JP2024081854A - Vehicle Structure - Google Patents

Abstract

[Problem] To provide a vehicle structure capable of providing excellent protection performance for an electric storage device unit in the event of a vehicle side collision. [Solution] A vehicle structure A includes a bracket 5 that is connected to bridge between a region including an inclined portion 20 of a side member 2 and a rocker 3, a plurality of connecting and fixing parts 7 that connect and fix an electric storage device unit 4 to the bracket 5, and a predetermined rigidity breaking point 50 provided on the bracket 5, the plurality of connecting and fixing parts 7 being aligned on a straight line with no inclination in the vehicle longitudinal direction in a bottom view, and the rigidity breaking point 50 being located on the outer side of the plurality of connecting and fixing parts 7 in the vehicle width direction and being provided as a plurality of rigidity breaking points aligned on a straight line with no inclination in the vehicle longitudinal direction in a bottom view, or being provided as at least one rigidity breaking point that extends without inclination in the vehicle longitudinal direction in a bottom view. [Selected Figure] Figure 1

Description

The present invention relates to vehicle structures such as automobiles.

As a specific example of a vehicle structure, there is a vehicle in which an electricity storage unit such as a battery is mounted under the floor of the vehicle compartment (for example, see Patent Documents 1 and 2).
A vehicle is generally provided with a pair of left and right side members that extend in the fore-and-aft direction of the vehicle and are spaced apart in the width direction as body frame members, and the energy storage unit is attached by bolting appropriate locations of the energy storage unit to the pair of side members.
According to such a configuration, the power storage device unit can be mounted on the vehicle space-efficiently by utilizing the pair of side members.

However, there is still room for improvement in the above-mentioned conventional technology, as described below.

That is, a pair of side members provided on a vehicle are often configured to include an inclined portion inclined with respect to the vehicle front-rear direction in a bottom view, such as an inclined portion that widens backward in a bottom view. Also, a plurality of connecting and fixing portions (bolt fastening portions, etc.) for the energy storage device unit may be provided on such an inclined portion.
However, in such a configuration, the arrangement of the multiple connecting and fixing parts in the vehicle width direction is irregular and misaligned with respect to each other. Therefore, when a side collision of the vehicle occurs, the side collision load acts on the multiple connecting and fixing parts at different times, and the side collision load is likely to concentrate on some of the connecting and fixing parts. In the case of a pole side collision, such a phenomenon becomes even more pronounced. In order to improve the protective performance of the energy storage device unit, it is desirable to appropriately resolve such problems.

JP 2019-73222 A JP 2021-133837 A

The present invention was conceived in light of the above-mentioned circumstances, and aims to provide a vehicle structure that can provide excellent protection for the power storage unit in the event of a side collision.

To solve the above problems, the present invention provides the following technical solutions:

A vehicle structure provided by the present invention includes a pair of left and right side members extending in a front-rear direction of the vehicle and spaced apart in the vehicle width direction, an electricity storage device unit mounted on the vehicle using the pair of side members, and a pair of left and right rockers extending in the front-rear direction of the vehicle and positioned outboard of the pair of side members in the vehicle width direction, wherein an inclined portion that is inclined in a bottom view is formed in an area of each of the side members that overlaps with the electricity storage device unit in the front-rear direction of the vehicle, the vehicle structure further includes a bracket connected to bridge between an area of each of the side members including the inclined portion and each of the rockers, and a bracket connecting the electricity storage device unit to the bracket. The bracket further comprises a plurality of connecting and fixing parts for connecting and fixing the bracket to the vehicle, and a rigidity breaking point that is provided on the bracket and becomes the starting point of buckling deformation of the bracket when a load of a predetermined amount or more is input to the bracket from the outer side in the vehicle width direction, wherein the plurality of connecting and fixing parts are arranged in a straight line without inclination in the fore-and-aft direction of the vehicle in a bottom view, and the rigidity breaking point is provided as a plurality of rigidity breaking points located on the outer side of the plurality of connecting and fixing parts in the vehicle width direction and arranged in a straight line without inclination in the fore-and-aft direction of the vehicle in a bottom view, or is provided as at least one rigidity breaking point extending so as to have no inclination in the fore-and-aft direction of the vehicle in a bottom view.

According to this configuration, the following effects can be obtained.
First, the multiple connecting and fixing parts that connect and fix the energy storage device unit and the bracket are aligned in a straight line without inclination in the fore-and-aft direction of the vehicle in a bottom view, and are not arranged in an inclined manner corresponding to the inclined parts of the side members. Therefore, in the event of a side collision of the vehicle, the side collision load can be applied to the multiple connecting and fixing parts simultaneously, and the side collision load is prevented from being concentrated on only a portion of the multiple connecting and fixing parts. Therefore, the side collision load is appropriately prevented from being concentrated on a portion of the energy storage device unit, and the protection performance of the energy storage device unit is improved.
Secondly, rigid breaking points are provided on the outer side of the multiple connecting and fixing parts in the vehicle width direction of the bracket, and these rigid breaking points buckle and deform the bracket when a side collision of the vehicle occurs and a side collision load of a predetermined level or more is input to the bracket. Therefore, this buckling deformation provides an effect of absorbing side collision energy, making it possible to mitigate the impact on the energy storage device unit. Another important effect here is that the rigid breaking points, like the multiple connecting and fixing parts, are aligned in a straight line without inclination in the vehicle fore-and-aft direction in bottom view, or extend without inclination in the vehicle fore-and-aft direction, so that the side collision load can act simultaneously on the multiple rigid breaking points or on each part of the rigid breaking points. This appropriately ensures that the side collision load acts simultaneously on the multiple connecting and fixing parts.
Thirdly, the electric energy storage unit is indirectly supported on the side member via a bracket, which is connected as a bridge between the side member and a rocker located on the outer side of the side member in the vehicle width direction. Therefore, the bracket serves as a member that receives the side impact load in the event of a side impact of the vehicle, and the presence of the bracket is expected to have the effect of increasing the strength of the vehicle against a side impact. This has the effect of further improving the protective performance of the electric energy storage unit.
Fourth, according to the present invention, there is no need to significantly increase the strength of the electricity storage unit itself or its surroundings as a countermeasure against side collisions of the vehicle, which is preferable in terms of reducing the vehicle weight and reducing manufacturing costs.

In the present invention, preferably, any one of the multiple connecting and fixing parts is a specific connecting and fixing part located farthest from each of the side members in the vehicle width direction, and further includes a reinforcing member that is overlapped and joined to the bracket so as to surround the periphery of the specific connecting and fixing part in a bottom view as a reinforcing member for reinforcing the bracket.

According to this configuration, the following effects can be obtained.
That is, the peripheral area of the specific connecting and fixing portion of the bracket is inherently likely to be insufficient in strength. In contrast, according to the above-mentioned configuration, such an area is rationally reinforced by the reinforcing member. Therefore, it is possible to avoid a problem in which the peripheral area of the specific connecting and fixing portion of the bracket is excessively deformed compared to other areas in the event of a side collision of the vehicle. In addition, the installation rigidity during normal vehicle driving can be ensured.

In the present invention, the bracket is preferably divided into at least two front and rear bracket portions arranged in the vehicle longitudinal direction and constituted by separate members.

This configuration makes it easy to optimize the specifications of the front and rear bracket parts (shape, size, strength, buckling deformation resistance against side impact load, etc.). It also makes it easier to assemble the brackets.

Other features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment of the invention, taken in conjunction with the accompanying drawings.

1A is a schematic bottom view of a main portion showing an example of a vehicle structure according to the present invention, and FIG. 1B is a schematic cross-sectional view taken along line II in FIG. FIG. 2 is a schematic exploded bottom view of the main part of FIG. 3 is a schematic exploded bottom view of a main portion of FIG. 1( a ) in a state where the main portion is further exploded compared to FIG. 2 . 1(b) is an enlarged cross-sectional view of part IV in FIG. 1(b) (corresponding to a schematic cross-sectional view of the main part II in FIG. 1(a)). 1(a) is a schematic cross-sectional view of a main part taken along line VV in FIG. 6 is a schematic cross-sectional view of a main part taken along the line VI-VI in FIG. 7 is a schematic cross-sectional view of a main part taken along line VII-VII of FIG. FIG. 2 is a schematic cross-sectional view of a main part showing Comparative Example 1 of the present invention.

The preferred embodiment of the present invention will be described in detail below with reference to the drawings.

A vehicle structure A shown in FIGS. 1 to 3 is applied to, for example, a cab-over type vehicle 1, and includes a pair of left and right side members 2 (indicated by a halftone dot pattern in FIG. 3), a pair of rockers 3, a power storage device unit 4, a pair of brackets 5 for mounting the power storage device unit 4, and a reinforcing member 6.
The vehicle structure A also includes a plurality of connecting and fixing portions 7 and a plurality of rigidity breaking points 50 provided on each bracket 5 .
In the figure, reference numeral 90 denotes a front wheel.

The pair of side members 2 are one of the body frame members, positioned at a distance in the vehicle width direction, and extend in the vehicle longitudinal direction from near the front end of the vehicle 1 toward the rear of the vehicle. Each side member 2 is constructed using a member with a hat-shaped cross section that is open on the top, as shown in, for example, Figure 1(b) and Figures 4 to 6. Although detailed illustrations are omitted, each side member 2 is joined to the underside of the floor section 10 (floor panel section).

The pair of side members 2 are generally spaced apart in the vehicle width direction greater at the rear of the vehicle 1 than at the front. The midpoint of the pair of side members 2 in the vehicle fore-and-aft direction is formed as an inclined portion 20 that widens in a bottom view and whose spacing in the vehicle width direction increases toward the rear of the vehicle. The inclined portion 20 and the power storage unit 4 overlap each other in the vehicle fore-and-aft direction.

The pair of rockers 3 are members located at the lower left and right sides of the vehicle 1, extending in the front-rear direction of the vehicle, and positioned outward in the vehicle width direction from the pair of side members 2. Each rocker 3 is formed with a hollow cross section, and constitutes a lower edge portion of a side door opening (not shown) on the side of the vehicle 1. In addition, the outer end portion in the vehicle width direction of the floor portion 10 is joined to the rocker 3.
In this vehicle structure A, cross members 80a, 80b connected between the pair of side members 2, a pair of inclined beam members 81, a torque box 82, etc. are appropriately provided. An opening 10a for maintenance is provided in the floor portion 10.

The power storage unit 4 is a unit equipped with a power storage device, and includes, for example, a battery cell, a cooling device, a control ECU, etc. The vehicle 1 is, for example, a hybrid vehicle or an electric vehicle, and the battery is for driving the vehicle. The power storage unit 4 is configured such that a flange-shaped or leg-shaped attachment portion 41 protrudes outward in the vehicle width direction from the unit main body portion 40 on which the battery is mounted.

The brackets 5 are members used to attach the power storage unit 4, and are provided to bridge the area including the inclined portion of the side member 2 and the rocker 3. More specifically, each bracket 5 is made of a panel material with a curved cross section, and as shown in Figures 4 to 6, the inner portion 51 in the vehicle width direction is placed on the side member 2 and bolted and welded. The outer portion 52 in the vehicle width direction of each bracket 5 is placed on the lower portion of the rocker 3 and bolted and welded.

The bracket 5 is divided into front and rear bracket portions 5a, 5b that are aligned in the fore-and-aft direction of the vehicle and are made of separate members. However, in the following explanation, unless otherwise specified, no distinction will be made between the front and rear bracket portions 5a, 5b, and they will be explained together as the bracket 5.

The multiple connecting and fixing parts 7 are portions for connecting and fixing the mounting part 41 of the power storage unit 4 to the bracket 5. The mounting part 41 is provided with a cylindrical part 70 through which a bolt 71 is inserted, for example, and the bracket 5 and the mounting part 41 are connected and fixed (bolted) using this bolt 71 and a nut 72 that screws onto it. The power storage unit 4 is indirectly supported by the side member 2 via the bracket 5.

The multiple connecting and fixing parts 7 are on a straight line La shown by a virtual line in FIG. 1( a ), and are aligned in a straight line without inclination in the front-rear direction of the vehicle when viewed from the bottom.
Therefore, for example, while the connecting and fixing portion 7 is located immediately below the side member 2 in FIG. 6, such a positional relationship is different in FIGS.

As shown in Figs. 1, 5 and 7, the reinforcing member 6 is a panel-shaped member that is overlapped on the bracket 5 and joined by welding so as to surround the periphery of the connecting and fixing portion 7 (7a) located at the front end among the multiple connecting and fixing portions 7. Preferably, this reinforcing member 6 is also welded to the mounting portion 41 of the power storage unit 4. The connecting and fixing portion 7a corresponds to an example of a "specific connecting and fixing portion" as referred to in the present invention. The region of the bracket 5 where the connecting and fixing portion 7a is provided has a larger width dimension in the vehicle width direction than other regions, and is therefore prone to insufficient strength. In contrast, the reinforcing member 6 is useful for appropriately preventing such a risk, and is also preferable in terms of ensuring the installation rigidity during normal driving of the vehicle 1.
As shown in FIG. 5 , a configuration may be adopted in which an additional reinforcing member 68 is further provided to separately connect the peripheral portion of the connecting and fixing portion 7 a of the bracket 5 to the side member 2 .

As can be seen clearly in FIG. 7, the bracket 5 is in the form of a panel with multiple downwardly protruding steps 55 of height Ha and width Wa in the vehicle's fore-aft direction formed at appropriate intervals in the vehicle's fore-aft direction. Each step 55 extends in the vehicle width direction. In contrast, each connecting and fixing part 7 is configured such that a cylindrical part 70 abuts against the underside of the step 55, and the parts of the bracket 5 where the steps 55 are formed are intended to be connected and fixed to the energy storage device unit 4.

The multiple rigidity breaking points 50 are locations that become the starting points of buckling deformation of the bracket 5 when a side collision of the vehicle 1 occurs and a load of a predetermined amount or more is input to the bracket 5 from the outer side in the vehicle width direction. In this embodiment, the rigidity breaking points 50 are locations where a portion of each of the multiple step portions 55 of the bracket 5 is formed as a bent cross-sectional bead portion (see Figures 4 to 6) that is bent, for example, into a substantially V-shaped cross section. Each rigidity breaking point 50 extends linearly in the vehicle fore-aft direction from one end of each step portion 55 to the other end in the vehicle fore-aft direction.

The rigidity breaking points 50 are provided at positions on the vehicle width outward side of the multiple connecting and fixing parts 7 so as to correspond to each of the multiple connecting and fixing parts 7. The rigidity breaking points 50 are also located on a straight line Lb shown by a virtual line in FIG. 1(a), and, like the multiple connecting and fixing parts 7, are aligned on a straight line with no inclination in the fore-and-aft direction of the vehicle when viewed from the bottom.

Next, we will explain the operation of the vehicle structure described above.

When a side collision occurs on the vehicle 1, as shown in FIG. 1(a), the side collision load F may be input to the side of the vehicle 1. In contrast, the multiple connecting and fixing parts 7 are on the above-mentioned straight line La, and are aligned in a straight line with no inclination in the fore-and-aft direction of the vehicle when viewed from the bottom. Therefore, the side collision load F acts on the multiple connecting and fixing parts 7 simultaneously, and is prevented or suppressed from concentrating on, for example, only one connecting and fixing part 7.

FIG. 8 shows comparative example 1 to this embodiment.
In Comparative Example 1, a plurality of connecting and fixing parts 7e that connect and fix the mounting part 41 of the power storage device unit 4 to the bracket 5e are arranged to overlap with the side member 2, and are arranged diagonally in a bottom view, similar to the inclined part 20 of the side member 2. In Comparative Example 1, when a side collision of the vehicle 1e occurs, the side collision load Fe acts intensively on some of the connecting and fixing parts 7e, and does not act much on the other connecting and fixing parts 7e located adjacent to them. As a result, the side collision load Fe cannot be borne over a wide range, and there is a risk that the power storage device unit 4 will be seriously damaged.
In contrast, according to the present embodiment, it is possible to appropriately eliminate or reduce such concerns.

A plurality of rigidity breaking points 50 are provided on the outer side in the vehicle width direction of the plurality of connecting and fixing parts 7 of the bracket 5, and these rigidity breaking points 50 become the starting points for buckling deformation of the bracket 5 when a side collision load F larger than a predetermined value is input to the bracket 5. Therefore, the buckling deformation of the bracket 5 provides an effect of absorbing side collision energy, and it is possible to mitigate the impact received by the power storage device unit 4.
As described above, the rigidity breaking points 50 are on the straight line Lb, and are arranged in a straight line without inclination in the fore-and-aft direction of the vehicle in a bottom view, similar to the multiple connecting and fixing parts 7. Therefore, the side impact load F acts on the multiple rigidity breaking points 50 simultaneously, and the impact mitigation effect can be further improved by deformation utilizing the multiple rigidity breaking points 50. Furthermore, it is appropriately ensured that the side impact load F acts on the multiple connecting and fixing parts 7 simultaneously, and the protection performance of the power storage device unit 4 can be further improved.

Bracket 5 serves as a member that receives a side collision load F when a side collision occurs, and the presence of bracket 5 itself is preferable for ensuring the strength of vehicle 1 against a side collision or the mounting rigidity of power storage unit 4 during normal driving of vehicle 1. Bracket 5 in this embodiment has a configuration in which multiple steps 55 are provided extending in the vehicle width direction, which is suitable for increasing the rigidity of bracket 5. In addition, the presence of reinforcing member 6 described above reliably prevents a problem in which a portion of bracket 5 becomes insufficient in strength, which is even more preferable.
In addition, in this embodiment, since each bracket 5 is divided into the front and rear bracket portions 5a, 5b, it is easy to make each of the front and rear bracket portions 5a, 5b have optimal specifications (shape, size, strength, buckling deformation property against a side impact load, etc.). Also, the overall assembly workability of the bracket 5 can be improved.

The present invention is not limited to the above-described embodiment. The specific configuration of each part of the vehicle structure according to the present invention can be freely designed and modified within the intended scope of the present invention.

In the above embodiment, a plurality of rigidity breaking points 50 are provided to correspond to a plurality of connecting and fixing parts 7, but the present invention is not limited to this. For example, the rigidity breaking point in the present invention may be a rigidity breaking point that extends in the vehicle longitudinal direction with the same length as the bracket 5, and if such a long rigidity breaking point is provided, it is also possible to provide only one rigidity breaking point. Of course, even such a rigidity breaking point is provided at a position on the outer side of the plurality of connecting and fixing parts 7 in the vehicle width direction.
The rigidity breaking point in the present invention is not limited to a bead portion where a part of the bracket is bent into a substantially V-shaped cross section, but may also be, for example, a thin-walled portion, a portion where a hole is formed, etc. In short, it may be a portion where the shape or rigidity is partially changed compared to the surrounding portions, and which becomes the starting point of buckling deformation of the bracket when a load of a predetermined value or more is input to the bracket from the outer side in the vehicle width direction.

The connecting and fastening portion in the present invention may employ connecting and fastening means other than bolts and nuts.
The bracket of the present invention may of course be divided into more portions than the front and rear bracket portions, but it may also be configured without such division.

The inclined portion of the side member in the present invention is not limited to an inclined portion that spreads out rearward in a bottom view, and may be, for example, an inclined portion that spreads out frontward in a bottom view. The inclined portion in the present invention is a portion formed on the side member and has an inclined shape in a bottom view, the position of which in the vehicle width direction changes as it moves toward the rear or front of the vehicle.
The power storage device unit is not limited to a unit having a battery as the power storage device, but may be a unit having a capacitor, for example.

A Vehicle structure 1 Vehicle 2 Side member 20 Inclined portion (of side member)
3 Rocker 4 Electricity storage unit 5 Brackets 5a, 5b Front and rear bracket portions 50 Rigidity breaking point 6 Reinforcement member 7 Connection and fixing portion

Claims (3)

A pair of left and right side members extending in a front-rear direction of the vehicle and spaced apart in a vehicle width direction;
an electricity storage device unit mounted on a vehicle by utilizing the pair of side members;
a pair of left and right rockers positioned outward in a vehicle width direction from the pair of side members and extending in a vehicle front-rear direction;
Equipped with
a vehicle structure, wherein each of the side members has an inclined portion that is inclined in a bottom view in a region that overlaps with the power storage unit in a vehicle front-rear direction,
a bracket that is connected between a region including the inclined portion of each of the side members and each of the rockers;
a plurality of connecting and fixing portions for connecting and fixing the power storage device unit to the bracket;
a rigidity breaking point that is provided on the bracket and that becomes a starting point of buckling deformation of the bracket when a load of a predetermined value or more is input to the bracket from an outer side in a vehicle width direction;
It also has
The plurality of connecting and fixing portions are aligned in a straight line without inclination in the front-rear direction of the vehicle in a bottom view,
A vehicle structure characterized in that the rigidity breaking point is located on the vehicle widthwise outer side of the multiple connecting and fixed parts, and is provided as multiple rigidity breaking points arranged in a straight line without inclination in the fore-and-aft direction of the vehicle in a bottom view, or is provided as at least one rigidity breaking point extending without inclination in the fore-and-aft direction of the vehicle in a bottom view. 2. A vehicle structure according to claim 1,
any one of the plurality of connecting and fixing portions is a specific connecting and fixing portion located farthest from each of the side members in a vehicle width direction,
The vehicle structure further includes a reinforcing member for reinforcing the bracket, the reinforcing member being overlapped and joined to the bracket so as to surround the specific connecting and fixing portion in a bottom view. 3. A vehicle structure according to claim 1 or 2,
A vehicle structure, wherein the bracket is divided into at least two front and rear bracket portions arranged in the fore-aft direction of the vehicle and constituted by separate members.

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