Vehicle Structure

The vehicle structure addresses uneven impact loads on power storage devices by aligning fixing parts and using strategically positioned break points, improving collision protection without additional weight or cost.

JP7608031B2Active Publication Date: 2025-01-06DAIHATSU MOTOR CO LTD
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Patent Information

Application Number
JP2022195352
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Filing Date
2022-12-07
Publication Date
2025-01-06
Estimated Expiration
2042-12-07

AI Technical Summary

Technical Problem

Existing vehicle structures with power storage devices under the floor suffer from uneven distribution of connecting and fixing parts, leading to concentrated side impact loads during collisions, which can damage the power storage device.

Method used

A vehicle structure with aligned, non-inclined connecting fixing parts and strategically positioned rigid break points on brackets, supported by reinforcing members, to distribute impact loads evenly and enhance energy absorption.

Benefits of technology

The solution ensures simultaneous application of impact loads across multiple points, reducing concentration and enhancing the protection performance of the power storage device without increasing weight or manufacturing costs.

✦ Generated by Eureka AI based on patent content.

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Patent Text Reader

Abstract

To provide a vehicle structure capable of making excellent the protection performance of a power storage device unit at the time of occurrence of vehicle side collision.SOLUTION: A vehicle structure A comprises: a bracket 5 which is connected between a region including an inclination part 20 of a side member 2 and a rocker 3; a plurality of connection stationary portions 7 which connect and fix a power storage device unit 4 to the bracket 5; and prescribed rigidness break points 50 which are arranged in the bracket 5. The plurality of connection stationary portions 7 are arrayed on a straight line without being inclined in a longitudinal direction of a vehicle in a bottom view. The rigidness break points 50 are positioned at the outer side of the plurality of connection stationary portions 7 in the vehicle width direction and arrayed on the straight line without being inclined in the longitudinal direction of the vehicle in the bottom view, or at least one rigidness break point extending without being inclined in the longitudinal direction of the vehicle in the bottom view.SELECTED DRAWING: Figure 1
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Description

[Technical field]

[0001] The present invention relates to vehicle structures such as automobiles. [Background technology]

[0002] 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, 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, for example, 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.

[0003] However, the above-mentioned conventional techniques still have room for improvement, as described below.

[0004] 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 bottom view, such as an inclined portion that widens rearward in bottom view. Also, such an inclined portion may be provided with a plurality of connecting and fixing portions (bolt fastening portions, etc.) for the energy storage device unit. 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. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-73222 A [Patent Document 2] JP 2021-133837 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention was devised under the circumstances described above, and has an object to provide a vehicle structure that can provide excellent protection performance for an energy storage device unit in the event of a side collision of the vehicle. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides the following technical solutions.

[0008] 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 in the vehicle width direction of the pair of side members, 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 vehicle front-rear direction, The bracket is connected between each rocker, a plurality of connecting and fixing parts for connecting and fixing the energy storage device unit to the bracket, and a rigidity breaking point provided on the bracket and which becomes the starting point of buckling deformation of the bracket when a predetermined or greater load is input to the bracket from the outer side in the vehicle width direction, the plurality of connecting and fixing parts being arranged in a straight line with no inclination in the fore-and-aft direction of the vehicle in a bottom view, and the rigidity breaking point being 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 with no inclination in the fore-and-aft direction of the vehicle in a bottom view, or being provided as at least one rigidity breaking point extending without inclination in the fore-and-aft direction of the vehicle in a bottom view.

[0009] 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 at an angle 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 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 when a side impact occurs, 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 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.

[0010] In the present invention, preferably, any one of the multiple connecting and fixing portions is a specific connecting and fixing portion that is positioned furthest 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 specific connecting and fixing portion in a bottom view as a reinforcing member for reinforcing the bracket.

[0011] According to this configuration, the following effects can be obtained. That is, the surrounding 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 surrounding 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.

[0012] In the present invention, preferably, the brackets are arranged in a line in the front-rear direction of the vehicle and are separate from each other. The bracket is divided into at least two front and rear portions formed by the body member.

[0013] With this configuration, it is easy to achieve optimal specifications for each of the front and rear bracket parts (shape, size, strength, buckling deformation property against side impact load, etc.) Also, the bracket assembly workability can be improved.

[0014] Other features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2A is a schematic bottom view of a main portion showing an example of a vehicle structure according to the present invention, and FIG. 2B is a schematic cross-sectional view taken along line II of FIG. [Diagram 2] FIG. 2 is a schematic exploded bottom view of the main part of FIG. [Diagram 3] 1(a) is a schematic exploded bottom view of a main part in a state where FIG. 1(a) is further exploded than FIG. 2. FIG. [Figure 4] 1(b) is an enlarged cross-sectional view of part IV in FIG. 1(b) (corresponding to a schematic cross-sectional view of a main part II in FIG. 1(a)). [Diagram 5] FIG. 2 is a schematic cross-sectional view of a main part of the VV in FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view of a main part taken along line VI-VI of FIG. [Figure 7] FIG. 7 is a schematic cross-sectional view of a main part taken along line VII-VII of FIG. [Figure 8] FIG. 1 is a schematic cross-sectional view of a main part showing Comparative Example 1 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0017] A vehicle structure A shown in Figures 1 to 3 is applied, for example, to a cab-over type vehicle 1, and includes a pair of left and right side members 2 (indicated with a halftone dot pattern in Figure 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 rigid breaking points 50 provided on each bracket 5 . In the figure, reference numeral 90 denotes a front wheel.

[0018] The pair of side members 2 are one of the body frame members, positioned at a distance from each other in the vehicle width direction, and extending in the vehicle front-rear direction from near the front end of the vehicle 1 toward the rear of the vehicle. Each side member 2 is formed using a member with a hat-shaped cross section that is open on the top, as shown in Fig. 1(b) and Figs. 4 to 6, for example. Although detailed illustrations are omitted, each side member 2 is joined to the underside of the floor portion 10 (floor panel portion).

[0019] The pair of side members 2 are generally spaced apart in the vehicle width direction greater at the rear side than at the front side of the vehicle 1. The intermediate locations of the pair of side members 2 in the vehicle front-rear direction are formed as inclined portions 20 that widen in a bottom view and whose mutual spacing in the vehicle width direction becomes greater toward the rear of the vehicle. The inclined portions 20 and the electricity storage device unit 4 overlap each other in the vehicle front-rear direction.

[0020] 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 the lower edge of a side door opening (not shown) on the side of the vehicle 1. The outer end of the floor portion 10 in the vehicle width direction is joined to the rocker 3. In addition, 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. The floor portion 10 is provided with an opening 10a for maintenance.

[0021] The power storage device 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, etc. The power storage device unit 4 is configured such that a flange-shaped or leg-shaped attachment portion 41 is provided protruding outward in the vehicle width direction from a unit main body portion 40 on which the battery is mounted.

[0022] The brackets 5 are members used for mounting the electricity storage device units 4, and are provided so as to bridge and connect between an 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 having a curved cross section, and as shown in Figs. 4 to 6, an inner portion 51 in the vehicle width direction is overlapped on the side member 2 and bolted and welded. Also, an outer portion 52 in the vehicle width direction of each bracket 5 is overlapped on a lower portion of the rocker 3 and bolted and welded.

[0023] The bracket 5 is divided into front and rear bracket portions 5a, 5b that are aligned in the vehicle longitudinal direction and are made of separate members. However, in the following description, unless otherwise specified, the front and rear bracket portions 5a, 5b will not be distinguished from each other and will be described collectively as the bracket 5.

[0024] The multiple connecting and fixing parts 7 are portions for connecting and fixing the mounting part 41 of the electricity storage device unit 4 to the bracket 5. The mounting part 41 is provided with a cylindrical part 70 into which a bolt 71 is inserted, for example, and the bracket 5 and the mounting part 41 are connected and fixed (bolted) together using this bolt 71 and a nut 72 that screws into the bolt 71. The electricity storage device unit 4 is indirectly supported by the side member 2 via the bracket 5.

[0025] The multiple connecting and fixing parts 7 are on a straight line La indicated 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. For this reason, for example, while in FIG. 6 the connecting and fixing part 7 is located immediately below the side member 2, in FIGS. 4 and 5, such a positional relationship is different.

[0026] As shown in Figs. 1, 5 and 7, the reinforcing member 6 is a panel-like 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 electricity storage device 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 compared to 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 that connects the periphery of the connecting and fixing portion 7a of the bracket 5 to the side member 2 is further provided.

[0027] 7, the bracket 5 is in the form of a panel having a plurality of downwardly protruding steps 55 each having a height Ha and a width Wa in the vehicle longitudinal direction, the steps 55 being formed at appropriate intervals in the vehicle longitudinal direction. Each step 55 extends in the vehicle width direction. In contrast, each connecting and fixing portion 7 is configured such that a tubular portion 70 abuts against the underside of each step 55, and the locations of the bracket 5 where the steps 55 are formed are intended to be connected and fixed to the energy storage device unit 4.

[0028] The rigidity breaking points 50 are portions 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 value 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 portions where each of the multiple step portions 55 of the bracket 5 is partially bent into a bent cross-sectional bead portion (see Figs. 4 to 6) that is bent into a substantially V-shaped cross section. Each rigidity breaking point 50 extends linearly in the vehicle longitudinal direction from one end to the other end of each step portion 55 in the vehicle longitudinal direction.

[0029] The rigidity breaking points 50 are provided in positions outward in the vehicle width direction from 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 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 vehicle fore-and-aft direction in bottom view.

[0030] Next, the operation of the above-mentioned vehicle structure will be described.

[0031] 1(a), when a side collision occurs, the side collision load F may be input to the side of the vehicle 1. In contrast, since 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 in a bottom view, the side collision load F acts on the multiple connecting and fixing parts 7 simultaneously, and the side collision load F is prevented or suppressed from concentrating on, for example, only one connecting and fixing part 7.

[0032] 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 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 significantly damaged. In contrast, according to the present embodiment, it is possible to appropriately eliminate or reduce such concerns.

[0033] 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 on the electricity 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 vehicle front-rear direction 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 electricity storage device unit 4 can be further improved.

[0034] 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 favorable for ensuring the strength of vehicle 1 against a side collision, or the mounting rigidity of electricity storage device unit 4 when vehicle 1 is normally traveling. 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. Also, the presence of reinforcing member 6 described above reliably prevents a problem in which a portion of bracket 5 becomes insufficient in strength, and Layer is preferred. 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 side impact load, etc.). Also, the overall assembly workability of the bracket 5 can be improved.

[0035] The present invention is not limited to the above-described embodiment, and the specific configuration of each part of the vehicle structure according to the present invention can be freely designed and modified in various ways within the intended scope of the present invention.

[0036] 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. The rigidity breaking point in the present invention may be, for example, 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. 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.

[0037] The connecting and fixing portion in the present invention may employ connecting and fixing 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 may also be configured without such division.

[0038] 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. [Explanation of symbols]

[0039] A. Vehicle Structure 1 vehicle 2 Side members 20 Inclined portion (of side member) 3 Rocca 4. Energy storage unit 5 Bracket 5a, 5b Front and rear bracket parts 50 Rigidity point 6 Reinforcement members 7 Connecting fixing part

Claims

1. 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 sloped portion that is sloped in a bottom view is formed in a region of each of the side members 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. 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. 3. A vehicle structure according to claim 1 or 2, A vehicle structure in which the bracket is divided into at least two front and rear bracket portions arranged in the vehicle fore-and-aft direction and constituted by separate members.

Citation Information

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