US-12617260-B2 - Vehicle body lower part structure

US12617260B2US 12617260 B2US12617260 B2US 12617260B2US-12617260-B2

Abstract

A vehicle body lower part structure includes: a side frame that connects a side sill to a battery pack that is arranged below a floor portion; and a battery frame that supports a battery within the battery pack. A first joint flange that is joined to a case bottom portion of the side frame is arranged such that a second joint flange that is joined to the case bottom portion of the battery frame overlaps an upper side in an upward-downward direction of the first joint flange.

Inventors

Yu IEMURA
Ken Yasui
Masaaki Tatsuwaki
Satoru Kawabe
Satoshi Yaita

Assignees

HONDA MOTOR CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20230906
Priority Date: 20220930

Claims (9)

1 . A vehicle body lower part structure, comprising: a side frame that connects a side sill to a battery pack that is arranged below a floor portion; and a battery frame that supports a battery within the battery pack, wherein a first joint flange that is joined to the battery pack of the side frame is arranged such that a second joint flange that is joined to the battery pack of the battery frame overlaps an upper side in an upward-downward direction of the first joint flange, wherein the battery frame comprises a protrusion portion that protrudes upward from a bend portion formed on an inner end portion in a vehicle width direction of the second joint flange, wherein an edge portion on the battery side of the first joint flange extends to a bend portion side, and wherein the edge portion comprises a first joint section that is joined to the battery pack.
2 . The vehicle body lower part structure according to claim 1 , wherein the second joint flange comprises a second joint section that is joined to the battery pack, and the first joint section is arranged closer to the battery than the second joint section.
3 . The vehicle body lower part structure according to claim 1 , wherein the battery frame forms a hollow cross-section together with the battery pack at the protrusion portion, and the battery is fastened to an inner end section in the vehicle width direction of the protrusion portion of the battery frame.
4 . The vehicle body lower part structure according to claim 3 , wherein the protrusion portion of the battery frame comprises a plurality of recess sections that are joined to the battery pack along a vehicle forward-rearward direction.
5 . The vehicle body lower part structure according to claim 1 , wherein the battery frame comprises a plurality of ridge lines that continue to the second joint flange and an outer surface section on an outside in the vehicle width direction of the protrusion portion, extend in the vehicle width direction, and are spaced from each other in a vehicle forward-rearward direction.
6 . The vehicle body lower part structure according to claim 1 , wherein the side frame comprises: a horizontal portion that is fixed to a lower portion of the side sill; and a vertical portion that connects the horizontal portion to the first joint flange, the horizontal portion and vertical portion are formed as hollow portions having a substantially L shape in a cross-section including a plurality of hollow cells, and the second joint flange of the battery frame is arranged at a position that is separated inward in a vehicle width direction from the vertical portion.
7 . The vehicle body lower part structure according to claim 6 , wherein a lower surface of the horizontal portion is formed such that a thickness of an inner region formed on the vertical portion side is thinner than an outer region formed on an outside in the vehicle width direction.
8 . The vehicle body lower part structure according to claim 6 , wherein a lower surface of the horizontal portion is arranged at a lower position than a lower surface of the battery pack, a lower surface of the vertical portion is formed in an inclination form having an upward gradient toward the first joint flange from the lower surface of the horizontal portion, and the lower surface of the vertical portion connects the lower surface of the horizontal portion to the first joint flange.
9 . The vehicle body lower part structure according to claim 1 , wherein the battery is formed in a rectangle shape in plain view and is arranged within the battery pack such that a long side is directed in a vehicle forward-rearward direction.

Description

CROSS-REFERENCE TO RELATED APPLICATION Priority is claimed on Japanese Patent Application No. 2022-158038, filed on Sep. 30, 2022, the contents of which are incorporated herein by reference. BACKGROUND Field of the Invention The present invention relates to a vehicle body lower part structure. Background As a vehicle body lower part structure, a structure is known in which a battery case that accommodates a plurality of batteries inside the battery case is arranged below a floor portion of a vehicle. As a vehicle body lower part structure, a structure is known in which both side portions in a vehicle width direction of a battery case are provided on a pair of side sills at a lower side of a vehicle body side part. In this type of vehicle, in order to ensure collision safety performance, it is important to protect a high-voltage battery in the battery case when a collision load is input to a vehicle body. Accordingly, in order to protect the battery, a vehicle body lower part structure has been proposed in which an easily pressure-broken portion (a portion that is easily broken by pressure) such as a bead is provided on a cross member connected to a side sill in a region that is located at an outer position in a vehicle width direction than that of the battery case (for example, refer to Japanese Patent No. 3132261). In the vehicle body lower part structure, the cross member starts breaking by pressure from the easily pressure-broken portion when a collision load toward the inside in the vehicle width direction is input to the side sill from a vehicle lateral direction. Therefore, it is possible to absorb collision energy before the impact load deforms the battery case. SUMMARY However, in the above vehicle body lower part structure of the related art, after the easily pressure-broken portion is broken by pressure at the time of input of a collision load, the easily pressure-broken portion forms a mass and is displaced in the direction of the battery. Therefore, there is a concern that the load is transmitted from the easily pressure-broken portion to the battery, and the battery is damaged. Accordingly, there is room for improvement in terms of collision safety performance. An aspect of the present invention aims at providing a vehicle body lower part structure capable of efficiently absorbing collision energy while preventing damage to a mounted battery at the time of input of a collision load. The aspect of the present invention aims at providing a vehicle body lower part structure that can improve collision safety performance and can contribute to the development of a sustainable transportation system. A vehicle body lower part structure according to an aspect of the present invention includes: a side frame that connects a side sill to a battery pack that is arranged below a floor portion; and a battery frame that supports a battery within the battery pack, wherein a first joint flange that is joined to the battery pack of the side frame is arranged such that a second joint flange that is joined to the battery pack of the battery frame overlaps an upper side in an upward-downward direction of the first joint flange. According to such a configuration, the second joint flange is arranged at the upper side in the upward-downward direction of the first joint flange so as to overlap the first joint flange. The first joint flange and the second joint flange are formed to accept deformation with respect to a collision load. Hereinafter, a region including the first joint flange and the second joint flange may be referred to as a “collision absorption portion”. Here, for example, when a collision load is input to the first joint flange of the side frame by a side collision such as a pole side collision, the first joint flange is pressed by the second joint flange from above. Thereby, it is possible to allow the collision absorption portion to be deformed downward by the collision load. Hereinafter, a side collision such as a pole side collision may be simply abbreviated as a “side collision”. It is possible to ensure a space that receives deformation of the collision absorption portion below the collision absorption portion. Therefore, it is possible to prevent a section that is not collapsed from being generated at the collision absorption portion, and it is possible to enhance the absorption efficiency of collision energy. The collision absorption portion is deformed downward, and thereby, it is possible to prevent the collision absorption portion from coming into contact with the battery arranged within the battery pack. Thereby, it is possible to efficiently absorb the collision energy while preventing damage to the mounted battery at the time of input of the collision load. Therefore, according to the present vehicle body lower part structure, it is possible to improve collision safety performance, and it is possible to contribute to the development of a sustainable transportation system. In the aspect desc