Protective structure for underfloor components

Abstract

To provide a protection structure for an underfloor component that has a getting on / off step and is able to protect underfloor components in the event of a side collision.SOLUTION: A protection structure for an underfloor component includes: an underfloor component 16 that is disposed under a vehicle floor and is a high-voltage component or a fuel tank; a getting-on / off step 30 disposed outside the underfloor component in a vehicle width direction; and a protection member 60 that is disposed between the underfloor component and the getting-on / off step; wherein the protection member has a contact wall 64 that faces the getting-on / off step in the vehicle width direction and is inclined in a direction toward an inner side in the vehicle width direction as the contact wall extends downward.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present specification discloses a protective structure for an underfloor part, such as a high-voltage part or a fuel tank, that is disposed under the floor of a vehicle. [Background technology]

[0002] Conventionally, a structure in which high-voltage components such as a battery, an inverter, and high-voltage cables, or a fuel tank, are arranged under the floor of a vehicle, has been known. Hereinafter, such high-voltage components or fuel tanks arranged under the floor will be referred to as "underfloor components." In addition to the underfloor components, some proposals have also been made to provide boarding and alighting steps at the widthwise ends of the vehicle to assist occupants in getting in and out.

[0003] For example, Patent Document 1 discloses a structure that includes a battery frame that supports a battery placed under the floor and a side step that is used when getting in and out of the vehicle. In Patent Document 1, the battery frame has a side frame on the outer side in the vehicle width direction, and the side step is integrally formed on the outer side in the vehicle width direction of this side frame. This configuration ensures the strength and rigidity of the side step while reducing the number of parts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-123956 Summary of the Invention [Problem to be solved by the invention]

[0005] Side collisions can occur, in which an obstacle strikes the side of a vehicle. Even in such a side collision, underfloor components such as high-voltage components or a fuel tank must be adequately protected. However, if a passenger access step is provided, the impact load during a side collision may be transferred to the underfloor components via the step, potentially resulting in insufficient protection of the underfloor components. Until now, this problem has not been adequately addressed.

[0006] Therefore, this specification discloses a protective structure for underfloor parts that has an entry / exit step and can adequately protect underfloor parts in the event of a side collision. [Means for solving the problem]

[0007] The protective structure for underfloor parts disclosed in this specification comprises an underfloor part that is arranged under the vehicle floor and is a high-voltage part or a fuel tank, an access step that is arranged outward in the vehicle width direction from the underfloor part, and a protective member that is arranged between the underfloor part and the access step, and is characterized in that the protective member faces the access step in the vehicle width direction and has an abutment wall that is inclined inward in the vehicle width direction as it extends downward.

[0008] With this configuration, when the boarding / alighting step collides with the abutment wall during a side collision, the inner end of the boarding / alighting step in the vehicle width direction receives a downward reaction force from the abutment wall. This causes the inner end of the boarding / alighting step to rotate downward. As a result, the boarding / alighting step can be effectively prevented from directly or indirectly colliding with underfloor components, and the underfloor components can be appropriately protected.

[0009] In this case, the boarding / alighting step has a first mounting portion that is fastened to a part of the vehicle body and a second mounting portion that is fastened to a part of the vehicle body on the inner side in the vehicle width direction of the first mounting portion, and when a downward force is applied to the inner end of the boarding / alighting step in the vehicle width direction, the fastening between the second mounting portion and the vehicle body may be released in priority over the fastening between the first mounting portion and the vehicle body.

[0010] With this configuration, in the event of a side collision, the step is supported at one point by the first mounting portion, making it easier for the step to rotate, thereby more reliably protecting the underfloor components.

[0011] In this case, the second mounting portion may have a fragile portion where stress is locally concentrated and prone to breakage or deformation when a downward force is applied to the inner end of the boarding / alighting step in the vehicle width direction.

[0012] With this configuration, the fastening between the second mounting portion and the vehicle body can be more reliably released in the event of a side collision.

[0013] Furthermore, the protective member may further include an underfloor skeleton, which is a body skeleton extending in the longitudinal direction of the vehicle, at a position under the floor of the vehicle between the abutment wall and the underfloor component, and a component support member attached to a bottom surface of the underfloor skeleton and supporting the underfloor component, wherein the protective member further includes an upper reinforcing member interposed between the abutment wall and the underfloor skeleton and transmitting a load directed inward in the vehicle width direction that is received from the abutment wall to the underfloor skeleton, and a lower reinforcing member interposed between the abutment wall and the component support member below the upper reinforcing member and transmitting the load directed inward in the vehicle width direction that is received from the abutment wall to the component support member.

[0014] This configuration allows the load acting on the abutment wall to be distributed and transmitted to the underfloor framework and the component support member, thereby suppressing deformation of the abutment wall and more reliably applying a downward reaction force to the entry / exit step, resulting in more reliable protection of the underfloor components.

[0015] In this case, two or more notches are formed on the inner edge of the bottom surface of the protective member in the vehicle width direction, the outer edge of the component support member in the vehicle width direction extends into the notches, and the periphery of the notches and the outer edge of the component support member in the vehicle width direction are spaced apart from each other in the vehicle width direction.

[0016] This configuration allows a portion of the collision load to be transmitted to the component support member during a side collision. Furthermore, before a side collision occurs, the notch and the component support member are spaced apart in the vehicle width direction, leaving a certain amount of clearance between them, which simplifies the assembly work of the protection member. [Effects of the Invention]

[0017] According to the underfloor component protection structure disclosed in this specification, the underfloor component can be appropriately protected in the event of a side collision. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view of the vehicle lower portion taken along a plane parallel to the vehicle width direction. [Figure 2] FIG. 2 is a perspective view of the mounting bracket as seen from below. [Figure 3] FIG. 2 is a schematic perspective view of a protective member. [Figure 4] FIG. 2 is a schematic perspective view of the periphery of a raised portion. [Figure 5] FIG. 4 is a cross-sectional view of the periphery of the protective member in a side collision. [Figure 6A] FIG. 4 is a diagram illustrating an example of a fragile portion. [Figure 6B] FIG. 10 is a diagram showing another example of a fragile portion. [Figure 6C] FIG. 10 is a diagram showing another example of a fragile portion. [Figure 7] FIG. 10 is a cross-sectional view showing another example of a protective structure for underfloor components. DETAILED DESCRIPTION OF THE INVENTION

[0019] The protective structure for the underfloor component 16 will be described below with reference to the drawings. Fig. 1 is a cross-sectional view of the underside of the vehicle taken along a plane parallel to the vehicle width direction. In the drawings referred to in the following description, "Fr," "Up," and "Rh" indicate the front, top, and right side of the vehicle, respectively.

[0020] As shown in FIG. 1, a floor panel 10 that functions as the floor surface of the passenger compartment is provided under the vehicle. The ends of the floor panel 10 in the vehicle width direction are joined to side sills 12. The side sills 12 are skeletal members that are long in the vehicle front-rear direction. The side sill 12 is formed by joining together a side sill inner 12i and a side sill outer 12o that is positioned further outward in the vehicle width direction than the side sill inner 12i. Both the side sill inner 12i and the side sill outer 12o are panel members with a generally hat-shaped cross section.

[0021] An under reinforcement 14 is joined to the bottom surface of the floor panel 10. The under reinforcement 14 is an underfloor framework placed under the floor to reinforce the floor panel 10. The under reinforcement 14 has a channel shape that opens upward and is long in the fore-and-aft direction of the vehicle.

[0022] A battery unit 18 is disposed below the floor panel 10 and inward in the vehicle width direction from the under reinforcement 14. The battery unit 18 is a high-voltage component that stores the power necessary for the vehicle to travel, and is an underfloor component 16 that is disposed under the vehicle floor. The battery unit 18 has a battery case 20 that houses the components of the battery. The battery case 20 is placed on and fixed to a component support member 22.

[0023] The component support member 22 is a member that supports the battery unit 18 under the floor. More specifically, the component support member 22 is a plate-shaped member on which the battery unit 18 can be placed. A raised portion 24 that partially rises upward is formed at the widthwise end of the component support member 22. FIG. 4 is a schematic perspective view of the periphery of this raised portion 24. A fastening hole 24c through which a fastening bolt (not shown) is inserted is formed in an upper surface 24a of the raised portion 24. The component support member 22 is fastened to the bottom surface of the under reinforcement 14 by the fastening bolt that is inserted into this fastening hole 24c.

[0024] As shown in FIG. 1, a boarding / alighting step 30 is attached to the bottom surface of the side sill 12. The boarding / alighting step 30 is a member that assists occupants in getting on and off the vehicle. The specific configuration of the boarding / alighting step 30 is not particularly limited. The boarding / alighting step 30 in this example has a step main body 32, a swing arm 34, and a mounting bracket 36. Note that the step main body 32 and the swing arm 34 are located on the front side of the cutting plane of FIG. 1 and would not normally be visible, but in FIG. 1 their shapes are shown by two-dot chain lines.

[0025] The step body 32 is a platform on which an occupant climbs up and down. When not in use, the step body 32 retreats to the inside in the vehicle width direction so as not to protrude significantly from the side wall of the vehicle, and when in use, it protrudes significantly to the outside in the vehicle width direction from the side wall of the vehicle. The step body 32 is connected to a mounting bracket 36 via a swing arm 34. The swing arm 34 has an upper end connected to the mounting bracket 36 and a lower end connected to the step body 32. The swing arm 34 swings around a rotation axis provided at its upper end, causing the step body 32 to move forward and backward in the vehicle width direction.

[0026] The mounting bracket 36 is fastened to a frame member of the vehicle, specifically, the bottom surface of the side sill 12. FIG. 2 is a perspective view of the mounting bracket 36 as viewed from below. As shown in FIG. 2, the mounting bracket 36 has a channel-shaped bracket main body 38 that opens downward and flanges 40 that protrude in the front-rear direction from both ends of the bracket main body 38 in the front-rear direction. The bracket main body 38 has a bracket ceiling 38a that faces downward and a pair of bracket side walls 38b that extend downward from both ends of the bracket ceiling 38a in the front-rear direction. The outer end of the bracket ceiling 38a in the vehicle width direction functions as a first mounting portion 42. The first mounting portion 42 is fastened to the side sill outer panel 12o via a first fastening bolt 46.

[0027] The flange 40 is located on the inner side in the vehicle width direction than the first mounting portion 42. The flange 40 protrudes outward in the front-to-rear direction from the upper end of the bracket side wall 38b. The flange 40 also functions as a second mounting portion 44 that is fastened to the side sill inner panel 12i via a second fastening bolt 48.

[0028] As shown in Fig. 1, a protective member 60 is also disposed between the boarding / alighting step 30 and the battery unit 18. The protective member 60 is a member that protects the battery unit 18, which is an underfloor component 16. The protective member 60 has a main body 62, an upper reinforcing member 80, and a lower reinforcing member 90. The protective member 60 will be described with reference to Figs. 1, 3, and 4. Fig. 3 is a schematic perspective view of the protective member 60.

[0029] As shown in FIG. 3, the main body 62 has an abutment wall 64, a bottom wall 66, a pair of side walls 68, and a pair of mounting flanges 70. As shown in FIG. 1, the abutment wall 64 is a wall that is located below the floor panel 10 and is positioned opposite the boarding / exiting step 30 in the vehicle width direction. This abutment wall 64 is inclined so as to progress inward in the vehicle width direction as it extends downward. The bottom wall 66 is a wall that extends inward in the vehicle width direction from the lower end of the abutment wall 64. As shown in FIG. 3, two notches 72 are formed at the inner end of the bottom wall 66 in the vehicle width direction, spaced apart in the front-to-rear direction of the vehicle.

[0030] Side walls 68 extend from both longitudinal ends of the abutment wall 64 and the bottom wall 66. A mounting flange 70 projects outward from the side wall 68 in the longitudinal direction of the vehicle. Fastening holes 70a are formed in the mounting flange 70. The main body 62 is fastened to the under reinforcement 14 (i.e., the frame member) via fastening bolts (not shown) inserted into the fastening holes 70a.

[0031] An upper reinforcing member 80 is joined to the upper part of the main body 62, and a lower reinforcing member 90 is joined to the lower part of the main body 62. As shown in FIG. 3 , the upper reinforcing member 80 is generally box-shaped and includes a bottom wall 86, an inner wall 84, an outer wall 82, and a pair of side walls 88. The outer wall 82 of the upper reinforcing member 80 is inclined to follow the abutment wall 64 of the main body 62 and overlaps the abutment wall 64 in the plate thickness direction. The inner wall 84 is also generally parallel to the side wall of the under reinforcement 14 so as to be able to abut the side wall of the under reinforcement 14 with its surface. A flange 89 protrudes rearward from the upper end of the side wall 88 at the rear of the vehicle. A fastening hole 89a is formed in this flange 89. The upper reinforcing member 80 is joined to the floor panel 10 via a fastening bolt (not shown) inserted through this fastening hole 89a.

[0032] The lower reinforcing member 90 has an upper wall 92, a step portion 94, and a lower wall 96. The upper wall 92 is inclined to follow the abutting wall 64 of the main body 62 and is overlapped with the abutting wall 64 in the plate thickness direction. The lower wall 96 is overlapped on the bottom wall 66 of the main body 62. A notch 98 is formed in the lower wall 96 at a position that overlaps with the notch 72 of the main body 62, similar to the main body 62. The step portion 94 is a stair-shaped portion that connects the upper wall 92 and the lower wall 96. The step portion 94 is located below the underreinforcement 14.

[0033] 4, the raised portion 24 has an upper surface 24a that is fastened to the under reinforcement 14 and raised surfaces 24b that extend downward from both ends of the upper surface 24a in the front-rear direction. Of these, the raised surfaces 24b are inserted into the notches 72, 98 of the protective member 60. Therefore, when the protective member 60 moves inward in the vehicle width direction during a side collision, the peripheral edges of the notches 72, 98 come into contact with the ends of the raised surfaces 24b, allowing a portion of the load acting inward in the vehicle width direction on the protective member 60 to be transmitted to the component support member 22. When the peripheral edges of the notches 72, 98 come into contact with the ends of the raised surfaces 24b, a large force is applied to the peripheral edges of the notches 72, 98. In this example, the bottom wall 66 of the main body 62 and the upper wall 92 of the lower reinforcing member 90 are stacked vertically, so that even if a large force is applied to the periphery of the notches 72, 98, deformation or damage to these can be effectively prevented.

[0034] 4, there is a certain amount of gap between the periphery of the notches 72, 98 and the end of the raised surface 24b. By allowing this gap, interference between the protective member 60 and the component support member 22 can be prevented even if the dimensional accuracy or the accuracy of the assembly position of the protective member 60 is somewhat poor. In other words, by designing in advance to allow for a gap between the protective member 60 and the component support member 22, the assembly work of the protective member 60 can be simplified.

[0035] Next, the reason for providing the protective member 60 described above will be explained with reference to FIG. 5. FIG. 5 is a cross-sectional view of the periphery of the protective member 60 during a side collision. During a side collision in which an obstacle collides with the side of the vehicle, as shown in FIG. 5, the side sill 12 and a portion of the floor panel 10 are compressed in the vehicle width direction. Without the protective member 60, the compressive deformation of the side sill 12 and the like would cause the entry / exit step 30 to move significantly inward in the vehicle width direction, and a portion of the step would collide with the battery unit 18 directly or indirectly via the component support member 22 or the like. In this example, the protective member 60 is provided to prevent the entry / exit step 30 from colliding with the battery unit 18.

[0036] As described above, the protective member 60 has an abutment wall 64 that faces the mounting bracket 36 of the entry / exit step 30 in the vehicle width direction. The abutment wall 64 is inclined so that it slopes inward in the vehicle width direction as it extends downward. Therefore, when the abutment wall 64 receives a force acting inward in the vehicle width direction, it can generate a downward reaction force. Therefore, during a side collision, when the mounting bracket 36 moves inward in the vehicle width direction and collides with the abutment wall 64, a downward force is applied to the inner end of the mounting bracket 36 in the vehicle width direction. Then, as shown in FIG. 5 , upon receiving this downward force, the mounting bracket 36 rotates around an axis around the first mounting portion 42 so that its inner end in the vehicle width direction moves downward. Hereinafter, this rotation of the mounting bracket 36 is referred to as the "retraction behavior." This retraction behavior effectively prevents the entry / exit step 30 from directly or indirectly colliding with the battery unit 18.

[0037] As described above, in this example, the first mounting portion 42 of the mounting bracket 36 is fastened to the side sill outer 12o, and the second mounting portion 44 is fastened to the side sill inner 12i. The second mounting portion 44 is a flange 40 that protrudes from the bracket main body 38 in the vehicle longitudinal direction. When a downward force is applied to the inner end of the mounting bracket 36 in the vehicle width direction, stress is concentrated at the base of the flange 40 more than at the first mounting portion 42, making it more likely to break. When the base of the flange 40 breaks, the mounting bracket 36 is released from the fastening relationship with the side sill inner 12i, and the mounting bracket 36 is now fastened only to the side sill outer 12o. In this state, the mounting bracket 36 is more likely to rotate around an axis approximately parallel to the vehicle longitudinal direction, centered around the vicinity of the first mounting portion 42. This more effectively prevents a collision between the boarding / alighting step 30 and the battery unit 18.

[0038] In addition, if the entire step 30 were to separate and fall off from the side sill 12 and ultimately the vehicle during a side collision, there would be a problem in that the movement of the step 30 would be uncontrollable. Therefore, in this example, the fastening at the second mounting portion 44 is configured to be released preferentially over the fastening at the first mounting portion 42, making it easier to maintain the fastening at the first mounting portion 42 during a side collision. Therefore, even during a side collision, the fastening between the step 30 and the side sill 12 via the first mounting portion 42 is maintained. This effectively prevents the step 30 from falling off the vehicle.

[0039] In order to apply a downward reaction force to the mounting bracket 36, the abutment wall 64 must maintain its inclined state without deforming as much as possible. Therefore, in this example, an upper reinforcing member 80 and a lower reinforcing member 90 are provided. A portion of the load applied from the mounting bracket 36 is transmitted and dispersed to the under-reinforcement 14 and the component support member 22 via these reinforcing members 80, 90. To enable the upper reinforcing member 80 to transmit the load without deforming, the upper reinforcing member 80 is made substantially box-shaped to improve its rigidity. Similarly, to enable the lower reinforcing member 90 to transmit the load to the component support member 22 without deforming, a stepped portion 94 is provided in the lower reinforcing member 90 to improve its rigidity. This configuration reduces the resistance of the abutment wall 64 to deformation, thereby more reliably applying a downward reaction force to the mounting bracket 36.

[0040] As is clear from the above description, in this example, an abutment wall 64 is provided between the step 30 and the battery unit 18, inclined so as to progress inward in the vehicle width direction as it extends downward. With this configuration, a downward reaction force can be applied to the inner end of the step 30 in the vehicle width direction during a side collision, thereby effectively preventing the step 30 from directly or indirectly colliding with the battery unit 18. Note that the configuration described so far is one example, and as long as the protective member 60 has the abutment wall 64, other configurations may be changed.

[0041] For example, a fragile portion 50 that is prone to fracture or deformation may be provided in the second mounting portion 44 to induce release of the fastening between the second mounting portion 44 and the side sill 12. For example, as shown in Fig. 6A, a notch 50a may be formed at the base of the flange 40, or as shown in Fig. 6B, a notch 50b may be formed in the fastening hole 44a. Furthermore, as shown in Fig. 6C, a slit 50c may be provided that connects the fastening hole 44a and the outer end of the mounting flange 70 in the vehicle width direction.

[0042] Furthermore, in the event of a side collision, the protective member 60 may have other configuration changes as long as it has a contact wall 64 that is inclined so as to progress inward in the vehicle width direction as it extends downward. For example, as shown in FIG. 7 , the protective member 60 may be configured without an upper reinforcing member 80 and a lower reinforcing member 90. Furthermore, the protective member 60 does not have to be a member provided exclusively for protecting the underfloor component 16. Therefore, for example, a vehicle frame member, such as a part of the under reinforcement 14 or a cross member (not shown), may be used as the protective member 60 having the abutment wall 64.

[0043] In addition, in the explanation so far, the battery unit 18 has been given as an example of the underfloor component 16 protected by the protective member 60. However, the underfloor component 16 may be any other component as long as it is a high-voltage component or a fuel tank located inside the boarding / exiting step 30 in the vehicle width direction. For example, the underfloor component 16 may be an inverter, a high-voltage cable, a fuel tank, etc. [Explanation of symbols]

[0044] 10 floor panel, 12 side sill, 14 under reinforcement, 16 underfloor parts, 18 battery unit, 20 battery case, 22 part support member, 24 raised portion, 30 boarding / alighting step, 32 step body, 34 swing arm, 36 mounting bracket, 38 bracket body, 40 flange, 42 first mounting portion, 44 second mounting portion, 46 first fastening bolt, 48 second fastening bolt, 50 weak portion, 60 protective member, 62 body, 64 abutment wall, 66 bottom wall, 68 side wall, 70 mounting flange, 72, 98 notch, 80 upper reinforcing member, 82 outer wall, 84 inner wall, 86 bottom wall, 88 side wall, 89 flange, 90 lower reinforcing member, 92 upper wall, 94 step portion, 96 lower wall.

Claims

1. an underfloor component disposed under the vehicle floor and being a high-voltage component or a fuel tank; an entry / exit step disposed on the outer side of the underfloor component in the vehicle width direction; a protective member disposed between the underfloor component and the boarding / exiting step; The protective member has a contact wall that faces the entry / exit step in the vehicle width direction and is inclined inward in the vehicle width direction as it extends downward, The boarding and disembarking step is a first mounting portion fastened to a portion of the vehicle body; a second mounting portion that is fastened to a part of the vehicle body on the inner side of the first mounting portion in the vehicle width direction; When a downward force is applied to the inner end of the step in the vehicle width direction, the fastening between the second mounting portion and the vehicle body is released with priority over the fastening between the first mounting portion and the vehicle body. A protective structure for underfloor parts characterized by the above.

2. The underfloor component protection structure according to claim 1, A protective structure for underfloor parts, characterized in that the second mounting portion has a weak portion where stress is locally concentrated and prone to breakage or deformation when a downward force is applied to the inner end of the boarding / alighting step in the vehicle width direction.

3. The underfloor component protective structure according to claim 1, further comprising: an underfloor skeleton that is a vehicle body skeleton extending in a front-rear direction of the vehicle at a position between the abutment wall and the underfloor component within the vehicle underfloor; a component support member that supports the underfloor component and is attached to a bottom surface of the underfloor framework; The protective member further comprises: an upper reinforcing member that is interposed between the contact wall and the underfloor framework and transmits a load that is received from the contact wall and directed inward in the vehicle width direction to the underfloor framework; a lower reinforcing member that is interposed between the contact wall and the component support member at a position below the upper reinforcing member and that transmits a load that is applied from the contact wall to the component support member in an inward direction in the vehicle width direction; A protective structure for underfloor parts, comprising:

4. The underfloor component protection structure according to claim 3, Two or more notches are formed on the inner edge of the bottom surface of the protection member in the vehicle width direction, an outer edge of the component support member in the vehicle width direction is inserted into the notch, a peripheral edge of the notch and an outer edge of the component support member in the vehicle width direction are spaced apart from each other in the vehicle width direction; A protective structure for underfloor parts characterized by the above.

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