Vehicular Rear Structure Reinforcement

Solution Overview

Problem

Conventional rear structures of vehicular bodies face increased weight and manufacturing costs due to the need for additional components to reinforce side rear members, and are prone to upward bending during rear crashes due to insufficient reinforcement.

Innovation Solution

A rear structure comprising a side sill, a hat-shaped side rear member with a kick-up portion, a cross member, and a reinforcement with a closed cross-section, which is disposed within the side rear member to form a box-shaped structure that enhances rigidity and prevents upward bending during crashes while minimizing the number and weight of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a large side member reinforcement is installed to the side rear members in addition to the bulkhead, then the upward bending of side rear members is prevented, but the weight of the vehicular body and manufacturing cost increase

Engineering Contradiction:

Improveresistance to upward bendingVSAvoidweight of vehicular body

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The reinforcement member is disposed inside the side rear member, forming a nested structure where the reinforcement is contained within the hollow portion of the side rear member. This nesting approach provides strengthening without adding external components, thereby preventing upward bending while minimizing weight increase.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The reinforcement member and side rear member are combined into an integrated structure where the reinforcement is positioned within the side rear member's hollow portion. This merging of functions allows the reinforcement to work together with the side rear member to resist upward bending forces during rear crashes.

Inventive Principle:

Principle #5Merging (Combining)

2Strength

If a large side member reinforcement is installed to the side rear members in addition to the bulkhead, then the upward bending of side rear members is prevented, but the manufacturing cost increases due to the increase in the number of components

Engineering Contradiction:

Improveresistance to upward bendingVSAvoidnumber of components

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The reinforcement member is disposed inside the side rear member, forming a nested structure where the reinforcement is contained within the hollow portion of the side rear member. This nesting approach provides strengthening without adding external components, thereby preventing upward bending while minimizing weight increase.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The reinforcement member and side rear member are combined into an integrated structure where the reinforcement is positioned within the side rear member's hollow portion. This merging of functions allows the reinforcement to work together with the side rear member to resist upward bending forces during rear crashes.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the side rear members are made with sufficient reinforcement to prevent upward bending, then the structural integrity is improved, but the weight and complexity of the structure increase

Engineering Contradiction:

Improvestructural integrity during rear crashVSAvoidweight of rear structure

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The reinforcement member is disposed inside the side rear member, forming a nested structure where the reinforcement is contained within the hollow portion of the side rear member. This nesting approach provides strengthening without adding external components, thereby preventing upward bending while minimizing weight increase.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The reinforcement member is specifically positioned at the kick-up portion of the side rear member, which is the area most susceptible to upward bending during rear crashes. This localized reinforcement provides targeted structural integrity where needed most, rather than uniformly strengthening the entire side rear member.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS7631918B2Rear structure of a vehicular body

Publication Date: 2009.12.15 NISSAN MOTOR CO LTD

AI summary

A rear structure of a vehicular body has side sills disposed at lateral ends of the vehicular body. The rear structure further has side rear members having a hat-shaped cross-section and having a kick-up portion that is upwardly inclined. The side rear members are bonded to the side sills at bonded portions, and extend toward a rear of the vehicular body. The rear structure further has a cross member connecting side sills in a lateral direction across the vehicular body. The cross member is connected to each of the side sills at connected portions at a rear of the kick-up portions. The rear structure further has reinforcements having a closed cross-section in a longitudinal plane and in a lateral plane. The reinforcements are disposed in the side rear members between the bonded portions and the connected portions.