Vehicle Lower Structure Catcher Bracket and Brace Rigidity

Solution Overview

Problem

The existing vehicle body lower structures face reduced rigidity and upward pressing of the floor panel during front collisions due to the S-shaped suspension member brace, which compromises the vehicle's stability and cabin space.

Innovation Solution

A vehicle body lower structure incorporating a catcher bracket with a collapse bead at its bent portion, which absorbs the load during collisions, and a suspension member brace combined with the catcher bracket, reducing the inclination and enhancing the bracing rigidity, thereby suppressing the rearward movement of the front suspension member and preventing upward pressing of the floor panel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the suspension member brace is formed in a straight shape, then the rigidity is improved, but the height difference between the suspension member and kick portion cannot be accommodated

Engineering Contradiction:

Improverigidity of suspension member braceVSAvoidaccommodation of height difference

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The suspension member brace is divided into multiple sections: a first brace portion extending from the suspension member, a second brace portion extending from the kick portion, and a connecting portion joining them. This segmentation allows each portion to be optimized independently - the first and second portions can be straight for rigidity, while the connecting portion accommodates the height difference through controlled deformation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The connecting portion of the suspension member brace is designed to dynamically change its configuration during collision. It transitions from an initial state with a specific angle to a deformed state where the angle changes, allowing it to absorb energy and accommodate height differences while maintaining overall structural integrity.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the suspension member brace has an S shape to accommodate height difference, then the adaptability is improved, but the rigidity is reduced due to bent portions

Engineering Contradiction:

Improveaccommodation of height differenceVSAvoidrigidity of suspension member brace

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The suspension member brace is divided into multiple sections: a first brace portion extending from the suspension member, a second brace portion extending from the kick portion, and a connecting portion joining them. This segmentation allows each portion to be optimized independently - the first and second portions can be straight for rigidity, while the connecting portion accommodates the height difference through controlled deformation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The connecting portion of the suspension member brace is designed to dynamically change its configuration during collision. It transitions from an initial state with a specific angle to a deformed state where the angle changes, allowing it to absorb energy and accommodate height differences while maintaining overall structural integrity.

Inventive Principle:

Principle #15Dynamics

3Stability of the object's composition

If the inner torque box receives the suspension member during collision, then the rearward movement is suppressed, but the floor panel is pushed upward narrowing cabin space

Engineering Contradiction:

Improvesuppression of rearward movementVSAvoidcabin space

Core Design Contradiction:

Stability of the object's compositionVSVolume of stationary object

Solution Approach 1:

The inner torque box structure is segmented into a main body portion and a separately provided reinforcement member. The reinforcement member is positioned to receive the suspension member during collision, while the main body portion maintains its distance from the floor panel. This segmentation prevents the floor panel from being pushed upward, preserving cabin space while still achieving rearward movement suppression.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The reinforcement member acts as an intermediary between the suspension member and the main body of the inner torque box. It specifically receives and manages the collision forces from the suspension member, preventing these forces from being transmitted to the floor panel and causing upward displacement.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The proposed structure improves the rigidity of the suspension member brace and prevents the upward pressing of the floor panel during front collisions, maintaining the vehicle's stability and cabin space.

Implementation Method 1

On a bent portion of the catcher bracket which is a boundary between the side wall and the rear wall, a collapse bead which becomes a starting point of collapse deformation in the up-and-down direction is formed.

Methodology Applied

Scientific EffectCollapse deformation: Deformation

Data Source

PatentUS10737728B2Vehicle body lower structure

Publication Date: 2020.08.11 TOYOTA JIDOSHA KK

AI summary

A catcher bracket is provided to protrude from a bottom wall of an inner torque box in a downward direction. Collapse beads which become starting points of collapse deformation in an up-and-down direction are formed on bent portions which correspond to boundaries between an inner wall and a rear wall and between an outer wall and the rear wall of the catcher bracket.