Vehicle Subframe Cross-Member with Upward Extension for Rigidity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing vehicle body rear subframe structure with a four-point support system lacks sufficient rigidity and strength, leading to compromised ride comfort and steering stability, while also increasing vehicle weight and manufacturing costs.
Innovation Solution
A subframe structure featuring a pair of side frames extending longitudinally, centrally spaced longitudinal members, and a cross-member with a first attachment portion, an extension portion, and a second attachment portion, where the cross-member is attached to the side frames, enhancing load transmission and rigidity without increasing overall weight or cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a four-point support structure is used for the rear subframe, then the overall weight and manufacturing cost are kept low, but the rigidity and strength are insufficient
Solution Approach 1:
The cross-member extends not only in the lateral direction but also in the vertical direction (upward extension portion), creating a three-dimensional load transmission path. This dimensional extension allows the structure to achieve higher rigidity and strength without simply adding more horizontal support points, thereby avoiding excessive weight increase.
Solution Approach 2:
The cross-member is divided into distinct functional segments: a first attachment portion connected to the longitudinal member, an extension portion that bridges laterally and vertically, and a second attachment portion connected to the vehicle body side frame. This segmentation allows each part to optimize its load-bearing function while maintaining overall structural efficiency.
2Reliability
If a four-point support structure is used for the rear subframe, then the manufacturing cost is kept low, but the ride comfort and steering stability deteriorate
Solution Approach 1:
The cross-member serves multiple functions simultaneously: it laterally connects the longitudinal members to the vehicle body side frames, vertically extends to accommodate suspension components, and provides attachment points for both the longitudinal members and the vehicle body. This multi-functionality eliminates the need for additional separate structural elements, maintaining manufacturing simplicity while improving reliability.
3Force
If the cross-member extends laterally outward and upward, then the load transmission efficiency is improved, but the structural complexity increases
Solution Approach 1:
The cross-member features localized structural variations: the extension portion extends upward only at the lateral extension needed for connection to the vehicle body side frame, while other portions maintain a simpler configuration. This local quality approach optimizes load transmission exactly where needed without unnecessarily complicating the entire structure.
Data Source
AI summary
A subframe structure includes: a pair of right and left vehicle body side frames disposed at side portions of a vehicle body; a pair of right and left longitudinal members extending along the pair of right and left vehicle body side frames at positions centrally spaced apart in a vehicle width direction for a predetermined distance from the vehicle body side frames; and a rear cross-member extending in the vehicle width direction between longitudinally rear portions of the pair of right and left longitudinal members. The rear cross-member has a first attachment portion, an extension portion, and a second attachment portion. The first attachment portion is attached to the longitudinal member, the extension portion extends from the first attachment portion in a laterally outward and upward direction, and the second attachment portion is attached to the vehicle body side frame at a laterally outer end portion of the extension portion.