Front Subframe Guide Structure for Frontal Collision Drop-Down
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle subframe structures face challenges in redirecting the engine and subframe to the lower side during a frontal collision without increasing weight or part count, particularly when the rear subframe is not mounted on an inclined portion of the vehicle body.
Innovation Solution
The subframe structure incorporates a leading guide portion integrated with the suspension arm mounting bracket, which abuts against a fastening member to guide the subframe and engine to the lower side after separation, utilizing a slit portion for relative movement and maintaining the fastening state during collisions, thus avoiding the need for additional components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated member is separately formed on the rear side to enable subframe separation and engine movement during collision, then the subframe can be led to the lower side after separation, but the weight and number of parts increase and productivity decreases
Solution Approach 1:
The patent integrates the leading guide portion directly into the rear portion of the subframe, merging the separation function and guidance function into a single integrated structure. This eliminates the need for separate dedicated members, thereby reducing weight and part count while maintaining the collision safety function of guiding the engine and subframe to the lower side after separation
2Reliability
If a dedicated member is separately formed on the rear side to enable subframe separation and engine movement during collision, then the subframe can be led to the lower side after separation, but the number of parts increases and productivity decreases
Solution Approach 1:
The leading guide portion is integrated as part of the subframe's rear portion structure, combining multiple functions (separation initiation and post-separation guidance) into a single component. This integration reduces the total number of parts and simplifies the assembly process, thereby improving productivity while maintaining collision safety
3Reliability
If the rear portion of the subframe is mounted on an inclined portion of the body, then the subframe can move to the lower side during collision, but the layout is restricted and cannot accommodate all fastening positions
Solution Approach 1:
Instead of relying on the body's inclined portion (horizontal plane guidance), the patent creates a vertical guidance mechanism through the leading guide portion integrated into the subframe. This dimensional change allows the subframe to be guided to the lower side through vertical movement rather than horizontal movement along an inclined surface, thereby providing layout flexibility for fastening positions while maintaining collision safety
Data Source
Figure 1
Figure 2
Figure 3
AI summary
[Problem] Provided is a subframe structure of a front suspension that leads a subframe and a vehicle driving apparatus to the lower side after the separation of a rear portion of the subframe due to a frontal collision without increasing the weight and the number of parts even when the rear portion of the subframe is not mounted on an inclined portion of a body. [Means for Solution] The subframe structure of the front suspension is characterized in that a subframe 30 that supports a vehicle driving apparatus in a mounting manner is provided, a rear portion 62 of the subframe 30 is mounted on a lower portion of a vehicle body 9 via a fastening member 76, fastening between the subframe 30 and the fastening member 76 is configured such that the rear portion of the subframe 30 is separated when a collision load to a vehicle rear side is applied to the subframe 30, an a leading guide portion 62d that abuts against the fastening member 76 and leads the subframe 30 to a lower side after separation from the fastening member 76 is integrally formed on the rear portion of the subframe 30.