member 24 is joined to the top surface 20a of the floor panel 20 at the flanges 24c.

[0030] The floor panel 20 has a raised portion 20c with a U-shaped cross-section. Each raised portion 20c protrudes upward such that the internal space S opens downward. Each raised portion 20c has, for example, a shape in which a part of the floor panel 20 bulges upward. The planar shape of the raised portion 20c is not limited and may be a rectangular shape (including a substantially rectangular shape with rounded corners), a polygonal shape other than a rectangular shape, a circular shape, or an elliptical shape, etc.

[0031] The raised portion 20c has no holes penetrating the floor panel 20. This is to prevent water or external air existing under the floor panel 20 from entering the upper side of the floor panel 20 through the holes.

[0032] The raised portion 20c is received in the internal space S1 of the lateral member 24 and is located at a position covered by the lateral member 24 from above. In other words, the raised portion 20c protrudes between the two side walls 24b of the lateral member 24 in a direction approaching the top wall 24a.

[0033] As Figure 2 shown, each raised portion 20c is provided at a position outside the central reinforcement 22 in the vehicle width direction and inside the outer reinforcement 23 in the vehicle width direction. The raised portion 20c may be provided only at a position covered by the front lateral member 25, may be provided only at a position covered by the rear lateral member 26, or may be provided at both a position covered by the front lateral member 25 and a position covered by the rear lateral member 26. The number of raised portions 20c provided at a position covered by the front lateral member 25 may be one or more than two. The number of raised portions 20c provided at a position covered by the rear lateral member 26 may be one or more than two.

[0034] As Figure 3 shown, a bracket 30 is provided to attach a component 100 such as a battery to the floor panel 20 (mount the component 100 on the lower side of the floor panel 20). The bracket 30 is composed of a single component and has a flat plate shape. The "flat plate shape" includes a substantially flat plate shape provided with ribs 31, ribs, etc. for enhancing rigidity. As Figure 1 shown, the bracket 30 is provided so as to cover (enclose) the entire raised portion 20c (the internal space S of the raised portion 20c) from the lower side. This is to suppress corrosion of the top surface 30a of the bracket 30 by preventing water from outside the vehicle from entering between the bracket 30 and the floor panel 20. In order to prevent water from entering between the bracket 30 and the floor panel 20, a sealant 32 for closing the gap between the edge 30c of the bracket 30 and the floor panel 20 may be continuously coated around the bracket 30.

[0035] The bracket 30 is joined to the lower surface 20b of the floor panel 20 at the peripheral portion around the convex portion 20c. The bracket 30 is joined to the floor panel 20 together with the flange 24c of the transverse member 24 by, for example, spot welding or laser spiral welding (LSW). Figure 1 The reference numeral W1 in the figure indicates the welding among the bracket 30, the floor panel 20, and the transverse member 24.

[0036] A reinforcing patch 33 may be provided on the top surface 30a of the bracket 30 to reduce the deformation of the bracket 30 in the up-and-down direction. However, the reinforcing patch 33 is not an essential component. The reinforcing patch 33 is a sheet-like component and is joined to the top surface 30a of the bracket 30 by spot welding or the like. Holes 30d and 33a are respectively provided in the bracket 30 and the reinforcing patch 33. The bolt 41 of the fastener 40 is inserted into the holes 30d and 33a. The reinforcing patch 33 has upright portions 33b extending upward on both sides of the fastener 40. The upright portions 33b extend upward in the inner space S of the convex portion 20c and terminate in the inner space S.

[0037] The fastener 40 includes a bolt 41 and a nut 42, and the bolt 41 is threadedly fixed to the nut 42.

[0038] The bolt 41 has a head 41a located on the lower side of the bracket 30 and a shaft 41b extending upward from the head 41a. A component bracket 101 provided on a component 100 (see Figure 3 ) is sandwiched between the head 41a and the bracket 30 together with a washer 43. The shaft 41b is inserted into holes 43a, 101a, 30d, and 33a respectively provided in the washer 43, the component bracket 101, the bracket 30, and the reinforcing patch 33, and is threadedly fixed to the nut 42. The distal end (upper end) 41b1 of the shaft 41b is located in the inner space S of the convex portion 20c.

[0039] The nut 42 is located on the upper side of the bracket 30 and the reinforcing patch 33, and at least a part of the nut 42 is located in the inner space S of the convex portion 20c. The nut 42 is joined to the top surface 33c except for the upright portion 33b of the reinforcing patch 33. The nut 42 is a welding nut. The nut 42 is joined to the reinforcing patch 33 by, for example, welding the protrusions (not shown) formed on the nut 42 by extrusion through projection welding or the like.

[0040] Next, the operations and beneficial effects of the embodiments of the present invention will be described.

[0041] When the vehicle is a plug - in hybrid vehicle (PHEV), a fuel tank and a battery can be installed on the lower side of the floor panel. Then, to upgrade (up - convert) the vehicle, it is necessary to remove the fuel tank and battery for the PHEV and newly install a battery for a battery - electric vehicle (BEV) different from the battery for the PHEV on the lower side of the floor panel.

[0042] Here, Figure 4 A comparative example different from the embodiments of the present invention is shown. Also in the comparative example, for ease of description, the same reference numerals denote components corresponding to the components of the embodiments of the present invention. The comparative example shows a case where the bracket 30 does not have a flat plate shape and is arranged to protrude downward from the floor panel 20.

[0043] In the comparative example, when removing the currently installed component 100 on the lower side of the floor panel 20 from the bracket 30 and newly installing a component (not shown) having a different shape from the removed component 100 or a component 200 larger than the removed component 100 on the lower side of the floor panel 20, the bracket 30 and the new component 200 may interfere with each other. As a result, the bracket 30 may damage the installation of the new component 200. Therefore, it may be difficult to upgrade the vehicle.

[0044] In contrast, in the embodiments of the present invention, as Figure 1 shown, the floor panel 20 includes a raised portion 20c that bulges upward so that the internal space S is open downward, and each bracket 30 has a flat plate shape and is arranged to cover the raised portion 20c from the lower side. Therefore, compared with the case where the bracket 30 is arranged to protrude downward from the floor panel 20, the protrusion of the bracket 30 downward from the floor panel 20 can be reduced.

[0045] Therefore, when removing the currently installed component 100 from the bracket 30 and newly installing a component (not shown) having a different shape from the removed component 100 or a component 200 larger than the removed component 100 on the lower side of the floor panel 20, the interference between the new component 200 and the bracket 30 can be reduced. Therefore, damage to the installation of the new component 200 caused by the bracket 30 can be suppressed. As a result, compared with the comparative example, the vehicle can be easily upgraded.

[0046] At least a part of the nut 42 is located in the internal space S of the raised portion 20c, and the distal end 41b1 of the shaft 41b of the bolt 41 is located in the internal space S of the raised portion 20c. Therefore, the nut 42 and the shaft 41b of the bolt 41 can be accommodated in the internal space S of the raised portion 20c. Therefore, even when the bracket 30 has a flat plate shape, damage to the fastening of the fastener 40 caused by the floor panel 20 can be suppressed.

[0047] Since the raised portion 20c of the floor panel 20 protrudes in a direction approaching the top wall 24a between the two side walls 24b of the transverse member 24, the raised portion 20c of the floor panel 20 can be received in the internal space S1 of the transverse member 24. Therefore, the raised portion 20c of the floor panel 20 does not appear in the passenger compartment of the vehicle, thus ensuring a wide foot space in the passenger compartment.

[0048] Since the bracket 30 is joined to the floor panel 20 together with the flange 24c of the transverse member 24, the stiffness of the joint between the bracket 30 and the floor panel 20 is increased.

[0049] Since the reinforcing patch 33 is provided on the top surface 30a of the bracket 30, even when the bracket 30 has a flat plate shape, the deformation of the bracket 30 in the vertical direction is reduced.

[0050] Since the reinforcing patch 33 includes the upright portions 33b extending upward on both sides of the fastener 40, the stiffness of the reinforcing patch 33 is increased compared to the case where the reinforcing patch 33 does not include the upright portions 33b, and the deformation of the bracket 30 in the vertical direction is effectively reduced by the reinforcing patch 33.

[0051] Since the raised portion 20c does not have a hole penetrating the floor panel 20, water and external air existing on the lower side of the floor panel 20 are prevented from entering the upper side of the floor panel 20 through the hole.

[0052] Since the bracket 30 is arranged to cover (seal) the entire raised portion 20c (the internal space S of the raised portion 20c) from the lower side, corrosion of the top surface 30a of the bracket 30 is suppressed by preventing water from outside the vehicle from entering between the bracket 30 and the floor panel 20.

Claims

1. A vehicle lower structure, characterized in that, Comprising: A floor panel; A bracket fixed to the floor panel; And A component mounted on the underside of the floor panel to be fastened to the bracket by a fastener, wherein The floor panel has a raised portion that bulges upward, such that the internal space is open downward; The bracket has a flat plate shape and is arranged to cover the raised portion from below; The fastener includes a bolt and a nut located on the upper side of the bracket, at least part of the nut being located in the internal space of the raised portion, and the bolt being threadedly fixed to the nut; and The bolt has a head located on the lower side of the bracket and a shaft extending upward from the head and inserted into a hole formed in the bracket, and the distal end of the shaft is located in the internal space of the raised portion, The vehicle underbody further includes a transverse member joined to the top surface of the floor panel, wherein The transverse member has a top wall, a pair of side walls, and flanges provided at the lower ends of the respective side walls; and The raised portion of the floor panel bulges in a direction approaching the top wall between the two side walls of the transverse member, The bracket is joined to the floor panel together with the flanges of the transverse member.

2. The vehicle lower structure according to claim 1, wherein, Further includes a reinforcing patch provided on the top surface of the bracket to inhibit deformation of the bracket.

3. The vehicle underbody structure according to claim 2, characterized in that, The reinforcing patch has upright portions extending upward on both sides of the fastener.

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