Vehicle Sub-Frame Mounting Unit Stiffness via Integrated Die-Cast Nut
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Solution Overview
Problem
Conventional mounting units for vehicle sub-frames face limitations in achieving sufficient stiffness to restrict excessive movement in both vertical and horizontal directions, particularly in suppressing back and forth or side to side motion, which affects the firm combination of the sub-frame with the vehicle body.
Innovation Solution
The proposed mounting unit features an enlarged welding joint with a lateral insertion of the mounting nut on the side member, incorporating a welding seat and flange structure that includes horizontal and vertical components, along with a member seat for connecting the fender upper member, enhancing stiffness in all directions through integrated aluminum die-casting and welding techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a conventional mounting unit with a simple nut and bracket structure is used, then the device complexity is low and ease of manufacture is high, but the stiffness in horizontal direction (back and forth supporting stiffness) is insufficient
Solution Approach 1:
The patent combines the mounting nut, bracket, and reinforcing member into a single integrated mounting unit structure. The mounting nut body incorporates both the bracket portion that attaches to the side member and the reinforcing member portion that provides horizontal stiffness, eliminating the need for separate components and complex assembly while achieving the required structural rigidity.
Solution Approach 2:
The mounting unit extends in multiple spatial dimensions with the bracket portion extending in one direction for attachment and the reinforcing member portion extending in another direction to provide horizontal stiffness. This multi-dimensional structure allows the single component to fulfill multiple structural functions that would otherwise require separate parts.
2Strength
If additional reinforcing members are added to increase vertical stiffness, then the vertical supporting stiffness is improved, but the device complexity increases and more vehicle body parts must be installed around the joint
Solution Approach 1:
The mounting unit integrates the reinforcing member function directly into the nut body structure. The reinforcing member portion is formed as an integral part of the mounting nut, eliminating the need for separate reinforcing members and reducing the total number of components that must be installed around the joint.
Solution Approach 2:
The mounting unit serves multiple functions simultaneously: the bracket portion provides attachment to the side member, the mounting nut portion secures the sub-frame, and the reinforcing member portion provides vertical stiffness. This multi-functional design eliminates the need for separate components for each function.
3Ease of manufacture
If the mounting unit structure is simplified without additional reinforcing members, then the device complexity is reduced and ease of manufacture is improved, but the back and forth and side to side supporting stiffness becomes insufficient
Solution Approach 1:
The mounting unit combines multiple structural elements into a single integrated component that provides both attachment functionality and horizontal stiffness reinforcement, simplifying the manufacturing process while maintaining the required structural performance.
Solution Approach 2:
The mounting unit is formed using aluminum die-casting, creating a composite structure with the welded joint to the side member. This manufacturing approach allows complex geometries with integrated reinforcing features to be produced as a single piece, achieving both manufacturing simplicity and structural stiffness.
4Strength
If a firm supporting structure is created through welding, then the reliability and stiffness are improved, but the weight of the mounting unit increases
Solution Approach 1:
The mounting unit utilizes aluminum die-casting to create a lightweight yet strong structure, and selectively applies welding only at critical joints where structural integrity is most needed. This hybrid approach achieves the required stiffness while minimizing weight compared to fully welded or heavier alternative structures.
Solution Approach 2:
The welding is applied locally at specific critical joints rather than throughout the entire structure. The reinforcing member portion and bracket portion are welded to the side member at strategic locations to provide maximum stiffness with minimum material and weight.
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
This solution provides a robust supporting structure that reduces noise, vibration, and harshness (NVH), improves vehicle performance, simplifies assembly, reduces weight, and lowers production costs by eliminating the need for additional brackets.
Implementation Method 1
a welding joint is enlarged in a state where the mounting nut is laterally inserted on a lower side of a side member
Implementation Method 2
integrated aluminum die-casting and welding techniques
Data Source
AI summary
A mounting unit for a sub-frame of a vehicle is provided. The mounting unit is used for engaging a front side member with the vehicle's sub-frame. The mounting unit includes a welding seat that is formed as a groove on a lower side of the front side member. The mounting unit further includes a mounting nut assembled with the front side member, a welding flange integrated with an external circumference and a head of the mounting nut and inserted into the welding seat to be combined with the welding seat, and a member seat that is formed outside the welding flange and with which a fender upper connecting member is combined.