Vehicle

Abstract

To provide an art for improving absorption of collision energy by deformation of a cross member.SOLUTION: A vehicle includes: a floor panel; a battery pack located below the floor panel; rockers each of which extends in a front-back direction along a side edge of the floor panel; and a cross member extending from the rocker along the floor panel in a lateral direction. The cross member has: an intermediate section located above the battery pack in the lateral direction; and outer end sections each of which is located between the intermediate section and the rocker and has strength smaller than that of the intermediate section. The outer end section of the cross member has a first member and a second member arranged parallel to each other along the lateral direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a vehicle. [Background technology]

[0002] Patent Document 1 describes a vehicle. In this vehicle, a cross member is provided with a weak portion. When a side collision occurs to the vehicle, the cross member is plastically deformed with the weak portion as the bending starting point. By controlling the deformation mode of the cross member by the weak portion, damage to the battery pack arranged under the floor panel is avoided. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-226972 A Summary of the Invention [Problem to be solved by the invention]

[0004] In order to avoid or suppress damage to a battery pack due to a side collision of a vehicle, it is effective not only to control the deformation mode of the cross member but also to increase the absorption of collision energy by the deformation of the cross member. This specification provides a technique for improving the absorption of collision energy by the deformation of the cross member. [Means for solving the problem]

[0005] The technology disclosed in this specification is embodied in a vehicle. In a first aspect, the vehicle includes a floor panel, a battery pack located below the floor panel, a rocker extending in the front-rear direction along the side edge of the floor panel, and a cross member extending in the left-right direction from the rocker along the floor panel. The cross member has a middle section located above the battery pack in the left-right direction, and an outer end section located between the middle section and the rocker and having a strength smaller than that of the middle section. The outer end section of the cross member has a first member and a second member that are parallel to each other along the left-right direction. Here, in this specification, "high strength" or "low strength" refers to the magnitude of the load when plastic deformation (also simply referred to as deformation) occurs.

[0006] In the above-mentioned vehicle, the strength of the cross member is smaller in the outer end section adjacent to the rocker than in the middle section located above the battery pack. With this configuration, when a side collision occurs to the vehicle, the outer end section of the cross member undergoes plastic deformation prior to the middle section. By suppressing the plastic deformation of the middle section, damage to the battery pack can be avoided or suppressed. Furthermore, the strength of the outer end section of the cross member affects the absorption of collision energy by deformation of the cross member. In this regard, the outer end section of the cross member has two members (i.e., a first member and a second member). Therefore, the strength of the outer end portion of the cross member can be increased, and the absorption of collision energy by deformation of the cross member can be improved.

[0007] In a second aspect, in the first aspect, the first member may have a shape that defines an internal space extending in the left-right direction between the first member and the floor panel. In this case, the second member may be joined to the first member within the internal space defined by the first member. With this configuration, the outer shape of the outer end portion of the cross member is defined by the first member, so the shape of the second member disposed in the internal space between the first member and the floor panel can be designed relatively freely. Therefore, the strength of the outer end portion of the cross member can be adjusted by changing the shape, arrangement, etc. of the second member.

[0008] In a third aspect, in the first or second aspect, the middle section of the cross member may have a third member that is continuous with the first member of the outer end section and defines an internal space extending in the left-right direction between the third member and the first member. In this case, the tensile strength of the material constituting the first member may be smaller than the tensile strength of the material constituting the third member. The tensile strength of the material constituting the second member may also be smaller than the tensile strength of the material constituting the third member. With this configuration, by changing the material constituting each member of the cross member, the strength of the outer end section can be made smaller than the strength of the middle section.

[0009] In a fourth aspect, in any of the first to third aspects, the middle section of the cross member may have a third member that is continuous with the first member of the outer end section and defines an internal space extending in the left-right direction between the floor panel and the first member. In this case, the plate thickness of the first member may be smaller than the plate thickness of the third member. The plate thickness of the second member may also be smaller than the plate thickness of the third member. With this configuration, by changing the plate thickness of each member of the cross member, the strength of the outer end section can be made smaller than the strength of the middle section.

[0010] In a fifth aspect, in any one of the first to fourth aspects, the first and second members may deform in directions away from each other when a load is applied from the left and right direction. With this configuration, when a side collision occurs to the vehicle, for example, the first member deforms upward and the second member deforms downward. At this time, the upward deformation of the first member suppresses the downward deformation of the second member, and the downward deformation of the second member suppresses the upward deformation of the first member. Inhibiting the deformation of each other in this way can realize a stable deformation mode. [Brief description of the drawings]

[0011] [Figure 1] 1 is a left side view showing a schematic configuration of a vehicle 10 according to an embodiment. [Diagram 2] 2 is a diagram for explaining the positional relationship between a battery pack 20, a floor panel 22, a locker 24, and a cross member 28. FIG. [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. 2 . [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 2 . [Diagram 5] An enlarged view of part V in Figure 2. [Figure 6] An example of deformation behavior when a side collision occurs to the vehicle 10 is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A vehicle 10 according to the embodiment will be described with reference to the drawings. The vehicle 10 according to the embodiment belongs to an electric vehicle having a motor 16 that drives wheels 14f, 14r, and is typically an electric vehicle (a so-called automobile) that runs on a road surface. However, some or all of the techniques described in the embodiment can also be adopted in an electric vehicle that runs on a track. Furthermore, the vehicle 10 is not limited to one that is driven and operated by a user, and may be one that is remotely operated by an external device or one that runs autonomously.

[0013] Here, the direction FR in the drawings indicates the front in the fore-aft direction (or length direction) of the vehicle 10, and the direction RR indicates the rear in the fore-aft direction of the vehicle 10. Furthermore, the direction LH indicates the left in the left-right direction (or width direction) of the vehicle 10, and the direction RH indicates the right in the left-right direction of the vehicle 10. Furthermore, the direction UP indicates the upward direction in the up-down direction (or height direction) of the vehicle 10, and the direction DW indicates the downward direction in the up-down direction of the vehicle 10.

[0014] As shown in FIG. 1, the vehicle 10 includes a vehicle body 12 and a plurality of wheels 14f, 14r. The vehicle body 12 has a passenger compartment 12c, which is a space for carrying passengers. The plurality of wheels 14f, 14r are rotatably attached to the vehicle body 12. The plurality of wheels 14f, 14r include a pair of front wheels 14f located at the front of the vehicle body 12 and a pair of rear wheels 14r located at the rear of the vehicle body 12. The pair of front wheels 14f are arranged coaxially with each other, and the pair of rear wheels 14r are also arranged coaxially with each other. The number of wheels 14f, 14r is not limited to four. Although not particularly limited, the vehicle body 12 is made of a metal such as a steel material or an aluminum alloy.

[0015] As shown in FIGS. 1 and 2, the vehicle 10 further includes a motor 16, a power control unit 18, and a battery pack 20. The motor 16 is a driving motor that drives a pair of front wheels 14f and is connected to the pair of front wheels 14f. The battery pack 20 is a power supply device that supplies power to the motor 16 and is electrically connected to the motor 16 via the power control unit 18. The battery pack 20 incorporates a plurality of secondary battery cells and is configured to be repeatedly charged by external power or regenerative power of the motor 16. The battery pack 20 is located below the floor panel 22 and is arranged along the floor panel 22. The power control unit 18 incorporates a DC-DC converter and / or an inverter, and controls the driving power supplied from the battery pack 20 to the motor 16 and the regenerative power supplied from the motor 16 to the battery pack 20 in response to, for example, a driving operation by a user.

[0016] The motor 16 is not limited to the pair of front wheels 14f, but may be configured to drive at least one of the multiple wheels 14f, 14r. The vehicle 10 may further include another motor that drives the pair of rear wheels 14r in addition to the motor 16 that drives the pair of front wheels 14f. The vehicle 10 may further include another prime mover such as an engine instead of or in addition to the motor 16. Furthermore, the vehicle 10 may include another power supply device such as a fuel cell unit or a solar panel in addition to or instead of the battery pack 20. The vehicle 10 is not limited to the electric vehicle described here, but may be a hybrid vehicle, a fuel cell vehicle, a solar car, or the like.

[0017] As shown in FIG. 2, the vehicle body 12 includes a floor panel 22 and a pair of rockers 24. The floor panel 22 is a plate-like member that constitutes the bottom surface of the vehicle interior 12c. Each of the pair of rockers 24 is a hollow member having a constant cross section along the front-rear direction, and constitutes a part of the framework of the vehicle body 12. The left rocker 24 is located on the left edge of the floor panel 22, and extends in the front-rear direction along the left edge of the floor panel 22 on the outer side of the floor panel 22 in the vehicle width direction. The pair of rockers 24 are provided symmetrically with respect to the left-right direction of the vehicle 10. Therefore, the right rocker (not shown) is located on the right edge of the floor panel 22, and extends in the front-rear direction along the right edge of the floor panel 22 on the outer side of the floor panel 22 in the vehicle width direction. Therefore, the floor panel 22 is provided between the pair of rockers 24. As an example, the battery pack 20 is fixed to each rocker 24 via an energy absorbing material 26.

[0018] Although not limited thereto, each of the pair of rockers 24 includes a rocker inner panel 24a and a rocker outer panel 24b. The rocker inner panel 24a is located on the inner side in the vehicle width direction, and the rocker outer panel 24b is located on the outer side in the vehicle width direction. The rocker inner panel 24a and the rocker outer panel 24b are joined to each other at their upper and lower edges, and a closed space extending in the front-rear direction is formed inside the rocker 24. However, in other embodiments, each rocker 24 is not limited to only the rocker inner panel 24a and the rocker outer panel 24b, and may be composed of three or more panels. In addition, the pair of rockers 24 may have a symmetrical shape or an asymmetrical shape.

[0019] As shown in FIG. 2-5, the vehicle body 12 further includes a cross member 28. The cross member 28 has a middle section IS and an outer end section OS. The middle section IS of the cross member 28 is located above the battery pack 20 in the left-right direction. The outer end section OS of the cross member 28 is located between the middle section IS of the cross member 28 and the rocker 24 in the left-right direction. As will be described in detail later, the strength of the outer end section OS is smaller than the strength of the middle section IS. Therefore, when a side collision occurs on the vehicle 10 and a load (collision load) acts on the cross member 28 in the left-right direction, the outer end section OS plastically deforms prior to the middle section IS.

[0020] The intermediate section IS of the cross member 28 has an intermediate cross member member 30. The intermediate cross member member 30 generally has a channel member structure and has a substantially U-shaped cross section with an open lower portion. The intermediate cross member member 30 extends in the left-right direction between a pair of rockers 24 along the upper surface of the floor panel 22. The intermediate cross member member 30 extends in the left-right direction, continuing from a first outer end cross member member 32 described later. Although not limited thereto, the intermediate cross member member 30 is joined to the floor panel 22 by welding or the like. As a result, the intermediate cross member member 30, together with the floor panel 22, forms an internal space extending in the left-right direction of the vehicle 10.

[0021] The outer end section OS of the cross member 28 has a first outer end cross member member 32 and a second outer end cross member member 34. The first outer end cross member member 32 generally has a channel member structure and has a substantially U-shaped cross section with an open lower portion. The first outer end cross member member 32 extends in the left-right direction between the pair of rockers 24 along the upper surface of the floor panel 22. Although not particularly limited, the first outer end cross member member 32 is joined to the floor panel 22 by welding or the like. As a result, the first outer end cross member member 32, together with the floor panel 22, forms an internal space extending in the left-right direction of the vehicle 10. As described above, the intermediate cross member member 30, together with the floor panel 22, also forms an internal space extending in the left-right direction of the vehicle 10. Therefore, the cross member 28, together with the floor panel 22, has a series of internal spaces extending in the left-right direction from the intermediate section IS to the outer end section OS.

[0022] The second outer end cross member 34 generally has a channel member structure and has a substantially U-shaped cross section with an open lower portion. The second outer end cross member 34 extends in the left-right direction within the internal space formed by the first outer end cross member 32 and the floor panel 22. At this time, the second outer end cross member 34 is arranged so as to be parallel to the first outer end cross member 32 along the left-right direction. The second outer end cross member 34 is joined to the first outer end cross member 32 by, for example, welding. Note that the first outer end cross member 32 in this specification is an example of the first member in the present technology, the second outer end cross member 34 in this specification is an example of the second member in the present technology, and the intermediate cross member 30 in this specification is an example of the third member in the present technology.

[0023] The tensile strength of the material constituting the first outer cross member 32 is less than the tensile strength of the material constituting the intermediate cross member 30. The tensile strength of the material constituting the second outer cross member 34 is also less than the tensile strength of the material constituting the intermediate cross member 30. As an example, the materials constituting the first outer cross member 32 and the second outer cross member 34 each have a tensile strength of 50 kg / mm 2 The material constituting the intermediate cross member 30 is a high-tensile steel plate (so-called high-tensile steel) having a tensile strength of 100 kg / mm 2 In this case, in the cross member 28, the outer end section OS has a strength about half that of the intermediate section IS. In other words, the strength of the combination of the first outer end cross member member 32 and the second outer end cross member member 34 is smaller than the strength of the intermediate section IS of the cross member 28.

[0024] In the above-described vehicle 10, the strength of the cross member 28 is smaller in the outer end section OS adjacent to the rocker 24 than in the intermediate section IS located above the battery pack 20. With this configuration, when a side collision occurs to the vehicle 10, as shown in FIG. 6, the outer end section OS of the cross member 28 is plastically deformed preferentially over the intermediate section IS. By suppressing the plastic deformation of the intermediate section IS, damage to the battery pack 20 can be avoided or suppressed. In addition, the strength of the outer end section OS of the cross member 28 affects the absorption of collision energy by the deformation of the cross member 28. In this regard, the outer end section OS of the cross member 28 has two members (i.e., the first outer end cross member member 32 and the second outer end cross member member 34). Therefore, the strength of the outer end section OS of the cross member 28 can be increased, and the absorption of collision energy by the deformation of the cross member 28 can be improved.

[0025] In the above embodiment, the intermediate cross member 30 and the first outer cross member 32 are made of different materials, and the intermediate cross member 30 and the second outer cross member 34 are made of different materials, so that the strength of the outer section OS in the cross member 28 is made smaller than the strength of the intermediate section IS. However, the above-mentioned material change is not necessarily required. In other embodiments, the plate thickness of each member may be changed. For example, the plate thickness of the first outer cross member 32 and the plate thickness of the second outer cross member 34 may be 1.2 mm, and the plate thickness of the intermediate cross member 30 may be 1.6 mm. In this way, by making the plate thickness of the first outer cross member 32 smaller than the plate thickness of the intermediate cross member 30 and the plate thickness of the second outer cross member 34 smaller than the plate thickness of the intermediate cross member 30, the strength of the outer section OS in the cross member 28 can be made smaller than the strength of the intermediate section IS. In still another embodiment, the material constituting each component of the cross member 28 may be changed, and the plate thickness of each component of the cross member 28 may be changed.

[0026] As an example, as shown in FIG. 2, the first outer cross member 32 has a first weak portion 36 and a second weak portion 38. Each weak portion 36, 38 is a bent portion of the first outer cross member 32 and has a lower strength than other portions of the first outer cross member 32. That is, when a load is applied to the first outer cross member 32 from the left and right direction, bending stress is likely to occur locally in each weak portion 36, 38, which is a bent portion. As a result, bending deformation occurs in each weak portion 36, 38 in preference to other portions of the first outer cross member 32. In this configuration, when a load is applied to the first outer cross member 32 from the left and right direction, as shown in FIG. 6, the first weak portion 36 and the second weak portion 38 become the starting points of bending, and the first outer cross member 32 is deformed upward.

[0027] In addition to the above, as shown in Figs. 2 and 5, the second outer cross member 34 has a first weak portion 40 and a second weak portion 42. Each weak portion 40, 42 is a bent portion in the second outer cross member 34, and has a lower strength than other portions of the second outer cross member 34. That is, when a load is applied to the second outer cross member 34 from the left and right direction, bending stress is likely to occur locally in each weak portion 40, 42, which is a bent portion. As a result, bending deformation occurs in each weak portion 40, 42 in preference to other portions of the second outer cross member 34. As an example, the second weak portion 42 has a first bent portion 42a and a second bent portion 42b. The second outer end cross member 34 extends in the left-right direction in a range from the end on the inner side in the vehicle width direction to the first weak portion 40, inclines downward in a range from the first weak portion 40 to the first bent portion 42a of the second weak portion 42, extends again in the left-right direction in a range from the first bent portion 42a to the second bent portion 42b, and inclines downward again in a range from the second bent portion 42b to the end on the outer side in the vehicle width direction. In this configuration, when a load is applied to the second outer end cross member 34 from the left-right direction, the first weak portion 40 and the second weak portion 42 each become the starting point of bending, and the second outer end cross member 34 deforms downward, as shown in FIG.

[0028] As a result of the above, the first outer end cross member member 32 and the second outer end cross member member 34 deform in directions away from each other (here, upward and downward) when a load is applied from the left and right direction. With this configuration, the upward deformation of the first outer end cross member member 32 suppresses the downward deformation of the second outer end cross member member 34, and the downward deformation of the second outer end cross member member 34 suppresses the upward deformation of the first outer end cross member member 32. As a result, a stable deformation mode can be realized.

[0029] However, each of the weak parts 36, 38, 40, 42 does not necessarily have to be a bent part. For example, as shown in Figs. 2 and 5, the second weak part 42 further has a through hole 42c. The through hole 42c penetrates two side walls of the second outer end cross member 34. The through hole 42c can locally reduce the strength of the second outer end cross member 34, similar to the first bent part 42a and the second bent part 42b. Therefore, in another embodiment, each of the weak parts 36, 38, 40, 42 may be a part provided with a through hole similar to the through hole 42c of the second weak part 42, instead of the bent part. In addition, the position in the left-right direction where each of the weak parts 36, 38, 40, 42 is provided is not particularly limited.

[0030] Although several specific examples have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical usefulness alone or in combination. [Explanation of symbols]

[0031] 10: Vehicle 12: Body 12c: Cabin 14f: Front wheel 14r: Rear wheel 16: Motor 18: Power control unit 20: Battery pack 22: Floor panel 24: Rocca 24a: Rocker inner panel 24b: Rocker outer panel 26: Energy absorber 28: Cross member 30: Intermediate cross member 32: First outer end cross member 34: Second outer end cross member 36: First weak part 38: Second weak part 40: First weak part 42: Second weak part 42a: 1st bending part 42b: 2nd bending part 42c: Through hole IS: Intermediate section OS: Outer end section

Claims

1. Floor panels and a battery pack located below the floor panel; A rocker extending in the front-rear direction along a side edge of the floor panel; A cross member extending in the left-right direction from the rocker along the floor panel; Equipped with the cross member has, in the left-right direction, a middle section located above the battery pack, and an outer end section located between the middle section and the rocker and having a strength less than that of the middle section, The outer end section of the cross member has a first member and a second member that are parallel to each other along the left-right direction. vehicle.

2. The first member has a shape that defines an internal space extending in the left-right direction between the first member and the floor panel, The vehicle of claim 1 , wherein the second member is joined to the first member within the interior space defined by the first member.

3. the intermediate section of the cross member has a third member that is continuous with the first member of the outer end section and defines an internal space extending in the left-right direction between the third member and the floor panel, a tensile strength of a material constituting the first member is smaller than a tensile strength of a material constituting the third member; 3. The vehicle of claim 2, wherein the tensile strength of the material constituting the second member is also less than the tensile strength of the material constituting the third member.

4. the intermediate section of the cross member has a third member that is continuous with the first member of the outer end section and defines an internal space extending in the left-right direction between the third member and the floor panel, The plate thickness of the first member is smaller than the plate thickness of the third member, The vehicle according to claim 2 or 3, wherein a plate thickness of the second member is also smaller than a plate thickness of the third member.

5. The vehicle according to claim 1 , wherein the first member and the second member are deformed in directions away from each other when a load is applied to the first member and the second member from the left-right direction.

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