Separable Rear Cradle Mount for Rear Impact Energy Absorption
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Solution Overview
Problem
The use of a multi-link rear axle in hybrid vehicles limits the deformation of the rear structure, reducing energy absorption potential and degrading performance in high-speed rear collisions, necessitating an improvement in rear impact damping performance.
Innovation Solution
A vehicle design featuring a multi-link rear axle with a fixing device comprising two parts that separate under a predetermined traction force, allowing the rear cradle to detach from the spars and increase compressibility during high-speed impacts, thereby enhancing energy absorption and reducing the rear overhang.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a multi-link rear axle is used in hybrid vehicles, then the structural integrity and support for the electric propulsion unit is improved, but the deformation capability and energy absorption potential of the rear structure is reduced
Solution Approach 1:
The fixing device is divided into two separable parts: a first part attached to the rear cradle and a second part attached to the side member. This segmentation allows the structure to maintain rigidity during normal operation while enabling controlled separation during high-speed impacts to restore deformation capability and energy absorption potential.
2Stability of the object's composition
If the rear cradle is firmly fixed to the side members, then the stability and support for the electric propulsion unit is improved, but the compressibility and shock absorption capability of the rear structure is reduced
Solution Approach 1:
The fixing device transitions from a static firmly-fixed state to a dynamic separable state under high tensile force. During normal driving, the device maintains stable attachment, but during high-speed rear impacts, the separable connection allows the rear cradle to detach and the side members to compress, providing adaptability for shock absorption.
3Loss of energy
If a separable fixing device is used to improve compressibility, then the energy absorption capability is improved, but the structural reliability under normal driving conditions may be reduced
Solution Approach 1:
The fixing device is designed with specific geometric parameters and material properties that create a threshold behavior. The device maintains reliable connection under normal driving forces but is configured to separate when tensile force exceeds a predetermined threshold during high-speed impacts, thus preserving both reliability and energy absorption capability.
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 solution improves the vehicle's ability to absorb shock energy during rear collisions by increasing the compressibility of the rear structure without increasing costs, while maintaining structural integrity under normal driving conditions.
Implementation Method 1
the two parts are configured to separate under the action of a tensile force greater than a predetermined threshold
Data Source
Figure 1~2
Figure 3~5
Figure 6~8
AI summary
The invention relates to an electric or hybrid motor vehicle (1) comprising a pair of longitudinal members (3) and a rear cradle (5) arranged to support an electric propulsion unit (7), the rear cradle (5) comprises a central zone extending in the transverse direction of the vehicle and extended at each of its ends by two arms (9, 11), respectively a front arm (9) and a rear arm (11), the rear cradle (5) is attached to the longitudinal members (3) by its front and rear arms (9, 11). The vehicle (1) is characterised in that each of the rear arms (11) of the rear cradle (5) is attached to the longitudinal members by means of an attachment device (17) in two parts which are configured to separate under the action of a tractive force greater than a predetermined threshold.